Effect of Environment on Growth and Feed and Water Consumption of Chickens

Abstract

Chicks were housed in controlled environment without a hover for the first 9 days after hatch in order to determine the optimum temperature for growth and efficiency of feed utilization. Thirty chicks were used in each experiment and a total of 72 experiments were performed. Mortality for all experiments was practically nil. Relative humidity was kept between 60 and 70% in all experiments. The chicks were allowed 12 hours ad libitum feeding time, divided into 3 or 4 periods with an equal dark period between each feeding period. The temperature was varied with different lots of chicks, from a mean temperature of 94°F. over the 9 days (96° for the first day and gradually reduced to 92°F. the ninth day) to a mean temperature of 82.5°F. over the 9 days (85°F. the first day and gradually reduced to 80°F. the ninth day). Maximum growth and efficiency of feed utilization were noted when the temperature was 94°–95°F. the first day dropping uniformly to 88°F. on the ninth day. The growth under these conditions equalled a 59% increase over the original weight in 9 days. (All weights of chicks were obtained 4 hours after the last feeding period, and therefore there was no feed in the crop.) The mean efficiency of feed utilization over the 9 days was 0.38. Both growth and efficiency became less as the temperature varied from this range: the greater the deviation, the greater the difference, until at 82.5°F. (85° to 80°F.) the increase in weight was only 44% and the efficiency 0.26. At 94°F. (96°-92°F.) the increase in weight was 54% and the efficiency 0.33. The amount of feed consumed increased approximately 1 gm per day per chick. On the ninth day after hatch the chick consumed approximately 2.35 gm of feed for every gm increase in weight and drank approximately 1.6 gm of water for each gm of feed consumed.