Andrighetto Igino, Serva Lorenzo, Fossaluzza Davide, Marchesini Giorgio
Dipartimento di Medicina Animale, Produzioni e Salute, Università degli Studi di Padova, 35020 Legnaro, Italy.
Animals (Basel). 2023 Feb 2;13(3):523. doi: 10.3390/ani13030523.
This study performed a yield gap analysis to help farmers understand whether their constraints were mainly due to nutritional factors or management and health issues. Twenty-nine farms were periodically evaluated. Milk yield (MY), dry matter intake (DMI), total mixed ration (TMR) composition and homogeneity index (HI), TMR digestibility, income over feed cost (IOFC), and MY summer-winter ratio (SWR) were collected. Farms were divided and compared according to the average annual MY: Low (L), Medium (M) and High (H), characterised by <31.1, 31.1-36.7 and >36.7 kg/head/day. An ANOVA mixed model and a stepwise regression to assess the relationship between nutritional variables and MY were run. H farms showed higher IOFC ( < 0.001), DMI ( = 0.006), DDM ( < 0.001), digestible crude protein (DCP, = 0.019), HI ( = 0.09), SWR ( = 0.041) and lower HI coefficient of variation ( = 0.04). The conversion of DDM into milk was higher in H and M farms. Stepwise regression for MY selected DDM and CP (R = 0.716, < 0.05). M farms were mainly constrained by nutritional factors, whereas L farms were also affected by other factors such as those related to management and health.
本研究进行了产量差距分析，以帮助农民了解他们的制约因素主要是由于营养因素还是管理和健康问题。对29个农场进行了定期评估。收集了牛奶产量（MY）、干物质摄入量（DMI）、全混合日粮（TMR）组成和均匀度指数（HI）、TMR消化率、饲料成本收益（IOFC）以及MY夏冬比率（SWR）。根据年平均MY将农场分为低（L）、中（M）和高（H）三组并进行比较，其特征分别为<31.1、31.1 - 36.7和>36.7千克/头/天。运行方差分析混合模型和逐步回归以评估营养变量与MY之间的关系。H组农场显示出更高的IOFC（<0.001）、DMI（=0.006）、可消化干物质（DDM，<0.001）、可消化粗蛋白（DCP，=0.019）、HI（=0.09）、SWR（=0.041）以及更低的HI变异系数（=0.04）。H组和M组农场中DDM转化为牛奶的效率更高。对MY的逐步回归选择了DDM和粗蛋白（R = 0.716，<0.05）。M组农场主要受营养因素制约，而L组农场还受到其他因素影响，如与管理和健康相关的因素。
