The aim of this study was to evaluate water balance and nitrogen excretion in Mediterranean buffaloes. Sixteen subjects were divided into 4 groups (n=4/group), according to their days in milk (DIM): Group L50 (DIM=50±8); Group L125 (DIM=125±55); Group L225 (DIM=225±26); Group NL (non-lactating). The study comprised a 14-day adaptation to diets and 14-day data collection during which feed intake and milk production were recorded daily. Measurements for individual buffaloes were made for water intake, diet, orts, milk, faeces and urine during the final 3 days. The analyses were performed according to OAOC. Lactating buffaloes had greater (P<0.05) DM and OM intake than NL buffaloes. Buffaloes in Group L50 had a lower (P<0.05) CP apparent digestibility than buffaloes in Groups L125 and L225, while Group NL showed a CP apparent digestibility similar to the other Groups. Group NL had a higher (P<0.05) real CP digestibility than Group L50, suggesting decreased N clearance by the kidneys and a greater N recycling by the gastrointestinal tract in the former buffaloes. Buffaloes in Groups L50 and NL had a negative N balance (-79±32 and -12±25 g, respectively) whilst buffaloes in Groups L125 and L225 had a positive N balance (26±27 and 16±45 g, respectively). Buffaloes in Group L50 had more (P<0.05) N in urine (204±28 g) than Groups L125 (157±16), L225 (171±26) and NL (87±22 g). The water balance was positive for buffaloes in all groups without differences. Drinking water intake (DWI) represented around 93% of total water intake (TWI) and this was similar across treatment groups. Buffaloes in Group L50 had a greater (P<0.05) DWI relative to TWI (96.3±1.2%) compared with buffaloes in Group NL (90.9±2.0%), L125 (89.1±2.2%) and L225 (92.8±0.6%).Overall, lactating buffaloes ingested a greater (P<0.05) amount of total water than non-lactating buffaloes and the former buffaloes excreted a greater (P<0.05) amount of water in both faeces and urine. There were high correlations between total water excretion and N intake (r=0.722; P<0.01) and total water excretion and N excretion (r=0.976; P<0.01).
Water balance and nitrogen excretion in buffaloes in different physiological conditions / Neglia, Gianluca; Campanile, Giuseppe; Rossi, P.; Salzano, Angela; Zullo, Gianluigi; Bifulco, Giovanna; Esposito, Luigi; Zicarelli, Luigi; Gasparrini, Bianca. - In: ITALIAN JOURNAL OF ANIMAL SCIENCE. - ISSN 1594-4077. - 12:suppl. 1(2013), pp. 110-110.
Water balance and nitrogen excretion in buffaloes in different physiological conditions
NEGLIA, GIANLUCA;CAMPANILE, GIUSEPPE;SALZANO, ANGELA;ZULLO, GIANLUIGI;BIFULCO, GIOVANNA;ESPOSITO, LUIGI;ZICARELLI, LUIGI;GASPARRINI, BIANCA
2013
Abstract
The aim of this study was to evaluate water balance and nitrogen excretion in Mediterranean buffaloes. Sixteen subjects were divided into 4 groups (n=4/group), according to their days in milk (DIM): Group L50 (DIM=50±8); Group L125 (DIM=125±55); Group L225 (DIM=225±26); Group NL (non-lactating). The study comprised a 14-day adaptation to diets and 14-day data collection during which feed intake and milk production were recorded daily. Measurements for individual buffaloes were made for water intake, diet, orts, milk, faeces and urine during the final 3 days. The analyses were performed according to OAOC. Lactating buffaloes had greater (P<0.05) DM and OM intake than NL buffaloes. Buffaloes in Group L50 had a lower (P<0.05) CP apparent digestibility than buffaloes in Groups L125 and L225, while Group NL showed a CP apparent digestibility similar to the other Groups. Group NL had a higher (P<0.05) real CP digestibility than Group L50, suggesting decreased N clearance by the kidneys and a greater N recycling by the gastrointestinal tract in the former buffaloes. Buffaloes in Groups L50 and NL had a negative N balance (-79±32 and -12±25 g, respectively) whilst buffaloes in Groups L125 and L225 had a positive N balance (26±27 and 16±45 g, respectively). Buffaloes in Group L50 had more (P<0.05) N in urine (204±28 g) than Groups L125 (157±16), L225 (171±26) and NL (87±22 g). The water balance was positive for buffaloes in all groups without differences. Drinking water intake (DWI) represented around 93% of total water intake (TWI) and this was similar across treatment groups. Buffaloes in Group L50 had a greater (P<0.05) DWI relative to TWI (96.3±1.2%) compared with buffaloes in Group NL (90.9±2.0%), L125 (89.1±2.2%) and L225 (92.8±0.6%).Overall, lactating buffaloes ingested a greater (P<0.05) amount of total water than non-lactating buffaloes and the former buffaloes excreted a greater (P<0.05) amount of water in both faeces and urine. There were high correlations between total water excretion and N intake (r=0.722; P<0.01) and total water excretion and N excretion (r=0.976; P<0.01).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
