Compensatory growth in immature sheep: III. Feed utilization by sheep subjected to feed deprivation followed by realimentation

Abstract

SUMMARYExperimental conditions and design were described in Part I. When compared with continuous growth, there was a 46% increase in rate of gain following refeeding, but no increase in intake per kg0·734 (MBS) per day. Part of the reason for this was the rapid accumulation of body water after realimentation. If the total cost of feed, including that of the weight-loss phase, is used to calculate the feed required per unit of gain, however, the sheep realimented at 26 kg to reach an empty body weight (EBW) of 45 kg had a requirement 27% higher than ad libitum continuously fed sheep taken to the same final EBW.The only treatment effect on digestibility or metabolizability of the diet that was not accounted for by level of intake was a depression immediately after underfeeding commenced. The metabolizable energy (ME) value later decreased markedly as a result of the relatively high proportion of gross energy lost in the urine (14·4%).There were no significant differences between normal growth and refeeding in maintenance requirement or efficiency of energy retention above maintenance. The combined figures were 107 ± 14 kcal ME/kg MBS/day and 52 ± 7% respectively.