Alpaca reproduction

The study was conducted to investigate the superovulatory response in aged female mice by adjusting gonadotropin dose at Department of Theriogenology, UVAS, Lahore, Pakistan from December 2013 to May 2014. Female BALB/c mice of different ages (4-6 weeks vs 7-9 weeks) were injected with five different concentration of eCG (0, 2.5, 5, 7.5 and 10 IU) and embryonic recovery and quality was evaluated. The embryonic recovery, was significantly high in both age groups (37.00±6.54 vs 10.20±0.96; 30.60±5.26 vs 9.40±0.92) 26.00±4.46 vs 8.60±1.32) at 7.5 IU as compared to control. In 4-6 weeks old mice, the embryonic recovery and grade I embryos at low dose (2.5 IU; 16.00±1.30 and 8.60±1.32) were comparable with high dose (5.0 IU; 17.20±3.55 and 7.20±1.11) in 7-9 weeks. This revealed injecting high dose to old females mice can improve superovulatory response considering factor of age can be nullified by adjusting the gonadotropins dose.

Background: One of the factors limiting successful processing of alpaca (Vicugna pacos) semen is the viscosity of seminal plasma. The viscous nature of the collected ejaculate has hindered sperm cryopreservation as well as artificial insemination (AI) under field conditions. Aims: The objective of this investigation was to evaluate recovery, motility, and plasma membrane integrity of alpaca spermatozoa after centrifugation in one of two different solutions at one of three different combinations of speed and time. Methods: A total of 24 ejaculates was recovered from seven reproductively sound Huacaya males using a modified artificial vagina (AV) after training the animals for semen collection. A 2 × 3 factorial treatment arrangement was utilized for this study. Ejaculates were divided into fractions for centrifugation in one of two solutions (Tris extender or PureSperm ® 80 density gradient solution) at one of three combinations of speed and time (492 × g for 15 min, 1968 × g for 10 min, or 4448 × g for 7 min). The experiment was replicated eight times. Results: Analysis revealed that centrifugation at 4448 × g for 7 min in PureSperm ® 80 provided a high recovery rate of spermatozoa with the highest sperm motility and functional integrity of plasma membrane post-centrifugation. Conclusion: Results suggest that adoption of this procedure (centrifugation at 4448 × g for 7 min in PureSperm ® 80) in the initial processing of alpaca ejaculates may enhance subsequent ability to use semen for AI and other assisted reproductive biotechnologies in this species.

The study was conducted to investigate the superovulatory response in aged female mice by adjusting gonadotropin dose at Department of Theriogenology, UVAS, Lahore, Pakistan from December 2013 to May 2014. Female BALB/c mice of different ages (4-6 weeks vs 7-9 weeks) were injected with five different concentration of eCG (0, 2.5, 5, 7.5 and 10 IU) and embryonic recovery and quality was evaluated. The embryonic recovery, was significantly high in both age groups (37.00±6.54 vs 10.20±0.96; 30.60±5.26 vs 9.40±0.92) 26.00±4.46 vs 8.60±1.32) at 7.5 IU as compared to control. In 4-6 weeks old mice, the embryonic recovery and grade I embryos at low dose (2.5 IU; 16.00±1.30 and 8.60±1.32) were comparable with high dose (5.0 IU; 17.20±3.55 and 7.20±1.11) in 7-9 weeks. This revealed injecting high dose to old females mice can improve superovulatory response considering factor of age can be nullified by adjusting the gonadotropins dose.

El presente estudio tuvo como objetivo evaluar el efecto del proceso del comportamiento sexual de la cópula con machos castrados (G1) en la inducción de la ovulación, comparando con el mismo efecto de machos vasectomizados (G2) y el efecto de la aplicación de plasma seminal (G3) en el útero en 45 alpacas con folículo preovulatorio ≥7 mm de diámetro, distribuidas (n=15) al azar en cada grupo experimental. La ocurrencia de ovulación se estimó el día 4 poscópula mediante receptividad sexual (aceptación o rechazo) al macho y verificada el día 7 y 11 con la detección del cuerpo lúteo (CL) vía ecografía transrectal. En G1, se determinó la secreción de plasma seminal los días -1, 15, 17 y 21 de la castración. Las fases del comportamiento sexual en el empadre controlado fueron similares entre G1 y G2. El día 4 poscópula una hembra de G1 había ovulado. En el día 7, la tasa de ovulación determinada por la presencia de cuerpo lúteo y receptividad sexual fue mayor (p<0.05) en G2 (93.3%) que ...

Marcos. Este es un artículo de acceso abierto, distribuido bajo los términos de la licencia Creative Commons Atribución 4.0 Internacional (CC BY 4.0) [https:// creativecommons.org/licenses/by/4.0/deed.es] que permite el uso, distribución y reproducción en cualquier medio, siempre que la obra original sea debidamente citada de su fuente original Comportamiento sexual y cópula de machos castrados en la inducción de la ovulación en alpacas Sexual behaviour and copulation of castrated males on the induction of ovulation in alpacas

ID of article: 075/JSAAS/2020 the morphometric parameters between the collection method and the animal was carried out using a random block design. Total motility was 16.27±11.96%, 14.68±11.21% and 12.44±7.27%; the sperm concentration of 247±186.70x10 6 EPZ/mL, 67.92±67.92x10 6 EPZ/mL and 100.32±56.13x10 6 EPZ/mL, the vitality was 62.86 ±15.92%, 63±15.21% and 70.16±14.33% in sperm collected by DCD, EE and AV respectively. Regarding the morphometric parameters, a length of 5.49±0.43µm, 5.53±0.41µm and 5.75±0.53µm was found, area 14.30±2.00 µm 2 , 15.05±1.77 µm 2 and 15.88±2.00 µm 2 , perimeter of 16.10±1.31µm, 17.11±1.20µm and 17.41 ± 1.43, width of 3.22±0.27µm, 3.30±0.32µm and 3.33±0.25µm and the acrosome percentage of 52.22±7.82µm, 49.52±7.47µm and 47.44±5.77µm in sperm collected by DCD, EE and AV respectively. The morphometric parameters of the size and shape of the sperm head and the intermediate piece showed significant statistical differences (p <0.01) between the collection methods and between the animals. In conclusion, the morphometric parameters of alpaca spermatozoa were influenced by collection method, and show variations between animals.

