Siyah alaca sığırlarda yaşama gücü, dölverimi ve süt verimi özelliklerini etkileyen bazı çevresel faktörler üzerinde araştırmalar

Abstract

80 inseminations per conception, as 2.4; gestation length, as 279.2 days and calving interval, as 419.0 days. The lactation length, the actual and 305 day milk yields that were calculated according to milking 3 times a day and dry period means were determined as 349.87 days, 61 11.16 kg, 5527.96 kg and 71.8 days, respectively. The effects of the year of calving, the age of dam, sex of calves and the season of calving on calf livability were studied. The effects of this factors on the 0-30 day calf livability rates were found to be insignificant. Neverthless, the factors of age of dam and season of calving had effects on the 0-90 day calf livability rates. Also, it was found that the factors of year of calving, age of dam and season of calving effected the 0-180 day calf livability rates. The year of insemination or calving was found to be effective on the pregnancy rate, the infertility rate, the pregnancy rate in the first breeding, the age at first calving, the interval from calving to first insemination, the days open, the interval from first insemination to conception, the number of inseminations per conception and the calving interval. Furthermore, it was found that the order of pregnancy had effects on the pregnancy rate, the infertility rate, the normally calving rate and the number of inseminations per conception. The season of insemination or calving were found to be effective on the pregnancy rate, the infertility rate, the pregnancy rate in the first breeding, the interval from calving to first insemination, the interval from first insemination to conception, the days open, the calving interval and the gestation length. The effects of the year of calving on the lactation length, the actual and 305 day milk yields were found to be statistically significant in the level of P<0.01. In this study, the degree of determinatios of the year of calving were calculated as 17.5, 17.0 and 27.4% for the lactation length,the actual milk yield and 305 day milk yield, respectively. While the effect of age at calving on the lactation length was found to be insignificant, it was found to be statistically significant on the actual milk yield and 305 day milk yield in the levels of P<0.05 and P<0.01 respectively. The 2 year old cows' actual and 305 day milk yields were found to be less than the cows at other ages. It was determined that the milk yield increased gradually until they got 5 years old and than decreased gradually at following ages. The effect of season of calving on actual milk yield was insignificant, while it was significant in the level of P<0.05 for the 305 day milk yield. Again, the effect of season of calving on the lactation length was found to be significant in the level81 of P<0.01. 305 day milk yield was determined to be more in the cows that were gave birth in autumn and winter than the cows that were gave birth in spring and summer. This study showed that the milk yield and calf livabilitiy chracteristics of the Black Pied cattle raised at Sakarya State Farm were rather fine. On the other hand some of the reproductive parameters were found to be lower than desired. By detecting the sterility and infertilty problems beforhand and treating the animals instantly, observing animals carefully for heat periods, and culling the animals that do not respond to the drug treatment in the farm, it is not surprising to see an increase on the reproductive performance of the animals. Along with that, it will be possible to see an increase on the level of calf livability, reproductive performance and milk yield characteristics by developing breeding, selection and culling programs on the light of the environmental factors that was found to have significant effects on the above characteristics in this study.80 inseminations per conception, as 2.4; gestation length, as 279.2 days and calving interval, as 419.0 days. The lactation length, the actual and 305 day milk yields that were calculated according to milking 3 times a day and dry period means were determined as 349.87 days, 61 11.16 kg, 5527.96 kg and 71.8 days, respectively. The effects of the year of calving, the age of dam, sex of calves and the season of calving on calf livability were studied. The effects of this factors on the 0-30 day calf livability rates were found to be insignificant. Neverthless, the factors of age of dam and season of calving had effects on the 0-90 day calf livability rates. Also, it was found that the factors of year of calving, age of dam and season of calving effected the 0-180 day calf livability rates. The year of insemination or calving was found to be effective on the pregnancy rate, the infertility rate, the pregnancy rate in the first breeding, the age at first calving, the interval from calving to first insemination, the days open, the interval from first insemination to conception, the number of inseminations per conception and the calving interval. Furthermore, it was found that the order of pregnancy had effects on the pregnancy rate, the infertility rate, the normally calving rate and the number of inseminations per conception. The season of insemination or calving were found to be effective on the pregnancy rate, the infertility rate, the pregnancy rate in the first breeding, the interval from calving to first insemination, the interval from first insemination to conception, the days open, the calving interval and the gestation length. The effects of the year of calving on the lactation length, the actual and 305 day milk yields were found to be statistically significant in the level of P<0.01. In this study, the degree of determinatios of the year of calving were calculated as 17.5, 17.0 and 27.4% for the lactation length,the actual milk yield and 305 day milk yield, respectively. While the effect of age at calving on the lactation length was found to be insignificant, it was found to be statistically significant on the actual milk yield and 305 day milk yield in the levels of P<0.05 and P<0.01 respectively. The 2 year old cows' actual and 305 day milk yields were found to be less than the cows at other ages. It was determined that the milk yield increased gradually until they got 5 years old and than decreased gradually at following ages. The effect of season of calving on actual milk yield was insignificant, while it was significant in the level of P<0.05 for the 305 day milk yield. Again, the effect of season of calving on the lactation length was found to be significant in the level

