Computed tomography evaluation of gilt growth performance and carcass quality under feeding restrictions and compensatory growth effects on the sensory quality of pork

Abstract

Restricted feed can affect the body composition of pigs. Body composition can be studied non-destructively in live pigs using computed tomography (CT). The objective was to investigate the effect of different feeding restriction strategies on the productive and carcass quality parameters of gilts during growth via CT images and the effects of such strategies on meat quality, sensory properties and consumer preferences. Moreover, we sought to determine whether CT is a suitable tool for this purpose in this type of study. Thus, 36 Pietrain x (Large White x Landrace) gilts were assigned to the following three feeding strategies: 1) ad libitum feeding (AL) during all fattening periods (AL-AL); 2) AL feeding between 30 and 70 kg target body weight (TBW) followed by restriction (84% of AL) until 120 kg TBW (AL-RV); and 3) restriction feeding (78% of AL) between 30 and 70 kg TBW followed by AL until 120 kg TBW (RV-AL). When the pigs reached 30, 70, 100 and 120 kg, they were CT scanned to obtain the carcass composition parameters. At 120 kg TBW, the pigs were slaughtered, and the carcass and meat quality was determined. The loins were collected for trained panel evaluation and consumer tests. The panellists evaluated the odour, flavour and texture attributes of cooked loins. A total of 120 consumers scored the overall acceptability, tenderness, odour and flavour. The results showed a decrease of 76% and 80% in the average daily gain and average daily feed intake during the restriction period compared with the ad libitum in the growth phase, respectively, and a decrease of 89% and 87% in these parameters during the fattening phase, respectively. A restriction reduces the body fat content during the period of the restriction. Differences in the carcass and cut composition and meat quality were not observed at the end of the experiment among the treatments. Regarding sensory quality, meat from the animals in the AL-AL treatment was tougher than that from animals in the RV-AL and AL-RV treatments. Nevertheless, these differences were not detected by consumers, who did not provide significantly different scores for acceptability. Thus, when preparing feeding strategies, these results should be considered to optimize costs and increase benefits. Furthermore, computed tomography represents a non-destructive technology suitable for determining carcass composition before slaughter.