ID of article: 075/JSAAS/2020 the morphometric parameters between the collection method and the animal was carried out using a random block design. Total motility was 16.27±11.96%, 14.68±11.21% and 12.44±7.27%; the sperm concentration of 247±186.70x10 6 EPZ/mL, 67.92±67.92x10 6 EPZ/mL and 100.32±56.13x10 6 EPZ/mL, the vitality was 62.86 ±15.92%, 63±15.21% and 70.16±14.33% in sperm collected by DCD, EE and AV respectively. Regarding the morphometric parameters, a length of 5.49±0.43µm, 5.53±0.41µm and 5.75±0.53µm was found, area 14.30±2.00 µm 2 , 15.05±1.77 µm 2 and 15.88±2.00 µm 2 , perimeter of 16.10±1.31µm, 17.11±1.20µm and 17.41 ± 1.43, width of 3.22±0.27µm, 3.30±0.32µm and 3.33±0.25µm and the acrosome percentage of 52.22±7.82µm, 49.52±7.47µm and 47.44±5.77µm in sperm collected by DCD, EE and AV respectively. The morphometric parameters of the size and shape of the sperm head and the intermediate piece showed significant statistical differences (p <0.01) between the collection methods and between the animals. In conclusion, the morphometric parameters of alpaca spermatozoa were influenced by collection method, and show variations between animals.

This study was conducted to develop simple superovulation protocols for dromedary camels using eCG. In experiment 1, camels received either 1000, 2000, 3000, 4000, 5000 or 6000 IU eCG. In experiment 2, camels received either 400 mg FSH (Folltropin-V) twice-daily over 5 days or 3000 IU eCG. In experiment 3, camels received 3000 IU eCG either at 2, 3, 4 or 5 days after ovulation induction. Ovarian response and embryo yield were evaluated in all experiments and embryos collected from camels treated with FSH and eCG were transferred to recipients to examine pregnancy rates. The mean number of ovulations (12.6 ± 1.5 and 13.3 ± 1.2 vs 3.4 ± 0.3, 6.2 ± 0.6 and 9.3 ± 1.0, respectively) and transferable embryos (4.6 ± 1.3 and 4.8 ± 1.0 vs 1.6 ± 0.2, 2.2 ± 0.4 and 1.1 ± 0.4, respectively) with 3000 and 4000 IU eCG doses were higher compared to 1000, 2000 and 6000 IU eCG doses (P < 0.05). Doses of 5000 and 6000 IU eCG resulted in a higher number of unovulatory follicles than other doses (P < 0.05). The FSH treatment resulted in higher number of ovulatory follicles (21.8 ± 1.3 vs 14.8 ± 1.7) and ovulations (18.5 ± 1.1 vs 13.9 ± 1.4) compared to eCG (P < 0.05). However, the number of transferable embryos and pregnancy rates were similar in these treatments. The timing of eCG treatment after ovulation induction did not affect the number of ovulatory follicles and transferable embryos but eCG treatment at 5 days after ovulation induction reduced the number of ovulations (P < 0.05). In conclusion, the optimal dose of eCG to induce superovulation is 3000e4000 IU and it produces a comparable embryo yield to FSH, and can be administered at 2e4 days after ovulation induction.

This study was performed to compare the effects of embryo quality on pregnancy outcome in recipient cows and heifers. Embryos obtained from 83 Holstein donors were used in the study. In order to synchronize the recipients, 500 µg of cloprostenol were administered intramuscularly (i.m.), twice, at an interval of 11 days. In all recipients, one embryo was transferred to the upper 1/3 of the uterine horn ipsilateral to the ovary with the corpus luteum on the 7th day after oestrus onset (day 0). Each recipient received an i.m. injection of 5 µg of buserelin at the time ofembryo transfer. Pregnancy examinations were performed by ultrasonography on the day 30th post-transfer. A total of 345 (262 grade 1, 64 grade 2 and 19 grade 3) fresh embryos were transferred to 171 recipient cows and 174 recipient heifers. The pregnancy rates of the recipient cows and heifers were 41.52% and 52.29%, respectively (p<0.05).The pregnancy rates achieved with first, second and third quality grade embryos were 45.16%, 25.0% and 12.5% in the cows (p<0.05), and 55.11%, 41.66% and 54.54% in the heifers (p>0.05), respectively. In conclusion, the pregnancy rates was significantly higher in heifers than in cows (p<0.05) and, the embryo quality had a significant impact on recipient pregnancy outcome (p<0.05). The effect of embryo quality on pregnancy was significant in cows (p<0.05), but not significant in heifers (p>0.05).

Early embryos of superior genotype are collected prior to their implantation in uterus, and they are implanted in the uterus of other females of inferior genotype where they complete its actual development which is referred to as embryo transfer. The chief objective of embryo transfer is to achieve greater rate of conception, increase in number of progeny per year from single female animal of superior genotype. Embryo transfer technique helps in increasing commercial production and it can also improve the genetic potential of livestock. The embryo transfer technique provides a rapid rate of improvement of the genetic quality of offspring at relatively lower cost than purchasing a live animal. The present review depicts the basic principles, applications and the different steps in the procedure of embryo transfer in animals.

Using laparoscopy, different degrees of sexual receptivity and time of ovulation after single copulation were determined in alpacas. Sexual receptivity was assessed with intact males in 39 adults (> 3 years old) and 37 yearlings (12-14 months) and then laparoscopy was performed to correlate it with size of ovarian follicles. Time of ovulation was also determined at two different times after copulation. Females exhibited three degrees of sexual receptivity: immediate and slow acceptance, and refusal, with no difference between yearlings and mature animals (P> 0.05). Female alpacas bred over a wide range of follicle size with no differences between ages (P> 0.05). Fifty percent of females ovulated at a normal time (30 h after copulation), 24% ovulated late (72 h), and ovulation was not observed in 26% of females. Forty percent of the animals that failed to ovulate were yearlings and 15% adults (P< 0.05). The average follicle size that ovulated was 8.1 mm, with 7 mm as the minimum size for ovulation, and with no association between follicle size and time of ovulation.

Resumption of ovarian follicle activity and uterine involution was studied in the post partum llama. Thirty-nine adult multiparous llamas were monitored by ultrasonography and analysis of urinary estrone sulfate for 30 d post partum at the La Raya Research Station in Peru. Uterine involution was measured in terms of reduction of length and diameter of both uterine horns. Correlation analysis was used to relate follicle size and concentration of estrone sulfate. Analysis of variance was used to determine rate of uterine involution relative to days post partum. The left ovary was palpated and sxxnned by Day 3 post partum in contrast to Day 1 post pat-turn for the right ovary. Ovulatory size follicles, 7 mm, were present by Day 7.4 post partum (range 4 to 14 d). Follicle growth was detected as early as Day 4 post partum with follicle size being less during the first follicle wave (7.4 mm) compared to the second and third waves (9 to 10 mm). Concentrations of urinary estrone sulfate were positively related (PcO.05) to follicular size, but to a lesser degree during the first follicle wave (19.4 ng/mg Cr), than to the second wave (25.4 nglmg Cr). Uterine involution, as measured by diameter, was different between the left (gravid) and right (nongravid) uterine horn (P<O.O5) for the 17 d post par-turn, and was also different from that of control females for the 21 d post partum. Uterine involution was complete in 63% of females by Day 21 post partum.

