Italian Journal of Animal Science (Oct 2014)
Nitrogen and phosphorus utilisation and excretion in dairy buffalo intensive breeding
Abstract
The aim of this study was to quantify nitrogen (N) and phosphorus (P) utilisation and excretion in intensive dairy buffaloes. Italian Mediterranean buffaloes were divided into 4 groups (n=6/group) as follows: Groups M50, M125 and M225 at 50, 125 and 225 days of lactation, respectively, and Group NL which was non-lactating. Lactating buffaloes had greater (P<0.05) dry matter and organic matter intake than NL buffaloes. Buffaloes in Group M50 had a lower (P<0.05) crude protein (CP) apparent digestibility than buffaloes in Groups M125 and M225. Group NL had a higher (P<0.01) real CP digestibility than Group M50. Buffaloes in Groups M50 and NL had a negative N balance (-79 and -12 g, respectively) whilst buffaloes in Groups M125 and M225 had a positive N balance (26 and 16 g, respectively). Buffaloes in Group M50 had more (P<0.05) N in urine (204 g) than Group NL (87 g). Buffaloes in Group NL had less (P<0.01) P in both faeces (12.9 g) and urine (0.8 g) compared with the three groups of lactating buffaloes combined (25 g in faeces and 12 g in urine) and they also had greater (P<0.05) P digestibility (68%) than lactating buffaloes combined (43%). The present study has shown that buffaloes have a relatively high efficiency of N and P utilisation.
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