基于饲养标准的家畜单位折算方法

Animal Unit Conversion Method Based on Feeding Standard

为解决载畜量核定工作中存在的家畜单位折算体系不健全、与畜牧业统计口径脱节等问题,根据肉牛单位、绵羊单位的定义和肉牛、肉羊、奶牛饲养标准中的代谢能或净能需求以及标准干草的代谢能或净能含量,研究确定肉牛单位、绵羊单位和不同生理阶段奶牛的标准干草需求及其家畜单位折算关系。结果表明:标准干草代谢能或净能含量分别为肉牛综合净能4.89 MJ/kg,奶牛产奶净能5.57 MJ/kg,绵羊代谢能8.68 MJ/kg;1个肉牛单位、绵羊单位的能量需求分别是肉牛单位72.10 MJ/d综合净能、绵羊单位18.46 MJ/d代谢能,其家畜单位折算关系是6.93∶1;不同生理阶段奶牛的平均产奶净能需求分别是断奶犊牛27.19 MJ/d、育成母牛52.07 MJ/d、初孕母牛70.11 MJ/d和中产泌乳母牛123.95 MJ/d,折合标准干草需要量分别为4.88 kg/d、9.35 kg/d、12.59 kg/d和22.25 kg/d,分别折合2.29、4.39、5.91和10.45个绵羊单位;生产上一般按照奶料比3.5∶1补充精饲料,则中产泌乳母牛对标准干草的平均需要量调整为15.06 kg/d;从天然草地的放牧压力和区域粗饲料的供需状况评价的角度,建议中产泌乳母牛与绵羊单位的折算系数由10.45调整为7.07。

In order to solve the imperfection of animal unit conversion system and the separation of animal unit conversion system and stock raising statistical caliber, the standard hay requirements and animal unit conversion factor of beef cattle unit, sheep unit and dairy cattle with various physiological phases were studied based on their metabolizable energy （ME） or net energy （NE） demand, the concept of beef cattle unit, and sheep unit as well as ME or NE content of standard hay. The results show that the ME or NE content of standard hay was 4.89 MJ·kg^-1 combined NE for beef cattle, 5.57 MJ·kg^-1 NE for lactation for dairy cattle, and 8.68 MJ·kg^-1 ME for sheep. The energy demands of animal units were 72.10 MJ·d^-1 combined NE for beef cattle unit and 18.46 MJ·d^-1 ME for sheep unit, their animal unit conversion factor was 6.93：1.00. The average lactation NE for dairy cattle with different physiological phases were 27.19 MJ·d^-1 for weaned calf, 52.07 MJ·d^-1 for heifer, 70. 11 MJ·d^-1 for pregnant heifer and 123.95 MJ·d^-1 for lactating cow with middle milk production, converted into standard hay demands were 4.88 kg·d^-1 for weaned calf, 9.35 kg·d^-1 for heifer, 12.59 kg·d^-1 for pregnant heifer, and 22.25 kg·d^-1 for lactating cow with middle milk production, their sheep unit conversion factor were 2.29, 4.39, 5.91 and 10.45, respectively. Concentrate fodder was brought to lactating cow in the proportion of 1.0 part concentrate fodder supply to 3.5 part milk production. So, the average standard hay for lactating cow with middle milk production was adjusted to 15.06 kg·d^-1. The conversion factor for lactating cow with middle milk production to sheep unit should adjust from 10.45 to 7.07 in the view of estimations of rangeland carrying capacity and regional coarse fodder supply and demand.