Feed currently constitutes 60 to 65% of the total cost of broiler production. Pellets are the primary feed form for commercially reared broilers. Understanding how to optimize pellet quality through precision thermo-mechanical processing may impact broiler performance and nutrient availability, and thus cost of production. Steam conditioning represents a manipulable thermo-mechanical processing variable. Corn-soybean meal-based diets were conditioned with 1 of 4 steam pressure × temperature combinations: 138 kPa at 82.2°C, 138 kPa at 93.3°C, 552 kPa at 82.2°C, or 552 kPa at 93.3°C. High steam pressure and temperature conditioning were shown to increase pellet quality. Three additional diets were prepared: unprocessed mash, the 552 kPa/93.3°C diet reground to mash, and a 50:50 combination of pellets and mash produced from the 552 kPa/93.3°C treatment to simulate a high fine percentage diet. All diets were fed to Cobb 500 broilers from 21 to 38 d, and nutrient availability was determined with Single Comb White Leghorn roosters. Broilers fed pellets conditioned with high steam temperature demonstrated decreased feed intake and feed conversion ratio. Amino acid and energy availability were not affected by variations in steam conditioning.

The Effect of Steam-Conditioning Practices on Pellet Quality and Growing Broiler Nutritional Value

The Effects of Feed Form, Grinding Method, Energy Level, and Gender on Broiler Performance in a Moderate (21 C) Environment

An experiment was conducted to evaluate the effects of feed form on lysine and dietary energy levels necessary for maximum body weight gain (BWG) and feed efficiency (FE) of male broilers from 14 to 30 d and to determine if birds realize a benefit in productive energy from consuming pelleted diets. A 2 x 3 x 2 factoria l treatment arrangement was achieved by feeding diets in two forms (mash and steam- conditioned pellets) with three levels of digestible lysine (0.85, 0.95 and 1.05 % of the diet) and two dietary energy levels (3050 and 3200 kcal ME/kg). Male broiler chicks were provided a nutritionally adequate diet (3100 kcal ME/kg and 22.7% CP) from 0-13 d. Four pens of 32 birds were fed each dietary treatment. Mean body weight and feed consumption were obtained at 14 and 30 d. Average feed intake (AFI) was used to calculate lysine conversion ratio and calories consumed per bird. Pellet-fed birds consumed significantly less digestible lysine (P=0.0061) to achieve the same amount of BWG as the mash-fed birds. Pellet-fed birds exhibited a linear increase in BWG (P=0.0188) with increasing lysine concentrations, while mash-fed birds did not display a growth response at digestible lysine levels greater than 0.85%. Birds fed 3200 kcal ME/kg diets had greater BWG (P=0.006) than those fed 3050 kcal diets. No feed form x dietary energy level interaction was observed for any parameter. Feed form had no effect on AFI (P=0.3784). These findings suggest that improved BWG obtained with pelleted diets may be the result of reduced energy expenditure during meal consumption, indicating that feed form may influence perceived nutrient needs.

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Influence of Feed Form on Dietary Lysine and Energy Intake and Utilization of Broilers from 14 to 30 Days of Age

The Effects of Feed Form, Protein Profile, Energy Level, and Gender on Broiler Performance in Warm (26.7 C) Environments

SUMMARY An experiment was conducted to determine if pelleting diets affected estimated digestible lysine needs for body weight gain (BWG) and feed efficiency (FE) of male broilers from 16 to 30 d. A 2 × 5 factorial treatment arrangement was achieved by feeding diets in 2 forms (mash and steamconditioned pellets) with 5 levels of digestible lysine (0.75, 0.85, 0.95, 1.05, and 1.15% of the diet). Six pens of 25 male broilers were fed each dietary treatment. Performance of birds fed pelleted diets with digestible dietary lysine levels above 0.95% was generally superior to that of birds fed mash diets, regardless of lysine level. Weight gain and FE data were fitted to an exponential model, and digestible lysine needs were estimated at 95% of the asymptote of the model. Dietary digestible lysine needs of mash-fed birds from 16 to 30 d for BWG and FE were 0.87 and 0.90%, respectively. Dietary digestible lysine needs for pellet-fed birds for BWG and FE were 1.00 and 0.99%, respectively. These data suggest that feed form is a factor influencing estimated lysine needs of broilers in dose-response studies.

J. L. Sell

Papers

The Influence of Method of Crumbling Diets Containing Different Levels of Protein and Lysine on Chick Performance