Milk progesterone profiles in various reproductive states in
dairy buffaloes under field conditions.
Qureshi, M.S.
, Habib,
G., Nawab,
G., Siddiwqui,
M.M., Ahmad,
N., Samad,
H.A. 
Veterinary Research Institute, Peshawar, Pakistan.
Abstract
Fifty-one dairy buffaloes in the last two months of
gestation were selected at seven private peri-urban farms in the Peshawar
district. Observations were recorded in buffaloes during normal (NBS, August
to January) and low breeding seasons (LBS, February to July). After
parturition, rectal examination of reproductive organs was carried out. Estrus
detection was made through visual observation and the use of intact bull.
Postpartum ovulation was confirmed by ovarian palpation per rectum and milk
progesterone levels (MPL), determined through radio-immunoassay. MPL was
higher (p < 0.01) at various intervals in NBS calves (1.97 +/- 0.30 ng/ml)
as compared to LBS calves (0.68 +/- 0.08 ng/ml). During LBS, MPL remained <
0.30 ng/ml up to the third fortnight and started rising later, reaching a peak
of 1.27 ng/ml during the sixth fortnight. During NBS, there was a sharp rise
in MPL during the second fortnight, reaching 3.64 ng/ml during the sixth
fortnight. MPL was significantly different on different experimental farms (p
< 0.01). MPL reached the lowest levels on the day of estrus (0.10 ng/ml),
reached it's peak on day 7 and started declining on day 17 of estrus. MPL
showed two postpartum elevations. In true anestrus buffaloes, MPL remained
consistently low. However, in the anestrus period, silent ovulations were also
noted, as reflected by increasing MPL without estrus signs. In pregnant
buffaloes, MPL remained > 1 ng/ml. Results of the study showed that the low
postpartum reproductive performance in dairy buffaloes during LBS was
primarily due to inadequate functioning of the corpus luteum in secreting
optimum concentrations of progesterone. The higher incidence of silent estrus
during LBS indicated improved management for the detection of
estrus.
