Effect of the feeding level during the fattening phase on the productive parameters, carcass characteristics and quality of fat in heavy pigs

The objective of this experiment was to study the effect of feeding restriction carried out at the beginning or at the end of the finishing period on the productive results, carcass characteristics and fat quality of Iberian pigs fattened with feed in confinement. During the finishing period (77 days, from 100 to 150 kg of liveweight), the Iberian pigs were given the following feeding treatments: 1. R+AL (restricted feeding from the beginning of finishing period to 43 days later and ad libitum feeding from 44 days to the slaughter); 2. AL+R (ad libitum feeding from the beginning of the finishing period to 43 days later and restricted feeding from 44 days to slaughter); 3. C: constant feeding. The productive results (weight at slaughter, average daily gain and carcass weight) were higher (P<0.001) in C pigs than in R+AL and AL+R. The treatment had not significant influence on carcass characteristics except for the variables dorsal fat thickness and ham weight with respect to carcass weight. The concentration of C18:1n-9 and total MUFA proportions observed in subcutaneous backfat were higher in AL+R and C groups than in R+AL (P<0.05), while the C18:0 and total saturated fatty acids proportions were lower in AL+R and C pigs than in R+AL (P<0.01). The dietary treatment had not significant influence on the fatty acids proportions detected in the intramuscular and in liver fat. The results obtained in this experiment suggest the future development of other experimental designs, to improve the productive results and quality of Iberian pigs fed with feed in confinement by means of feeding restriction strategies.