Effect of Grain Particle Size on Performance.

Abstract

Diets were prepared with corn, wheat, or sorghum ground in a hammer mill and sieved to obtain coarse, medium, and fine particle size fractions. Their effect on broiler performance from hatch to 7 d and from 7 to 21 d of age was studied. The effect of particle size on the size and pH of the gastrointestinal organs was also determined. The three textures obtained for each grain were uniform in geometric mean diameter (GMD) and geometric standard deviation (GSD). Grain by texture interactions were not significant. Independent of grain source, the best performance was obtained with diets prepared from the medium texture. In these diets, the GMD of the grains varied from 1.13 to 1.23 mm and the GSD from 1.19 to 1.35. The fine fraction (GMD .57 to .67 mm) resulted in the lowest performance and that resulting from the coarse fraction (GMD 2.01 to 2.10 mm) was intermediate. At 7 and 21 d of age, gizzard weight and content were positively related to particle size. At the age of 21 d, duodenum weight and content was highest in chicks fed the fine diets. The pH of the gizzard content decreased with increasing grain particle size, whereas that of the small intestinal content increased. Some grain effects were also observed on the gastrointestinal tract. Gizzard weight was greatest in the cornfed birds. Wheat-fed chicks had the heavier intestines and contents. After overnight feed deprivation, feed consumption by 7-d-old chicks was related to the particle size during the first 2 h of refeeding, with greater intake of medium and coarse grains.

Efeitos da forma física da ração e da linhagem de frangos de corte sobre a digestibilidade dos nutrientes e determinação de energia líquida

“…Esses valores de DGM estão dentro da faixa preconizada por Nir et al (1994b) et al (2004). O aumento dos valores de energia em torno de 1% pode estar relacionado com maior consumo e melhor digestibilidade de alguns nutrientes (Zelenka, 2003).…”

Efeitos do tamanho da partícula e da forma física da ração sobre o desempenho, rendimento de carcaça e peso dos órgãos digestivos de frangos de corte

“…A velocidade de passagem de partículas maiores é mais lenta do que a de partículas menores, e a das dietas peletizadas mais rápida do que a das fareladas (Nir et al, 1994). O menor tamanho das partículas não parece ter efeito negativo sobre o desempenho dos frangos, mesmo após serem transformadas em peletes (Nir et al, 1995).…”

Morphometric Features and Glycoconjugate Pattern of Rabbit Intestine are Affected by Particle Size of Pelleted Diets

“…The strong influence of feed structure over the physiological functions of the digestive tract has been observed in pigs (Brunsgaard, 1998;Kim et al, 2009) and broiler chickens (Engberg et al, 2002;Amerah et al, 2009;Jacobs et al, 2010). Smaller sized particles improve the performance in the broiler chickens (Nir et al, 1994a(Nir et al, ,b, 1995. The number of goblet cells increased with the passage from duodenum to distal colon in both experimental samples, fact that has already been demonstrated for other mammals Schumacher 1995b, 2001;Karam, 1999;Jacobs et al, 2009).…”