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Study on Rumen Degradability and Intestinal Digestibility of Mutton Sheep Diets with Different Concentrate-to-Forage Ratios and Nonfiber Carbohydrates/Neutral Detergent Fiber Ratios
by
,
Xunyu Guo
1, 
Lei Sun
2,
Zibin Zheng
1,
Xiaogao Diao
3,
Liwen He
1,
Xiaoling Dong
2,* and
Wei Zhang
1,* 1
State Key Laboratory of Animal Nutrition and Feeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
2
Beijing DaBeiNong Technology Group Co., Ltd., Beijing 100095, China
3
Sanya Institute, China Agricultural University, Sanya 572025, China
*
Authors to whom correspondence should be addressed.
Animals 2024, 14(19), 2816; https://doi.org/10.3390/ani14192816 (registering DOI)
Submission received: 2 August 2024
/
Revised: 25 September 2024
/
Accepted: 26 September 2024
/
Published: 29 September 2024
(This article belongs to the Section Small Ruminants)
Simple Summary
At present, indoor feeding is the primary method for fattening mutton sheep in China, where high-concentrate feeding is the common way to achieve high growth performance in the short term, and dietary cost accounts for most of the feeding expenditure. However, increasing feed costs and metabolic diseases, like rumen acidosis and urinary calculi, are likely to compromise the production benefits of such a fattening mode. Exploring low-cost alternative feeds and optimized dietary concentrate levels would contribute to better production benefits. In this study, an in situ method and in vitro three-step method were used to investigate the optimum dietary concentrate-to-forage ratio, NFC/NDF (Nonfiber Carbohydrates/Neutral Detergent Fiber) ratio, and raw materials combination, ultimately providing a reference for the efficient and high-quality fattening of mutton sheep. It is concluded that a dietary concentrate-to-forage ratio in the range of 70:30~80:20 and NFC/NDF of 1.5~2.0 are recommended for fattening mutton sheep, and it is feasible to partly substitute soybean meal with unconventional protein feedstuff like cottonseed meal and rapeseed meal. In addition, the nutritional values of sunflower seed hulls and rice hulls are lower than that of peanut vine for mutton sheep. Such a study is of great significance to the high-quality development of the mutton sheep industry.
Abstract
This study was conducted to investigate the rumen degradability and intestinal digestibility of mutton sheep diets different in concentrate-to-forage ratio, NFC/NDF, and ingredient combination, providing a guideline for the selection of a fattening diet for mutton sheep. Twenty-eight diets composed of four raw material combinations and seven concentrate-to-forage ratios and four three-year-old mutton sheep with permanent rumen fistulas were used in the experiments. The nutrient composition of the diets was first analyzed, and then an in situ method and in vitro three-step method were separately used to measure the rumen degradability and intestinal digestibility, mainly focusing on the effects of dietary concentrate-to-forage ratio and NFC/NDF as well as the effects of soybean meal and soybean meal replacement and peanut vine and peanut vine replacement. The results showed that a dietary concentrate-to-forage ratio of 70:30~80:20 and an NFC/NDF ratio of 1.5~2.0 are recommended for fattening mutton sheep, and low-cost cottonseed meal and rapeseed meal can be feasible alternative protein sources to soybean meal. In addition, the nutritional values of sunflower seed hulls and rice hulls for mutton sheep are lower than that of peanut vine. Such a study can provide practical guidelines for enterprises and farmers, being of important significance for the high-quality development of the mutton sheep industry.
