Influence of feed texture and early quantitative feed restriction on performance, growth development and carcass composition of two broiler strains

Two multifactorial experiments (2 strains x 2 feeding schedules x mash/pellet), using in total 768 chickens, were conducted to evaluate the influence of feed texture on performance, growth development and carcass composition of quantitatively feed restricted broilers. The quantitative feed restriction started from d 4 until d 7 and consisted of a feed supply of 80% of the determined ad libitum intake of the previous 24 h. After the period of restriction, all birds were fed ad libitum. Both trials were conducted under a constant lighting schedule of 23 h light and 1 h dark. In both trials, and for both strains, restriction did not influence final body weight and feed conversion significantly, except for Ross 308 chickens fed mash diets in the first trial. On the other hand, using pellets instead of mash, zootechnical performances were significantly improved. Growth rate on pelleted feeds was 6 to 7% higher (P < 0.05) than on mash feeding. Total loss levels were variable and none of the effects were significant in either trial, although in trial 2 there was a tendency for a higher total loss due to feed texture especially with the Ross 308 strain (12.8 versus 3.6% for pellet and mash feeding, respectively). Feed restriction induced a global trend for a lower total loss. In general, feed restriction did not result in compensatory growth, however a different growth pattern could be observed due to feed texture. No consistent effects of feed restriction and feed texture on carcass composition were found. It can be concluded that many factors can play a role in the ability of the bird to realise a higher growth rate after early, temporary feed restrictions. The present experiment showed that feed texture plays an important role.