Comparison of different protein sources in enriched grain mixture for fattening lambs

Author: T.S. Brand and G.D. van der Merwe
Year: 1993
Issue: 1
Volume: 23
Page: 13 - 17

A triticale/oat grain mixture (2: 1) was enriched with either a commercially available formula or a locally composed supplement in addition to different protein sources (urea, urea plus fish-meal, urea plus cottonseed oilcake, urea plus bitter lupins or bitter lupins only) to be approximately equal in protein content and in vitro organic matter digestibility. Oaten hay (milled through a 12-mm screen) was supplied separately at ca. 10% of ad libitum intake. The different diets were fed to SA Mutton Merino lambs (4 ram and 4 ewe lambs/diet) on an individual basis from approximately 15 weeks of age (25-40 kg). Values for the grain and hay intake, average daily gain (ADG) and feed conversion ratio (FCR, kg feed /kg gain) of the lambs were monitored over the same growth interval. No significant differences were observed between treatments or sexes in terms of grain intake, hay intake or total dry matter intake. Lambs on the diet containing 30% lupins consumed ca. 14% less grain/lamb/d than the mean grain intake of all the lambs (1147 g/lamb/d) on an absolute basis. No significant differences (P > 0.05) in terms of ADG, FCR, or days in the feedlot were observed between diets, while ram lambs performed better than ewe lambs in terms of ADG (P 0.01), days in the feedlot (P 0.01) and FCR (P 0.05). The lack of response to the different protein sources may be explained by the fact that the non-degradable protein (UDP) requirement of lambs over 25 kg was fulfilled by the triticale/oat grain mixture. It was concluded that the protein content of the feed grain as well as the price and availability of different protein sources will determine strategies for inclusion in diets for fattening lambs.

 

Keywords: Enriched grain, finishing, lambs oats, protein source, triticale
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