Sheep Rumen Fermentation Characteristics Affected by Feeding Frequency and Feeding Level When Fed Fresh Forage.

Xuezhao Sun,Ao Chen,David Pacheco,Simone O Hoskin,Dongwen Luo

doi:10.3390/ani10010007

Abstract

Simple SummaryRuminant production relies on nutrients obtained from feed fermentation in the rumen. In grazing ruminant production systems, fresh forage is the major or sole source of feed. Feeding frequency and feeding level are two important factors affecting rumen fermentation. This study investigated how these factors affect the fermentation of fresh forage in the rumen for in-depth evaluation of the nutritional value of two types of forages and for better understanding of their digestion by ruminants. To achieve the objectives of the study, fresh chicory or perennial ryegrass was fed to sheep hourly or twice-daily at low or high feeding levels. The results indicated that rumen fermentation was affected by forage species, feeding frequency, feeding level and their interactions and the differences in rumen fermentation were more apparent when feeding was performed hourly rather than twice-daily. This study highlighted the importance of feeding frequency on manipulating sheep ruminal metabolism when fed fresh forage.Feeding frequency and feeding level are two important factors affecting rumen fermentation characteristics, but few studies on these have been conducted on fresh forage. Eight rumen-fistulated sheep were fed either fresh chicory or perennial ryegrass hourly in the first period (d 14 to 21) of the experiment and twice-daily in the second period (d 22 to 27) at 1.3 or 2.2 times the requirement of metabolizable energy for maintenance. When fed hourly, but not twice-daily, rumen fluid pH value was affected by forage species and feeding level. The total concentrations of short-chain fatty acid (SCFA) were similar at both feeding levels when fed chicory hourly, but they were greater at the higher feeding level in comparison with the lower feeding level when fed perennial ryegrass. However, forage species and feeding level did not affect rumen fluid total SCFA concentration when sheep were fed twice-daily. Therefore, rumen fermentation characteristics were affected by forage species, feeding frequency, feeding level and their interactions and the differences in fermentation characteristics were more apparent when feeding was performed hourly rather than twice-daily. This study highlighted the importance of feeding frequency on manipulating sheep ruminal metabolism when fed fresh forage.

Highlights

Animal nutrition studies focuses on how animals respond to different feeds and feeding technologies
The rumen fluid pH value was higher for sheep fed hourly with chicory than fed with perennial ryegrass (p = 0.073; Figure 1a)
The pH value of rumen fluid was higher in sheep fed a low feeding compared to a high feeding level

Summary

Introduction

Animal nutrition studies focuses on how animals respond to different feeds and feeding technologies. Feeding frequency affects many aspects of ruminants, including rumen fermentation function [4], dry matter voluntary intake and feed digestion [5], feces and urine excretion [6], and animal performance [7,8] and behavior [9]. Herbs, such as chicory, are increasingly used as alternative forage species for dairy and meat production either in their monocultures or mixtures with legumes [10,11]. Such knowledge is necessary to improve the understanding of rumen function as well as the interpretation of research findings because of the potential interactions between those factors

Methods

Results

Discussion

Conclusion