Post-partum estrus of the cows in the DTRI [Dairy Training and Research Inst., College, Laguna, Philippines] herd
2001
Rojas, A.M. | Wagelie, E.G. | Abilay, J.P.
A study of the intervals from parturition to post-partum estrus was made on 68 cows that gave birth in the DTRI herd from July, 1968 to Jan 1969. The cows were observed during parturition and daily thereafter for the manifestation of post-partum estrus. Records and data observed on the incidence of post-partum estrus effect of age, abnormal parturition, blood composition, birth-weight of calf and weight of dam, involution of the estrus, and health of the cows were studied to determine their effects on the occurrence of post-partum estrus. For most of the cows, the number of days from calving to first estrus was 22 to 51 or an average of 36 days. The birth-weight of the calf and weight of the dam at parturition did not affect the incidence of post-partum estrus. Cows calving during the months of Oct, Nov, and Dec tended to come in heat earlier than those cows during the other months. Likewise, more cows manifested post-partum estrus during the same months. Cows 12 and 18 years of age had the longest intervals from parturition to the first heat; while younger cows tended to come in the heat at earlier intervals. Examination of the uterus during the manifestation of post-partum estrus showed that the uterus of the cows that exhibited post-partum estrus below 50 days did not show signs of complete involution. A study of abnormal calvings indicated an apparently longer interval (79.8 days) from calving to post-partum estrus, except for those cows that aborted which had shorter interval. Similarly, blood composition of the cows showed an apparent effect on post-partum interval. However, conclusive evidence was not established because of the limited number of cows involved in this particular portion of the study. This is an important aspect in breeding management worthy of further investigation with the use of sufficient number of cows
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