Papers by Peregrino Duran
Journal of Buffalo Science
High-fertile and productive dairy animals are important to satisfy the growing population's d... more High-fertile and productive dairy animals are important to satisfy the growing population's demand. Sire fertility is one of the essential factors that regulate the overall pregnancy rate of dairy herds. However, sire fertility varies from 10 to 90%, suggesting that male fertility largely accounts for varying fertility levels across the herd. Sub-fertile bulls and females should be identified and discarded promptly to improve the dairy herd's productivity. The most dominant factors implicated in culling are poor semen quality, poor semen freezability (<35% post-thaw motility), and poor libido for the bulls and hard breeders for females that cause huge economic loss to the raisers. Understanding the basic mechanism of male and female fertility has undergone tremendous change in recent times owing to the advancement of molecular tools judging the essential molecules responsible for fertility. Presently, a new molecular niche has surfaced in testes, strongly influencing the ...
International Journal of Applied Sciences and Biotechnology, 2014
Transvaginal ultrasound-guided follicular aspiration (TUFA) has become a popular tool for embryo ... more Transvaginal ultrasound-guided follicular aspiration (TUFA) has become a popular tool for embryo production in vitro due to its high degree of repeatability in terms of recovering oocytes from live animals. In Study 1, the quantity and quality of oocytes from Bulgarian Murrah buffalo cows (n=10) of varying ages (Group 1, 8-12; and Group 2, 13-17 years) were assessed. Group 1 buffalo donor cows yielded significantly higher (P<0.05) number of oocytes vs Group 2 buffalo donor cows (71 vs 29 oocytes, respectively), though in terms of oocyte quality, no difference was observed. In Study 2, oocytes collected (n=100) in Study 1 were matured, fertilized in vitro and the resulting zygotes were cultured which developed to blastocyst stage embryos. The maturation, fertilization and blastocyst development rates obtained were 53.0%, 40.0% and 32.5%, respectively. In Study 3, the viability of resulting blastocyst stage embryos was determined by transferring to recipient cows. Of 10 recipients ...
Application of Ultrasound for the Genetic Improvement of the Meat Production Performance of Pigs(豚の産肉能力の遺伝的改良への超音波利用に関する研究)
Technical aspects of the recovery, handling and transfer of embryos
Calf production of water buffalo bulls classified as high and low fertilities by fourier harmonic analysis
PROCEEDINGS OF THE 4TH INTERNATIONAL CONFERENCE OF ANIMAL SCIENCE AND TECHNOLOGY (ICAST 2021)
Selection of Water Buffalo Oocytes with Developmental Competence in Vitro
Philippine Journal of Veterinary and Animal Sciences, 2009
To establish the criteria of oocyte selection and optimize the success rate of in vitro embryo pr... more To establish the criteria of oocyte selection and optimize the success rate of in vitro embryo production (IVEP) in water buffaloes, a series of experiments were conducted. Cumulus-oocytes complexes (COCs) were classified and grouped to examine the following: morphology of the oocytes (rank A, with 5 layers of dense cumulus mass, rank B, with 2 140 I¼m). Meiotic competence and embryo development after in vitro fertilization were assessed. Results showed that rank A COCs with homogeneous ooplasm, compact cumulus cells, and > 120 I¼m ooplasm had the highest meiotic and developmental competence with optimum development when fertilized at 24-26 h of in vitro maturation. COCs with heterogeneous ooplasm and loose cumulus cells were developmentally competent but required shorter duration (20-22 h) of in vitro maturation. Ranks C, D and E oocytes had high degeneration rate. Oocytes with ooplasm Key words: cumulus cells, development potential, embryo, meiotic competence, oocytes, water bu...
Fourier harmonic analysis (FHA) assessed the sperm nuclear shape of 31 buffalo bulls with known f... more Fourier harmonic analysis (FHA) assessed the sperm nuclear shape of 31 buffalo bulls with known fertility to identify the bull with top conception rates of 28-36% and lowest conception rates of 13-19%. The FHA model developed for water buffalo, identified harmonic amplitude 1 as critical in selecting optimum cutoff values based on discriminant analysis. Using the model, 44 other bulls were classified as High(n=12) or Low-fertile (n=10), while the rest (n=22) were mid-fertile bulls. Five bulls from Highand Low-fertility groups were randomly selected for semen quality tests. The tests included fertilization of buffalo oocytes, sperm motility parameters and Hypo-osmotic swelling (HOS) of the plasma membrane integrity. Results showed higher cleavage and blastocysts development with significant difference of hatching rates (P=0.021) for bulls that were predicted to be of Highvs. Low-fertility. Progressive motility (67.2±2.9 vs. 51.9±2.9%), straightness (85.4±0.7 vs. 81.3±0.7) and lineari...
