...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of dairy science >Methane production, rumen fermentation, and diet digestibility of Holstein and Jersey dairy cows being divergent in residual feed intake and fed at 2 forage-to-concentrate ratios
【24h】

Methane production, rumen fermentation, and diet digestibility of Holstein and Jersey dairy cows being divergent in residual feed intake and fed at 2 forage-to-concentrate ratios

机译：荷斯坦奶牛和泽西奶牛的甲烷产量，瘤胃发酵和日粮消化率在剩余饲料摄入量上有所不同，并以2种草料与精料的比率进行饲喂

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Improving feed efficiency of dairy cows through breeding is expected to reduce enteric methane production per unit of milk produced. This study examined the effect of 2 forage-to-concentrate ratios on methane production, rumen fermentation, and nutrient digestibility in Holstein and Jersey dairy cows divergent in residual feed intake (RFI). Before experimental onset, RFI was estimated using a random regression model on phenotypic herd data. Ten lactating Holstein and 10 lactating Jersey cows were extracted from the herd and allocated to a high or low pre-experimental RFI group of 5 animals each within breed. Cows were fed ad libitum with total mixed rations either low (LC) or high (HC) in concentrates during 3 periods in a crossover design with a back-cross and staggered approach. Forage-to-concentrate ratio was 68: 32 for LC and 39: 61 for HC. Cows adapted to the diets in 12 to 24 d and feces were subsequently collected on 2 d. Afterward, gas exchange was measured in respiration chambers and rumen liquid was collected once after cows exited the chambers. Pre-experimental RFI was included in the statistical analysis as a class (low and high RFI) or continuous variable. Methane per kilogram of dry matter intake (DMI) was lower for Holsteins than Jerseys and the response to increased concentrate level was more pronounced for Holsteins than Jerseys (27.2 vs. 13.8%); a similar pattern was found for the acetate: propionate ratio. However, methane production per kilogram of energy-corrected milk (ECM) was unaffected by breed. Further, total-tract digestibility of neutral detergent fiber was higher for Jerseys than Holsteins. For RFI as a class variable, DMI, methane production regardless of the expression, and digestibility were unaffected by RFI. For RFI as a continuous variable, DMI was lower and methane per kilogram of DMI was higher for cows with negative (efficient) than positive (inefficient) RFI values, and neutral detergent fiber digestibility was higher for Holsteins with negative than positive RFI values, but not for Jerseys. Daily methane production and methane per kilogram of ECM were unaffected by RFI. In conclusion, methane per kilogram of DMI of Jerseys was lowered to a smaller extent in response to the HC diet than of Holsteins. When pre-experimental RFI was used as a continuous variable, higher methane per kilogram of DMI was found for cows with negative RFI than positive RFI values, but not for methane per kilogram of ECM. These findings call for validation in larger studies.
机译：通过育种提高奶牛的饲料效率，有望减少单位产奶量的肠甲烷产量。这项研究检查了两种饲草与精料比对荷斯坦奶牛和泽西奶牛的甲烷产量，瘤胃发酵和养分消化率的影响，这些奶牛的剩余饲料摄入量有所不同。在实验发作之前，使用表型畜群数据的随机回归模型估计RFI。从牛群中提取出十头泌乳的荷斯坦奶牛和十头泌乳的泽西奶牛，并将它们分配给实验前高或低的RFI组，每组5只动物。通过交叉设计和交错方法，在3个时期内随意给母牛饲喂低浓度（LC）或高浓度（HC）的总混合饲料。 LC的草料-精料比为68：HC：39：61。在12到24 d内适应饮食的母牛，随后在2 d收集粪便。此后，在呼吸室中进行气体交换测量，并在母牛离开呼吸室后收集一次瘤胃液。实验前的RFI作为一类（低和高RFI）或连续变量包括在统计分析中。荷斯坦奶牛的每千克干物质摄入甲烷含量低于泽西岛，荷斯坦奶牛对浓缩液水平提高的反应比泽西岛更明显（27.2比13.8％）。对于乙酸盐：丙酸盐比率，发现了类似的模式。但是，每千克能量校正乳（ECM）的甲烷产量不受品种影响。此外，泽西岛中性洗涤剂纤维的总消化率比荷斯坦牛更高。对于RFI作为类变量，DMI，无论其表达如何的甲烷产量和消化率均不受RFI影响。对于RFI作为连续变量，RFI值为负（有效）的母牛的DMI较低，而RFI值为正（无效）的母牛的每千克DMI的甲烷较高，RFI值为负的荷斯坦牛的中性洗涤剂纤维消化率更高，但是不适用于球衣。 RFI不影响每日甲烷产量和每千克ECM甲烷含量。总而言之，对HC饮食的反应，泽西岛每公斤DMI的甲烷降低幅度要小于Holsteins。当使用实验前的RFI作为连续变量时，发现RFI值为负的奶牛每公斤DMI的甲烷含量高于RFI值为正的奶牛，但每公斤ECM的甲烷含量却没有。这些发现要求在更大的研究中进行验证。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号