@conference {3672,
	title = {A comparison of microbial protein synthesis in beef steers fed ad libitum winter ryegrass or fodder beet},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {75},
	year = {2015},
	month = {07/2015},
	pages = {251-256},
	address = {Dunedin},
	abstract = { Microbial protein synthesis of steers (liveweight 286{\textpm}9 kg) was compared with diets of ad libitum winter grass and fodder beet
with 1 kg DM of lucerne silage. The experimental design was a four-by-two treatment comparison (experiment 1 and 2), using
11 day individual pen trials with total faecal and urinary collection. The trials assessed in vivo digestibility of diets, and diurnal
variations in rumen parameters (pH volatile fatty acid, ammonia and urea concentrations) and urine and faeces production and
N excretion. Microbial protein production was estimated from purine derivatives determined from total urine collection. Dry
matter digestibility, voluntary dry matter intake and microbial protein supply to the steers, and the mean diurnal rumen pH, were
higher in the steers fed the fodder-beet treatment than in those fed the winter-grass treatment. Fodder beet supplied almost twice
as much microbial protein as winter grass despite a lower crude protein concentration of the diet. Total rumen VFA and ammonia
concentrations were lower for the fodder-beet treatment than for winter grass but the rumen urea concentration was higher in
the fodder-beet treatment. The observed high microbial protein supply with the fodder beet diets is likely the result of ruminal
and extra-ruminal adaptations to greater nitrogen recycling in low dry matter diets of high energy density and low crude protein
concentrations.},
	issn = {1176-5283},
	author = {Prendergast SL and Gibbs SJ}
}
