The Nutritional Value of High-Lysine Barley Determined in Rats, Young Pigs and Growing Pigs
✍ Scribed by Jørgensen, Henry; Gabert, Vince M; Eggum, Bjørn O
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 223 KB
- Volume
- 73
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
Three experiments, the Ðrst with rats, the second with young pigs and the third with growing pigs, were carried out to compare the nutritional value of cv Lysimax, a newly developed high-lysine barley, to cv Lami, a conventional barley grown in Denmark. In the diets for rats and growing pigs the barleys were the sole protein source while in the experiment with young pigs the barleys made up to 649 g kg~1 of the respective diets. The lysine content of cv Lysimax was 52É6% higher than that of cv Lami ; 4É99 g 16 g N~1 compared to 3É27 g 16 g N~1. The contents of threonine, tryptophane, methionine and cystine of cv Lysimax were 3É80, 1É41, 1É80 and 2É27 g 16 g N~1, respectively ; being 18É4, 8É5, 9É8 and 5É1% higher than in cv Lami. Conversely, the contents of glutamic acid and proline in cv Lysimax were 15É79 and 7É40 g 16 g N~1, respectively, being 36É1 and 40É0% lower than in cv Lami. In the experiment with rats, the higher lysine content and the lower content of glutamic acid and proline in cv Lysimax resulted in a 34É8% increase (P \ 0É05) in biological value (BV) ; 0É867 for cv Lysimax compared to 0É643 for cv Lami. True protein digestibilities and energy digestibilities in rats fed cv Lysimax were 0É019 and 0É010 units lower (P \ 0É05) than for cv Lami. For young pigs the increased lysine content and the lower content of glutamic acid and proline of cv Lysimax increased (P \ 0É05) nitrogen (N) retention from 10É9 to 12É4 g day~1, respectively, and increased (P \ 0É05) apparent BV from 0É690 to 0É734, respectively. The digestibility of energy was 0É030 units lower (P \ 0É05) for the diets with cv Lysimax than for the diets with cv Lami. Likewise, with growing pigs the increased lysine content and the lower content of glutamic acid and proline increased (P \ 0É05) N retention from 6É4 to 10É8 g day~1 and apparent BV from 0É271 to 0É495, respectively. The apparent ileal digestibilities of lysine, threonine, tryptophane, methionine and cystine were similar (P [ 0É05) between the barleys. It is concluded that the development of high-lysine barley varieties could be beneÐcial for meeting the requirements of essential amino acids for monogastrics. Moreover, N excretion into the environment was substantially reduced due a reduction in the prolamine fraction which is rich in glutamic acid and proline.