This study was aimed at investigating pregnancy rates achieved with multiple ovulation and embryo transfer in Simmental cows, which are characterized by a high milk yield. For this purpose, eight cows were used as donors and for each donor, recipient groups of 10 animals, including both heifers and cows, were established. Recipients were synchronized by two intramuscular injections of prostaglandin F2α 11 days apart. The treatment of the donors consisted of the intravaginal placing of a CIDR on day 0, the application of 400mg FSH in decreasing doses, starting on day four, the administration of prostaglandin F2α and the removal of CIDR on day 8. The donors were inseminated twice on day 9 and once on day 10. Uterine flushing was performed, transcervically, on day 7 after insemination. The ovulation rate was determined as 12.25±1.42. Sixteen transferable embryos (2.0±3.23, 88.9%) were collected. The 12 embryos of Grade 1 quality and the 4 embryos of Grade 2 quality were transferred by transcervical route to 12 heifers and 4 cows, respectively. The pregnancy rates achieved in the heifers and cows were 50% and 25%, respectively (P>0.05). As a result, the MOET scheme applied in Fleckvieh Simmental Cows produced satisfactory superovulatory responses and resulted in the collection of quality embryos. The embryo recovery rate was poor but, overall, the ovulation rate, the quality of the collected embryos and the pregnancy rates achieved under field conditions in this preliminary study were considered to be satisfactory.

The objetive of this research work was to study the effect of the frequency of copulation during the post-ovulatory estrous on the embryonic mortality in alpacas. Forty four female alpacas were selected having a post-partum sexual rest >20 days and bearing in the ovaries a pre-ovulatory follicle >7 mm of diameter. Animals were mated (time of coitus: >15 minutes) using a male with proven fertility and received 6 g of busereline i.m. after copula to ensure ovulation. Three experimental groups were then ramdomly organized: the first group (S 1 , n = 14) did not receive additional matings, the second gropup (S 2 , n = 15) received an additional mating on day three post-ovulation, and the third group (S 3 , n = 15) received additional matings on days three and four postovulation. Ovulation was confirmed through ultrasound images by disappearance of the pre-ovulatory follicle 42 hours post-mating and the presence of a corpus luteum on day 5 post-ovulation. In addition, the size of the corpus luteum, morfological changes of the uterine horns and presence of an embryo were recorded on days 13-14 and 19 postmating. These observations were complemented with the observation of sexual receptivity using a male on days 6, 13-14, 19 and 26 post-mating. Ovulation rate was 91%. There was a higher tendency on embryo survival at day 19 post-mating in those alpacas that received an additional mating on days 3 (S 2 = 80%) and 3 and 4 (S 3 = 85%) post-ovulation than in those animals without additional mating (S 1 = 75%). An additional study in four inducedovulated alpacas was done to detect fertilized ova at days 2, 3 and 4 post-ovulation. Recovery of the fertilized ova from oviduct was possible only until day 3 post-ovulation.

The pattern of ovulation in mammals is generally considered to be either spontaneous or induced by copulation, with environmental and social factors playing a key role in determining the specific mode of ovulation that would maximize the reproductive potential of the species. This study aims to determine whether the Namaqua rock mouse (Micaelamys namaquensis (A. Smith, 1834)) is a spontaneous or induced ovulator. Females were divided into three treatments differing in the degree of contact with a male. Namely, seven control females had no contact with a male; a further seven separated females had only chemical, auditory, and visual contact with a male; whereas six females had intermittent periods of full contact with a vasectomized male. Ovarian size, follicular development, and plasma progesterone concentrations were compared between the three treatments. Penile morphology was also investigated. Corpora lutea were found in all three treatments and the penis was smooth without any r...

An experiment was conducted with 24 healthy cyclic cows between 2 nd to 5 th lactation by under intensive system of rearing. The animals were randomly divided into Control (C) and Experiment (E) groups with 12 animals in each The control and experiment groups were again further subdivided in groups C 1 and C 2 & E 1 and E 2 comprising six in each. Onset of oestrus was considered as day 0 for superovulatory treatment. The animals of groups C 1 and C 2 & E 1 and E 2 were injected with 5 ml NSS (i/ml) & 21μg GnRH (i/m) (Buserelin acetate) on day 8 of the oestrous cycle, respectively. Each of the experimental animals of groups C 1 and E 1 was superovulated with 400 mg FSH (i/m) in divided and equal doses at 12 h intervals for four days on day 10 to 13 of the oestrous cycle and consequently, each of the experimental animals of groups C 2 and E 2 was also superovulated with 2000 I.U.PMSG injection (i/m) as single dose on day 10 of the oestrous cycle. PGF 2 α 2ml was injected (i/m) at morning time on day 12 of oestrous cycle. At the superovulatory oestrus, all the animals were bred three times at 12 h intervals using frozen semen. The animals were examined per rectally on day 6 of the induced oestrus after first insemination to detect the superovulatory response. Flushing was performed on day 7 of induced oestrus to retrieve embryos from the superovulated cows. In the present experiment, superovulatory response in GnRH treated groups of cows (groups E 1 and E 2) were found to be better as compared to that of the animals of control groups but the duration of induced oestrus (h) recorded in groups C 2 (49.02 ± 0.07 h) and E 2 (50.40 ± 0.27 h) were found to be significantly higher (P<0.05) than the value recorded in groups C 1 and E 1 .

Con el reciente desarrollo científico surgió la pregunta de si la ovulación espontánea e inducida son distintas entidades o son partes individuales de una continuidad, que hoy ha recibido el nombre de "celo y ovulación facilitados por el macho". Esta rígida clasificación hay que tomarla con precaución, ya que es posible que los varios mecanismos involucrados en la ovulación espontánea e inducida, puedan coexistir en una determinada especie. Existe información abundante que varias especies que siendo típicamente ovuladoras espontáneas, bajo ciertas condiciones se comportan como inducidas. Es posible que hormonas del macho puedan provocar la ovulación por lo que éstas serían ovulaciones inducidas por feromonas masculinas. El llamado "Efecto Macho" (Ram Effect), es usado en la Inseminación Artificial de ovejas, para sincronizar el celo de las hembras en forma natural, ya que las feromonas producidas por el carnero que se encuentran en la lana y secreciones de la piel, son percibidas por el olfato de las hembras, sincronizando y adelantando la estación de monta. Otros estímulos son visuales, auditivos y posturales, que parecen actuar en los Camélidos Sudamericanos. Las varias investigaciones realizadas en los CSA, han encontraron porcentajes variables de hembras que ovularon, ya sea por la sola presencia del macho (olfato?), por la monta de las hembras sin permitir la intromisión del pene (táctil), por monta de hembra a hembra (táctil), por montas interrumpidas, por sentarse junto a una pareja en cópula (olfato, auditivo) por el sonido gutural del macho en cópula (auditivo), y por otros estímulos no identificados. Las tasas de ovulación se incrementan en la estación reproductiva (Diciembre a Marzo). Las evidencias de ovulación han sido diagnosticadas por la conducta sexual de rechazo al macho, por laparoscopia, por el elevación de los niveles de progesterona en sangre y, por ultrasonografía. Existe también lo que se llama "ovulaciones tardías", es decir, ovulan entre 3-4 días del contacto con el macho, y no a las 24-30 horas como sucede en inyección de LH o monta con deposición seminal. Se requieren de mayores investigaciones, para lograr descubrir el o los estímulos facilitadores de ovulación en los CSA.

