Effect of Particle Size on Performance.

Abstract

Three experiments were conducted to study the effect of particle size obtained by grinding wheat and sorghum in a hammer mill (HM) or roller mill (RM) on broiler performance. Broilers were fed a mash diet or crumbles to 4 wk of age, then pellets to 7 wk of age. When fed as a mash, diets produced with RM-ground grain improved performance. The effect of grinding was additive to that of pelleting. The interactive effects observed between grinding method and the form of the feed on body weight and feed intake were explained by the higher response to pelleting when grains were ground in HM vs RM. The positive effect of grinding in RM on feed utilization was found to be additive to that of pelleting in all three experiments. The response of females to feed texture was less pronounced than that of males. In males, feeding pellets vs mash increased mortality due to ascites threefold, whereas grinding method had no effect. Females were less susceptible to ascites than males, and feed texture had no effect in this respect. The effects of grinding and pelleting on the gastrointestinal tract segments were additive. The main effects of feed texture were a significant increase in stomach weight and that of its contents following HM grinding and a decrease in these following pelleting, with no interactions between the two.

Effect of phytase with or without multienzyme supplementation on performance and nutrient digestibility of young broiler chicks fed mash or crumble diets

“…This coincided with the greater digestibility of EE (9.5%) and CF (23.4%), and resulted in a higher production index (27.5%). These results are similar to those reported by Nir et al (1995), Engberg et al (2002), Svihus et al (2004) and Cutlip et al (2008). These improvements have been variously attributed to increased nutritional density, increased nutrient intake, changes in the physical form of the feed, reduced feed wastage, decreased energy expenditure while eating (McKinney and Teeter, 2004;Skinner-Noble et al, 2005;Amerah et al, 2007;Cerrate et al, 2009;Yang et al, 2010), increased starch digestibility (Parsons et al, 2006), and improved apparent metabolisable energy (AME) and nutrient retention (Svihus et al, 2004;Adeyemi et al, 2008) mechanical action resulted in a rupture of the cell walls and thus made encapsulated nutrients of the feedstuff more accessible to digestive enzymes (Vande and Schrijver, 1988;Cutlip et al, 2008).…”

Effects of sorghum on broilers gastrointestinal tract

“…Those authors did not observe any influence of feed physical form on cecum weight. Although Dahlke et al (2003) and Nir et al (1995) demonstrated that dietary particle size affects intestinal weight and size, Garcia et al (2005), did not observe any effect of the substitution of corn by sorghum on intestinal relative weight, which is consistent with the findings of the present study.…”

Influência da forma física da ração e da linhagem sobre o desempenho e rendimento de cortes de frangos de corte

“…Essa maior precocidade da linhagem Cobb, somada ao grande consumo das rações peletizadas, pode aumentar a necessidade de oxigênio com conseqüente aumento da incidência de doenças metabólicas. Estes resultados foram semelhantes aos observados por Nir et al (1995) e Leeson et al (1999) Bertechini et al (1991b), Murakami et al (1995) e Stringhini et al (2003. Meinerz et al (2001) Com relação à linhagem é importante ressaltar semelhanças em relação às principais variáveis de desempenho (consumo e conversão alimentar) e rendimento de cortes nobres (peito e coxas + sobrecoxas), com exceção do ganho de peso, em que as aves da linhagem Cobb, alimentadas com ração peletizada, obtiveram maiores ganhos; e da viabilidade, em que as aves da linhagem Cobb, também alimentadas com rações peletizadas, apresentaram maior susceptibilidade às doenças metabólicas (ascite e morte súbita).…”