Weight to reestablish the ovarian luteal cyclic activity in cross bred milk cows in anestrus

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 cro ssbred Holstein-Zebu cows, thin and with the ovaries inactive, an overall c ondition of anestrus caused by prolonged period of feed restriction. Eighte en animals were allocated into two groups: 1) six animals, with average bod y 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 31 5.0 +/- 29.4 kg, being fed for weight gain until OLCA reestablishment (grou p II). Blood for progesterone RIA and body weight were taken weekly. The OL CA was evaluated by the progesterone level, rectal examination of the ovari es at 12-day intervals and by visual observation three times a day. An aver aged 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 t o 24.7 +/- 4.5% of the anestrus animal's weight, or 3 7.7% of 206.2 kg lost in the restricted phase in order to undergo anestrus. Six animals of contr ol group (1) were in anestrus. The results showed the influence of feed lev el on the luteal ovarian function and the need of weight gain in order to r eestablish the estrus cycle in dry cross bred dairy cows, thin and in anest rus.