Effects of repeated cycles of feed intake shifts on growth, feed efficiency and endocrine profiles of wether lambs

TitleEffects of repeated cycles of feed intake shifts on growth, feed efficiency and endocrine profiles of wether lambs
Publication TypeJournal Article
Year of Publication1993
AuthorsEstell R.E., Havstad K, Heird C.E., Fredrickson E.L., Hallford D.M., Shupe, W. Larry
JournalSmall Ruminant Research
Volume10
Pagination103-118
Date PublishedMarch 1, 1993
KeywordsCarcass weight, Endocrine profile, feed intake, growth, Lamb
Abstract

Fifteen wether lambs (average BW 28.8 ± 1.8 kg) were used in a 128-d trial to examine effects of cyclical feeding changes on growth, feed efficiency and endocrine profiles. Control lambs were fed a 40% concentrate diet (40C) at 1.5 × NEm requirement during period 1 (64 d). Another group (1x/2x) was fed 40C at 1 and 2 x NEm in 4-d intervals during period 1; a third group (70/10) 70% and 10% concentrate diets in 4-d intervals during period 1. To achieve dry matter intake comparable to controls, 70/10 lambs were fed at 1.79 (70C) and 1.21 (10C) × NEm. All lambs were placed on the control diet during period 2 (32 d) and increased to 2 x maintenance during period 3 (32 d). During period 2, ADG and gain/feed of control lambs tended to be greater (P<0.10) than for lambs fed alternating treatments. Liver weight as a percentage of hot carcass weight was greater (P<0.05) for controls than for lambs fed alternating treatments. Hot carcass weight (P=0.07) and dressing percentage (P=0.09) tended to be greater for the 70/10 treatment than for controls. The 1x/2x treatment lowered (P<0.05) serum cholesterol compared with other groups on d 65, but not on d 0 or 129. Smaller liver weight per unit of hot carcass weight for lambs in the 1x/2x and 70/10 treatments suggests a possible reduction of maintenance requirements.

URL/files/bibliography/398.pdf
DOI10.1016/0921-4488(93)90054-L