Superovulation plays an important role in the embryo transfer (ET) programs. The objective of this study was to evaluate the effects of Gonadotropin-releasing hormone (GnRH) or human chorionic gonadotropin (hCG) treatment on ovarian response in PMSG-superovulated ewes. Intravaginal pessaries containing 40 mg fluorogestone acetate (FGA) were inserted in all ewes (n=14) and remained in situ for 14 days. Two days prior to pessary removal, all ewes were treated with 1000 IU of PMSG. On the day of sponge removal (day 0), the females were randomly assigned to 3 treatments. The first group (T1; n=3) received no further treatment, while second group (T2; n=5) treated inter-muscular with GnRH (100 ug) at day 1, finally the third group (T3; n=6) treated inter-muscular with hCG (500 IU) during days 0-2. On day 8, laparotomy was performed to assess numbers of corpora lutea (CL) and anovulatory follicles (AF). Blood samples were collected for analysis of serum progesterone (P ) using radioimmuno...

There is growing worldwide interest in commercial rearing of South American camelids (llamas, alpacas, guanacos and vicuna) for the companion animal market and for the production of high quality natural fibres as part of alternative agro-enterprises. Multiple ovulation and embryo transfer (MOET) could increase the progeny from genetically superior individuals and facilitate international camelid embryo trade. Management of reproduction in camelids to enable MOET is complicated as they do not have cyclical spontaneous ovulation but show waves of follicular development and regression; ovulation is generally induced by copulation. We have previously demonstrated that superovulation can be achieved and that multiple embryos can be successfully recovered non-surgically in camelids (Bourke et al. Proc. 12th Int.Cong.Anim. Reprod. 1, 193-195, 1992). The objectives of the present study were to test the feasibility of synchronising donor and recipient ovarian activity and to assess the probability of establishing pregnancy following non-surgical embryo transfer. Ten adult llama recipients were synchronised as follows: When each donor was naturally mated, a recipient with a single mature follicle was selected from a large group of potential recipients which were monitored regularly by transrectal ultrasonography to assess normal follicular development. To synchronise ovulation and subsequent CL development, 8 pg of GnRH analogue (Receptal; Hoechst, Milton Keynes, UK) was given im to both the donor and assigned recipient. Time to ovulation was assessed by transrectal ultrasonography at 30 to 60 min intervals in the peri-ovulatory period. Twelve camelid embryos, from llama (n=8) and guanaco (n=4) donors, recovered 6 to 8 d after ovulation, were transferred to 10 llama recipients. The embryos, all hatched blastocysts, ranging in size from 0.6 mm diameter to 5.0 mm in length, were washed in Ovum Culture Medium (ICN-Flow, Herts, UK), loaded into 0.25 ml A.I. straws and transferred, within 2 h of recovery, using a Cassou gun manipulated transcervically. Either 1 (8 recipients) or 2 embryos (2 recipients) were deposited near the tip of the uterine horn, ipsilateral to the CL. Recipients were subsequently monitored by ultrasound. Ovulation was induced and synchronised with a mean time interval &SEM) from GnRH injection of 28.2 + 0.75 h in recipients and 29.0 + 0.21 h in donors. All of the recipients had a functional CL on day of transfer (mean CL diameter 12.1 _& 0.05 mm and plasma progesterone concentration 29.2 +-2.77 nmol I"). Pregnancies were established in 5 llama recipients (50%), 3 of which had received llama embryos and 2 of which had received guanaco embryos. These successful transfers resulted from embryos of 0.6 to 1.2 mm diameter, collected 6 to 7 d after ovulation. Since al1 of the foetuses were located in the left uterine horn even though the embryos had been deposited ipsilateral to the CL,transuterine migration had occurred in some recipients. Four of the pregnancies were carried to term (344+ 5.6 d after transfer) and the other pregnancy was maintained until 304 d after transfer. None of the recipients which received 2 embryos subsequently had twin foetuses but one had a singleton offspring. This study has demonstrated that pregnancies can be successfully established in South American camelids following embryo transfer to recipients with an identified CL arising from a single treatment of GnRH during the presence of a mature follicle.

The viscous seminal plasma (SP) is currently a major impediment to the handling of ejaculate and the development of some biotechnologies in South American camelids. The vas deferens-collected spermatozoa of alpacas is a useful technique to avoid this problem. On the other hand, SP contains a large protein component that has been implicated in the function of spermatozoa within the female reproductive tract. In this sense, the low fertility achieved using transcervical insemination with frozen-thawed spermatozoa in alpacas could be improved by adding SP. This study aimed to evaluate the effect of the whole SP on some in vitro parameters of alpaca spermatozoa after the freezing-thawing-process and the fertility after artificial insemination. It would contribute to a better understanding of the interaction between thawed sperm cells and SP. Spermatozoa were obtained by surgically diverted vas deferens. The samples were diluted with a Tris-based extender, packaged in straws, and frozen....

The objetive of this research work was to study the effect of the frequency of copulation during the post-ovulatory estrous on the embryonic mortality in alpacas. Forty four female alpacas were selected having a post-partum sexual rest &gt;20 days and bearing in the ovaries a pre-ovulatory follicle &gt;7 mm of diameter. Animals were mated (time of coitus: &gt;15 minutes) using a male with proven fertility and received 6 g of busereline i.m. after copula to ensure ovulation. Three experimental groups were then ramdomly organized: the first group (S 1 , n = 14) did not receive additional matings, the second gropup (S 2 , n = 15) received an additional mating on day three post-ovulation, and the third group (S 3 , n = 15) received additional matings on days three and four post-ovulation. Ovulation was confirmed through ultrasound images by disappearance of the pre-ovulatory follicle 42 hours post-mating and the presence of a corpus luteum on day 5 post-ovulation. In addition, the size ...

