Effect of beak trimming at hatch and oat hulls inclusion in the diet on growth performance, preference behaviour for coarse particles and gastrointestinal tract traits of brown-egg pullets from 1-35 days of age

The effects of infra-red beak treatment (IRBT) at hatch and the inclusion of oat hulls (OH) in the diet on growth performance, water intake (WI), preference behaviour for coarse particles and the development of the gastrointestinal tract (GIT), was studied in brown-egg pullets from 1 to 35 days of age. The experimental design was completely randomized with 4 treatments arranged as a 2 x 2 factorial with beak treatment (IRBT vs. sham) and OH inclusion (0 vs. 30 g/kg diet) as main effects. Each treatment was replicated 20 times and the experimental unit was a cage with 10 pullets. Growth performance and water intake were determined by week and cumulatively. Preference behaviour for coarse particles and the development of selected organs of the GIT, were determined at 28 and 35 days of age, respectively. No interactions between IRBT and OH inclusion were detected for any of the traits studied at any age, and therefore, only main effects are discussed. Cumulatively (1-35 days of age), IRBT increased mortality (P<0.01) and reduced feed consumption (P<0.001), body weight (BW) gain (P < 0.01) and water intake (P < 0.001), but improved feed conversion (P < 0.001) of the pullets. Oat hulls inclusion did not affect BW gain, BW uniformity or energy conversion ratio, but reduced pullet mortality (P = 0.099) and water to feed ratio (P < 0.05). The interactions detected between age and IRBT on pullet performance were numerous. From 1-21 days of age, BW gain was better for the sham than for the IRBT pullets but an opposite effect was observed from 29 to 35 days of age (P < 0.01). Similarly, from 1 to 28 days of age, BW uniformity and WI were higher for the sham than for the IRBT pullets but no differences were detected from 29 to 35 days of age. Preference behaviour for coarse particles, measured at 28 days of age, was greater for the sham than for the IRBT pullets (P < 0.001). In summary, infra-red beak treatment increased mortality from 1 to 7 days of age and reduced pullet performance from 1 to 28 days of age but not thereafter. Young pullets show a clear preference to consume coarse particles. Oat hulls inclusion increased feed intake and decreased mortality and water to feed ratio of the pullets but did not affect energy efficiency or the development of the gastrointestinal tract.