Asian-Australasian Journal of Animal Sciences
- 제13권12호
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- Pages.1691-1698
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- 2000
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- 1011-2367(pISSN)
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- 1976-5517(eISSN)
DOI QR Code
Effect of Replacing Corn and Wheat Bran With Soyhulls in Lactation Cow Diets on In Situ Digestion Characteristics of Dietary Dry Matter and Fiber and Lactation Performance
- Meng, Qingxiang (College of Animal Science & Technology, China Agricultural University) ;
- Lu, Lin (College of Animal Science & Technology, China Agricultural University) ;
- Min, Xiaomei (College of Animal Science & Technology, China Agricultural University) ;
- McKinnon, P.J. (American Soybean Association Beijing Office) ;
- Xiong, Yiqiang (American Soybean Association Beijing Office)
- 투고 : 2000.05.16
- 심사 : 2000.07.11
- 발행 : 2000.12.01
초록
An in situ digestion trial (Experiment 1) and a lactation trial (Experiment 2) were conducted to determine the effects of replacing corn and wheat bran with soyhulls (SH) in lactating dairy cow diets on the extent and kinetics of digestion of DM and NDF, and lactation performance. In experiment 1, five mixed feeds consisting of mixed concentrate and roughages (50:50 on a DM basis) were formulated on isonitrogenous and isoenergetic bases to produce five levels (0, 25, 50, 75 and 100%) of SH replacement for corn and wheat bran. SH had high in situ digestion (92 and 89% for potentially digestible DM and NDF) and fairly fast digestion rate (7.2 and 6.3 %/h for DM and NDF). Increasing level of SH replacement resulted in increased NDF digestibility (linear, p=0.001-0.04) and similar DM digestibility (beyond 12 h incubation, p=0.10-0.41). As level of SH replacement increased, percentage of slowly digestible fraction (b) of DM increased (linear, p=0.03), percentage of rapidly digestible fraction (a) of DM tended to decrease (linear, p=0.14), and DM digestion lag time tended to be longer (linear, p=0.13). Percentage of potentially digestible fraction (a+b) and digestion rate (c) of slowly digestible fraction of dietary DM remained unaltered (p=0.36-0.90) with increasing SH in the diet. Increasing level of SH for replacing corn and wheat bran in the diet resulted in increases in percentages of b (quadratic, p<0.001), a (linear, p=0.08), a+b (quadratic, p=0.001) and a tendency to increase in c for NDF (linear, p<0.19). It was also observed that there was a satisfactory fit of a non-linear regression model to NDF digestion data (