The adaptation of energy utilization in the laying hen to warm and cool ambient temperatures

Abstract

Two experiments have been performed to study the acclimatization of laying hens to cool or warm environmental temperature, using the comparative slaughter procedure to measure energy utilization. In the first experiment the energy balances over a 3-week period at either 10 or 35 °C were compared; in the second experiment a comparison was made of the energy balances over six consecutive weekly periods at similar cool and warm temperatures.The first experiment confirmed that production could be maintained (88 %) in the warm environment even though food intake was markedly reduced (95 and 63 g/day at 10 and 35 °C respectively). In both environments a loss of body weight indicated, that energy intake was insufficient to meet demands for at least part of the period.During the first week of the second experiment there was a small loss of body weight in the cool environment and food consumption was slightly depressed. The results for energy intake, egg production and heat production suggest that acclimatization was complete after 1 week. In the warm environment egg production fell initially (62 %) but returned to a high level (86 %) during the second week. However, energy intake, body weight and heat production did not reach steady levels until the fourth week. Comparing the first 3 weeks with the subsequent 3 weeks the daily ME consumption was 137 and 161 kcal/kg^ and the daily heat production was 126 and 116 kcal/kgJ. Similar, although less marked differences were observed in the cool environment. These results therefore emphasize the need to allow adequate time for acclimatization to the environment in studies of energy metabolism.heat production decreases throughout the temperature range from -10 to 40 C. Shannon & A number of reports (Bray & Gessell, 1961;Brown (1969) investigated the time required for Payne, 1966a, 6;Mowbray & Sykes, 1971) have hens to adjust their fasting catabolic rate when the shown that high levels of egg production can be temperature was increased from 22 to 28 °C and achieved in warm climates, up to 30 C C constant found that there was no further decline after 12 temperature, provided that attention is given to days. There appears to be no information on the nutrient intake, adjusting dietary levels to com-fully fed, light weight, modern hybrid hen during pensate for the reduced food intake. However, periods of high egg production, there is little quantitative information on the The work reported in this paper was therefore effects of environmental temperature on energy undertaken to provide information on the effect metabolism and the efficiency of energy utilization, of temperature on energy metabolism and to study found that heat production the time required for acclimatization to a new of fasted birds or birds fed at approximately environment. Hens at peak production were maintenance energy intakes was lower at 29 °C exposed to both cool and warm environments; the than at 22 °C. Using white leghorn hens in their temperature in the former was slightly below the second laying period Romij...

Effects of defeathering and insulative jackets on production by laying hens at low temperatures

“…Low temperatures decreased production only slightly. The general lack of temperature or defeathering effects on production was similar to that reported by Davis et al (1972Davis et al ( , 1973) who found no difference in production between 7 and 35 °C.…”

“…Lower temperatures (minimum of 17.7 °C) resulted in larger eggs but decreased efficiency of food utilisation. Davis et al (1972Davis et al ( , 1973 compared egg production at 7 and 35 °C and reported a 20% decrease in efficiency at 7 °C. Egg production was maintained at both temperatures.…”

Measurement of Bioavailable Energy in Poultry Feedingstuffs: A Review

“…Confirmation of the absence of an effect of IE on TME is provided by Sibbald (1977cSibbald ( , 1979c), Slinger (1979a,b, 1980a), Edmundson (1980) Sykes (1972). There is another aspect of feed input of importance.…”

An energy response curve for a commercial white leghorn laying‐strain cross

“…In all cases linear regression was appropriate, indicating similar efficiencies above and below maintenance. While recognising that ME consumed in excess of maintenance may not have been used exclusively for egg production, making such an assumption gives an availability of 75% when the energy content of egg is 6-7 kj/g (Tasaki and Sasa, 1970;Davis et al, 1972). The higher efficiencies reported above may, as Farrell (1975) suggests, be due to the contribution of tissue energy to energy balance.…”