Cates W F, Christensen D A
Can Vet J. 1983 May;24(5):145-7.
The conception rate of cows in the Cumberland House area of Saskatchewan fed native forage grown in the area was observed to be unacceptably low. Supplementation with 12g of calcium and of phosphorus daily, and provision of cereal silage seemingly improved conception rates. It would appear that phosphorus may have been the first limiting nutrient and that a portion of the improved pregnancy rate was due to phosphorus supplementation. The low energy content of the forage, especially in years when it was badly weathered, was also judged to be a factor in conception rate in the subsequent year. It was also noted that there is a potential widespread phosphorus problem for beef cattle in Saskatchewan based on Feed Testing Service analyses of feeds.
据观察，在萨斯喀彻温省坎伯兰大厦地区，以当地种植的天然草料喂养的奶牛受孕率低得令人难以接受。每日补充12克钙和磷，并提供谷物青贮饲料，似乎提高了受孕率。看来磷可能是首要限制营养元素，受孕率提高的部分原因是补充了磷。草料的能量含量低，尤其是在遭受恶劣天气影响的年份，这也被认为是次年受孕率的一个影响因素。根据饲料检测服务对饲料的分析，还指出萨斯喀彻温省的肉牛可能普遍存在磷缺乏问题。
