Responses of fast and slow growth broilers fed all vegetable diets with variable ideal protein profiles

Abstract

-One thousand eight hundred and ninety male broilers of two strain crosses (fast and slow initial growth) were fed different ideal protein profiles in four-phase feed programs: 1 to 7, 8 to 21, 22 to 34 and 35 to 40 days of age. All vegetable, corn-soybean meal feeds were formulated to maintain the Met+Cys:Lys and Thr:Lys relationships at 75 and 65%, respectively, on true digestible basis. Three ideal protein profiles were used: low, medium and high. From 1 to 21 days of age, half of the birds fed low and high diets were changed to high and low diets, respectively. Birds on the medium diet were kept on the same diet until the end of the study. A 3 × 2 (ideal protein profile x strain cross) factorial design was used for the period from 1 to 21 days and a 5 × 2 design thereafter. Carcass and commercial cuts were performed at 34 and 40 days of age to determine corresponding live weight and carcass yields. In general, the fast strain growth was superior in comparison to the low one when live performance and carcass and commercial cuts were evaluated. Live performance was positively affected by the increases in the dietary protein profiles; however, processing yield parameters could not be related with the dietary parameters. The low diets, which have similar protein contents to those used in some integrations, were shown to produce poor responses and, therefore are not recommended for broilers from 1 to 40 days of age. Alternating low and high ideal protein profiles at 21 days could result in similar feed conversions, and therefore, can lead to production cost reduction.

Effect of different bedding materials on growth performance, physiological response and economic efficiency in three commercial broiler strains

“…Bedding material that had the highest moisture holding capacity provided dry conditions for longer periods of time thus promoting feed intake and body weight gains. Coneglian et al (2010) reported parallel results when rearing the broiler birds of different strains on the ground corn cob. In interaction, Cobb-500 strain showed the highest weight gain on rice husk while the lowest weight gain was observed in Ross-308 on corn pulp might signal towards the fact that wet litter conditions increased volatilization of ammonia from the litter (Nagraj, 2007).…”

Effect of different dietary concentrations of Amino Acids on the performance of two different Broiler Strains

“…Cobb 500 broilers fed alternated diets with different AA concentrations (Low-High-High and MediumHigh-High) from 1 to 14, 15 to 28 and 29 to 42 days of age, showed the same FI and BWG at 42 d than those fed High-High-High AA concentrations (Corzo et al, 2010). In a similar study, broiler performance was evaluated by feeding three protein profiles, including Medium (similar to those used in the Brazilian industry), High (15% higher) and Low (15% lower), from 1 to 21 and 22 to 42 days (Coneglian et al, 2010). Body weight was similar between Low-High and High-Low programs.…”

“…These results contradict previous findings that showed that broilers fed diets containing higher AA concentrations had higher carcass (Nasr, 2011) and breast (Corzo et al, 2010) yields. However, other studies did not observe any influence on carcass yields when dietary CP was reduced (Coneglian et al, 2010;Khan et al, 2011). The same effect was observed when increasing Lys levels were offered (Si et al, 2001).…”

Dietary Green Seaweed Compromises Overall Feed Conversion Efficiency but not Blood Parameters and Meat Quality and Stability in Broiler Chickens

“…The Cobb 500 broiler is a modern commercial chicken hybrid known for high feed efficiency, fast growth rates and competitive breast meat yields at various processing stages when compared to other commercial hybrids currently produced around the world [1]. Under intensive poultry production systems, feed costs contribute close to 70% of the total production cost, which is due to increases in global feed prices.…”