Techna, BP 10, F-44220 Couëron, France.
J Anim Sci. 2011 Oct;89(10):3170-88. doi: 10.2527/jas.2010-3504. Epub 2011 May 6.
Along with the fast genetic improvement, nutritional and environmental effects on poultry growth performance have made it necessary to develop growth models that have the flexibility to adapt to different genotypes and growing conditions. A mechanistic simulation model of energy and nutrient utilization in growing turkeys is presented herein. The model consists of simulating the average homeorhetic and homeostatic regulations associated with the utilization of circulating glucose, fatty acid, AA, and acetyl-CoA for protein and lipid retention in carcass, viscera, and feathers in a turkey population. Homeorhesis plays a major role in the control of protein and lipid turnover for the definition of genetic potential and feed intake, whereas homeostasis adjusts growth rate through protein and lipid turnover rates and, therefore, BW gain and feed intake to the growing conditions. Also, homeostasis enables the maintenance of a dynamic balance state during all the growing period through the control of circulating nutrient concentration. The model was developed and calibrated with experimental data that described energy utilization in male and female growing turkeys. Then, the ability of the model to adapt to genotypes and to predict the average response of a turkey population to dietary energy was evaluated. Model calibration showed simulations of energy and nutrient utilization that fitted well with the experimental data because ME was satisfyingly partitioned into heat production and energy retention as protein and lipid, and nutrient intake accurately partitioned BW gain into carcass, viscera, and feathers. The evaluation of the model was also satisfactory because BW gain and feed-to-gain ratio were globally in accordance with the observations in different male and female genotypes, in spite of an overestimation of the feed-to-gain ratio during the first weeks of age. Model evaluation showed that the BW gain and feed intake response of growing turkeys to dietary energy was accurately predicted. The model can therefore be used in different growing conditions as it is capable of simulating the growth of different turkey genotypes fed under changing environmental and nutritional contexts.
随着遗传改良的快速发展，营养和环境对家禽生长性能的影响使得开发能够适应不同基因型和生长条件的生长模型变得必要。本文提出了一种生长火鸡能量和营养素利用的机理模拟模型。该模型包括模拟与循环葡萄糖、脂肪酸、AA 和乙酰辅酶 A 用于在火鸡群体中保留胴体、内脏和羽毛中的蛋白质和脂质的同源调节和同型调节。同源调节在定义遗传潜力和饲料摄入量方面对蛋白质和脂质周转率的控制起着主要作用，而同型调节通过蛋白质和脂质周转率以及因此通过 BW 增益和饲料摄入量来调整生长速度以适应生长条件。此外，同型调节通过控制循环营养浓度使整个生长期间保持动态平衡状态。该模型是使用描述雄性和雌性生长火鸡能量利用的实验数据开发和校准的。然后，评估了模型适应基因型和预测火鸡群体对日粮能量的平均反应的能力。模型校准表明，能量和营养素利用的模拟与实验数据拟合良好，因为 ME 令人满意地分为热产生和蛋白质和脂质的能量保留，并且营养素摄入量准确地将 BW 增益分为胴体、内脏和羽毛。模型评估也令人满意，因为 BW 增益和饲料增重比总体上与不同雄性和雌性基因型的观察结果一致，尽管在生命的最初几周高估了饲料增重比。模型评估表明，生长火鸡对日粮能量的 BW 增益和饲料摄入量反应得到了准确预测。因此，该模型可以在不同的生长条件下使用，因为它能够模拟不同火鸡基因型在不断变化的环境和营养背景下的生长。
