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Title
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Effects of linseed processing method (ground
versus extruded) and dietary crude protein
content on performance, digestibility, ruminal
fermentation pattern, and rumen protozoa
population in growing lambs
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Abstract
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Thirty-six male lambs (averaging BW ΒΌ 24.4 kg) were assigned in a completely randomised
design with the factorial arrangement (nine lambs per each treatment) to assess the effects of
linseed processing method (ground vs. extruded) and dietary crude protein content (12% vs.
15%, DM basis) on performance, digestibility, ruminal fermentation, and protozoa population.
Treatments were; (1) ground linseed with 12% CP (GLS-12CP), (2) ground linseed with 15% CP
(GLS-15CP), (3) extruded linseed with 12% CP (ELS-12CP), and (4) extruded linseed with 15% CP
(ELS-15CP). The study lasted 84 d, and the lambs had free access to experimental diets and
water. Outcomes showed that dry matter intake, digestibility of organic matter, and crude protein were increased in lambs fed ground linseed compared to extruded linseed. Feeding
extruded linseed decreased urinary allantoin concentration, total purine derivatives (PD), the
ruminal proportion of propionate, and blood concentration of glucose and HDL-cholesterol compared to ground linseed diets. Regarding dietary protein content, results showed that dry matter
intake, urinary concentration of allantoin and total PD were increased in 15CP diets compared
to 12CP diets. Considering the interaction, results showed that average daily gain was improved
in GLS-15CP treatment compared to other experimental treatments. In conclusion, results show
that grinding the linseed is more beneficial compared to its extrusion in lamb nutrition.
Moreover, 15CP diets had a beneficial effect when fed with either ground or extruded linseed
and seem to compensate, to some extent, the negative effects of extruded linseed on the gain
of growing lambs.
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