Mjc. Bosman et al., Growth, carcass and sensory characteristics of m. longissimus lumborum from wethers fed silage diets made from maize or various sorghum varieties, S AFR J AN, 30(1), 2000, pp. 36-42
Citations number
22
Categorie Soggetti
Animal Sciences
Journal title
SOUTH AFRICAN JOURNAL OF ANIMAL SCIENCE-SUID-AFRIKAANSE TYDSKRIF VIR VEEKUNDE
Growth, carcass characteristics and eating quality of meat from South Afric
an Mutton Merino wethers fed maize or different sorghum silage diets were s
tudied. Forty newly weaned wethers (20 kg) were randomly allocated to 10 di
etary treatments, viz. non-bird-resistant grain sorghum silage (NGS), maize
silage (MS), bird-resistant grain sorghum silage (BGS), forage sorghum sil
age (FSS) and a standard non-silage control diet consisting of equal propor
tions of maize meal and milled lucerne hay (C). Silage was included at 2 le
vels, namely 50% or 70% of the total diet on dry matter basis. Average dail
y gains of wethers were recorded from weaning to slaughter at 45 kg live ma
ss. Carcass mass, dressing percentage, subcutaneous fat thickness and carca
ss length were recorded Samples from the left m. longissimus lumborum were
minced and stewed to determine foreign odours and flavours, while samples f
rom the right m. longissimus lumborum were oven-roasted for subsequent sens
ory evaluation by an analytical sensory panel. Growth responses did not dif
fer between wethers fed MS, NGS or BGS at inclusion levels of 50% or 70%. F
SS at the 70% inclusion level resulted in poorer growth rates (p < 0.05) an
d longer feeding periods (p < 0.05) compared to the other silage diets. The
best feed conversion efficiencies and shortest finishing periods were reco
rded by feeding MS at either the 50% or the 70% inclusion level, NGS at the
50% inclusion level, or BGS at the 50% inclusion level. Dressing percentag
es and subcutaneous fat thicknesses of wethers fed BGS and FSS at a 70% inc
lusion level were lower (p < 0.05) compared to those fed the other silage d
iets. No significant differences in sensory characteristics or cooking loss
es and no sensory defects were observed among wethers fed different silage
diets.