Effects of tropical climate and season on growth, chemical composition of muscle and adipose tissue and meat quality in pigs

Abstract

The effects of tropical climate and season on growth performance, meat quality and chemical composition of muscle and adipose tissue were determined on ad libitum fed Large White pigs. Individually housed animals placed in a tropical climate in a semi-open room were compared to those kept in a climatic room at constant 20 °C and 75% relative humidity (control climate, CC). During the cool season in the tropical climate (CTC), the ambient temperature averaged 24.8 ± 3.6 °C and relative humidity was 83 ± 14%. Corresponding figures for the warm season in the tropical climate (WTC) were 27.9 ± 3.0 °C and 81 ± 12%, respectively. The voluntary feed intake (VFI) of animals reared in CTC weighing between 35 and 94 kg decreased by 9% (P < 0.001) and average daily gain by 12% (P < 0.01), as compared to CC, whereas their carcasses were leaner at slaughter (P < 0.05). Ultimate pH of muscles longissimus dorsi (P < 0.01) and biceps femoris (P < 0.05) was higher in the tropical climate than in CC whereas moisture loss of the biceps femoris and semispinalis muscles was lower (P < 0.05). The lipid content of leaf fat declined in WTC (P < 0.05), as compared to CC. Exposition to the tropical climate resulted in a lower lipid content of the outer layer of backfat (P < 0.05) and a higher degree of unsaturation of fat in the entire backfat (P < 0.01), as compared to CC. Neither the chemical composition of backfat inner layer and M. longissimus dorsi nor the degree of unsaturation of lipids in the latter were significantly altered by the environment. The results suggest that tropical climate may have a favourable influence on pork quality.