The Correlations Of Henhouse Ambient Temperature In The Summer And Winter And Production Performance And Metabolism Indexes In Nick-brown Laying Hens

The experiments have been performed to study the effects of ambient temperature onproduction performance, breathe frequency, body temperature and the digestion of majornutrients in half-opened henhouse in the summer (high ambient temperature) and the winter(low ambient temperature) in Nick-Brown laying hens.Experiment1: The correlations of high ambient temperature in the summer andproduction performance and metabolism indexes in Nick-Brown laying hens.A total of1600Nick-Brown laying hens (26-weeks-old), divided into four replicatescontaining400birds in each, were housed for7weeks in half-opened henhouse in NorthwestA＆F University livestock and poultry ecological farms. The daily average of ambienttemperature in the henhouse, daily average of chickens intake, production performance(laying rate, egg broken ratio, egg weight, egg production and feed conversion efficiency)and digestion metabolism indexes (crude proteins, energy, crude fats) in the model ambienttemperature were detected. To establish the regression model is through analysed thecorrelation with ambient temperature and the experimental indexes. The results are asfollowings:1.There was a strong quadratic correlation between daily feed intake and ambienttemperature (P<0.01, R2=0.91276), and the fitted regression equation wasy=0.96226-0.07485x+0.00566x~2. The intake of laying hens was decreased when ambienttemperature raised from20.20℃to32.57℃investigated in this study.2. There was a strong correlation between breathe frequency and ambient temperature(P<0.01, R2=0.91276), and the fitted regression equation was y=-670.00688+27.74750x. Thebreathe frequency of laying hens was increased27.5times/min with henhouse ambienttemperature raised1℃from24.00℃to35.35℃.3. There was a strong correlation between body temperature and ambient temperature(P<0.01, R2=0.89668), and the fitted regression equation was y=37.30596+0.14343x. Thebody temperature of laying hens was lifted0.14℃when henhouse ambient temperatureraised1℃from24.00℃to35.35℃.4. There was a weak quadratic correlation between apparent energy digestibility and ambient temperature (P<0.01, R2=0.69267), and the fitted regression equation wasy=2.53508-0.14235x+0.00282x~2. The apparent energy digestibility of laying hens was ascend,and then it was fallen, when henhouse ambient temperature climbed from20.20℃to30.98℃. The worst apparent energy digestibility of laying hens was when henhouse ambienttemperature was25.24℃.5. There was no significant difference among the laying rate, egg broken ratio, eggweight, egg production, feed conversion efficiency, egg quality and digestion metabolismindexes (crude proteins, energy and crude fats apparent digestibility) with the effects ofambient temperature from20.20℃to32.57℃.Experiment2: The correlations of low ambient temperature in the winter, production performanceand metabolism indexes in Nick-Brown laying hens.A total of1600Nick-Brown laying hens (54-weeks-old), divided into four replicatescontaining400birds in each, were housed for3weeks in half-opened henhouse in NorthwestA＆F University livestock and poultry ecological farms. The detected experimental indexeswere same as the experiment1. The results are as followings:1. There was a strong quadratic correlation between daily feed intake and ambienttemperature (P<0.01, R2=0.91717), and the fitted regression equation wasy=135.03231+2.95370x-0.34903x~2. The intake of laying hens was decreased when ambienttemperature raised from4.55℃to11.79℃investigated in this study.2. There was a weak quadratic correlation between apparent energy digestibility andambient temperature (P<0.05, R2=0.58833), and the fitted regression equation wasy=0.96226-0.07485x+0.00566x~2. The apparent energy digestibility of laying hens was ascend,and then it was fallen, when henhouse ambient temperature climbed from4.55℃to10.46℃. The apparent energy digestibility of laying hens was worst when henhouse ambienttemperature was6.61℃.3. There was no significant difference among the laying rate, egg broken ratio, eggweight, egg production, feed conversion efficiency, egg quality, digestion metabolism indexes(crude proteins and crude fats apparent digestibility) when the effects of ambient temperaturefrom4.55℃to11.79℃. But the breathe frequency and body temperature was notsignificant difference with the ambient temperature from3.85℃to15.45℃.Conclusion:(1)The intake of laying hens was decreased when ambient temperatureraised from20.20℃to32.57℃in the summer and from4.55℃to11.79℃in thewinter.(2) The respiration rate and body temperature were climbed when ambienttemperature increased from24.00℃to35.35℃.(3)There was a curvilinear relationshipbetween the apparent energy digestibility of laying hens and ambient temperature from 20.20℃to30.98℃in the summer and from4.55℃to10.46℃in the winter. Theapparent energy digestibility of laying hens was fallen, and then it was increased whenhenhouse ambient temperature ascended.