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Lactation performance and nitrogen utilization of dairy cows on diets including unfermented or fermented yellow wine lees mix.

D. M. Wang

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06-24-2020

Abstract:

317
Lactation performance and nitrogen utilization of dairy cows on diets including unfermented or fermented yellow wine lees mix.
K. Y. Yao1, Z. H. Wei1, Y. Y. Xie1, D. M. Wang*1, H. Y. Liu1, M. R. Ma2, J. X. Liu1. 1Institute of Dairy Science, College of Animal Sciences, Zhejiang University Hangzhou, China, 2College of Agriculture and Bioengineering, Jinhua Polytechnic Jinhua, China.

Yellow wine lees (YWL) consist of a high content of CP (about 25%) with relatively low price, and the CP quality may be improved by microbial fermentation. This study was conducted to investigate lactation performance and nitrogen (N) utilization in dairy cows receiving unfermented and fermented YWL mix as alternative protein source for soybean meal. Fifteen multiparous mid-lactation Chinese Holstein dairy cows with similar parity (2.30, SD 0.32), DIM (190, SD 15.2) and milk yield (25.0, SD 0.45 kg) were used in a replicated 3 � 3 Latin square design. The designed TMR contained: (1) 18% soybean meal (Control), (2) 11% unfermented YWL mix (UM), and (3) 11% fermented YWL mix (FM), respectively. Diets were isonitrogenous and isocaloric, with a forage-to-concentrate ratio of 60:40. Each period lasted for 20 d, with the first 15 d for adaptation. Contents (%DM) of CP, NDF, and ADF were 26.3, 36.4, and 15.6; and 31.3, 41.1, and 19.0 for unfermented and fermented YWL, respectively. Data on lactation performance and N utilization taken over 5 d measurements were analyzed using the PROC MIXED procedure with repeated measurement in SAS software. The DM intake (P = 0.04), milk yield (P = 0.02), and milk protein yield (P = 0.02) were higher in cows fed the control and FM diets than in the UM-fed cows (Table 1). Milk composition, feed efficiency, and N efficiency were not different (P > 0.05) among the 3 groups. The cows fed the UM diet showed lower microbial protein (P = 0.04) and metabolizable protein (P < 0.01) than the cows fed the control or FM diets. Feeding of the FM-fed cows tended to have greater income over feed cost than the control (P = 0.06). In summary, both unfermented and fermented YWL can be used as a protein source in the diets for lactating cows and inclusion of the fermented YWL had no adverse effects on lactation performance and N utilization but with greater profit.Table 1. Feed intake and lactation performance in dairy cows

ItemControlUMFMSEMP-value
DM intake, kg/d19.4a18.1b19.5a0.430.04
Milk yield, kg/d21.5a23.2b24.3a0.39002
Milk protein yield, g/d846a814a855a13.40.02
Milk composition, %
 Fat4.504.364.340.120.57
 Protein3.453.503.520.080.16
 Lactose4.554.644.590.090.26
 Total solids12.812.712.70.180.91
Income over feed cost, US$9.359.529.920.260.06
a,bMeans with different superscripts differ (P < 0.05).

Keywords: yellow wine lees, lactation performance, nitrogen utilization.