COMPARATIVE RESPONSES OF LARGE WHITE X LANDRACE AND THE INDIGENOUS NIGERIAN PIGS TO DIETS OF VARYING PROTEIN CONCENTRATION

Abstract

A total of 60 pigs made up of 30 Large White x Landrace pigs (LW X LD) and 30 indigenous Nigerian pigs were allocated to five groups of 12 pigs each, such that there were 3 barrows and 3 gilts of each breed within the group. These were individually fed one of 5 dietary protein levels (12%, 14%, 16%, 18% and 20% CP), from an approximate initial weight of 9 kg to a terminal weight of approximately 68 kg, at which weight all pigs were slaughtered for carcass appraisal. Protein level increments significantly improved both rate and efficiency of gain of the LW X LD pigs, being best on the 20% protein diet. For the IND pigs, best rate of gain was obtained on the lowest protein level, while at levels of protein above 16%, an obvious decline in rate of gain resulting from further increases in protein levels were observed. Feed efficiency in the IND pigs was improved when protein levels in diets were increased from 12% to either 14% or 16%. This improvement was more obvious at lower weight class intervals, than when pigs were reared to heavy weights. Carcass traits were improved in both breeds as protein levels were increased, the improvements being more marked for the LW X LD pigs. There were highly significant breed differences for growth, feed efficiency and all carcass measurements. Significant breed x ration interaction was obtained for growth rate, feed efficiency and most carcass traits, except percentages bone, skin and shoulder, carcass length and dressing percentage. The results indicate obvious differences in protein and amino acid requirements for growth and best carcass quality, which are discussed in relation to inherently different capacities for proteinaceous and fatty tissue growth.