The Lysine Requirement of the Growing Boar versus Barrow

Abstract

Five experiments were conducted to determine if boars and barrows differ in the level of dietary lysine required to maximize growth rate, efficiency of feed utilization, carcass leanness and N retention. In Exp. 1, 48 boars and 48 barrows were fed fortified corn-soybean meal diets calculated to contain 14 (grower) and 12% protein (finisher) and supplemented with 0, .15 or .30% lysine from 27 to 105 kg body weight. The basal diets analyzed .60 and .47% lysine, respectively. Linear improvements in feed/gain (P less than .01), backfat thickness (P less than .10), longissimus muscle area (P less than .01), and ham-loin (P less than .05) and lean cuts percentage (P less than .1) were observed in boars as dietary lysine increased. In barrows, however, growth rate, feed:gain ratio and carcass characteristics (except longissimus muscle area) were not significantly affected by dietary lysine level. In Exp. 2, 18 boars and 18 barrows initially averaging 64 kg body weight were fed a 12% protein diet (.47% lysine) supplemented with 0, .15 or .30% lysine. Linear (P less than .05) increases in N retention occurred in boars, but not barrows, as dietary lysine was increased. In Exp. 3 and 4, 140 boars (34 to 103 kg) were fed a 14-12% protein sequence (analyzed .61 and .48% lysine) supplemented with 0, .1, .2, .3 or .4% lysine. In Exp. 5, 60 boars (23 to 103 kg) were fed a 16-14% protein sequence (analyzed .83 and .68% lysine) supplemented with 0, .075, .15 or .225% lysine.(ABSTRACT TRUNCATED AT 250 WORDS)

Welfare of entire male pigs is improved by socialising piglets and keeping intact groups until slaughter

“…By keeping the sexes separated, at least half of the pigs are not influenced by the entire males' higher frequency of aggressive and sexual interactions. Furthermore, entire males and females have different nutritional requirements (Williams et al, 1984;Yen et al, 1986) and entire males have a better feed efficiency than the other sexes (Andersson et al, 1997). If reared separately, the feeding regime can be adopted for each sex and thus nutrient leakage from manure could be decreased because the full production capacity of entire males is used.…”

NAKED OATS (Avena nuda) WITH AND WITHOUT LYSINE SUPPLEMENTATION, FOR BOARS AND BARROWS: GROWTH, CARCASS AND MEAT QUALITY, ENERGY AND NITROGEN METABOLISM

“…Although meat quality (flavor, tenderness, juiciness) was improved by the inclusion of naked oats in the diet, carcass (Fortin et al 1983) and second, the greater need for, or the more sensitive response to protein (amino acid) supplementation of the diet by the boar than either the barrow or the gilt (Prescott and Lamming 1967;Fuller 1980;Williams et al 1984).…”

Lisina digestível para suínos machos não castrados de alto potencial genético em fase de crescimento

“…O melhor desempenho proporcionado pelo aumento da deposição proteica na carcaça dos machos não castrados é acompanhado do aumento da exigência de aminoácidos na dieta (WILLIAMS et al, 1984). Considerando suínos na mesma faixa de peso corporal, os machos castrados e as fêmeas exigem menores concentrações de lisina na dieta em relação aos machos não castrados (YEN et al, 1986), o que, em situações práticas, impossibilita o fornecimento das mesmas dietas para fêmeas, machos castrados e não castrados.…”

“…Além disso, considera-se que os níveis de lisina preconizados pela literatura estejam desatualizados, uma vez que os suínos contemporâneos, geneticamente selecionados para maior deposição proteica na carcaça, apresentam maiores exigências de lisina e dos demais aminoácidos para o máximo desempenho (GRANDHI & NYACHOTI, 2002). Entre os níveis propostos na literatura estão os de 0,86% de lisina total para suínos dos 25 aos 55kg (WILLIAMS et al, 1984); 0,87% de lisina total dos 25 aos 70kg (CASTAGNA et al, 1999); e 0,89% de lisina total dos 30 aos 60kg (DONZELE et al, 1994). Por sua vez, as tabelas brasileiras (ROSTAGNO et al, 2005) não apresentam informações quanto à exigência nutricional dos suínos machos não castrados.…”