Effects of multiple vitamin E levels and two fat sources in diets for swine fed to heavy slaughter weight of 150 kg: I. Growth performance, lean growth, organ size, carcass characteristics, primal cuts, and pork quality

The study objective was to evaluate the effect of two fat source and graded levels of vitamin E (VE) supplementation on growth performance, carcass characteristics, and meat quality of pigs at heavy slaughter weight (150 kg). A total of 48 individually-fed pigs (24 barrows, 24 gilts; 28.44 ± 2.69 kg) were blocked by sex and weight and randomly assigned to eight dietary treatments in a 2 × 4 factorial arrangement. Fat treatments were 5% tallow (TW) and distiller’s corn-oil (DCO) in the diets. The VE treatments included four levels of α-tocopheryl-acetate (11, 40, 100, and 200 ppm). Growth performance, carcass traits, organ weight, primal cuts, and pork quality were measured. Increasing dietary VE supplementation levels linearly increased overall Average daily gain (ADG) and average daily feed intake (P < 0.05), with an interaction between fat sources and VE supplementation levels on cumulative ADG (P < 0.05) during phases 1 and 3 (28 to 100 kg) and 1 to 4 (28 to125 kg) wherein ADG in the pigs fed the DCO diet, but not the TW diet, increased with increasing dietary VE supplementation level. A similar interaction was observed in 24 h pH and picnic shoulder (P < 0.05). No notable effect of fat source was observed in growth performance. With increasing dietary VE supplementation levels, there were quadratic responses in pork pH at 45 min and 24 h postmortem with the highest value in 40 and 100 ppm of VE levels while TBARS values on day 7 postmortem decreased linearly (P < 0.05). Compared with the TW diet, the DCO diet resulted in greater TBARS values during 7 postmortem (P < 0.05; day 5, P = 0.09). These results demonstrated that increasing dietary VE supplementation level could enhance growth rate and feed intake and reduce lipid peroxidation of pork whereas the diet containing DCO as a fat source could negatively affect pork shelf-life and carcass characteristics and that increasing VE supplementation level had no notable interaction with fat sources for carcass characteristics.