Influence of L-lactic acid on the efficacy of microbial phytase in broiler chickens
Zobac, P.(Vyzkumny Ustav Vyzivy Zvirat, Pohorelice (Czech Republic))E-mail:[email protected] | Kumprecht, I.(Vyzkumny Ustav Vyzivy Zvirat, Pohorelice (Czech Republic)) | Suchy, P.(Veterinarni a Farmaceuticka Univ., Brno (Czech Republic)) | Strakova, E.(Veterinarni a Farmaceuticka Univ., Brno (Czech Republic)) | Broz, J.(DSM Nutritional Products, Animal Nutrition and Health R and D, Basel (Switzerland)) | Heger, J.(Vyskumny Ustav Zivocisnej Vyroby, Nitra (Slovak Republic))
Two growth trials and a metabolism trial were conducted in broiler chickens (22 to 42 days old) in order to evaluate the effects of two dietary levels of L-lactic acid (1.03 or 2.06 g/kg) and microbial 6-phytase (750 U/kg), added either separately or in combination, on growth rate, feed conversion, dressing percentage and utilization of selected nutrients. The diet contained either 19.4% crude protein (CP) and reduced levels of P (total and non-phytate ones), or 17% CP and a standard level of P. In both cases, single lactic acid did not show any positive effect. In contrast, phytase addition led to the increase of final weight and feed conversion. These effects were statistically significant whith the low-P diets. The beneficial effect was stronger when microbial phytase was added to the diets containing L-lactic acid. Apparent digestibility of N and fat in the low-P diets was not affected by dietary treatments. When compared with the standard diet, the combination of phytase and L-lactic acid increased daily P retention by 37.6%. P excretion was significantly reduced in all treatments fed low-P diets supplemented by both test products, either separately or in combination. A numerical decrease in N excretion was noted in both treatments fed low-protein diets.
显示更多 [+] 显示较少 [-]