Nitrogen use efficiency in dairy cattle | Eficiencia de utilización del nitrógeno en el vacuno lechero
2011
Rodríguez Prado, M.E., Universitat Autònoma de Barcelona, Bellaterra (España). Servei de Nutrició i Benestar Animal | Calsamiglia, S., Universitat Autònoma de Barcelona, Bellaterra (España). Servei de Nutrició i Benestar Animal | Ferret, A., Universitat Autònoma de Barcelona, Bellaterra (España). Servei de Nutrició i Benestar Animal
A comparative study was conducted to determine the dietary and production performance parameters associated with the efficiency of N utilization (g milk protein/100 g N intake) in dairy cattle. Data from published papers on dairy trials conducted in the US (n=35) and the EU (n=43) were collected and results summarized. The higher and lower quartiles were compared. Average efficiency of N utilization was low and similar between the US and EU trials (26.9 and 27.0, respectively). However, the dietary profile and conditions that determined the highest efficiency differed between the two dataset. In the US dataset, with diets based in corn silage, the highest efficiency was obtained in highest producing animals, and increased as the level of non-fiber carbohydrates increased and the level of protein decreased. In the EU dataset, the highest efficiency was also obtained in the highest producing animals, but in diets containing low forage and forage with high fiber and low protein content. Data indicate that highest producing animals have better efficiency of N utilization, and that research to reduce N emission to the environment in the EU should concentrate on the development of forages with high digestibility and intake (low in fiber) but low in protein content.
اظهر المزيد [+] اقل [-]