title: Effect of sequential feeding on nitrogen excretion, productivity, and meat quality of broiler chickens.
abstract: The aim of this trial was to investigate the effect of a 24-h cycle sequential feeding program on nitrogen excretion, incidence of foot pad lesions, productive performance, quality traits, and chemical composition of broiler chicken breast meat. In total, 1,320 one-day-old male Cobb 700 chicks were split into 2 groups of 6 replicates each. From 1 to 10 d of age, all of the chickens received the same prestarter diet (ME 3,058 kcal/kg; CP 226 g/kg). The control group (CON) received 1 of 3 diets for 24-h cycles: starter (ME 3,162 kcal/kg; CP 205 g/kg), grower (ME 3,224 kcal/kg; CP 192 g/kg), and finisher diets (ME 3,242 kcal/kg; CP 184 g/kg) from d 11 to 18, 19 to 38, and 39 to 44 of age, respectively. The sequential feeding group (SF) received the same diets as the CON birds for half of the day, and then low-protein and isoenergetic diets for the remaining half of the day. Birds submitted to the SF program showed better utilization of dietary nitrogen compared with the CON birds (45.0 vs. 46.1% of N excreted/N ingested, respectively; P < 0.05), and consequently the SF birds had lower nitrogen excretion compared with the CON birds (24.8 vs. 25.9 N g/kg of BW, respectively; P < 0.01). The SF birds exhibited a significantly lower incidence (7 vs. 13%) of foot pad lesions and consumed 70 g of feed/bird more than the CON birds. The SF birds also had a significantly higher feed conversion rate compared with that of the CON birds (1.84 vs. 1.78, respectively). The SF breast meat exhibited a significantly lower ultimate pH, a higher cook loss, and a lower lipid content compared with the values found for the CON group. The SF approach in poultry husbandry had positive repercussions on environmental and animal welfare aspects, but adversely affected feed efficiency, and altered some meat traits (mainly pH and cook loss).
authors.affiliation: Department of Food Science, University of Bologna, Ozzano dell'Emilia, Italy. federico.sirri@unibo.it
authors.forename: F
authors.initials: F
authors.lastname: Sirri
authors.forename: A
authors.initials: A
authors.lastname: Meluzzi
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000254:growth & development; D004032:Diet / Q000662:veterinary*; D008297:Male; D008460:Meat / Q000592:standards*; D009584:Nitrogen / Q000378:metabolism*; D015430:Weight Gain
chemical_list: D009584:Nitrogen