In vitro digestion characteristics of various combinations of elephant grass hay, gliricidia hay or silage, soybean meal and corn meal in rations for sheep

Juliana Caroline Santos Santana,Luís Carlos Vinhas Ítavo,Antonio Leandro Chaves Gurgel,Gelson Dos Santos Difante,Jucileia Aparecida Da Silva Morais,Vinicius Da Silva Oliveira,Maria Juciara Silva Teles Rodrigues

doi:10.17138/tgft(8)147-152

Abstract

This study examined fermentation rates and kinetics of sheep rations based on combinations of elephant grass hay, gliricidia (Gliricidia sepium) hay or silage, soybean meal and corn meal using in vitro techniques. Three rations were prepared, namely: Control (elephant grass hay + soybean meal + corn meal); gliricidia hay (elephant grass hay + soybean meal + corn meal + gliricidia hay); and gliricidia silage (elephant grass hay + soybean meal + corn meal + gliricidia silage). A fixed ratio of roughage:concentrate of 55:45 was maintained for all rations, which were isocaloric and designed to support sheep gains of 200 g/day. The gliricidia replaced 57.6% of the soybean meal in the rations containing gliricidia and 81.8% of the elephant grass hay. Fermentation rates and kinetics, in vitro dry matter digestibility (IVDMD) and degradability of the rations were evaluated. Rations containing gliricidia as both hay and silage had higher (P<0.05) IVDMD than the Control ration (67.8 and 66.2 vs. 59.8%). The degradability of the ration containing gliricidia hay was higher (P<0.05) than that of the gliricidia silage ration (57.8 vs. 50.5%), whereas the Control showed an intermediate value (54.4%). The ration containing gliricidia hay and the Control produced more gas in the first 24 h than the ration containing gliricidia silage, and the gliricidia hay ration showed the shortest colonization time. Peak gas production occurred for the ration with gliricidia silage later than for the other rations. The study showed that substituting soybean meal with preserved gliricidia can result in higher digestibility of sheep rations. Feeding studies with animals are now warranted to verify these laboratory findings.

Highlights

Pasture-based production systems are limited primarily by variations in climatic conditions, which directly interfere with plant growth (Euclides et al 2019), resulting in negative impacts on animal performance, especially during the dry season (Emerenciano Neto 2018; Braga et al 2019)
This study examined fermentation rates and kinetics of sheep rations based on combinations of elephant grass hay, gliricidia (Gliricidia sepium) hay or silage, soybean meal and corn meal using in vitro techniques
It was set up as a completely randomized design with 3 treatments, i.e. 3 rations formulated for sheep, namely: Control – basal ration of elephant grass hay-soybean meal-corn meal; gliricidia hay – elephant grass hay-gliricidia haysoybean meal-corn meal with only 42.6% of the soybean meal supplement contained in Control; and gliricidia silage – elephant grass hay-gliricidia silage-soybean meal-corn meal with 42.6% of the soybean meal supplement contained in Control

Summary

Introduction

Pasture-based production systems are limited primarily by variations in climatic conditions, which directly interfere with plant growth (Euclides et al 2019), resulting in negative impacts on animal performance, especially during the dry season (Emerenciano Neto 2018; Braga et al 2019). The use of high-protein feedstuffs in sheep rations is a common practice worldwide and soybean meal ranks highly as a protein source. Since its chemical and productive characteristics are similar to those of other leguminous species, it is a viable option for animal feeding, especially in regions where water deficit is a constant problem (Fernandes et al 2017; Santana et al 2019; Fernandes et al 2020). Incorporating it in rations should allow a reduction in the level of soybean meal required to supply the protein needs of the sheep

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Discussion

Conclusion