Higher TDN level increase N excretion in Kacang Goats

The aim of this study was to evaluate the correlation between nitrogen intake and nitrogen excretion in different total digestible nutrients (TDN) level. Thirty five heads of male Kacang goats were used and fed by two different levels of TDN (60% and 65%). Feces and urine from all goats were collected separately, then analyzed to get the percentage of crude protein. The parameters measured were N intake, N feces, N urine, and N total and calculated in weight (g/day). The data was analyzed by linear regression to determine the correlation and equation between N intake and N excretion, then evaluated by t-test. The result showed that N intake was significant different and had a negative strong correlation with N feces and N total (-0.73 and -0.68, respectively) in TDN 60%, while positive strong correlation with N feces and N total (0.75 and 0.67, respectively) in TDN 65%. The higher nitrogen intake increased N urine either in TDN 60% or 65% (r = 0.27 and r = 0.45, respectively). TDN 60% in feed reduced N excretion with the increase of N intake. Based on the results of this study, it can be concluded that TDN 60% gave the lower N excretion in high N intake than TDN 70%.