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Not AvailableYak is one of the most important economically useful animals for highlanders. The decline in the yak population demandseffective measures for conservation and multiplication of elite germplasm. In vitro production of embryos and theircryopreservation and transfer to suitable recipients for production of elite calves may contribute to fulfill the objectives.The work was conducted at the National Research Center on Yak over a period of 3 years. The ovaries of slaughteredanimals were used for collecting oocytes through aspiration of follicles followed by slicing of ovaries in the conventionalmethod. Trials were conducted using 7 cyclic parous yaks for ultrasound-guided ovum pickup (OPU) at Nyukmadung farm(2700 m above mean sea level). The technique followed was similar to that in buffaloes with slight modification.Categories of oocytes classified A (2–3 layers of cumulus) and B (at least one layer of cumulus) obtained through theprocesses were subjected to in vitro maturation using standardized maturation medium (TCM-199 + 10% follicularfluid + sodium pyruvate + ඔ-glutamine + 10% heat inactivated oestrus cow serum + pFSH + 17β oestradiol). The frozen-thawed yak sperm were capacitated using the swing-up method before their incubation with matured oocytes using BOmedium. Oocytes matured for 24 h were washed 5 to 6 times with BO medium and then co-incubated with in vitrocapacitated spermatozoa (0.1 to 0.25 million) for fertilization (8–10 oocytes per group) in 100-µL droplets of BO mediumunder mineral oil in 35-mm Petri dishes and placed in a CO incubator (5% CO , 90% RH) at 38.5°C for 16 to 18 h. Thepresumed zygotes were washed several times in mCR2aa (modified Charles Rosenkrans) washing medium and thencultured in culture medium for 7 days on original beds of granulosa cells. The rates of maturation and fertilization ofoocytes collected by conventional and OPU technique were comparable. This may be attributed to greaternumbers of good quality oocytes recovered in the conventional method. Embryos developed up to the stage of compactmorula and blastocysts (24.66% through conventional and 22.73% through OPU) were cryopreserved using thevitrification method for further study. Thirteen embryos were transferred non-surgically to one each of 13 yak recipients; 5became pregnant and only 1 recipient transferred with a cryopreserved-thawed embryo, developed through OPU,delivered one male calf, leading to the first successful production of an IVF yak calf in the world. The present findings aresuggestive of using the OPU technique for in vitro embryo production, though resulting in lower numbers of transferableembryos, because availability of ovaries for conventional IVF is a major constraint in yak.Not Availabl

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Not AvailableIn vitro yak embryo production through conventional and ovum pickup methods.Not Availabl

Parâmetros sangüíneos e urinários, no pré e pós parto, de búfalas criadas em sistema exclusivo de pastejo The blood and urinary values in the pre and pos-parturient period of buffaloes, kept on exclusive pasture feeding

Foi avaliada a ocorrência de alterações nas concentrações de glicose sanguínea, proteína plasmática total, hematócrito e presença de corpos cetônicos na urina de oito búfalas leiteiras da raça Murrah, com idade variando entre 5 e 10 anos, com no mínimo duas lactações, clinicamente sadias, desde 60 dias antes até 60 dias pós-parto. As concentrações médias de glicose sangüínea e o valor médio do hematócrito diminuíram significativamente no pós-parto (p<0,05). As concentrações de proteína plasmática total não sofreram variações significativas do pré para o pós-parto. No período pré-parto os corpos cetônicos só foram detectados na urina de uma búfala; entretanto, a partir do 32º dia de lactação foram detectados em todos os animais. Houve uma relação direta entre a coloração da urina positiva para o teste de Rothera e as concentrações de glicose sangüínea. Pode-se concluir que na fase inicial da lactação as búfalas utilizadas sofreram um déficit energético, caracterizado pela diminuição nas concentrações sangüíneas de glicose e presença de corpos cetônicos na urina, e que a lactação causou um declínio progressivo no hematócrito, enquanto que as concentrações da proteína plasmática total não sofreram variações do pré para o pós-parto.<br>Eight lactating buffaloes of the Murrah breed were used from 60 days before up to 60 days after calving, in order to evaluate alterations in the concentration of blood glucose, total plasmatic protein, haematocrit and the presence of ketonic bodies in the urine. The 5 to 10- year old buffaloes were clinically healthy and had had at least two lactations. During the experimental period the animals were maintained on Brachiaria brizantha pasture and supplemented with a mineral mixture and water.The media concentrations of blood glucose and the media values of the haematocrit diminished significantly after calving (p<0,05). The concentrations of total plasmatic protein did not show significant variation during the pre and post-calving period. The ketonic bodies in the pre-calving period were only detected in the urine of one buffaloe, but after the 32nd day of lactation ketonic bodies were detected in all animals. There was a direct relationship between the color of the urine positive by the Rothera test and blood glucose concentrations. It can be concluded that at the beginning of lactation the buffaloes had an energetic deficit, characterized by a decline of blood glucose concentrations and the presence of ketonic bodies in the urine, and that lactation caused a progressive decline of the hematocrit, but that the concentration of total plasmatic protein did not vary during the pre and post-calving period