One of the factors limiting successful processing of alpaca (Vicugna pacos) semen is the viscosity of seminal plasma. The viscous nature of the collected ejaculate has hindered sperm cryopreservation as well as artificial insemination (AI) under field conditions. The objective of this investigation was to evaluate recovery, motility, and plasma membrane integrity of alpaca spermatozoa after centrifugation in one of two different solutions at one of three different combinations of speed and time. A total of 24 ejaculates was recovered from seven reproductively sound Huacaya males using a modified artificial vagina (AV) after training the animals for semen collection.  A 2 × 3 factorial treatment arrangement was utilized for this study. Ejaculates were divided into fractions for centrifugation in one of two solutions (Tris extender or PureSperm®80 density gradient solution) at one of three combinations of speed and time (492 × g for 15 min, 1968 × g for 10 min, or 4448 × g for 7 min). The experiment was replicated eight times. Results: Analysis revealed that centrifugation at 4448 × g for 7 min in PureSperm®80 provided a high recovery rate of spermatozoa with the highest sperm motility and functional integrity of plasma membrane post-centrifugation. Results suggest that adoption of this procedure (centrifugation at 4448 × g for 7 min in PureSperm®80) in the initial processing of alpaca ejaculates may enhance subsequent ability to use semen for AI and other assisted reproductive biotechnologies in this species

RESUMEN El objetivo del presente estudio fue evaluar el efecto del estadio del desarrollo folicular del folículo dominante (fd) al momento de la cópula, sobre la ovulación y supervivencia embrionaria en alpacas. Se utilizaron 116 animales con descanso post-parto ≥15 días, que fueron evaluadas por ecografía transrectal para distribuirlas en 4 grupos: G1 (fd en esta-dio de crecimiento, diámetro: 6 mm), G2 (fd en estadio de crecimiento, diámetro: ≥ 7 y ≤ 12 mm), G3 (fd en estadio estático, diámetro: ≥7 mm) y G4 (fd en estadio de regresión, diámetro: ≥7 mm). Posteriormente, fueron sometidos a monta controlada, a excepción de 5 alpacas del grupo G1 que rechazaron al macho. El día del empadre fue considerado el día 0. Evaluaciones ecográficas adicionales se realizaron los días 2 (ocurrencia de ovula-ción), 9 (presencia y tamaño del cuerpo lúteo); 20, 25, 30 y 35 (presencia de vesícula embrionaria o embrión). El día 15 post cópula se realizó la prueba de receptividad sexual. El 97.3% de al...

RESUMEN El presente estudio fue realizado con el propósito de evaluar el efecto de varias fracciones de plasma seminal de llamas, según su peso molecular (PM), sobre la induc-ción de la ovulación. Se utilizó 54 llamas hembras sin cría y en óptimo estado reproductivo, con folículo dominante &gt;7 mm de diámetro determinado por ecografía transrectal por tres días consecutivos. Los animales se distribuyeron al azar a uno de los seis tratamientos: A) fracción de plasma seminal con PM &gt;30 kDa, B) fracción de plasma seminal con PM entre 10 y 30 kDa, C) fracción de plasma seminal con PM entre 5 y 10 kDa, D) fracción de plasma seminal con PM &lt;5 kDa, E) plasma seminal completo, y F) PBS. Los animales fueron tratados con una solución de 1.5 ml de la fracción de plasma seminal o placebo correspondiente por vía intramuscular. Las llamas fueron evaluadas por ecografía en el día 2 y 9 post-tratamiento para determinar la tasa de ovulación y el tamaño del cuerpo lúteo. Los resultados indicaro...

El estudio tuvo por objetivo evaluar el sitio de deposición del plasma seminal sobre la tasa de ovulación y formación del cuerpo lúteo en alpacas. Se seleccionaron 91 hembras no lactantes con folículos ≥7 mm detectados por ecografía transrectal. Se sincronizó la onda folicular con la aplicación de 5 mg de LH, y 12 días después, se determinó la presencia de un folículo dominante (≥7 mm). Las hembras se distribuyeron al azar en seis tratamientos: G 1 =16 (Plasma seminal vía intramuscular), G 2 =15 (PBS vía intramuscular), G 3 =16 (Plasma seminal vía intrauterina), G 4 =15 (PBS vía intrauterina), G 5 =15 (Plasma seminal vía intrauterina con curetaje), G 6 =14 (PBS vía intrauterina con curetaje). La tasa de ovulación y presencia de cuerpo lúteo se determinó mediante ecografía el día D 2 y D 8 (D 0 = inicio del tratamiento). Se tomó muestras de sangre los días D 0 , D 3 y D 9 para determinar perfiles séricos de progesterona mediante RIA. La tasa de ovulación fue de 93.8, 37.5 y 66.5% para G 1 , G 3 y G 5 , respectivamente, y no se registraron ovulaciones en los otros grupos. Se encontró que las alpacas G 1 producirían 25 veces más ovulaciones con respecto al G 3. Los resultados sugieren que la absorción del factor inductor de ovulación (FIO) del plasma seminal es vía sistémica y que el curetaje facilitaría la absorción del FIO incrementando el efecto ovulatorio del plasma seminal.

RESUMEN El objetivo del presente estudio fue evaluar el efecto del estadio del desarrollo folicular del folículo dominante (fd) al momento de la cópula, sobre la ovulación y supervivencia embrionaria en alpacas. Se utilizaron 116 animales con descanso post-parto ≥15 días, que fueron evaluadas por ecografía transrectal para distribuirlas en 4 grupos: G1 (fd en esta-dio de crecimiento, diámetro: 6 mm), G2 (fd en estadio de crecimiento, diámetro: ≥ 7 y ≤ 12 mm), G3 (fd en estadio estático, diámetro: ≥7 mm) y G4 (fd en estadio de regresión, diámetro: ≥7 mm). Posteriormente, fueron sometidos a monta controlada, a excepción de 5 alpacas del grupo G1 que rechazaron al macho. El día del empadre fue considerado el día 0. Evaluaciones ecográficas adicionales se realizaron los días 2 (ocurrencia de ovula-ción), 9 (presencia y tamaño del cuerpo lúteo); 20, 25, 30 y 35 (presencia de vesícula embrionaria o embrión). El día 15 post cópula se realizó la prueba de receptividad sexual. El 97.3% de al...

The embryo transfer is a reproduction biotechnology that includes the induction of superovulation of the donor females, the embryo recovery and their transfer in the uterus of receptor females. The efficiency of the embryo transfer depends on the results obtained in the superovulatory treatments. The variability of the ovary reaction to induction to superovulation treatments had been an important factor limiting the current commercial application in embryo transfer to cows. In the last years, for reducing the variability of ovaries reaction to gonadotropes hormones stimulation, progestagen hormones are frequently used. In our embryo recovery experiments performed on cows, we induced the superovulation with gestagen hormones, pituitary extracts of FSH and PgF 2 α. We used two subcutaneous implants with 3 mg of norgestomet (SMB). The first implant was introduced on the external side of the ear and in the same time a solution-SMB was injected (Day 0). The second implant was introduced ...

