Comparison of feeding diets diluted with sorghum-sudangrass silage or low-quality grass on nutrient intake and digestibility and growth performance of Holstein dairy heifers.

Autor:	Li L; Department of Dairy Science, University of Wisconsin, Madison 53706; College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, PR China., Esser NM; Marshfield Agricultural Research Station, University of Wisconsin, Marshfield 54449., Ogden RK; USDA Agricultural Research Service, US Dairy Forage Research Center, Marshfield, WI 54449., Coblentz WK; USDA Agricultural Research Service, US Dairy Forage Research Center, Marshfield, WI 54449., Akins MS; Department of Dairy Science, University of Wisconsin, Madison 53706. Electronic address: msakins@wisc.edu.
Jazyk:	angličtina
Zdroj:	Journal of dairy science [J Dairy Sci] 2019 Nov; Vol. 102 (11), pp. 9932-9942. Date of Electronic Publication: 2019 Sep 11.
DOI:	10.3168/jds.2018-16168
Abstrakt:	This study was carried out to evaluate the nutrient intakes and growth of dairy heifers offered an alfalfa silage-corn silage diet (CON; 14.3% crude protein, 61.1% total digestible nutrients, 47.9% neutral detergent fiber) compared with diets containing 1 of 2 types of sorghum-sudangrass (SS) silages: conventional or photoperiod sensitive. The objective of the study was to determine the potential to use SS to control dry matter (DM) and nutrient intakes and weight gain. Both diets were similar in nutrient composition, with approximately 13% crude protein, 60 to 61% total digestible nutrients, and 55% neutral detergent fiber. Seventy-two Holstein heifers (16-18 mo at study initiation) were blocked by initial body weight (light = 422 ± 12.8 kg; medium = 455 ± 14.8 kg; heavy = 489 ± 16.7 kg) with 3 pens assigned to each weight block (8 heifers/pen; 24 heifers/block). The 3 diets were randomly allocated to the pens within each block and offered for 12 wk. Heifers offered the CON diet had greater DM, protein, and energy intakes compared with those offered the SS silage-based diets due to the greater neutral detergent fiber concentration of the SS diets. With lower DM and nutrient intakes, average daily gain was in the recommended range (0.8-1 kg/d for Holstein heifers) for heifers offered the SS silage-based diets (mean of 0.92 kg/d for both SS diets vs. 1.11 kg/d for CON). Sorting behaviors for heifers offered both SS diets were more aggressive against long, medium, and short particles compared with those of heifers offered the CON diet; however, heifers sorted large particles from photoperiod-sensitive silage more aggressively than those from conventional silage. Based on this study, SS silage-based diets can control the DM and energy intakes for heifers and maintain optimum growth rates, with harvesting at a shorter chop length likely helping to alleviate sorting issues. (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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