Buffalo Bulletin, 2017
Aimed at producing genetically superior water buffaloes for increased milk and meat purposes, the... more Aimed at producing genetically superior water buffaloes for increased milk and meat purposes, the Philippines through the Philippine Carabao Center endeavoured to develop the advance reproductive biotechnologies. The efficiency of the in vitro embryo production in the production of genetically superior animal was assessed. In Study 1, the viability of in vitro derived vitrified embryos (2n=50) were assessed by non-surgical transfer to river (2n=50) recipients. Study 2 examined the efficiency of swamp buffloes (2n=48) as surrogate mothers of river buffalo embryos, and Study 3 examined the possibility of twinning in water buffaloes by embryo transfer. A Satellite Embryo Biotechnology Laboratory was established in India to secure ovaries from slaughtered river buffaloes and oocytes were collected, matured and fertilized in vitro and cultured for embryo development. In vitro fertilization was carried out using top three progeny tested bulls from National Dairy Development Board of India...
Journal of Buffalo Science
In vitro embryo production (IVEP) is a promising tool with many applications in producing calves ... more In vitro embryo production (IVEP) is a promising tool with many applications in producing calves from genetically superior animals desired for propagation and in the conservation and revival of endangered species. The techniques of IVEP were adopted from cattle and refined to suit the water buffalo requirements. From the collection of ovaries from a local abattoir and the collection of oocytes by ovum pick up from live animals, gamete storage, collection techniques, handling of ovaries and oocytes to keep the viability and developmental competence, selection of oocytes to the type of culture media and in vitro culture condition, and treatment of the sperm cells for in vitro fertilization are all-important components of the process that requires careful and precise action to ensure success. Trials on intracytoplasmic injection, the use of sex-sorted sperm cells as a tool for producing sex-predetermined embryos, and the somatic cell nuclear transfer are methods that can be used to pro...
Incidence of chromosome abnormalities in early stage water buffalo embryos derived from IVF
Advance Reproductive Technologies in Water Buffalo
The Effects of Operator, Interpreter and Machine on Ultrasonic Estimates of Carcass Traits in Pigs
Production of Embryos from Prepuberal Buffaloes Using Ultrasound-Guided Ovum Pick Up and In-Vitro Embryo Production (OPU-IVEP) Techniques
Philippine Journal of Veterinary and Animal Sciences, 2009
Transvaginal ultrasound-guided ovum pick-up (OPU) was performed to compare oocyte recovery and em... more Transvaginal ultrasound-guided ovum pick-up (OPU) was performed to compare oocyte recovery and embryo production between unstimulated and hormonally stimulated prepuberal buffaloes. Four prepuberal calves were injected twice with 250 IU of equine chorionic gonadotropin (eCG) given 7 days apart, inserted intravaginally with control internal drug release (CIDR) on the second injection of eCG, and injected with follicle stimulating hormone (FSH) 7 days after for three consecutive days in decreasing doses. Four prepuberal calves were used as control. An intra-vaginal transducer of 5/7.5MHz attached to an ultrasound machine was used for OPU. Oocytes were recovered using 18G needle attached to the collecting tube anchored to the vacuum pump which was set to produce a negative pressure of 40-80 mmHg. Usable cumulus cell-oocyte complexes (COCs) were matured and fertilized in vitro and examined for developmental competence during culture in vitro. A total of 54 COCs were recovered from the t...
