Body composition and protein and fat accretion in various body components in growing gilts fed diets with different protein levels but estimated to contain similar levels of ideal protein.

Abstract

A comparative slaughter technique was used to determine the effect of dietary protein levels on body composition and protein and fat accretion in various body components in Yorkshire gilts. Diets were formulated to contain similar levels of idea protein. Eight gilts were slaughtered at 20 kg BW to determine initial body composition. Twenty-four gilts were assigned to each of three dietary treatments (16.6, 15.0 and 13.0% CP) during the growing period (20 to 55 kg BW). During the finishing period (55 to 100 kg BW), dietary CP levels were reduced by approximately two percentage units. Eight gilts per treatment were slaughtered at 55 kg BW, and the remaining pigs were slaughtered at 100 kg BW. At slaughter, the pits were divided into three components: carcass, empty gastrointestinal tract, and other non-carcass parts. Half of the carcass was further dissected into retail cuts. None of the carcass retail cuts was affected (P > .10) by the dietary CP levels, except trimmed ham was smaller (P < .05) in gilts fed the 13% CP growing and 11% CP finishing diets. Far content in the empty body (P = .12) and in the carcass (P = .06) was highest and the empty body water accretion rate was lowest (P = .05) in gilts fed the 13% CP growing and 11% CP finishing diets. Other aspects of chemical body composition, protein and fat accretion rates, and estimated lean yields were not affected by dietary CP level (P > .10).

Desempenho e composição corporal de suínos alimentados com rações com baixos teores de proteína bruta

“…Quando o teste F da análise de variância foi significativo para o efeito de tratamento, a diferença entre tratamentos foi avaliada pelo teste t múltiplo, tendo-se utilizado a opção LSD do SAS (Saville, 1990;Tuitoek et al, 1997;Le Bellego et al, 2001). O peso de abate foi usado como covariável nas variáveis: retenção de proteína e lipídeos.…”

“…O valor médio encontrado neste experimento foi de aproximadamente 15,5%, muito semelhante aos valores médios da literatura (Tuitoek et al, 1997;Le Bellego & Noblet, 2002;Kerr et al, 2003). Na maior parte dos trabalhos consultados, verifica-se que o consumo de proteína não altera a concentração protéica da carcaça (Tuitoek et al, 1997;Gómez et al, 2002;Le Bellego & Noblet, 2002), embora haja exceções (Kerr et al, 2003).…”

“…Por meio da análise dos resultados de vários estudos, pode-se afirmar que dietas com baixa proteína reduzem o nitrogênio excretado e podem propiciar retenção de nitrogênio similar à obtida com ração convencional, desde que os aminoácidos essenciais sejam suplementados, para evitar deficiências nutricionais Kerr et al, 2003). Contudo, em muitos dos experimentos realizados para testar rações com baixos teores de proteína bruta, o menor nível protéico avaliado esteve próximo de 14% (Gatel & Grosjean, 1992;Tuitoek et al, 1997). É possível que isso ocorra, porque a redução acentuada da concentração protéica implica na necessidade de inclusão de outros aminoácidos sintéticos além da lisina, treonina, metionina e triptofano, como por exemplo a valina e a isoleucina (Le Bellego & Noblet, 2002).…”

Comparison of total tract digestibility and nitrogen balance between Cinta Senese and Large White pigs fed on different levels of dietary crude protein

“…The researches were carried out on pigs belonging to improved breeds modulating the quantitative and qualitative content of dietary protein and aimed at verifying growth and carcass performances (Tuitoek et al, 1997;Chen et al, 1999;Kerr et al, 2003), at studying ileal digestibility In bold the periods of digestibility trial. a Preceded by a 7-day period on floor for adaptation to diet.…”

Performance and carcass characteristics of swine at 50 kg fed diets with different energy levels and reduced levels of crude protein

“…Thus, part of the liquid energy that could be used in this process is used for lipid synthesis, which is deposited in the form of fat that can reduce the quality of the animal carcass, and consequently the efficiency of the utilization of lysine for weight gain (LE BELLEGO et al, 2001;TUITOEK et al, 1997). On the other hand, there have reports that these amino acids can reach the sites of protein synthesis in the cells faster (BATTERHAN & BAYLEY, 1989), and that they can interfere with animal growth due to the relative amounts present in the diets of animals or the energy required for their metabolism.…”