81 of P<0.01. 305 day milk yield was determined to be more in the cows that were gave birth in autumn and winter than the cows that were gave birth in spring and summer. This study showed that the milk yield and calf livabilitiy chracteristics of the Black Pied cattle raised at Sakarya State Farm were rather fine. On the other hand some of the reproductive parameters were found to be lower than desired. By detecting the sterility and infertilty problems beforhand and treating the animals instantly, observing animals carefully for heat periods, and culling the animals that do not respond to the drug treatment in the farm, it is not surprising to see an increase on the reproductive performance of the animals. Along with that, it will be possible to see an increase on the level of calf livability, reproductive performance and milk yield characteristics by developing breeding, selection and culling programs on the light of the environmental factors that was found to have significant effects on the above characteristics in this study.80 inseminations per conception, as 2.4; gestation length, as 279.2 days and calving interval, as 419.0 days. The lactation length, the actual and 305 day milk yields that were calculated according to milking 3 times a day and dry period means were determined as 349.87 days, 61 11.16 kg, 5527.96 kg and 71.8 days, respectively. The effects of the year of calving, the age of dam, sex of calves and the season of calving on calf livability were studied. The effects of this factors on the 0-30 day calf livability rates were found to be insignificant. Neverthless, the factors of age of dam and season of calving had effects on the 0-90 day calf livability rates. Also, it was found that the factors of year of calving, age of dam and season of calving effected the 0-180 day calf livability rates. The year of insemination or calving was found to be effective on the pregnancy rate, the infertility rate, the pregnancy rate in the first breeding, the age at first calving, the interval from calving to first insemination, the days open, the interval from first insemination to conception, the number of inseminations per conception and the calving interval. Furthermore, it was found that the order of pregnancy had effects on the pregnancy rate, the infertility rate, the normally calving rate and the number of inseminations per conception. The season of insemination or calving were found to be effective on the pregnancy rate, the infertility rate, the pregnancy rate in the first breeding, the interval from calving to first insemination, the interval from first insemination to conception, the days open, the calving interval and the gestation length. The effects of the year of calving on the lactation length, the actual and 305 day milk yields were found to be statistically significant in the level of P<0.01. In this study, the degree of determinatios of the year of calving were calculated as 17.5, 17.0 and 27.4% for the lactation length,the actual milk yield and 305 day milk yield, respectively. While the effect of age at calving on the lactation length was found to be insignificant, it was found to be statistically significant on the actual milk yield and 305 day milk yield in the levels of P<0.05 and P<0.01 respectively. The 2 year old cows' actual and 305 day milk yields were found to be less than the cows at other ages. It was determined that the milk yield increased gradually until they got 5 years old and than decreased gradually at following ages. The effect of season of calving on actual milk yield was insignificant, while it was significant in the level of P<0.05 for the 305 day milk yield. Again, the effect of season of calving on the lactation length was found to be significant in the level81 of P<0.01. 305 day milk yield was determined to be more in the cows that were gave birth in autumn and winter than the cows that were gave birth in spring and summer. This study showed that the milk yield and calf livabilitiy chracteristics of the Black Pied cattle raised at Sakarya State Farm were rather fine. On the other hand some of the reproductive parameters were found to be lower than desired. By detecting the sterility and infertilty problems beforhand and treating the animals instantly, observing animals carefully for heat periods, and culling the animals that do not respond to the drug treatment in the farm, it is not surprising to see an increase on the reproductive performance of the animals. Along with that, it will be possible to see an increase on the level of calf livability, reproductive performance and milk yield characteristics by developing breeding, selection and culling programs on the light of the environmental factors that was found to have significant effects on the above characteristics in this study.