Relationships between digestibilities of food components and characteristics of wheats ( Triticum aestivum ) introduced as the only cereal source in a broiler chicken diet

Abstract

1. The aim of the experiment was to establish relationships between chemical or physical characteristics of wheats (Triticum aestivum) and digestibilities of food components in broiler chickens fed on wheat-based diets. Twenty-two wheat samples, each differing by their cultivar origin, were included at 550 g/kg in diets offered to male Ross broiler chicks. The other main ingredients were soya bean meal (340 g/kg) and rapeseed oil (68.5 g/kg). Diets were given as pellets. 2. In vitro viscosities of wheats measured as potential applied viscosity (PAV) or real applied viscosity (RAV) varied between 1.91 and 6.03, or between 0.95 and 3.81 ml/g (dry matter basis), respectively. Hardness of wheats varied between 17 (soft) and 95 (very hard), and lipase activity of wheats varied from 1 to 13.6 (relative scale). 3. PAV and RAV values were not significantly correlated with hardness. PAV and RAV values were correlated with (80:20) ethanol:water insoluble, water soluble arabinoxylans (r = 0.961, 0.932, respectively), with the amount of water retained by cell walls (r = 0.656, 0.492, respectively), and with lipase activity (r = 0.600, 0.532, respectively. 4. Hardness was correlated with ash (r = -0.484), nitrogen (r = 0.534), mean particle size of wheat flours (r = 0.631), and specific energy of pelleting (r = -0.574). 5. Wheat diets were evaluated in two assays with 3-week-old chicks, with 11 diets per assay. In each assay, a balance experiment was carried out using the total collection method. Growth performance was also measured during the balance experiment. 6. In vitro viscosity parameters were negatively correlated with diet AMEn (P < 0.05), lipid digestibility (P < 0.05) and, to a lesser extent, protein digestibility (P < 0.05). In vitro viscosity data were positively correlated with food:gain ratio (P < 0.05) and water loss parameters (P < 0.05), and were not significantly (P > 0.05) correlated with starch digestibility. 7. Wheat hardness-related parameters were correlated (P < 0.01) with individual starch digestibility (hardness, proportion of coarse particles in wheat flour, specific energy of pelleting: r = -0.273, -0.305, 0.212, respectively). 8. Wheat lipase activity was negatively correlated with individual lipid (r = -0.179; P < 0.05) and starch (r = -0.225; P < 0.01) digestibilities and with individual diet AMEn (r = -0.266; P < 0.001). Individual diet AMEn values were correlated (r = 0.175) with the values calculated by the EU AMEn prediction equation (Fisher and McNab, 1987). Among the correlations observed between the individual measured AMEn:EU predicted AMEn ratio and wheat parameters (P < 0.05), the correlation obtained with wheat lipase was the highest (r = -0.195). The correlations with lipase could be explained in part by strong correlations between lipase and in vitro viscosity parameters.

Comparison of gastrointestinal transit times between chickens from D+ and D− genetic lines selected for divergent digestion efficiency

“…However, nutritional conclusions with wheat were somewhat different because the level of viscosity was much lower with wheat than with barley or rye (Marquardt et al, 1994;Carré et al, 2002), with weak negative relationships between in vitro viscosity and nutritional value of wheat (Carré et al, 2002). Negative relationships were also found between particle size or hardness of wheat and starch digestibility in growing chickens (Carré et al, 2002 and2005a).…”

“…Negative relationships were also found between particle size or hardness of wheat and starch digestibility in growing chickens (Carré et al, 2002 and2005a). Besides this negative effect of coarse particles, it -E-mail: bernard.carre@tours.inra.fr was proposed that coarse particles could also be positive on digestion efficiencies in growing chickens because coarse particles might result in a larger gizzard and better control of gastric emptying with subsequent improved digestion efficiencies (Hetland et al, 2004).…”

“…These problems were mainly attributed to the high intestinal viscosity produced by watersoluble non-starch polysaccharides occurring in these cereals (Jensen et al, 1957;Murphy et al, 2009), resulting in negative effects on protein and lipid digestibilities (Choct and Annison, 1992;Carré et al, 2002), and increased intestinal retention time (Danicke et al, 1999). Therefore, enzyme feed additives were proposed to be used for alleviating viscosity problems in growing chickens (Marquardt et al, 1994).…”

Breeding for efficiency in the broiler chicken: A review

“…The digestive efficiency of a modern commercial production breed was shown to be lower than that of a high digestive efficiency line (Carré et al 2002(Carré et al , 2008Péron et al 2007), indicating that selection strategies have not led to the maximum potential digestive efficiency broilers are capable of. In both the experiments carried out by Carré et al (2002) and Péron et al (2007), broilers were placed on modern wheatbased diets.…”

“…In both the experiments carried out by Carré et al (2002) and Péron et al (2007), broilers were placed on modern wheatbased diets. When placed on similarly soft wheat grain-based diets (Sideral and Sciphon wheat, respectively), the commercially breed showed moderate digestive efficiencies of protein, starch and lipid when compared with the lines specifically selected for high and low digestion efficiencies.…”