Han Rui, Jiang Hailong, Che Dongsheng, Bao Nan, Xiang Dong, Liu Feifei, Yang Huaming, Ban Zhibin, Qin Guixin
Department of Animal Science and Technology, Jilin Agricultural University, Changchun. China.
Jilin Provincial Key Lab of Animal Nutrition and Feed Science, Jilin Agricultural University, Changchun. China.
Protein Pept Lett. 2017;24(5):425-431. doi: 10.2174/0929866524666170223100044.
This study aimed to evaluate the effect of temperature and dietary fat level on growth performance, heat production, nutrient oxidation and nitrogen balance in growing pigs. Thirty-two pigs (Duroc × Landrace × Large White) with initial weight of 25±1.91 kg were assigned to treatments in 2×4 factorial design. All pigs were fed with two isoenergetic and isoproteic diets of different fat levels (low fat level: 3.68% fat of dry matter (DM) and high fat level: 8.39% fat of DM) under four environmental temperatures (23, 18, 13 and 8 ºC). Heat production (HP) and nutrient oxidation were calculated from gas exchange via measurement with respiration chambers. The results showed that there was no interaction effect on growth performance by the temperature and dietary fat level. The average daily feed intake (ADFI) was lower (P < 0.001), the average daily gain (ADG) was higher (P < 0.001) and feed utilization was more efficient at 23 ºC than 13 and 8 ºC (P < 0.001). Dietary fat had no effect on growth performance and feed utilization at the four different temperatures. A significant interaction (P < 0.001) between temperature and dietary fat level on oxidation of carbohydrate (OXCHO) and fat (OXF) was observed. HP, OXF and OXCHO were significantly increased (P < 0.001) as environment temperatures decreased. Increasing dietary fat generated an increase in the OXF and decrease in the OXCHO (P < 0.001). No significant difference was observed in protein oxidation (OXP) of two factors. The intakes of nitrogen, nitrogen excretion in feces (FN) and urine (UN) by the pigs kept in 8 ºC environment were highest. Nitrogen digestibility decreased as environmental temperature decreased, with the most efficient gains obtained at 23 ºC. However, nitrogen retention was not influenced by environmental temperature. Dietary fat level did not affect nitrogen balance. No significant interaction between temperature and dietary fat level was observed for nitrogen balance. These results indicated that the rate of growth and nutrition utilization in pigs fed ad libitum are influenced by the environmental temperatures in which they are maintained, and the oxidation of nutrition utilization of the pig to different environmental temperatures is altered by the dietary fat supplementation.
本研究旨在评估温度和日粮脂肪水平对生长猪生长性能、产热、养分氧化及氮平衡的影响。选用32头初始体重为25±1.91 kg的杜洛克×长白×大白三元杂交猪，按2×4析因设计进行处理。所有猪在四种环境温度（23、18、13和8℃）下分别饲喂两种等能、等蛋白但脂肪水平不同的日粮（低脂水平：干物质（DM）中脂肪含量为3.68%；高脂水平：DM中脂肪含量为8.39%）。通过呼吸室测量气体交换来计算产热（HP）和养分氧化。结果表明，温度和日粮脂肪水平对生长性能无交互作用。23℃时平均日采食量（ADFI）较低（P<0.001），平均日增重（ADG）较高（P<0.001），饲料利用率比13℃和8℃时更高（P<0.001）。在四种不同温度下，日粮脂肪对生长性能和饲料利用率均无影响。观察到温度和日粮脂肪水平对碳水化合物氧化（OXCHO）和脂肪氧化（OXF）存在显著交互作用（P<0.001）。随着环境温度降低，HP、OXF和OXCHO显著增加（P<？0.001）。日粮脂肪增加会使OXF增加，OXCHO降低（P<0.001）。两因素的蛋白质氧化（OXP）未观察到显著差异。8℃环境下饲养的猪的氮摄入量、粪便氮排泄量（FN）和尿液氮排泄量（UN）最高。随着环境温度降低，氮消化率下降，23℃时增重效率最高。然而，氮保留不受环境温度影响。日粮脂肪水平不影响氮平衡。温度和日粮脂肪水平对氮平衡未观察到显著交互作用。这些结果表明，自由采食的猪的生长速度和营养利用率受饲养环境温度影响，日粮添加脂肪会改变猪对不同环境温度的营养利用氧化情况。
