No abstract

Cassava tuber peels were analysed for their chemical composition. Graded levels were included in the diets of young pigs in 2 separate experiments to determine their nutritive value for growth and their effect on carcass characteristics. Cassava peels made up 11.8% of the tuber and contained 19.10 MJ/kg, gross energy and 140.90 ppm free cyanide. In the first experiment, involving 40 individually fed pigs averaging 9.35 kg liveweight, levels of 0, 7.50, 15.0, 22.50 and 30.00% of cassava peels were included in iso-nitrogenous diets. There were no significant differences in growth performance between the dietary treatments (P > 0.05). In the second experiment, 32 individually penned pigs averaging 35.17 kg were fed iso-nitrogenous (16% CP) and iso-caloric (15.02 MJ/kg ME) diets in which cassava peels were included in the diets at levels of 0, 19, 38 and 57 per cent. There were no significant differences in average daily gain, average daily feed intake and feed/gain between treatments. Carcass weights and measurements were also not significantly different (P > 0.05). The use of cassava peels as a partial replacement for maize in young pig diets was shown to be cost effective. It was established in the study that up to a 57% level of inclusion had no deleterious effect on the pigs.

Forty growing pigs were used in an experiment to determine the probable cause of retarded growth or weight loss in animals suffering from trypanosomiasis caused by Trypanosoma brucei, T. congolense or T. simiae. Animals infected with T. brucei or T. congolense had mild or symptomless infections with no significant effect on packed cell volume (PCV), voluntary feed intake, mean liveweight gain, feed conversion efficiency, carcass traits or feed cost per unit of weight gain. Uninfected pigs gained slightly more and required slightly less feed per unit of weight gain than pigs infected with T. brucei or T. congolense but the differences were non-significant. Pigs infected with T. simiae showed a marked drop in PCV and a significantly poor performance which was reflected in curtailment of feed intake, impaired feed conversion efficiency, growth failure, poor carcass traits and extremely high and uneconomical feed cost per unit of weight gain. Growth failure or weight loss in trypanosomiasis would appear to be due largely to the combined effect of reduced feed intake and impaired efficiency of feed conversion.

No abstract

Amino acid analysis and 2 growth studies were carried out to determine the effect of period of boiling of full-fat soyabeans on their nutritive value for weanling and growing pigs. Soyabeans were boiled in water for 15, 20, 25 or 30 minutes in Experiment 1 and 25, 30, 35 or 40 minutes in Experiment 2. Forty cross-bred (Large White x Hampshire) pigs were used in each of the experiments. Period of boiling had no effect on amino acid analysis of full-fat soyabeans. Weanling pigs had the best growth performance when soyabeans were boiled for 30 minutes ad this was not significantly different (P>0.05) from the soyabean meal control diet. Period of boiling of full-fat soyabeans did not significantly (P>0.05) affect the performance of the heavier pigs, although improvfement was observed up to 30 minutes of boiling.