The effect of dietary conjugated linoleic acid supplementation on production efficiency and meat quality of pigs

[摘要] The objectives of this study were to determine the effects of a commercial dietary CLA feed supplement on the production and meat quality parameters of pigs under commercial production conditions. It included the study of the chemical and sensory stability of processed meat products manufactured from the meat of such animals. One hundred and forty four Landrace x Large White crossbred pigs, weighing ± 30 kg, were randomly divided into two groups of seventy two pigs each, that were assigned to one of two dietary treatments. Diets consisted of a control diet supplemented with 1% SFO and the experimental diet where 0.5% SFO was replaced with 0.5% CLA. Each dietary group was further divided into three gender groups (boars, barrows and gilts) that consisted of twenty four pigs each. Each gender group was further divided into two slaughter weight groups (70 kg and 90 kg) consisting of twelve pigs each. Pigs were fed until the average live weight of the pigs was ± 70 kg for the porkers and ± 90 kg for the baconers. Growth performance (weight increase, ADG and FCR) and carcass characteristics (warm and cold carcass mass, dressing percentage, carcass length, shoulder and buttock circumference, pH, backfat thickness, eye muscle thickness and LMC) were assessed. Animals receiving the CLA diet had improved FCR and carcasses with thinner backfat and higher LMC, compared to animals on the SFO diets. This resulted in a higher frequency of P and O classification of carcasses from CLA supplemented pigs. Backfat, belly fat and M. longissimus thoracis quality of the dietary treatment and slaughter weight groups were compared. Baconers had improved technological properties compared to porkers. Dietary CLA supplementation resulted in improved technological properties of backfat and belly fat, demonstrated by decreased IV; RI; DBI; UFA; MUFA; PUFA; MUFA/SFA ratio; PUFA/SFA ratio;9 desaturase index; C16:1 + C18:1/C16:0 + C18:0 ratio and increased C18:0; cis-9, trans-11; trans-10, cis-12; SFA; AI; C16:0 + C18 and ratios of C18:0/C18:2; C18:2/C18:1; C16:0/C18:2. M. longissimus thoracis from CLA supplemented pigs had higher a*-values, drip loss and WHC. Dietary CLA supplementation resulted in a decrease of health and nutritional properties of M. longissimus thoracis, demonstrated by increased SFA content and AI, while UFA, MUFA, PUFA, n-6, n-3 and ratios of MUFA/SFA and PUFA/SFA decreased. Technological and health properties were inversely related. The decreased health properties must be weighed against the numerous health benefits, ranging from improved immune function to prevention of cancer that can be attributed to CLA supplementation. Conjugated linoleic acid isomers were deposited into the neutral- and glycolipid fraction of subcutaneous adipose tissue and into the phospholipid fraction of IMF. Processed products (patties, bacon and salami) were manufactured from meat from the experimental treatment groups. The chemical stability and sensory properties of fresh meat and processed products manufactured from the experimental treatment groups were compared. Conjugated linoleic acid also demonstrated antioxidant properties in animal feed. Sensory analysis indicated the small effect of dietary CLA supplementation on the sensory properties of fresh and processed pork products. In the case of fresh pork chops and pork patties, dietary CLA supplementation had a stabilizing effect on the a*-value of the products. The lipid stability of pork patties was improved by dietary CLA supplementation as indicated by TBARS values. Salami from the CLA groups was firmer. That could be ascribed to the fat hardening effect of CLA. Pork and pork products enriched with CLA can be considered functional foods and even 'nutraceuticals with positive effects on human health. South African pig producers may therefore consider marketing CLA enriched pork products as a health food. The potential advantages and the premium that can be earned on such meat has to be balanced against the reality of increased feed cost.

[发布机构] University of the Free State