Prediction of nitrogen excretion in lactating cows
1997
Terada, F. (National Inst. of Animal Industry, Kukizaki, Ibaraki (Japan)) | Kurihara, M. | Nishida, T. | Shioya, S.
Relationship between nitrogen excretion and feeding performance was investigated to predict the amount of nitrogen excretion. To obtain the prediction equations of the amount of nitrogen excretion, results of 95 nitrogen balance trials with lactating cows under environment controlled rooms (18 and 20 degrees C) were used. The equation obtained was as follows: N/FCM = -14.48 x ln(FCM) + 0.806 x CP + 0.769 x DMI + 31.4 square-R = 0.864 (N/FCM: nitrogen excretion (feces plus urine) per 1 kg fat corrected milk, g, FCM: fat corrected milk, kg, CP: crude protein content in dry matter, %, DMI: dry matter intake, kg). Partial corelation coefficients were -.906, .842 and .769 for lnFC+M,CP and DMI, respectively. Therefore increasing milk yield, depression of CP content and improvement of feed quality are useful to reduce nitrogen excretion
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