Brangus ırkının İç Anadolu şartlarında büyüme, yaşama gücü ve besi performansının tesbiti

Abstract

The study was conducted to investigate the livability, growth, performance of Brangus Cattle obtained by frozen Embrio Transfer to Brown Swiss and Holstein heifers in the Middle Anatolian Conditions. The same traits were also compared with Brown Swiss breed. The growth performance was carried out from birth to 18 months of age. Frozen Brangus embrios imported from USA were non-surgical ly transferred to 64 Brown Swiss and 31 Holstein heifers. Recipient heifers were synchronized by two prostaglandin injections 1 1 days apart. Transfers were performed 7 days after the estrous. The pregnancy tests were carried out by rectal palpation 45 days after insemination. Thawed embrios were classified as, 69 morula, 11 early blastocyst, 14 blastocyst and 1 expanded blastocyst. The quality classes were excellent Gl), good (G2) and fair (G3) and the number of embrios in each class were 45, 43 and 7 respectively. The overall pregnancy rate was 29.47 % The rates were 39.28 % in (Gl) and 25.80 % in (G2) embrios. The highest pregnancy rate was obtained from blastocyst phase embrio trasfers and the ratio was 62. 50 %. The average birth weights in Brangus and Brown Swiss breeds were 36.65 and 40.44 kg in males and 33.25 and 34.75 kg, in females respectively. The live weights in the breeds at 12 months of age were 415.19 and 277.85 kg in males and 336.35 and 217.33 kg in the females in the above order. The average values in wither heights at birth Brangus and Brown Swiss males were 70.12 ad 77.70 cm and in the females were 67.93 and 78.12 cm, respectively. At 12 months of age the superiorities males were reversed and the averages were 126.35 and 111.71 cm in the males and 119.35 and 107.50 cm in the females. At 18 months of age the same trends were continued.97 Similar results were obtained for body length, heart girth and cannon bone circumference measurements. The differences in live weights and growth traits were not statistically significant between the breeds at birth. However, Brangus breed had higher values in all traits at the fallowing periods of measurements (p<0.01). Viabilities of the animals were studied in two stages of the life. The viabilities in the breeds between 0-6 months were 91.67 % and 96.08 %; and between 0-18 months were 83.33 % and 94.12 %. The disease rate in the groups from birth to 18 months were 35.00 % and 33.88 %, respectively. Differences between the groups were not statistically significiant. Some important statistics of reproductive performances in Brangus and Brown Swiss were as following: The ages at first breeding were 20.00 and 20.29 months, ages at first calving were 29.36 and 29.56 months; Conception rates were 100 % and 97.22 %, calving rates were 87.50 % and 85.70 %, the average number of inseminations per conception were 2.25 and 1.74; the percentages of abortions, premature births and stillbirths were 12.5 % and 14.28 %; the lenght of pregnancies were 279.14 and 288.76 days, respectively. The weights at slaughterings were set as 600 kg for Brangus Bulls and 500 kg for Brown Swiss. The average daily gains in the fattening period were 1087 and 1126 g in the above order. Feed conversion efficiencies were 9.79 and 9.25; dressing percentages of hot carcases 61.33 and 59.07 %; lean ratios in carcasses 69.98 and 77.09 %, bone ratios 17.62 and 15.61 %, fat ratios 9.24 and 5.10 %. The results indicated that Brangus cattle were well adapted to the Central Anatolian conditions and they demonstrated satisfactory performances. On the other hand it was found that the performances of the Brown Swiss animals were as good as or even better than Brangus for some traits. However Brangus Calves had smaller birth weight indicating that less calving problems would be encountered in case of Brangus Sperm is used for the terminal crossings of native cows.