Effects of cultivar,pelleting and enzyme addition on nutritive value of barley in poultry diets

1. The effect of pelleting process and Trichoderma viride enzymes (TVE) addition on apparent metabolisable energy, corrected for nitrogen balance (AMEn) and on productive value of practical diets containing 40 and 45% of three different barley cultivars and one wheat were studied in poultry.

2. The effect of the pelleting process on AMEn was inconsistent and was dependent on the cereal included and the addition of enzyme.

3. The growth trial showed a significant effect of enzyme addition to pelleted diets over the whole growth period (0 to 42 d). Addition of TVE improved weight gain and food efficiency by 1.3% and 2.9%, respectively and decreased food intake by 1.6% between 0 and 22 d. In the finisher period (23 to 42 d) TVE improved efficiency by 2.8% and reduced food intake by 2.9%.

4. The incidence of sticky droppings was related to the viscosity of barley used, and enzyme supplementation reduced it. Both pelleting and enzyme addition increased dry matter content of excreta.

5. At the end of the experiment, 14 animals per treatment were slaughtered and carcass yield, viscera weight and abdominal fat were determined.     

Effect of nephropathogenic infectious bronchitis viruses on renal function in young male broiler chickens

1. The acute effects of challenge with Australian T‐strain infectious bronchitis virus (IBV) on renal function were evaluated, following primary vaccination in 1‐d‐old male broilers.

2. Challenge with T‐strain IBV decreased body weight and induced kidney hypertrophy and kidney asymmetry.

3. Haematocrit was reduced in birds challenged with the Australian T‐strain IBV and plasma uric acid was elevated in unvaccinated birds exposed to the IBV challenge.

4. Challenge with T‐strain IBV caused significant increases in urinary water losses, accompanied by decreased urine osmolality and increased fractional excretion of sodium, calcium and potassium.

5. Vaccination at 1‐d‐old with Vic S‐strain IBV provided a limited degree of protection against an heterologous challenge with T‐strain IBV at 15 d of age.