Effect of Sodium Bicarbonate Supplementation on Fatty Acid Composition of Lambs Fed Concentrate Diets at Different Ambient Temperature Levels

Demba B Jallow,Liang Chou Hsia

doi:10.19026/ijava.6.5232

Abstract

The objective of this study was to evaluate the effect of ambient temperature and sodium bicarbonate (NaHCO3) supplementation in diets for growing lambs on meat fatty acids composition. A slaughter study was carried out on 12 male Black Belly Barbados lambs randomly drawn from a prior growth trial (245 days). The lambs were divided into four equal groups and allotted in a 2�2 factorial design. The lambs were allotted at random to two dietary treatments of a basal diet (35: 65 roughage: concentrate) or basal diet supplemented with 4% NaHCO3 at different ambient temperatures (20 and 30�C) in an environment controlled chamber for 10 days. Lambs were slaughtered for carcass evaluation at about 262 days of age (245 days of growth trial, 7 days adaptation and 10 days of experimental period). Samples for fatty acids analysis were taken from the leg muscles and longissimus dorsi region (between the 12th and 13th rib). Ambient temperature influenced (p<0.05, p<0.01, p<0.001and p<0.05) C18:2t isomers, C20:4, C20:3 n-6 and C20:4 n-6 levels on the longissimus dorsi muscle, with higher C20:3 n-6 (p<0.001) but lower C20:4 n-6 (p<0.05) levels in lambs under the higher ambient temperature. The fatty acids C18:1c, C18:2t and C20:5 levels on the leg muscle were also significantly influenced (p<0.01, p<0.001 and p<0.01 resp.) by dietary treatments with higher levels in lambs fed NaHCO3 diet. These results indicated that NaHCO3 supplementation at low ambient temperatures significantly decreased fatty acids levels.

Highlights

To consumer demands for lean and digestible meat of high quality and good taste, fattening schemes wean lambs approximately 6-8 weeks and place them on high-concentrate diets for an extra 5-7 weeks (Bodas et al, 2010; Mohammad et al, 2010)
On the longissimus dorsi muscle, C6:0 and MUFA C14:1 were higher (p
The levels of palmitic (C16:0) acid, that is reported to be involved in increasing total and LDL cholesterol in plasma and enhancing risks for human health (Scollan et al, 2006), were not significant (p>0.05) in meat from the leg muscle higher values were recorded in lambs in higher ambient temperature group compared to the other group

Summary

Introduction

To consumer demands for lean and digestible meat of high quality and good taste, fattening schemes wean lambs approximately 6-8 weeks and place them on high-concentrate diets for an extra 5-7 weeks (Bodas et al, 2010; Mohammad et al, 2010). NaHCO3 could alter the proportions of the volatile fatty acids in the rumen by modifying either bacteria and ciliate protozoal population or rate and extent of degradation of feed (Santra et al, 2003). These changes in volatile fatty acid pattern could affect fatty acid composition of the meat. The objective of this study was to evaluate the effect of ambient temperature on meat fatty acid composition of lambs’ concentrate diets with or without NaHCO3 supplementation

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Conclusion