Influence of frequency of nitrogen fertilizer application on milk production from cows grazing tropical grass pastures
1987
Davison, T.M. (Queensland Dept. of Primary Industries, Kairi (Australia)) | Shepherd, R.K. (Queensland Dept. of Primary Industries, Townsville (Australia). Ooonoonba Veterinary Lab.) | Brown, G.W. (Queensland Dept. of Primary Industries, Wacol (Australia). Herd Improvement Lab.)
Holstein-Friesian cows were grazed for 2 years on pasture receiving either 200 or 400 kg N per ha per year at application frequencies of 3, 6 or 12 weeks. There were no treatment effects on fat-corrected milk yield, butterfat percent or butterfat yield. The non-protein N content of milk was increased by the high level of N fertilizer in the first 24 weeks of lactation. Frequency of fertilizer application had no effect on yield of pasture on offer, crude protein or mineral content of pasture. The higher level of nitrogen fertilizer produced small increases in yield of pasture on offer, crude protein content in the pasture and crude protein content in the diet. Phosphorus concentration in the pasture was decreased and calcium and magnesium concentrations were increased by the higher level of nitrogen fertilizer.
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