Effect of wheat inclusion and xylanase supplementation on duodenal enzyme activity, nutrient retention, and egg production in egg white laying hens from 25 to 33 wks of age | Efectos de la inclusión de trigo y suplementación con xilanasas del pienso sobre la actividad enzimática intestinal, la retención de los nutrientes y la productividad en gallinas de 25 a 33 semanas de edad
2011
Mirzaie, S., Universidad de Teheran, Karaj (Irán). Dept. de Ciencia Animal | Zaghari, M., Universidad de Teheran, Karaj (Irán). Dept. de Ciencia Animal | Aminzadeh, S., Universidad de Teheran, Karaj (Irán). Dept. de Ciencia Animal | Serrano, M.P., Universidad Politécnica de Madrid (España). Dept. de Producción Animal | Hivazad, M., Universidad de Teheran, Karaj (Irán). Dept. de Ciencia Animal | Mateos, G.G., Universidad Politécnica de Madrid (España). Dept. de Producción Animal
A trial was conducted to examine the effects of increasing levels of wheat in the diet and the supplementation of the diet with a xylanase (ES) on N and ether extract retention, pH of the GIT, productive performance, and endogenous enzyme activity at the duodenum. The basal diet consisted on soybean meal and corn and the wheat was introduced at expenses of corn (Table 1). The experiment was completely randomized with 8 treatments arranged factorially with 4 levels of wheat (0, 23, 46, and 69% that corresponded to a xylans content of the diet of 1.8, 2.0, 2.2, and 2.4 g/100 g, respectively) and two levels of xylanase supplementation (none or added) as recommended by the supplier (Tricoderma langibrachiatum; Marquette, Barceul, France). Each treatment was replicated 5 times and the experimental unit was a cage with 6 hens. The inclusion of wheat in the diet did not influence feed intake, egg production or weight gain of the hens but decreased (P < 0.05) egg weight and egg mass, and impaired FCR (Table 2). The ES improved egg mass and BW gain (P < 0.05) but did not affect feed intake, egg weight, feed efficiency or BW gain. Also, the inclusion of wheat in the diet decreased (P < 0.001) fat retention at 33 wks of age but did not influence N retention. The ES improved (P < 0.05) fat retention but did not affect that of N. The inclusion of wheat in the diet increased amylase (P < 0.01) and lipase (P < 0.01) activities in the duodenum but did not affect aminopeptidase activity. The ES did not influence any enzyme activity. Diet did not affect the pH of any of the segments of the GIT. It is concluded that wheat with a high NSP content supplemented with xilanases, could be used in diets for laying hens at levels of 69% until the peak of egg production without jeopardizing productivity or duodenum enzyme activity. However, the level of linoleic acid has to be taken into account when wheat is included in the diet in substitution of corn to avoid a reduction in egg weight.
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