Some effects of formaldehyde treatment of barley / linseed meal diets of feed intake and growth rate of Friesian calves.

Abstract

Proc. Aust. Soc. Anim. Prod. (1974) 10; 82 SOME EFFECTS OF FORMALDEHYDE TREATMENT OF BARLEY/LINSEED MEAL DIETS ON FEED INTAKE AND GROWTH RATE OF FRIESIAN CALVES M.J. SHARKEY*, C. KAT*, and R.S. JEFFERY* Summary The intakes and growth rates of Friesian bull calves reared indoors in pens were compared when they were fed 5 litres of whole milk per day to seven weeks of age with ad libitum quantities of pelleted diets available in the interval between 2 and 16 weeks. These diets comprised five protein levels, 14, 17.5, 21, 24.5 and 28% crude protein obtained by varying the proportions of linseed meal and hammermilled barley in the diet. Each of the diets was given either untreated or treated with formaldehyde. Intakes and growth rates of calves were significantly greater (P- < 0.05) for the diets treated with formaldehyde. Intake and growth rate for the untreated diets were not significantly affected by levels of crude protein but tended to be greater at higher levels of crude protein for the diets treated with formaldehyde. The experiment was repeated using a crossover design and a dietary crude protein of 21% and as before significantly higher intakes and growth rates were obtained for the diets treated with formaldehyde. In both experiments liveweight gain was linearly related to gross energy intake and the feed conversion ratios were not affected by crude protein level or treatment with formaldehyde. I. INTRODUCTION The rate and efficiency of growth in young calves depends upon their intake of digested energy, the fraction of that energy accounted for by absorbed protein and the biological value of the absorbed protein (Black 1970). Feed proteins differ widely in the extent to which they are degraded during fermentation with rumen microorganisms. Recently developed techniques for reducing the solubility of protein in the rumen (Ferguson, Hemsley and Reis 1967) raise the possibility of treating protein to improve its utilization by ruminants and so to produce greater weight gains. This paper reports a series of tests at Werribee, Victoria, in which Friesian calves were fed diets based on linseed meal and barley. In half of the diets formaldehyde treatment was applied to each dietary component before pelleting. II. MATERIALS AND METHODS (a) Experiment 1 In September 1971, 30 calves were weaned at 2 days of age and reared indoors on diets which included whole milk (5 l/day) until they were, 7 weeks old and pelleted mixtures of linseed meal and hammermilled barley (ad libitum) after the calves were 14 days old. Each of these latter components were treated with formaldehyde in half of the diets. The calves were reared in individual pens and the observations were terminated when the calves were 16 weeks old. Three calves were randomly allotted to each treatment when they were 14 days old at a mean liveweight of 37.1 kg. The 10 treatments consisted of five dietary levels of crude protein (C.P.), 14, 17.5, 21, 24.5 and 28% C.P. with or without formaldehyde treatment (1.0 or 0 g per 100 g crude protein). The method for applying formaldehyde was similar to that described by Sharkey et al. (1972). The linseed meal and hammermilled barley were each individually treated with formaldehyde. Molasses, ground limestone and sodium chloride were added to each mixture before pelleting at the rate of 3.0, 1.0 and 0.5% respectively by weight. Treatment of the diets was assessed to be effective because there was a marked reduction in ammonia production when the treated diets were fermented in vitro with rumen organisms. The gross energy values of pellets were determined by * Department of Agriculture, Victoria, S.S. Cameron Laboratory, Werribee, 3030. 82 combustion of samples of each diet in an adiabatic bomb calorimeter. The values ranged between 18.8 MJ/g for the diet of 14% C.P. to 20.5 MJ/g for the diet of 28% C.P. Vitamin D was fed orally to each calf at weekly intervals at the rate of 10 1-U. per kg liveweight per day. Liveweights, feed intakes and feed conversion ratios were taken at weekly intervals. Results over the time interval 2 to 12 weeks were examined by analysis of variance using the mean value for each animal as replicates. The mean performance of each animal between 2 and 7, 8 and 12 and 13 and 16 weeks of age was also examined using a stepwise regression programme operating at a 5% level of significance utilizing the following model : where (Y) = liveweight change (g/day) the independent variables were : MJ = gross energy CP = crude protein F = formaldehyde no treatment intake (MJ/day) level such that 1 = 14% . . . 