Feed restriction followed by realimentation in prepubescent Zebu females

Abstract

In the present study, the effect of restricting the feed intake for 77 days and subsequent compensatory growth for 50 days of Sindi females were evaluated. Eighteen animals with an initial age of 21 months and a mean weight of 211.7 kg were placed into three groups according to the following alimentary regimens: feed ad libitum, feed restricted to 20 % dry matter, and feed restricted to 40 % dry matter. In the feed restriction phase, the nutrient intake decreased (P<0.001) with an increase in the restriction level. As a consequence, the observed decrease in ingestion and serum concentrations of total protein, albumin and globulin, urea, glucose, calcium, and phosphorus were inversely proportional (P<0.001) to the restriction level. Significant differences in the nutrient intake and serum concentration were not observed in the realimenta tion phase (P<0.05). When animals in the control group reached the end of the feed-restriction phase, their weights (P<0.05) were similar to those in the 20 % restricted group, and both obtained a final weight that was greater than that of animals in the 40 % restricted group. In the feed-restriction phase, the control group had a similar mean daily weight gain (P>0.05) to animals in the 20 % restricted group and (P<0.05) 40 % restricted group. However, in the realimentation phase, the 40 % restricted group obtained greater weight gain rates (P<0.05), better food conversions, and partial compensatory gains. In particular, none of the restricted groups reached the final weight of the control group. In the feed-restriction phase, ingested nitrogen, nitrogen excreted in urine and feces, nitro gen balance and retained nitrogen decreased (P<0.05) with an increase in the restriction level. In the realimentation phase, none of the nitrogen balance variables were influenced by the restriction level (P<0.05). Females in the 40 % restricted group presented better food conversion rates and greater weight gains in the realimentation phase. Based on the ani mals’ compensatory weight gain, a feed-restriction rate of 20 and 40 % can be adopted as a nutritional management practice for prepubescent Sindi females.