Tissue weights and body composition of two genetic lines of barrows and gilts from twenty to one hundred twenty-five kilograms of body weight1,2

Abstract

Barrows and gilts of 2 genetic lines with differing lean gain potentials (high-lean = 375 g of fat-free lean/d; low-lean = 280 g of fat-free lean/d) were used to determine tissue and organ weights and compositions from 20 to 125 kg of BW. The experiment was a 2 (genetic line) x 2 (sex) x 5 (BW) factorial arrangement of treatments in a completely randomized design conducted with 2 groups of pigs in 6 replicates (n = 120 pigs). Six pigs from each sex and genetic line were slaughtered at 20 kg of BW and at 25 kg of BW intervals to 125 kg of BW. At slaughter, the internal tissues and organs were weighed. Loin and ham muscles were dissected from the carcass and trimmed of skin and external fat, and the ham was deboned. Residuals from the loin and ham were combined with the remaining carcass. Body components were ground, and their compositions were determined. The results demonstrated that tissue weights increased (P < 0.01) as BW increased. Loin and ham muscle weights increased but at a greater rate in the high-lean line and in gilts resulting in genetic line x BW and sex x BW interactions (P < 0.01). Liver and heart expressed on a BW or a percentage of empty BW basis increased at a greater rate in the high-lean line resulting in a genetic line x BW interaction (P < 0.01). Liver and intestinal tract weights were heavier in barrows than in gilts, significant only at 45 (P < 0.05), 75 (P < 0.01), and 100 (P < 0.05) kg of BW. Loin and ham muscles from the high-lean genetic line and gilts had greater (P < 0.01) water, protein, and ash contents compared with the low-lean genetic line and barrows resulting in genetic line x BW and sex x BW interactions (P < 0.01). The remaining carcass (minus loin and ham muscles) had greater (P < 0.01) amounts of water and protein, and less (P < 0.01) fat in the high-lean genetic line and gilts. The high-lean genetic line and gilts had more total body water, protein, and ash, but less body fat, with these differences diverging as BW increased, resulting in a genetic line x BW interaction (P < 0.01). The results indicated that liver and heart weights were greater in high-lean pigs, reflecting the greater amino acid metabolism, whereas the liver and intestinal tract weights were greater in barrow than gilts, reflecting their greater feed intakes and metabolism of total nutrients consumed.

Níveis de fósforo disponível em dietas para suínos dos 15 aos 30kg

“…Ganho de peso diário de suínos dos 15 aos 30kg, segundo a concentração de fósforo disponível na dieta. Apesar do padrão de resposta similar para GPD, as diferenças verificadas entre os trabalhos quanto aos níveis de Pd recomendados que proporcionaram os melhores resultados divergem entre os estudos em razão do potencial genético dos suínos para deposição de tecido muscular (Mahan, 2006;Wiseman et al, 2007 Considerando o aumento linear no CRD dos animais no presente estudo, a melhora verificada na CA permite inferir que, além do aumento no GPD até o nível de 0,450% de Pd, o aumento da concentração de Pd na dieta pode ter modificado a composição do ganho de peso, favorecendo a maior deposição muscular e a menor deposição de gordura nos animais alimentados com as dietas contendo as maiores concentrações de Pd. Segundo Stahly et al (2001), dietas deficientes em Pd, além de comprometerem o ganho de peso e a eficiência alimentar dos suínos, podem resultar em maior conteúdo de gordura corporal, influenciando de forma negativa a relação entre a deposição de proteína e de gordura na carcaça.…”

Available phosphorus levels in diets for swine from 15 to 30 kg genetically selected for meat deposition

“…This fact is probably associated, among other factors, to the possible genetic difference of animals in relation to the meat deposition potential. Assessing the total content of minerals in loin and ham of pigs from two distinct genotypes, Wiseman et al (2007) observed that the calcium and phosphorus concentrations were higher in strains with higher meat deposition potential. These results show that the phosphorus requirements may vary according to the potential of pigs for growing of lean tissue.…”

Feasibility of Increasing the Slaughter Weight of Finishing Pigs

“…The protein content of the loin and ham is sometimes slightly greater in gilts than in barrows; at other times, however, it does not differ between the two sexes (Latorre et al, 2004;Wiseman et al, 2007;Park et al, 2009a,b; Table 7). Muscular protein content usually is not affected significantly by SW within a given genotype (Unruh et al, 1996;Latorre et al, 2004); however, the protein content in the loin sometimes increases with increasing SW in lean-type pigs (Piao et al, 2004; Table 7).…”

“…Moreover, Wiseman et al (2007) and Schinckel et al (2008) have reported that muscles of a high-lean genetic line (375 gm fat-free lean gain/day) had greater growth rates and greater contents of protein and moisture, lesser daily fat gain, and lesser fat content than those of a low-lean genetic line (280 gm fat-free lean gain/day). In the studies of the present author's team, the fat content of the ham was not influenced by sex or SW (Park et al, 2009a,b), whereas the composition of fatty acids of the loin was not consistent [Lee et al, 2006;Park et al, 2007;Park et al, 2009a,b (unreported therein)].…”