Location: Poultry Research2019 Annual Report
1. Identify optimum stocking densities and spatial allocation of feed and water resources for antibiotic free production of commercial broiler chickens. 1.1. Determine optimum stocking density for three classes of market weight broilers representing food service (2 kg), retail (3 kg), and further processing (4 kg). 1.2. Evaluate interaction of feeder and drinker space to define feed and water access requirements for heavy broiler chickens. 2. Assess energy and input resource requirements for environmental control strategies for modern broiler housing. 2.1. Evaluate interactions of fan placement and inlet design on energy and water use requirements. 2.2. Evaluate effect of light control techniques to provide enhanced photoperiod and intensity control on production efficiency in heavy broilers.
Birds and feed will be weighed at each feeding phase change; body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) will be calculated. On the final day of the trial, 10 male and 10 female birds per pen will be randomly selected for processing to obtain yield data. The sampled birds will be tagged, group weighed per pen and feed will be removed 12 h before birds will be transported to the Mississippi State University Poultry Processing plant. The birds will be electrically stunned, bled, scalded, and mechanically processed. Measurements will include carcass weight, dressing percentage, fat pad percentage, and pectoralis major and pectoralis minor breast meat yield. Foot pad examination will be performed on all processed birds per Olanrewaju et al. (2011). In addition, each carcass will be evaluated for skin defects (skin scratches, tears, and blisters).
Field measurements have indicated that tunnel ventilated broiler houses operating with wind speeds in excess of 500 ft/min exhibit an imbalance in face velocity through evaporative pads. Pad area and length are based upon a design face velocity of 350 ft/min; recent observations show that face velocity can vary five- to six-fold along the length of pad (100 to 600 ft/min). This imbalance creates a “dead” zone with very low air velocities at the start of the pad which can comprise up to 20% of the house area. Excessive speed at the trailing end of the pad reduces evaporative efficiency. The end result is overall reduced cooling efficiency and an over-reliance on air speed to compensate for inadequate evaporative cooling systems, increasing flock heat stress and all the attendant production declines.
Olanrewaju, H.A., Purswell, J.L., Collier, S.D., Branton, S.L. 2019. Effect of light intensity adjusted for species-specific spectral sensitivity on blood physiological variables of male broiler chickens. Poultry Science. 98(3):1090-1095. https://doi.org/10.3382/ps/pey487.
Olanrewaju, H.A., Collier, S.D., Purswell, J.L., Branton, S.L. 2019. Effects of light-sources and photoperiod on hemato-physiological indices of broilers grown to heavy weights. Poultry Science. 98(3):1075-1082.