Performance of Broiler Chickens Fed Low Protein, Limiting Amino Acid Supplemented Diets Formulated Either on Total or Standardized Ileal Digestible Amino Acid Basis.

The aim of present experiment was to investigate the effect of protein reduction in commercial broiler chicken rations with incorporation of de-oiled rice bran (DORB) and supplementation of limiting amino acids (valine, isoleucine, and/or tryptophan) with ration formulation either on total amino acid (TAA) or standardized ileal digestible amino acids (SIDAA). The experimental design consisted of T1, TAA control; T2 and T3, 0.75% and 1.5% protein reduction by 3% and 6% DORB incorporation, respectively by replacing soybean meal with supplemental limiting amino acids to meet TAA requirement; T4, SIDAA control, T5 and T6, 0.75% and 1.5% protein reduction by DORB incorporation (3% and 6%) with supplemental limiting amino acids on SIDAA basis. A total of 360 d-old fast growing broiler chicks (Vencobb-400) were divided into 36 homogenous groups of ten chicks each, and six dietary treatments described were allocated randomly with six replications. During 42 days trial, the feed intake was significantly (p<0.05) reduced by TAA factor compared to SIDAA factor and protein factor significantly (p<0.05) reduced the feed intake at 1.5% reduction compared to normal protein group. This was observed only during pre-starter phase but not thereafter. The cumulative body weight gain (BWG) was significantly (p<0.05) reduced in TAA formulations with protein step-down of 1.5% (T3, 1,993 g) compared to control (T1, 2,067 g), while under SIDAA formulations, BWG was not affected with protein reduction of 1.5% (T6, 2,076 g) compared to T4 (2,129 g). The feed conversion ratio (FCR) was significantly (p<0.05) reduced in both TAA and SIDAA formulations with 1.5% protein step-down (T3, 1.741; T6, 1.704) compared to respective controls (T1, 1.696; T4, 1.663). The SIDAA formulation revealed significantly (p<0.05) higher BWG (2,095 g) and better FCR (1.684) compared to TAA formulation (2,028 g; 1.721). Intake of crude protein and all limiting amino acids (SID basis) was higher in SIDAA group than TAA group with resultant higher nitrogen retention (4.438 vs 4.027 g/bird/d). The nitrogen excretion was minimized with 1.5% protein reduction (1.608 g/bird) compared to normal protein group (1.794 g/bird). The serum uric acid concentration was significantly reduced in T3 (9.45 mg/dL) as compared to T4 (10.75 mg/dL). All carcass parameters were significantly (p<0.05) higher in SIDAA formulation over TAA formulation and 1.5% protein reduction significantly reduced carcass, breast and thigh yields. In conclusion, the dietary protein can be reduced by 0.75% with TAA formulation and 1.5% with SIDAA formulation through DORB incorporation and supplementation of limiting amino acids and among formulations, SIDAA formulation was better than TAA formulation.

Egg shell and yolk quality characteristics of layers fed with sugarcane press residue in soya and fish based diets.

AIM: Sugarcane press residue (SPR), a by-product of sugarcane industry, which is rich in inorganic salts was assessed at different levels in both soya based and fish based diets of layers for egg shell and yolk quality characteristics. MATERIALS AND METHODS: SPR was incorporated in 32-week-old white leghorn layer diets at 0%, 5%, 10% and 15% either in the soya based or fish based diets to form T1 to T8 diets, respectively. Each diet was offered to five replicates of four laying hens each constituting a total of one sixty birds kept for 84 days under colony cages. RESULTS: Mean egg shell thickness obtained from eggs of experimental hens measured was 0.342, 0.329, 0.320, 0.322, 0.319, 0.332, 0.328 and 0.336 mm in T1 through T8 groups, respectively. About the main factor effects, both showed non-significant results. Similarly, influence of different treatment diets, in imparting colour to the yolks, was found to be non-significant (p>0.05) at different 28-day time intervals. Further, the average yolk index values ranged non-significantly from 0.360 (T6) to 0.383 (T4). CONCLUSION: The SPR can be incorporated into layer diet as a source of inorganic as well as organic nutrients without affecting its egg quality characteristics.

Impact of second line limiting amino acids' deficiency in broilers fed low protein diets with rapeseed meal and de-oiled rice bran.

AIM: To study the impact of deficiency of second line limiting amino acids (SLAA; valine, isoleucine and tryptophan) on the production performance and carcass characteristics of commercial broilers. MATERIALS AND METHODS: A control (T1) corn-soy diet was formulated to contain all essential AA on standardized ileal digestible basis; While in T2-a 'moderate SLAA deficit' diet was formulated by replacement of soybean meal with 6% rapeseed meal and T3-a 'high SLAA deficit' diet was formulated by replacement of soybean meal with 6% de-oiled rice bran. Each of these treatments was allotted to six replicates of ten chicks each. During the 42 days experimental period, growth performance, carcass parameters and intake of metabolizable energy (ME), crude protein (CP) and AA were studied. RESULTS: The cumulative body weight gain, feed conversion ratio, carcass cut weights and yields of carcass, breast and thighs were decreased (p<0.05) in T3 compared to T1. The absolute intake of ME, lysine, methionine + cysteine and threonine were not affected while intake of CP and all SLAA were reduced in SLAA deficit diets. The relative intake of ME, lysine, methionine + cysteine, threonine and SLAA reduced in T3 in comparison to T1. The relative weights of internal organs were not affected by treatments while the abdominal fat percentage was increased linearly to the magnitude of SLAA deficiency. CONCLUSION: The deficiency of SLAA decreased performance, carcass yields and impaired utilization of ME, CP and AA linearly to the magnitude of the deficiency.