The embryo transfer is a reproduction biotechnology that includes the induction of superovulation of the donor females, the embryo recovery and their transfer in the uterus of receptor females. The efficiency of the embryo transfer depends on the results obtained in the superovulatory treatments. The variability of the ovary reaction to induction to superovulation treatments had been an important factor limiting the current commercial application in embryo transfer to cows. In the last years, for reducing the variability of ovaries reaction to gonadotropes hormones stimulation, progestagen hormones are frequently used. In our embryo recovery experiments performed on cows, we induced the superovulation with gestagen hormones, pituitary extracts of FSH and PgF 2 α. We used two subcutaneous implants with 3 mg of norgestomet (SMB). The first implant was introduced on the external side of the ear and in the same time a solution-SMB was injected (Day 0). The second implant was introduced ...

Early embryos of superior genotype are collected prior to their implantation in uterus, and they are implanted in the uterus of other females of inferior genotype where they complete its actual development which is referred to as embryo transfer. The chief objective of embryo transfer is to achieve greater rate of conception, increase in number of progeny per year from single female animal of superior genotype. Embryo transfer technique helps in increasing commercial production and it can also improve the genetic potential of livestock. The embryo transfer technique provides a rapid rate of improvement of the genetic quality of offspring at relatively lower cost than purchasing a live animal. The present review depicts the basic principles, applications and the different steps in the procedure of embryo transfer in animals.

Response to the superovulatory hormone treatments varied for the type of breed and doses of superovulatory hormone used. Ovarian response of 42 cross bred HF (50%, 75%) and pure dairy cows were evaluated based on ultrasonographic count of CL and embryo recovery for quality assessment. Ovarian response rate was significantly higher (P&lt;0.05) in the crossbreds than in the pure bred cows. The maximum response achieved (CL count, mean ± SE) was 14.6±1.1 and the least with 11.2±1.1, 75% HF at 650IU and pure HF at 800IU, respectively. Significantly higher (p&lt;0.05) number of UFO were collected at a dose of 500 IU while transferable embryos were higher at 650IU in both the 50% HF and 75% HF cows. Pure bred cows responded fairly with more CL and produced higher number of transferable embryos at a dose of 800 IU FSH. In conclusion, the optimal dose for maximum response (CL count) exhibited in cross breed HF cows is 650 IU.

The objective of the experiment was to study the number of oocytes recovered, their quality and the recovery rate after superovulation, in order to use the oocytes, as a cytoplasm recipient in a nuclear transfer program. A total of 38, New Zealand White mature, doe rabbits were divided into 3 groups, according to the chosen dose of Follicle Stimulating Hormone (FSH); 21 mg (group A), 28 mg (group B) and 40 mg (group C). Five IM injections of FSH were given at 12 hr interval by increasing doses for group A and B and a constant dose for group C. The ovulation was induced by giving 100 iu human chrorionic gonadotropin (hCG) and mating by a vasectomized buck. The oocytes were collected following ovariectomy and direct flushing. The number of corpora lutea (CL), non hemorrhagic and hemorrhagic follicles were counted. The number of CL were 24.5±8.8, 21.3±11.6 and 20.4±8.6 (P&gt;0.05) respectively. The recovery rate in group A, (77.7%) was higher than those of group B, (55.7%) and C, (50.9...

The study of factors responsible for eliciting ovulation in rabbits has been hampered by the lack of a suitable method of monitoring the ovaries in vivo. Ovarian imaging by ultrasound biomicroscopy was used in two experiments designed to determine the effects of seminal plasma on the ovulatory response in rabbits. In Experiment 1, female rabbits were group-housed and treated intramuscularly with saline, gonadotropin releasing hormone (GnRH), or seminal plasma of llamas or rabbits (n = 4 to 6 per group). Rabbits were euthanized eight days later to evaluate the ovarian response by ultrasound biomicroscopy ex situ. No differences among groups were detected in the proportion of rabbits that ovulated or in the number and size of corpora lutea. The high incidence of ovulation in the negative control group was unexpected, and confounded determination of an ovulation-inducing effect of seminal plasma. In Experiment 2, female rabbits were caged individually, and treated as in Experiment 1 (n...

In an effort to conserve a threatened Canadian species, Bison bison athabascae, we developed an embryo collection protocol subsequent to superovulatory treatment involving two doses of FSH diluted in hyaluronan given 48 h apart. The follicular response to superstimulatory treatment was satisfactory, but many follicles did not ovulate, thus limiting the number of embryos collected. Based on recent results in cattle, where replacement of the final doses of FSH with a low dose of eCG resulted in the recovery of a greater number of ova/embryos, the objective of the present study was to evaluate the effect of adding eCG to the superovulatory protocol to increase ovulation rate, embryo collection, and embryo quality in wood bison during the breeding season (September). Ovarian synchronization was induced in wood bison (n = 24) by treatment with a luteolytic dose of prostaglandin (500 mcg, Cloprostenol) followed 8 days later by transvaginal ultrasound-guided follicular ablation. Follicular...

Using laparoscopy, different degrees of sexual receptivity and time of ovulation after single copulation were determined in alpacas. Sexual receptivity was assessed with intact males in 39 adults (> 3 years old) and 37 yearlings (12-14 months) and then laparoscopy was performed to correlate it with size of ovarian follicles. Time of ovulation was also determined at two different times after copulation. Females exhibited three degrees of sexual receptivity: immediate and slow acceptance, and refusal, with no difference between yearlings and mature animals (P> 0.05). Female alpacas bred over a wide range of follicle size with no differences between ages (P> 0.05). Fifty percent of females ovulated at a normal time (30 h after copulation), 24% ovulated late (72 h), and ovulation was not observed in 26% of females. Forty percent of the animals that failed to ovulate were yearlings and 15% adults (P< 0.05). The average follicle size that ovulated was 8.1 mm, with 7 mm as the minimum size for ovulation, and with no association between follicle size and time of ovulation.

Resumption of ovarian follicle activity and uterine involution was studied in the post partum llama. Thirty-nine adult multiparous llamas were monitored by ultrasonography and analysis of urinary estrone sulfate for 30 d post partum at the La Raya Research Station in Peru. Uterine involution was measured in terms of reduction of length and diameter of both uterine horns. Correlation analysis was used to relate follicle size and concentration of estrone sulfate. Analysis of variance was used to determine rate of uterine involution relative to days post partum. The left ovary was palpated and sxxnned by Day 3 post partum in contrast to Day 1 post pat-turn for the right ovary. Ovulatory size follicles, 7 mm, were present by Day 7.4 post partum (range 4 to 14 d). Follicle growth was detected as early as Day 4 post partum with follicle size being less during the first follicle wave (7.4 mm) compared to the second and third waves (9 to 10 mm). Concentrations of urinary estrone sulfate were positively related (PcO.05) to follicular size, but to a lesser degree during the first follicle wave (19.4 ng/mg Cr), than to the second wave (25.4 nglmg Cr). Uterine involution, as measured by diameter, was different between the left (gravid) and right (nongravid) uterine horn (P<O.O5) for the 17 d post par-turn, and was also different from that of control females for the 21 d post partum. Uterine involution was complete in 63% of females by Day 21 post partum.

