日粮peNDF水平对泌乳牛咀嚼活动、瘤胃发酵及乳成分的影响
发布时间：2018-11-15 16:53
【摘要】：本试验旨在研究相同日粮结构下,不同物理有效中性洗涤纤维(peNDF)水平对泌乳牛咀嚼活动、瘤胃发酵以及乳成分的影响。研究选取30头、2胎次、体重约650 kg、产后120 d、日均产奶量33.2 kg、体况相近的健康荷斯坦奶牛为试验对象。采用单因素试验设计,通过控制TMR的搅拌时间(10 min、18 min和60 min)得到不同peNDF水平的日粮,研究其对奶牛采食与反刍活动、瘤胃发酵参数及乳成分等的影响。主要研究结果如下:1.延长TMR的搅拌时间显著降低日粮中peNDF8.0的含量(P0.01)。以宾州粗饲料颗粒分级筛进行测定,10 min、18 min和60 min组对应的peNDF8.0含量分别为11.25%、10.56%和9.02%。2.降低日粮peNDF8.0水平显著增加奶牛的日采食次数(P0.05),降低剩料中NDF的含量(P0.01)、瘤胃pH(P0.01)、羧甲基纤维素酶(P0.001)、微晶纤维素酶(P=0.018)和β-葡聚糖酶活性(P=0.045),但不影响木聚糖酶的活性(P=0.751)。3.随peNDF8.0水平的降低,瘤胃总挥发性脂肪酸无显著变化;乙酸比例降低(59.92%、58.57%和56.08%,P=0.003);丙酸比例升高(24.91%、26.54%和29.12%,P=0.002);乙丙比降低(2.42、2.26、1.93,P=0.003)。4.降低日粮peNDF8.0水平对乳脂率、乳蛋白率、乳糖、非脂固形物和乳尿素氮等乳成分均无显著影响(P0.05)。以上结果表明,在本试验条件下,保证奶牛健康和较佳瘤胃发酵的日粮peNDF水平为10.56%,对应的搅拌时间为18 min。
[Abstract]:The purpose of this study was to study the effects of different physical and effective neutral detergent fiber (peNDF) levels on mastication, rumen fermentation and milk composition of lactating cattle under the same dietary structure. A total of 30 healthy Holstein cows with a body weight of about 650 kg, and a similar daily milk yield of 33.2 kg, were selected. By controlling the stirring time of TMR (10 min,18 min and 60 min), the diets with different peNDF levels were obtained by single factor design. The effects of different peNDF levels on feeding and ruminant activities, rumen fermentation parameters and milk composition of dairy cattle were studied. The main results are as follows: 1. Prolonging the stirring time of TMR significantly reduced the content of peNDF8.0 in diet (P0.01). The contents of peNDF8.0 in 10 min,18 min and 60 min groups were 11.25% and 9.02%, respectively. The decrease of dietary peNDF8.0 level significantly increased the daily intake times of dairy cows (P0.05), decreased the content of NDF, pH (P0.01), carboxymethyl cellulase (P0.001) in rumen, decreased the content of NDF (P0.01), and decreased the level of carboxymethyl cellulase (P0.001) in rumen. The activities of microcrystalline cellulase (P0. 018) and 尾-glucanase (P0. 045) did not affect the activity of Xylanase (P0. 751). 3. With the decrease of peNDF8.0 level, the total volatile fatty acids in rumen did not change significantly, but the ratio of acetic acid decreased (58.57% and 56.08% respectively). The ratio of propionic acid to propionic acid was increased (24.91%, 26.54% and 29.12%, P0. 002), and the ratio of ethylc to c was decreased (2. 42%, 2. 26% and 1. 93% P0. 003). The decrease of dietary peNDF8.0 level had no significant effect on milk composition, such as milk fat rate, milk protein rate, lactose, non-fat solids and milk urea nitrogen (P0.05). The results showed that the dietary peNDF level of healthy and better rumen fermentation of dairy cows was 10.56 and the stirring time was 18 min..
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S823.5
[Abstract]:The purpose of this study was to study the effects of different physical and effective neutral detergent fiber (peNDF) levels on mastication, rumen fermentation and milk composition of lactating cattle under the same dietary structure. A total of 30 healthy Holstein cows with a body weight of about 650 kg, and a similar daily milk yield of 33.2 kg, were selected. By controlling the stirring time of TMR (10 min,18 min and 60 min), the diets with different peNDF levels were obtained by single factor design. The effects of different peNDF levels on feeding and ruminant activities, rumen fermentation parameters and milk composition of dairy cattle were studied. The main results are as follows: 1. Prolonging the stirring time of TMR significantly reduced the content of peNDF8.0 in diet (P0.01). The contents of peNDF8.0 in 10 min,18 min and 60 min groups were 11.25% and 9.02%, respectively. The decrease of dietary peNDF8.0 level significantly increased the daily intake times of dairy cows (P0.05), decreased the content of NDF, pH (P0.01), carboxymethyl cellulase (P0.001) in rumen, decreased the content of NDF (P0.01), and decreased the level of carboxymethyl cellulase (P0.001) in rumen. The activities of microcrystalline cellulase (P0. 018) and 尾-glucanase (P0. 045) did not affect the activity of Xylanase (P0. 751). 3. With the decrease of peNDF8.0 level, the total volatile fatty acids in rumen did not change significantly, but the ratio of acetic acid decreased (58.57% and 56.08% respectively). The ratio of propionic acid to propionic acid was increased (24.91%, 26.54% and 29.12%, P0. 002), and the ratio of ethylc to c was decreased (2. 42%, 2. 26% and 1. 93% P0. 003). The decrease of dietary peNDF8.0 level had no significant effect on milk composition, such as milk fat rate, milk protein rate, lactose, non-fat solids and milk urea nitrogen (P0.05). The results showed that the dietary peNDF level of healthy and better rumen fermentation of dairy cows was 10.56 and the stirring time was 18 min..
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S823.5
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