The plane of nutrition and compensatory growth in pigs

Abstract

1. An experiment was carried out with forty individually-fed Large White × Wessex pigs to examine the growth rates of females (gilts) and castrated males after varying periods of time on a restricted plane of nutrition.2. Compensatory growth was made by pigs in all treatments when some restriction in the plane of nutrition had been previously imposed.3. The immediate growth response after the restriction ceased was directly related to the duration of the period of restriction.4. In pigs on a restricted scale of feeding to 80 lb. live-weight, no compensatory growth was observed until a later stage in growth, whereas pigs on a restricted scale for a much longer period to 160 lb. live-weight showed immediate and significant compensatory growth.5. In the periods immediately after the food restriction was lifted, gilts responded more than castrated males on all treatments.6. The effect on the overall growth rate from 45 to 200 lb. live-weight became progressively worse as the period of restriction was prolonged and in no case did the compensatory growth fully compensate for the setback suffered during restriction.7. There were no significant differences in overall food conversion efficiency and it appears that pigs with an even rate of gain and an interrupted growth rate may be equally efficient.8. There were no significant differences in carcass length or dressing-out percentage although a moderate degree of restriction up to 120 lb. live-weight improved grading results, these being related, to non-significant improvements i n food conversion and therefore possibly to a lower carcass fat content.