The addition of bone meal to meat meal and soya bean meal diets for young pigs.

Abstract

THE ADDITION OF BONE MEAL TO MEAT MEAL AND SOYABEAN MEAL DIETS FOR YOUNG PIGS D.F. EVANS* and JANE LEIBHOLZ* An experiment was conducted to determine the effect of adding bone meal to wheat and meat meal based diets or wheat and soyabean meal based diets when fed to pigs from four to eight weeks of age. The diets contained 0.80, 1.55 or 3.05% calcium and each diet was fed to eight pigs. The level of bone meal in the diets containing soyabean meal did not affect the growth rate of the pigs, but in the diets containing meat meal the addition of bone meal reduced weight gain and feed conversion efficiency. The digestibility of dry matter, nitrogen and calcium was significantly reduced by the addition of bone meal in both the soyabean meal and meat meal diets. There was no difference in the performance of the pigs fed the soyabean or meat meal based diets containing 0.80% calcium. I. INTRODUCTION Meat meals have been shown to be variable in composition (Duckworth, Woodham and McDonald 1961) and have often been considered unsatisfactory as the sole source of supplemental protein in the diets of growing pigs (Kennedy et al. 1974). Meat meals of moderate ash content have been shown to besuperior to those of high ash content (Sathe and McClymont 1964). Also, it has been suggested that the poor performance of pigs fed diets containing meat meals is due to their poor protein quality (Kennedy et al. mm' 1974). The high ash content of meat meals is due to the inclusion of bone in the raw material for the manufacture of meat meal. Hence the present experiment was designed to determine the effect of increasing the bone content in the diet of pigs while maintaining an adequate level of lysine and methionine in the diets. Lysine and methionine are the first limiting amino acids in-meat meals (Kennedy - al. 1974). et 11. MATERIALS AND METHODS The experiment was of a randomized block design with six dietary treatments. The composition of the diets is presented in table 1. Bone meal was added to a meat meal based diet or a soyabean meal based diet to formulate three levels of calcium: 0.80, 1.55 and 3.05%. The meat meal used was manufactured from soft offal (stomachs and intestines) and the calcium content was low enough (3.59%) to allow supplementation with bone meal to the required levels. The meat meal was dry rendered at atmospheric pressure for three h and the final temperature reached during ' rendering was 12O'C. The diets were equalised for crude protein (22%), calculated digestible energy (14.7 MJ/kg), total lysine (1.20%) and total methionine plus cystine (0.80%). The diets were fed ad lib. to 48 cross-bred, male pigs, arranged in * M.C. Franklin Laboratory, Department of Animal Husbandry, University of Sydney, Camden, N.S.W. 2570. 409 TABLE1 Composition of diets (%)# four blocks (blocked for weight), from four to eight weeks of age, Each diet was randomly allocated to one pen of two pigs within each block. Weight gain and feed consumption wwerecorded weekly and all faeces were collected in the second and fourth weeks of the experiment, Feed and faeces samples were dried to constant weight at 95'Ce Nitrogen was measured by Kjeldahl techniques, calcium by an atomic absorption spectrophotometer and amino acids on a Technicon TeSeMe analyser after hydrolysis in 6N HCl for 24 h at 11O'Ce Differences between diets were tested by an analysis of variance and treatment means were separated by Duncan's Multiple Range Test (Steel and Torrie 1960). III, RESULTS The average daily gain and feed conversion efficiency of the pigs fed the soyabean meal based diets were better than those of the pigs fed the meat meal based diets (table 2). The weight gain of the pigs was not significantly affected by the level of bone meal included in the soyabean meal diets, but growth rate was depressed when 3e7 or geS% bone meal was added to the meat meal diets. The weight gain and feed conversion efficiency of the pigs fed the meat meal diet with the lowest level of bone meal (Ml) was equal to that of the pigs fed the soyabean meal diets. The digestibility of dry matter, the soyabean meal based diets than the digestibilities were depressed by the tion of calcium increased as the level IVe nitrogen and calcium was greater for meat meal based diets although all addition of bone meal. The absorpof calcium in the diet increased, DISCUSSION . In the present experiment the level of bone meal added to the meat meal diets was at a concentration which is similar to that measured in commercial meat and bone meals (Leibholz and Moss 1967). The level of bone meal in the soyabean meal basal diets fed to the pigs did not affect their performance as is also shown by KennedyI et ale (1974). p e a r s t ap that the tolerance of pigs to high calcium levels is greater than in the ,rat (Kennedy - ale 1974) or the chick (Batterham, Manson and Kirton 1970). et Undoubtedly, the absence of an effect of high calcium levels is dependent upon adequate dietary levels of other minerals (Davis 1959) and vitamins (Sathe and McClymont 1965). The reduced performance of the pigs fed the diets containing high levels of bone meal added to the meat meal based diet may.be partly due to the depression of feed intake although the differences in intakes on the diets were non-significant, Also, the reduction in pig performance may be due to an imbalance of the essential amino acid content produced by the bone meal (Eastoe and Long 1960). The total essential amino acid content of the meat meal diets was less than that of the soyabean meal diets except for lysine and methionine. The addition of bone meal depressed the digestibility of dry matter and nitrogen to a similar extent in the soyabean meal diets as the meat meal diets without depressing growth in the former. At the lowest level of bone meal inclusion pigs fed the meat meal based diet performed as well as pigs fed the soyabean meal based diet, The meat meal was manufactured from soft offal and Skurray and Herbert 411 (1974) reported that these meat meals were superior in nutritional value to those manufactured from hard Offale This effect was due to the higher content of available essential amino acids in the soft offal, In conclusion, it is suggested that the performance of pigs between four and eight weeks of age fed diets containing mat meal or soyabean meal ad lib. is similar if the level of bone included in the diets is lowe However, further experiments are required to compare 'boneless' meat meals with other meat meals and meat and bone meals. Ve ACKNOWLEDGMENTS We are grateful to Mayfair Farms for the supply of the pigs, to the Metropolitan Meat Industry Board for the manufacture and donation of meat meal, bone meal and tallow, and to Pfizer Agricare Ptye Ltde for the donation of the premix. This project was financed by the Rural Credits Development Iiiu?de Vie REFERENCES (1970) l BATTERHAM, EeSe, MANSON, MeBe, and KIRTON, HeCe Australian Journal of experimental Agriculture and Animal Husbandry, 10: 384. DAVIS, G.K, (1959). F ed eration Proceedings, 18: Bulge DUCKWORTH, Je, ,WOODHAM, AeA.3 and MCDONALD, Ie(lg6l)e Journal of the Science of Food and Agriculture, 12: 407. EASTOE, JeEe, and LONG, JOAN Ee (1960) Journal of the Science of Food .and Agriculture, 11: 87. KENNEDY, JeJe, AHERNE, FeXTICELLEHER, DeL.9 and CAFFREY, PeJe Irish Journal of agricultural Research, 13: le LEIBHOLZ, JANE, and.MOSS, FePe (1967). Australian Journal of agricultural, Research, 18: 157. SATHE, B.S.3 and Mc&ONT, GeLe (1964). 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