The Effect of Food Restriction During Rearing on Fasting Heat Production of Layer Strain Pullets and Hens

Abstract

Fasting heat production was measured in darkened respiration chambers at three chronological and three physiological ages during rearing and laying in a layer strain to determine the effects of food restriction during rearing. There were three rearing treatments (42 to 162 days of age) in which birds were allowed ad libitum food intake (F) or were restricted by time (TR), in which birds were allowed continuous ad libitum food intake for about 24 hr in every 72 hr, or by proportion (PR), in which birds were offered each day 60 to 70% of the quantity consumed by F birds the previous day. Liveweight at 163 days of age was reduced by 19 and 15% for TR and PR birds, respectively, compared to F birds. Ad libitum food consumption was allowed during the laying period. Chronological age measurements were carried out at 140 days of age (prelay), 332 days of age, and 370 days of age. Physiological age measurements were carried out at sexual maturity (first egg), peak production (28 days after first egg) and postpeak production (98 days after first egg). Fasting heat production, measured under conditions that minimized physical activity, was not altered after correction for liveweight changes by the food restriction treatments. Based on this and other published studies, it was postulated that physical activity may play an important role in determining the effects of food restriction in poultry.

Modeling life-time energy partitioning in broiler breeders with differing body weight and rearing photoperiods

“…Increased visit frequency is also a measure of locomotive activity, and increased locomotive activity increased ME m requirements ( van Kampen, 1976 , MacLeod et al., 1982 , MacLeod et al., 1988 ). Therefore, increased visit frequency could also be linked to increased HP ( Johnson and Farrell, 1984 ). A linear regression between HP and daily visit frequency up to week 21 showed that 1 extra visit per day corresponded to a 0.076 kcal increase in HP, after correcting for the fixed effects and interactions between BW treatment, photoschedule, and age ( P < 0.001; R 2 = 0.96; results not shown).…”

Relationship between starvation heat production and body size in the domestic fowl

“…This statement does not discount work prior to these studies but is based on technological advancements and improved knowledge with regard to factors such as thermoneutral environment, acclimatisation and length of the period of measurement. Since the work of Brown (1965, 1967), a considerable number of reports have given details of the metabolic rates of appropriately starved poultry, hereafter referred to as starvation heat production (SHP) and of W. In addition, a large number of such measurements have been provided by studies on the SHP of pullets and laying hens as affected by undernutrition during rearing (Balnave^ a/., 1979; Johnson and Farrell, 1984).…”

“…(1978) Balnave et al (1978) MacLeod and Shannon (1978) MacLeods al. (1979) Balnave et al (1979) Balnave et al (1979) Siregar and Farrell (1980 4 Johnson and Farrell (1983) Johnson and Farrell (1984) Johnson and Farrell (1984) Johnson and Farrell (unpublished) …”