Multiple ovarian follicles were induced to grow and ovulate in llamas by administration of equine chorionic gonadotropin (eCG) followed by either copulation or injection of human chorionic gonadotropin (hCG). Forty-five parous female llamas weredividedrandomlyintofivetreatmentgroups:control(n=8),1O0(n=7),500(n=10),1OOO(n=10)or2000(n=10) IU eCG. Ultrasonography was used to monitor ovarian activity during the ovarian cycle, urinary estrone sulfate during the follicular phase, and pregnanediol during the luteal phase. The number of follicles was not different (P > 0.05) between control and females receiving 100 IU eCG. Follicular growth was increased (P < 0.05) seven days after treatment with doses of at least 500 IU eCG. A mean number of 4.7, 4.6, and 6.4 follicles was observed for doses of 500 IU, 1000 IU, and 2000 IU eCG, respectively. Concentrations of urinary estrone sulfate increased (P<O.OS) threefold in animals with multiple follicles (101 ng mg-' creatinine (Cr)) compared with animals bearing single follicles (29.7 ng mg-' Cr) , Cystic follicles occurred in two, two, and nine animals receiving 500 IU, 1000 IU and 2000 IU eCG, respectively. Twenty females were induced to ovulate with either single copulation (11) or 750 IU hCG administration (9). Corpora lutea were observed in 59.9% and 78.8% (P < 0.05) of females stimulated with single copulation or hCG, respectively. Mean number of corpora lutea was 3.4 and 5.4, respectively. Concentrations of pregnanediol were 9.3 and 7.7 ng mg-' Cr, respectively, at day 7 after copulation or hCG. Although 2000 IU eCG provoked multiple follicle development, most of them became cystic. Doses of 500 and 1000 IU eCG were optimal doses for inducing multiple follicle growth in llamas, while hCG administration was superior to copulation for stimulating ovulation.

Using laparoscopy, different degrees of sexual receptivity and time of ovulation after single copulation were determined in alpacas. Sexual receptivity was assessed with intact males in 39 adults (> 3 years old) and 37 yearlings (12-14 months) and then laparoscopy was performed to correlate it with size of ovarian follicles. Time of ovulation was also determined at two different times after copulation. Females exhibited three degrees of sexual receptivity: immediate and slow acceptance, and refusal, with no difference between yearlings and mature animals (P> 0.05). Female alpacas bred over a wide range of follicle size with no differences between ages (P> 0.05). Fifty percent of females ovulated at a normal time (30 h after copulation), 24% ovulated late (72 h), and ovulation was not observed in 26% of females. Forty percent of the animals that failed to ovulate were yearlings and 15% adults (P< 0.05). The average follicle size that ovulated was 8.1 mm, with 7 mm as the minimum size for ovulation, and with no association between follicle size and time of ovulation.

Resumption of ovarian follicle activity and uterine involution was studied in the post partum llama. Thirty-nine adult multiparous llamas were monitored by ultrasonography and analysis of urinary estrone sulfate for 30 d post partum at the La Raya Research Station in Peru. Uterine involution was measured in terms of reduction of length and diameter of both uterine horns. Correlation analysis was used to relate follicle size and concentration of estrone sulfate. Analysis of variance was used to determine rate of uterine involution relative to days post partum. The left ovary was palpated and sxxnned by Day 3 post partum in contrast to Day 1 post pat-turn for the right ovary. Ovulatory size follicles, 7 mm, were present by Day 7.4 post partum (range 4 to 14 d). Follicle growth was detected as early as Day 4 post partum with follicle size being less during the first follicle wave (7.4 mm) compared to the second and third waves (9 to 10 mm). Concentrations of urinary estrone sulfate were positively related (PcO.05) to follicular size, but to a lesser degree during the first follicle wave (19.4 ng/mg Cr), than to the second wave (25.4 nglmg Cr). Uterine involution, as measured by diameter, was different between the left (gravid) and right (nongravid) uterine horn (P<O.O5) for the 17 d post par-turn, and was also different from that of control females for the 21 d post partum. Uterine involution was complete in 63% of females by Day 21 post partum.

Multiple ovarian follicles were induced to grow and ovulate in llamas by administration of equine chorionic gonadotropin (eCG) followed by either copulation or injection of human chorionic gonadotropin (hCG). Forty-five parous female llamas weredividedrandomlyintofivetreatmentgroups:control(n=8),1O0(n=7),500(n=10),1OOO(n=10)or2000(n=10) IU eCG. Ultrasonography was used to monitor ovarian activity during the ovarian cycle, urinary estrone sulfate during the follicular phase, and pregnanediol during the luteal phase. The number of follicles was not different (P > 0.05) between control and females receiving 100 IU eCG. Follicular growth was increased (P < 0.05) seven days after treatment with doses of at least 500 IU eCG. A mean number of 4.7, 4.6, and 6.4 follicles was observed for doses of 500 IU, 1000 IU, and 2000 IU eCG, respectively. Concentrations of urinary estrone sulfate increased (P<O.OS) threefold in animals with multiple follicles (101 ng mg-' creatinine (Cr)) compared with animals bearing single follicles (29.7 ng mg-' Cr) , Cystic follicles occurred in two, two, and nine animals receiving 500 IU, 1000 IU and 2000 IU eCG, respectively. Twenty females were induced to ovulate with either single copulation (11) or 750 IU hCG administration (9). Corpora lutea were observed in 59.9% and 78.8% (P < 0.05) of females stimulated with single copulation or hCG, respectively. Mean number of corpora lutea was 3.4 and 5.4, respectively. Concentrations of pregnanediol were 9.3 and 7.7 ng mg-' Cr, respectively, at day 7 after copulation or hCG. Although 2000 IU eCG provoked multiple follicle development, most of them became cystic. Doses of 500 and 1000 IU eCG were optimal doses for inducing multiple follicle growth in llamas, while hCG administration was superior to copulation for stimulating ovulation.

