Alpha-amylase supplementation of broiler diets based on corn

Abstract

A 42-d trial was conducted to study the influence of exogenous alpha-amylase on digestive and performance traits in broilers fed a corn-soybean meal diet. There were two treatments (control and alpha-amylase supplemented diet) and six replicates (14 Cobb male chicks caged together) per treatment. At 7 d of age, alpha-amylase supplementation improved daily gain by 9.4% (P < or = 0.05) and feed conversion by 4.2% (P < or = 0.01). At the end of the trial, birds fed the alpha-amylase-supplemented diet ate more and grew faster (P < or = 0.05) and hadbetter feed conversion (P < or = 0.10) than broilers fed the control diet. Also, alpha-amylase supplementation improved apparent fecal digestibility of organic matter and starch (P < or = 0.01) and AMEn of the diet (P < or = 0.001). However, no effects were detected for CP or fat digestibility. Nutrient digestibility and AMEn of the diet increased with age (P < or = 0.001); however, no interactions of alpha-amylase x age were observed for any trait. Coefficients of apparent ileal and fecal digestibility of starch at 28 d of age were similar, which indicated that most of the undigested starch was not fermented in the hindgut of the chick. alpha-Amylase supplementation reduced relative pancreas weight (P < or = 0.001) but did not affect the weight of the remaining organs. Age consistently reduced intestinal viscosity and relative weights of all the organs (P < or = 0.001). The data indicated that alpha-amylase supplementation of a corn-soybean meal diet improved digestibility of nutrients and performance of broilers.

The nutritive value of maize cultivars for broiler chickens

“…In other studies, a slightly higher viscosity of jejunal digesta of 21-day-old broilers receiving a diet with about 60% maize grain was reported (Gonzàlez-Alvarado et al, 2007). A similar pH level to that in our study was determined in 22-day-old broiler chickens receiving a diet with about 50% maize grain by Gracia et al (2003), while almost twice lower values were obtained by Gonzàlez-Alvarado et al (2007). The results of our study showed that differences in the composition of maize cultivars had no influence on the development of the gastrointestinal tract.…”

“…Nonetheless, the significant negative correlation between IDF, amino acid digestibility, and AME N values suggest the antinutritional potency of the maize IDF fraction, possibly by a cage effect. Due to supplementation of the maize-based diets with different enzymes (xylanase, α-galactosidase, β-mannanase, pectinase, α-amylase), an improvement of broiler performance was reported (Gracia et al 2003;Cowieson, 2005). It can be attributed to release of the cage effect as well as to increased degradation of the cell walls and greater utilization of hexoses and pentoses from the small intestine.…”

Avaliação de complexo enzimático e betaína natural em rações para frangos de corte criados em aviário comercial

“…Entretanto, em outro estudo com frangos de corte sob suplementação com enzima amilase, foram observados maior ganho diário de peso (P<0,05) e melhor conversão alimentar (P<0,05) (Gracia et al, 2003).…”

The effect of particle size of full-fat rapeseed and of multi-carbohydrase enzyme supplementation on nutrient digestibility and performance in broilers

“…Nevertheless, performance parameters were positively affected during the first 14 days of life as well as during the entire experiment. Some authors (Mahagna et al, 1995;Gracia et al, 2003;Cowieson et al, 2004) suggested that the use of exogenous enzymes could improve bird performance via limiting endogenous amino acid loss. Cowieson et al (2004) suggest that endogenous losses decrease by enzymatic degradation of antinutritional factors.…”

“…Cowieson et al (2004) suggest that endogenous losses decrease by enzymatic degradation of antinutritional factors. Mahagna et al (1995) and Gracia et al (2003) proposed that exogenous amylase and protease may supplement endogenous production of enzymes. The above hypotheses seem to be supported by the better nitrogen retention after enzyme supplementation on day 14, as recorded in the present experiment.…”