4.1 Article

Effect of increasing dietary proportion of plantain on milk production and nitrogen use of grazing dairy cows in late lactation

期刊

ANIMAL PRODUCTION SCIENCE
卷 61, 期 8, 页码 770-779

出版社

CSIRO PUBLISHING
DOI: 10.1071/AN20440

关键词

urinary nitrogen; urea nitrogen

资金

  1. New Zealand Scholarship

向作者/读者索取更多资源

The study found that offering cows adjacent plantain strips increased their dry matter and metabolisable energy intake, but did not improve milk yield or nitrogen use efficiency, instead influencing urea metabolism.
Context. Plantain has shown promise as a forage that can mitigate nitrogen (N) losses from farm systems, although adoption and regulation requires knowledge of the minimum amount of forage area or diet quantity to observe an effect. Aims. A grazing study was conducted to evaluate the effect of offering increasing proportions of spatially adjacent plantain (PL) and perennial ryegrass-white clover (PRGWC) on milk production and N utilisation of dairy cows. Methods. Forty-eight late lactating cows blocked into replicated (n = 3) groups of four cows were randomly allocated to one of the following four forage treatments based on percentage area of plantain: 0%, 15%, 30%, or 60%. Cows were allocated 25 kg DM/cow.day of forage above ground level daily on the basis of metabolisable energy requirements. Dry matter intake was estimated from the difference between pre- and post-grazing pasture mass, using a calibrated electronic rising-plate meter. Milk production was measured as yield and milk solids, while N use was estimated from total milk N excretion and spot subsamples of blood, urine and faeces. Key results. Offering cows spatially adjacent strips of PL increased apparent dry matter intake compared with PRGWC pasture alone (16.4 vs 15.1 kg DM/cow.day, P = 0.027) and apparent metabolisable energy intake (203 vs 188 MJ/kg.cow.day, P < 0.001). Milk yield (16.1 kg/cow.day), milk solids production (1.6 kg/cow.day) and fat concentration (5.69%) were unaffected by the proportion of plantain in the diet. PL offered at 60% of the area increased milk protein concentration compared with PRGWC (4.65 vs 4.36%, P < 0.01). There was no treatment effect on total apparent N intake (563 g N/cow.day), N excretion in milk (113 g N/cow.day) and N-utilisation efficiency (20 g milk N/100 g N consumed). However, total milk urea, blood urea and urine urea N concentrations declined with increasing plantain in the diet, reflecting an influence on urea metabolism. Conclusions. Offering plantain to grazing dairy cows did not improve milk yield or N-use efficiency, but influenced urea metabolism. Implications. Sowing plantain in spatially separate strips within perennial ryegrass-white clover pastures is a useful option to achieve target levels of plantain in the diet and, in conjunction with other mitigation strategies, can be used to improve the sustainability of pastoral dairy farming.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.1
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据