Abstract:
3B WEANER PIG PERFORMANCE ON DIETS CONTAINING CASEIN, FREE AMINO ACIDS OR CONVENTIONAL PROTEINS D.I. OFFICER*, E.S. BATTERHAM* AND D.J. FARRELL** As part of a project to determine the utilisation of amino acids by weaner pigs a number of experimental diets are being examined. These include a casein based-diet and a chemical diet containing free amino acids that was developed by Chung and Baker (1991). The amino acid digestibility of both of these diets is high, which is a pre-requisite for these studies. Preliminary results with the casein diet were, however, disappointing. This might be improved with the inclusion of NaHCO, (Baker, personal communication). The objectives of the research were to determine the optimaI level of inclusion of NaHCO, to the casein diet and to compare piglet responses when given both experimental diets with that achieved with two control diets. Six diets were used - a commercial super creep (Super creep) which contained cooked cereals, the free amino acid diet (FAA) with starch/sucrose/lactose as the energy sources (Chung and B&r 1991), a casein/fish/soya diet with sucrose as the energy source (Sucrose), the casein diet (Casein), and the casein diet supplemented with 10 or 20 g/kg NaHCO,. All diets were formulated to have an available lysine/DE ratio between 0.8-0.84 g/MJ and offered ad libitum. Piglet performance was assessed from weaning at 3 weeks of age until 20 kg (Table 1). Table 1 Weaner piglet performance over the 5-20 kg growth phase Piglets given the FAA and Casein diets grew more slowly and had higher FCRs than those given the super creep or sucrose-based diets. The addition of 10 g/kg NaHC4 to the casein diet tended to improve performance, but these differences were not statistically significant (P > 0.05). These results show that neither the casein nor the FAA diets were capable of producing growth rates comparable with the commercial super creep or sucrose-based multiple protein diets. Whilst the addition of 10 g/kg NaHCO, to the casein diet tended to improve performance, growth was stiI.I reduced by other as yet undetermined factor/s. The lower performance of the piglets given the FAA diet may have been due to the method of feeding. Chung and Baker (1991) stored their mixed diet in a deep freezer and offered the feed for 1 h, twice daily. In contrast, we stored the diet at room temperature and offered the diets ad libitum. It is possible chemical reactions within the FAA diet under our experimental conditions may have contributed to the lower piglet performance. This aspect is being investigated. CHUNG, T.K. AND BAKER, D.H. (1991) * Journal of Nutrition 121:979-984. ** WoIIongbar Agricultural Institute, Wollongbar, NSW 2477 Dept. Biochemistry, Microbiology and Nutrition, University of New England, Armidale 2351