Motility and Membrane Integrity of Ejaculated Bovine Spermatozoa Extended and Cryopreserved in L-Carnitine Tris-Egg Yolk Extender
This study was conducted to examine if L-carnitine supplementation in the Tris-egg-yolk extender ... more This study was conducted to examine if L-carnitine supplementation in the Tris-egg-yolk extender can improve the motility characteristics, membrane integrity, and in vitro fertilization potential after cryopreservation of ejaculated bovine spermatozoa. It was carried out on January to May 2013 at the University of Wisconsin-Madison. L-carnitine at final concentrations of 0.5, 1, 10, and 30mM were added to Tris-egg yolk extender where semen was suspended at 100x10 sperm cells/mL. Tris-egg yolk without carnitine served as control. Motility characteristics and functional integrity of membrane were examined by computer assisted sperm analysis and hypo-osmotic swelling test at 2, 6, and 24 hour at room temperature. The post-thaw effect of L-carnitine was likewise assessed. Each treatment suspension was cryopreserved in Tris-egg yolk with 7% glycerol, stored in liquid nitrogen and subjected to computer assisted sperm analysis and hypo-osmotic swelling test post-thawing. Lastly, the fertil...
Philippine Journal of Veterinary and Animal Sciences, 2015
Hypo-osmotic swelling test (HOST) is a method of assessing the functional integrity of sperm plas... more Hypo-osmotic swelling test (HOST) is a method of assessing the functional integrity of sperm plasma membrane which in turn was claimed as indicator of sperm fertility. Standard protocol of HOST has been established in different species but not in buffaloes. Thus, the current study was conducted to establish the HOST assay for buffalo frozen-thawed sperm cells. Frozen-thawed sperm cells were incubated in different osmolalities (0, 50, 100, 150, 200, 250, and 300 mOsm) of sodium citrate-fructose solution to assess sperm reaction. Then, the effectiveness of sucrose vs. fructose was compared as sugar component of the HOST solution. Results showed higher (P<0.05) number of HOS positive (+) spermatozoa in 150 mOsm compared to 0, 250 and 300 mOsm/L though no significant difference was observed with 50, 100, and 200 mOsm/L. Sucrose- and fructose-containing solutions are both effective in enhancing swelling among treated spermatozoa. The results demonstrated that 150 mOsm is the efficient...
豚における枝肉形質の超音波測定値についてのオペレ-タ-,解析者および機械の効果
Effect of Time on Maturation and Embryo Development Rates of Buffalo Oocytes In Vitro
Philippine Journal of Veterinary and Animal Sciences, 2001
Two studies were conducted to examine the effect of time on buffalo oocytes in vitro maturation (... more Two studies were conducted to examine the effect of time on buffalo oocytes in vitro maturation (IVM) and embryo development after in vitro fertilization (IVF). The general objective is to come up with a concrete basis for technical procedure on collection and length of preservation of ovaries and oocytes IVM for improved rate of in vitro embryo production. Study 1 examined the effects of short (3-4 hr) and long (5-6 hr) periods of ovary collection and preservation on the subsequent development potential of buffalo oocytes after IVF. A total of 132 oocytes were randomly distributed into two groups - long period and short period. Results revealed that cleavage and blastocyst development rates are higher in the short period than in the long period, 58.57% vs. 46.77% and 21.43% vs.12.9%, respectively (P<0.05). Study 2 assessed the optimum time for IVM to obtain higher percentage of oocytes at Metaphase II stage (MII, mature stage) and determine the best time for IVF in water buffalo...
Effects of sequential media system in improving development of preimplantation stage water buffal... more Effects of sequential media system in improving development of preimplantation stage water buffalo embryos were examined. Oocytes were collected from slaughterhouse-derived ovaries and cultured and fertilized in vitro (IVF). After IVF, presumptive zygotes were divided into two groups; the treatment group (SMS group) was in vitro cultured (IVC) by sequential media system while the control group was by the traditional culture system. Sequential media system involved IVC of fertilized oocytes in 1% PL medium (1% Fetal Bovine Serum (FBS) in TCM 199 supplemented with 0.4 mM pyruvate (P) and 5 mM lactate (L)) for the first 72 hr of IVC; then in 15% PL medium (15% FBS) from ~72 to 120 hr of IVC; and in 15% PLG medium (15% FBS and 1 mg/ml glucose) from ~120 hr onwards. Culture medium in the control group was 10% FBS in TCM 199 throughout the culture period. Cleavage and blastocysts developments were assessed. Cleavage rate was not different between treatments; 68.6% vs. 66.3%. However, moru...
Somatic cell nuclear transfer as a tool for the multiplication of genetically superior water buffaloes: the Philippine initiatives
Lactation pattern of Philippine Carabao, Murrah buffalo and its crosses
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Papers by Peregrino Duran