Skip to main content Accessibility help

Effect of the levels of N fertilizer, grass and supplementary feeds on nitrogen composition and renneting properties of milk from cows at pasture

  • John E. Hermansen (a1), Steen Ostersen (a1) and Ole Aaes (a1)


In a 2 × 2 × 3 factorial design grazing experiment we investigated the effect of fertilizer (none or 240 kg N/ha), amounts of clover grass available (low or high) and type and level of daily supplementary feed for each cow (3·5 kg barley, 3·5 kg concentrate mixture rich in protein and fat, or both, 7 kg) on the protein composition and renneting properties of their milk. The experiment was carried out in two successive grazing seasons (years) and included a total of 79 Danish Holstein cows. The effect on milk protein composition was determined in both years whereas the effect on renneting properties was determined only in the second year. Fertilization of the clover grass significantly decreased total milk protein concentration (− 1·4 g/kg; P < 0·01) and tended also to decrease the relative proportion of whey protein N. Fertilization had no effect on renneting properties. Increased availability of clover grass significantly increased milk protein concentration (1 g/kg; P < 0·05) and resulted in significantly poorer renneting properties, that is increased clotting time (P < 0·01) and decreased coagulum development. These effects seemed to be mediated through an effect on the pH of the milk (+ 0·05; P < 0·05) as the effect was markedly reduced when statistical correction was made for the actual pH. Use of the protein- and fat-rich concentrate mix (3·5 kg) significantly reduced the total protein content of the milk (P < 0·05) and increased the proportion of non-protein N (NPN) in total N compared with use of the other supplementary feeds (P < 0·05). We found no effect on renneting properties of the different supplementary feeds. Throughout the grazing season and independent of the main treatments, the NPN proportion of milk N increased at the expense of casein N. At the same time, renneting properties became poorer, especially with high clover grass availability.



Hide All
Aaes, O. & Kristensen, E. S. 1992 [The production of the cow and of the pasture at different levels of N fertilization, grazing intensity and type and level of concentrate.] Paper presented at the Annual Meeting of the National Institute of Animal Science, Herning, Denmark
Barbano, D. M. & Dellavalle, M. E. 1987 Rapid method for determination of milk casein content by infrared analysis. Journal of Dairy Science 70 15241528
Bastlan, E. D., Brown, R. J. & Ernstrom, C. A. 1991 Plasmin activity and milk coagulation. Journal of Dairy Science 74 36773685
DePeters, E. J. & Cant, J. P. 1992 Nutritional factors influencing the nitrogen composition of bovine milk: a review. Journal of Dairy Science 75 20432070
Grainger, C. & Wilhelms, G. 1979 Effect of duration and pattern of underfeeding in early lactation on milk production and reproduction of dairy cows. Australian Journal of Experimental Agriculture and Animal Husbandry 19 395401
Grandison, A. S., Ford, G. D., Owen, A. J. & Millard, D. 1984 Chemical composition and coagulating properties of renneted Friesian milk during the transition from winter rations to spring grazing. Journal of Dairy Research 51 6978
Grandison, A. S., Manning, D. J., Thomson, D. J. & Anderson, M. 1985 Chemical composition, rennet coagulation properties and flavour of milks from cows grazing ryegrass or white clover. Journal of Dairy Research 52 3339
International Dairy Federation 1964 Determination of the casein content of milk. Brussels: IDF (FIL-IDF Standard no. 29)
Journet, M. & Rémond, B. 1980 [Influence of feeding and season on the N fractions of cows' milk.] Lait 60 140159
Kristensen, V. Friis, Munksgaard, L., Møller, P. D., Anderson, P. E., Kristiansen, K. Rotvig, Munksgaard, L., Werner, H. & Skovborg, E. Bülow 1987 [The effect of nitrogen fertilizer on the protein value of grass silage for dairy cows and on the quality of the milk.] Beretning, Fœllesudvalget for Statens Planteavls- og Husdyrbrugsforsøg no. 11
Lolkema, H. 1993 Cheese yield as an instrument for process control–experience in Friesland, The Netherlands. In Factors Affecting the Yield of Cheese, pp. 156197. Brussels: IDF (International Dairy Federation Special Issue no. 9301)
Macheboeuf, D., Coulon, J.-B. & D'Hour, P. 1993 Effect of breed, protein genetic variants and feeding on cows' milk coagulation properties. Journal of Dairy Research 60 4354
Ng-Kwai-Hang, K. F., Hayes, J. F., Moxley, J. E. & Monardes, H. G. 1982 Environmental influences on protein content and composition of bovine milk. Journal of Dairy Science 65 19931998
Palmquist, D. L. 1984 Use of fats in diets for lactating dairy cows. In Fats in Animal Nutrition, pp. 357381 (Ed. Wiseman, J.). London: Butterworths
Rook, J. A. F. & Thomas, P. C. 1980 Principles involved in manipulating the yields and concentrations of the constituents of milk. Brussels: IDF. (International Dairy Federation Bulletin no. 125 6672)
Rowland, S. J. 1938 The determination of the nitrogen distribution in milk. Journal of Dairy Research 9 4246
SAS 1985 SAS User's Guide: Statistics. Gary, NC: SAS Institute
Storry, J. E., Grandison, A. S., Millard, D., Owen, A. J. & Ford, G. D. 1983 Chemical composition and coagulating properties of renneted milks from different breeds and species of ruminant. Journal of Dairy Research 50 215229
Thomson, D. J., Beever, D. E., Haines, M. J., Cammell, S. B., Evans, R. T., Dhanoa, M. S. & Austin, A. R. 1985 Yield and composition of milk from Friesian cows grazing either perennial ryegrass or white clover in early lactation. Journal of Dairy Research 52 1731
Wolfschoon-Pombo, A. & Klostermeyer, H. 1981 [The NPN fraction of cows' milk. 3. Effect of number and stage of lactation.] Milchwissenschaft 36 721724


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed