Abstract:
20A THE UTILIZATION OF LYSINE IN COTTONSEED MEAL AND MEAT MEAL BY PIGS D.J. FARRELL* and J. SWAINSTON** There is uncertainty about the utilization of both free lysine,and of lysine in protein supplements (Batterham 1979). Values range from 0.35 for The .object of the experiment cottonseed mealto 0.90 for soybean meal. presented here was to determine whether large differences in the avail- . ability of lysine in protein supplements exist such that production performance of pigs is influenced. Six pigs were grown from 20 to 40 kg liveweight (W) on each of 5 diets (Table 1) supplemented with minerals, vitamins and Cr203. Pigs were housed in a pig unit (22 + 3oC) and fed individually, once daily, using the formula: feed (g/d) = 120 wOo7? Utilization of lysine was calculated using data of Batterham (1979), and for the grain mixture, a value o-f 0.85 was used. The results are'also shown in Table 1. TABLE 1 Diet composition (g/kg), determined chemical analyses (g/kg) (as is basis) and results of the growth trial. Diets 2 and 5 gave the highest growth rate and lowest FCR, these were generally different (PcO.05) from diets 1, 3 and 4. 'The only difference in composition between diets 1 and 2 was the addition of free lysine to diet 2. . The large response would suggest that itis well utilized even when diets are offered once daily. Batterham (1979) showed that under such a feeding regime utilization was about 50%. Differences in DE between some diets did notappear to influence interpr,etation of results. The very low values calculated for available lysine for most diets was not supported by growth rates and FCR particularly on diet 5. Although Batterham's (1979) 'coefficients for lysine utilization may allow correct ranking of protein supplements, it appears that the coefficients for cottonseed meal (0.35) and meat meal (0.50) are too low. BATTERHAM, E.S. (1979). In 'Recent Advances in Animal Nutrition l-979', PJL editors W. Haresign and D. Lewis (Butterworths: London).. * Department of Biochemistry and Nutrition, University of New England, Armidale, N.S.W. 2351. ** Fielders Stock Feeds, 53 Belmore Street, Tamworth, N.S.W. 2350.