El presente estudio tuvo como objetivo evaluar la eficiencia de recuperación de embriones de ovulación simple, la calidad de los embriones y la fertilidad de la transferencia embrionaria interespecie. Se utilizaron 9 alpacas donadoras y 40 llamas receptoras. Se les hizo el seguimiento ecográfico para determinar la presencia de folículos ovulatorios. Las donadoras fueron cubiertas mediante monta natural y el lavado de los cuernos uterinos se realizó a los 7 días de la cópula. Luego del lavado uterino se aplicó cloprostenol a las donadoras para inducir luteólisis y reiniciar una nueva onda folicular. Se realizaron cuatro lavados con un intervalo de 15 días entre lavados. Las transferencias de los embriones se hicieron en el día 7 (grupo I) y 6 (grupo II) pos-inducción de la ovulación con buserelina a las receptoras. Se recolectó el 58.3% de los embriones. El 57.2, 23.8 y 19.0% de los embriones fueron de grado 1, 2 y 3, respectivamente. No hubo embriones de grado 4. La fertilidad a los...

South American camelids are induced ovulators and require a stimulus to trigger the LH surge Ž. Ž. responsible for the ovulation. Seminal plasma SP of fertile alpacas Lama pacos was tested using a bioassay of pituitary cells to study the effect of seminal plasma on LH release. Plates Ž 5

There is growing worldwide interest in commercial rearing of South American camelids (llamas, alpacas, guanacos and vicuna) for the companion animal market and for the production of high quality natural fibres as part of alternative agro-enterprises. Multiple ovulation and embryo transfer (MOET) could increase the progeny from genetically superior individuals and facilitate international camelid embryo trade. Management of reproduction in camelids to enable MOET is complicated as they do not have cyclical spontaneous ovulation but show waves of follicular development and regression; ovulation is generally induced by copulation. We have previously demonstrated that superovulation can be achieved and that multiple embryos can be successfully recovered non-surgically in camelids (Bourke et al. Proc. 12th Int.Cong.Anim. Reprod. 1, 193-195, 1992). The objectives of the present study were to test the feasibility of synchronising donor and recipient ovarian activity and to assess the probability of establishing pregnancy following non-surgical embryo transfer. Ten adult llama recipients were synchronised as follows: When each donor was naturally mated, a recipient with a single mature follicle was selected from a large group of potential recipients which were monitored regularly by transrectal ultrasonography to assess normal follicular development. To synchronise ovulation and subsequent CL development, 8 pg of GnRH analogue (Receptal; Hoechst, Milton Keynes, UK) was given im to both the donor and assigned recipient. Time to ovulation was assessed by transrectal ultrasonography at 30 to 60 min intervals in the peri-ovulatory period. Twelve camelid embryos, from llama (n=8) and guanaco (n=4) donors, recovered 6 to 8 d after ovulation, were transferred to 10 llama recipients. The embryos, all hatched blastocysts, ranging in size from 0.6 mm diameter to 5.0 mm in length, were washed in Ovum Culture Medium (ICN-Flow, Herts, UK), loaded into 0.25 ml A.I. straws and transferred, within 2 h of recovery, using a Cassou gun manipulated transcervically. Either 1 (8 recipients) or 2 embryos (2 recipients) were deposited near the tip of the uterine horn, ipsilateral to the CL. Recipients were subsequently monitored by ultrasound. Ovulation was induced and synchronised with a mean time interval &SEM) from GnRH injection of 28.2 + 0.75 h in recipients and 29.0 + 0.21 h in donors. All of the recipients had a functional CL on day of transfer (mean CL diameter 12.1 _& 0.05 mm and plasma progesterone concentration 29.2 +-2.77 nmol I"). Pregnancies were established in 5 llama recipients (50%), 3 of which had received llama embryos and 2 of which had received guanaco embryos. These successful transfers resulted from embryos of 0.6 to 1.2 mm diameter, collected 6 to 7 d after ovulation. Since al1 of the foetuses were located in the left uterine horn even though the embryos had been deposited ipsilateral to the CL,transuterine migration had occurred in some recipients. Four of the pregnancies were carried to term (344+ 5.6 d after transfer) and the other pregnancy was maintained until 304 d after transfer. None of the recipients which received 2 embryos subsequently had twin foetuses but one had a singleton offspring. This study has demonstrated that pregnancies can be successfully established in South American camelids following embryo transfer to recipients with an identified CL arising from a single treatment of GnRH during the presence of a mature follicle.

Introduction: The enteric disorders represent a serious hazard for bovine and camelid breeding. The aim of this study was to examine the frequency of detection and molecular characteristics of enteric coronavirus (CoV) infections in cattle, alpaca, and llama herds bred in family-based farms in Brazil and Peru. Methodology: Stool samples were collected from calves from Brazil and camelids from Peru for detection and characterization of CoV by reverse transcription polymerase chain reaction (RT-PCR) and sequence analysis. Results: 46.5% (47/101) samples from calves and 26.8% (70/261) from alpaca tested positive for CoV. All strains belong to lineage A1 of the Betacoronavirus genus. Phylogenetic analysis showed high identity between CoV strains detected in calves and alpacas. Conclusions: This study characterised CoV strains from dairy cattle herds in the state of Rio de Janeiro, Brazil, and indicated that this virus is spread among the state herds. The results also indicate widespread...

This paper reviewed the impact of thermally-induced oxidative stress on reproduction in ewes. Thermally-induced oxidative stress is associated with excess generation of reactive oxygen species (ROS) during aerobic respiration and metabolic activities within the body. Excess ROS have been implicated in pathophysiologic mechanisms impairing reproductive processes, including changes in cyclic luteal and endometrial processes, poor follicular development, ovulation, fertilisation, embryogenesis, embryonic implantation, and placental differentiation and foetal growth. High levels of ROS during pregnancy result in pregnancy disorders such as spontaneous abortions, embryopathies, preeclampsia, foetal growth restriction, pre-term abortion and low-birth weight. Thermally-induced stress occurs as a result of extreme cold and hot temperatures, and its impact on animals is determined by nature of management practices being used in the farm. Heat stress suppresses reproductive hormonal expression and activities, resulting in poor reproductive performances, including the exhibition of poor oestrus behaviour and mating ability; while cold stress suppresses reproductive neuroendocrine axis, which adversely affects conception rates and mating behaviours. Other oxidative stress factors exerting negative effects on reproduction are poor nutrition, solar radiation, environmental pollutants, high ambient temperature and high relative humidity, expressed as temperature-humidity-index. The stressors contribute to adverse pregnancy outcomes, increase in the susceptibility of offspring to disease by compromising the offspring immune status and overall reproductive performance in ewes. The link between oxidative stress and reproductive processes such as spermatogenesis, oogenesis, fertilisation, embryonic development, implantation and foetal growth are critical therapeutic and prophylactic interventions in reproductive medicine. The role of oxidative stress in reproductive processes and the state of knowledge on the association between oxidative stress and pregnancy outcomes in ewes are elucidated. It is concluded that oxidative stress is an important silent condition undermining reproductive performance in sheep resulting in serious economic loss. Reduction of its impacts will enhance productivity and performance in ewes.