5 = 28% treatment such that treatment = -1 and = 1. (b) Experiment 2 Milk feeding, feed ingredients and methods of preparation of formaldehyde treated diets were identical to those used in experiment 1. A crossover design was used in which 10 calves of mean liveweight 38.5 kg were randomly allotted to 2 groups at 14 days of age. One group received pellets treated with formaldehyde and the other group received untreated pellets until the calves were 5 weeks old. The diet of each calf was changed at 5, 8 and 11 weeks and the study concluded when the calves were 14 weeks old. Results for the total period, 2 to 14 weeks, were examined by analysis of variance using the results of individual animals as replicates to compare voluntary feed intake, liveweight gains and feed conversion ratios. III. RESULTS In both experiments the intake and growth rate were significantly greater (P < 0.05) in the calves fed the formaldehyde treated diets than in those fed the untreated diets (Table 1). TABLE 1 Liveweight gain, feed intake and efficiency of feed conversion of calves aged 2 to 12 and 2 to 14 weeks in experiments 1 and 2 respectively 83 The DM intakes and growth similar at all levels of crude there was a trend for greater (Table 2) (Interaction CP x F, rates of calves fed diets without formaldehyde were protein but in the calves fed the treated diets DM intake and growth rate up to a level of 24% C-P. P > 0.05). TABLE 2 Effect of formaldehyde and protein levels on intake and growth rate of calves between 2 and 12 weeks of age (experiment 1) Liveweight gain of calves between 2 and 12 weeks of age was dependent'(P < 0.05) on energy intake alone (Table 3). From 13 to 16 weeks gain was dependent on energy intake but in addition there was a significant interaction (CP x F P < 0.05). TABLE 3 Regression equations relating liveweight gain of calves (g/day) to intake (MJ), and levels of crude protein (C-P.), and formaldehyde (F) IV. DISCUSSION The clear response in intake and growth rate of calves following formaldehyde treatment of each dietary component suggests that this treatment may be beneficial in obtaining faster weight gains in early weaned calves, Similar benefits in intake and growth rate to formaldehyde treatment of the whole diet have been obtained (Faichney and Davies 1973), but these benefits were not evident in 15 month old steers where only the barley component of the diet was treated (Lloyd Davies and Faichney 1973) and indeed in our experiment were not evident in calves older than 12 weeks. 84 The absence of a response in growth rate and feed conversion of our calves fed untreated diets at protein levels greater than 14% is puzzling in relation to the clear response to untreated protein obtained by Faichney However, different plant proteins, peanut meal and Lloyd Davies (1972). and linseed meal were used in the two experiments. The overall growth rates of our calves was almost identical to that obtained by Kellaway, Grant and Chudleigh (1973) for diets without fibre, but was about 25% less than that obtained where straw chaff was available. v. ACKNOWLEDGEMENTS We acknowledge the assistance of Mr R. Jardine, Victorian Department of Agriculture, for the statistical analysis, and Messrs A. Fry and J. Ward for care of the calves. VI. REFERENCES BLACK, J.L. (1970). Ph.D. Thesis, University of Melbourne. Aust. J. agric. Res. 23: 167. FAICHNEY, G.J., and LLOYD DAVIES, H. (1972). Aust. J. agric. Res. 24: 613. FAICHNEY, G.J., and LLOYD DAVIES, H. (1973). Aust. J. Sci. FERGUSON, K-A., HEMSLEY, J.A., and REIS, P.J. (1967). 30: 215. Aust. J. exp. KELLAmY, R.C., GRANT, T., and CHUDLEIGH, J.W. (1973). Agric. Anim. Hush. 13: 225. Aust. J. exp. Agric. Anim. LLOYD DAVIES, H., and FAEHNEY, G-J. (1973). Hush. 13: -m 142. SHARKEY, M.r, PEARCE, G-R., SIMMONS, E.K., JEFFERY, R.S., and CLARK, Aust. J. exp. Agric. Anim. Husb. 12: 596. JENNIFER (1972). C 85