Lambs production fed without roughage in different feed supply levels

Abstract

This study aimed to evaluate the production of castrated Santa Ines ram lambs fed diets without roughages in different levels of feed supply. Fifty castrated Santa Ines male sheep with an average body weight of 20 kg and an average age of four months were used in the experiment. The following treatments were tested: FS100 - animals receiving a diet ad libitum ; FS95 - animals receiving 95% of the amount of feed supplied in FS100; FS90 - animals receiving 90% of the amount supplied in FS100; FS85 - animals receiving 85% of the amount supplied in FS100; and FS80 - animals receiving 80% of the amount supplied in FS100. A randomized complete design was adopted. From the 7th to the 10th day of each period, feed intake was quantified, and the apparent digestibility coefficients were estimated from the intake and fecal production. A marginal analysis of variation in the feed cost was performed. Results were analyzed statistically by ANOVA and regression at 0.05 probability level using SAS (version 9.2) software. The intake of feed and nutrients decreased linearly as the feed supply was reduced (P<0.05). The most attractive marginal rate of return was obtained with FS100, providing 1409%. The amount of feed supplied to feedlot ram lambs consuming diets without roughage changes their intake, causing variations in weight gain but not in the digestion of the feed. The decrease in the feed cost was not proportional to the variation in body weight, making the restricted levels of feed supply less attractive. DOI: 10.15528/2176-4158/rcpa.v17n2p122-128