Effects of Environmental Temperature on Egg Production, Food Intake and Water Consumption in Laying White Leghorns

白レグの産卵,採食,飲水におよぼす環境温度の影響

Ito Toshio

Moriya Tesshu

Yamamoto Sadaki

Mimura Ko

広島大学水畜産学部紀要

Journal of the Faculty of Fisheries and Animal Husbandry, Hiroshima University

白レグ産卵鶏15羽(1年鶏10羽,2年鶏5羽)を供試し,産卵鶏の産卵,採食,飲水におよぼす環境温度(25～35℃,2.5℃間隔,各温度感作10～15日)の影響を,環境調節室内で実験し,次の知見を得た.

1) 採食量は温度上昇と共に減少し,25～35℃において,温度1℃あたりの減少率は1.6%であった.飲水量は温度上昇と共に増加し,摂取飼料1gあたりの飯水量も急激に増加し,30℃で25℃の1.5倍,32.5℃で2倍,35℃で3倍に達した.

2) 産卵率は35℃において73%と最低で,一日あたりの卵生産量も最低であったが,飼料消費あたりの産卵効率は61%と最高であった.

3) 破卵,軟卵をのぞいた正常卵の生産効率は,32.5℃において53%と最高で,一方35℃においては42%であった.35℃では,破卵,軟卵の出現率が31%にも達した.32.5℃では25℃を基準にした場合,15%の卵生産効率の増加がみられ,この点について考察した.

In order to investigate the effects of environmental temperature on egg production, food intake and water consumption in laying White Leghorns, this experiment was performed. Fifteen hens (10 of them were 1 year old hens, 5 were 2 years old hens) were kept in the temperature room from 25 to 35°C changing by 2.5°C at each interval during 10-15 days. The results obtained were as follows;

1) The higher the temperature becomes, the lesser food intake was observed. The decreasing rate was 1.6% per Centigrade rise of environmental temperature from 25°C to 35°C. Water consumption increased with the rise of temperature. Each ratio of water consumed per one g of food intake was about 2 times at 32.5°C, and about 3 times at 35°C as much as that at 25°C.

2) Egg production rate was lowest at 35°C, being 73%. Daily egg production was also lowest at 35°C, but food efficiency for egg production, was highest at 35°C, being 61%.

3) Excluding abnormal eggs, net efficiency for egg production was highest at 32.5°C, being 53%, but being 42% at 35°C. Appearing rate of abnormal eggs was attained to 31% at 35°C. Comparing 25°C with 32.5°C, the latter temperature regime had by 15% higher food converting efficiency. The reason for the highest food converting rate for egg production at 32.5°C was discussed.

Zoology [ 480 ]

eng

広島大学水畜産学部

[ISSN] 0440-8756

[NCID] AN00213563

[NAID] 40018463931