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Pigs intended for Denomination of Protected Origin Teruel ham should be slaughtered at 130 kg of BW to optimize productive performance and carcass quality traits, but a considerable proportion of carcasses from gilts are rejected due to the lack of cover fat depth. A total of 120 pigs [Duroc × (Landrace × Large White); initial average BW: 100.3 ± 2.5 kg] were used to investigate the effects of sex (barrows and gilts) and dietary total Lys restriction (7.0, 6.5, and 6.0 g•kg−1) on growth performance and carcass, meat, and fat characteristics. Pigs were intended for high-quality dry-cured ham from Spain (called Teruel ham), and a minimum fat thickness at the gluteus medius muscle (GM) is required (16 mm) for carcasses to be acceptable. Animals were slaughtered when they reached 129.0 ± 3.6 kg of BW. There were 6 treatments arranged factorially (2 sexes × 3 dietary Lys concentrations) and 4 replicates of 5 pigs per treatment.
Barrows consumed more feed (P = 0.001) and tended to have less G:F (P = 0.06) than gilts. Carcasses from barrows were fatter (P = 0.001) and had heavier main trimmed lean cuts (P = 0.008) than gilts. A greater proportion of final acceptable carcasses for Teruel ham (P = 0.001) was observed in barrows than in gilts because of the greater percentage of carcasses that fulfill the minimum fat depth at GM required (P = 0.001). Meat from barrows had greater content of intramuscular fat (P = 0.02) than meat from gilts. Also, subcutaneous fat from barrows had less proportion of PUFA than fat from gilts (P = 0.02). A reduction in dietary Lys concentration decreased ADG (P = 0.004) and ADFI (P = 0.001) in pigs. In addition, backfat depth (P = 0.007) and fat at GM (P = 0.07) increased as dietary Lys decreased. The proportion of carcasses that fulfilled the minimum fat depth at GM required for Teruel ham increased as dietary Lys decreased in feed, but this effect was greater in gilts than in barrows (sex × Lys, P = 0.02). Meat and fat quality was not influenced by dietary treatment. The restriction of dietary Lys from 7.0 to 6.0 g•kg−1 reduced ADG without any effect on G:F, and increased the carcass fat thickness and the proportion of acceptable carcasses in gilts intended for dry-cured ham production.
We conclude that different feeding programs with different dietary Lys concentrations may be needed for barrows and gilts intended for production of dry-cured hams where a minimum carcass fat depth is required.
JA Rodríguez-Sánchez, MA Sanz, M Blanco, MP Serrano,M Joy and MA Latorre, 2011. Journal of Animal Science, 89: 3651-3662. http://dx.doi.org/10.2527/jas.2010-3791