A study was carried out to determine the weight gain and the minimal weight needed to reestablish the ovarian luteal cyclic activity (OLCA) in dry crossbred Holstein-Zebu cows, thin and with the ovaries inactive, an overall condition of anestrus caused by prolonged period of feed restriction. Eighteen animals were allocated into two groups: 1) six animals, with average body weight of 322.0 ± 27.0 kg, receiving maintenance diet specific for the low body weight (group I); 2) twelve animals with average body weight of 315.0 ± 29.4 kg, being fed for weight gain until OLCA reestablishment (group II). Blood for progesterone RIA and body weight were taken weekly. The OLCA was evaluated by the progesterone level, rectal examination of the ovaries at 12-day intervals and by visual observation three times a day. An averaged body weight of 392.7 ± 29.4 kg was needed for the reestablishment of the OLCA. The total mean weight gain was 77.7 ± 11.2 kg, corresponding to 24.7 ± 4.5% of the anestrus animal's weight, or 37.7% of 206.2 kg lost in the restricted phase in order to undergo anestrus. Six animals of control group (1) were in anestrus. The results showed the influence of feed level on the luteal ovarian function and the need of weight gain in order to reestablish the estrus cycle in dry cross bred dairy cows, thin and in anestrus.
corpus luteum; weight condition; cattle
