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Energy and nitrogen balance of lactating dairy cows given mixtures of urea-treated whole-crop wheat and grass silage

Published online by Cambridge University Press:  02 September 2010

J. D. Sutton
Affiliation:
Centre for Dairy Research, Department of Agriculture, University of Reading, Earley Gate, Reading RG6 6AT
S. B. Cammell
Affiliation:
Centre for Dairy Research, Department of Agriculture, University of Reading, Earley Gate, Reading RG6 6AT
D. E. Beever
Affiliation:
Centre for Dairy Research, Department of Agriculture, University of Reading, Earley Gate, Reading RG6 6AT
D. J. Humphries
Affiliation:
Centre for Dairy Research, Department of Agriculture, University of Reading, Earley Gate, Reading RG6 6AT
R. H. Phipps
Affiliation:
Centre for Dairy Research, Department of Agriculture, University of Reading, Earley Gate, Reading RG6 6AT
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Abstract

Energy and nitrogen balances were carried out with four multi-porous Holstein/Friesian cows offered four diets in a Latin-square experiment to evaluate urea-treated whole-crop wheat as a partial grass silage replacement for lactating dairy cows. Grass silage (GS) was produced from the primary growth of a perennial ryegrass sward. Spring wheat (cv. Axona) was harvested at 603 g dry matter (DM) per kg and preserved with 20 (WCW-20) or 40 (WCW-40)kg urea per t DM. The diets were 6 kg DM of a dairy concentrate daily with one of four forage treatments offered ad libitum. The forage treatments were GS alone, a 2:1 DM ratio of GS with WCW-40 (2:1 40), or a 1:2 DM ratio of GS with WCW-20 (1:2 20) or WCW-40 (1:2 40). Each period lasted 4 weeks with energy and nitrogen balances being carried out in respiration chambers over 6 days in the last week. Replacement of GS by diets containing WCW resulted in significant increases in DM intake (P < 0·01). Changes in milk yield and composition were small and non-significant but yields of milk fat and protein were higher on WCW diets than on GS diets (P< 0·05). With increasing proportions of WCW in the diet there were significant linear falls in apparent digestibility of DM (P < 0·001), organic matter (F < 0·001), neutral-detergent fibre (F < 0·01), acid-detergent fibre (F < 0·01), starch (F < 0·001) and nitrogen (P < 0·01). Gross energy intakes (P < 0·01) and faecal (P < 0·001), methane (P < 0·05) and milk (P < 0·05) energy outputs were higher with the WCW diets than with GS but urine energy and heat losses were unaffected. In consequence there were no significant differences among the diets in digestible or metabolizable energy (ME) intakes. However dietary ME concentrations (MJ ME per kg corrected DM) fell with increasing WCW inclusion from 11·54 on GS to a mean of 9·96 on the 1:2 diets (P < 0·001). It was calculated that the ME concentration of the WCW was only 8·1 MJ/kg corrected DM at maintenance intake, considerably lower than values used conventionally. There were no significant diet effects on the partition of ME or on the partial efficiency of ME utilization for milk production (k1). The increasing inclusion of WCW increased N losses in urine (P < 0·05) and faeces (F < 0·01) with no net effect on N digested or retained though there was a small increase in milk N output (P < 0·01). It is concluded that low digestibility is the major cause of the small milk response to the partial substitution of urea-treated WCW for grass silage with no evidence of a reduction in the efficiency of utilization of ME.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1998

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References

Agricultural and Food Research Council. 1993. Energy and protein requirements of ruminants. An advisory manual prepared by the Technical Committee on Responses to Nutrients. CAB International, Wallingford.Google Scholar
Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Cammell, S. B., Beever, D. E., Skelton, K. V. and Spooner, M. C. 1981. The construction of open-circuit calorimeters for measuring gaseous exchange and heat production in sheep and young cattle. Laboratory Practice 30: 115119.Google Scholar
Cammell, S. B., Thomson, D. J., Beever, D. E., Haines, M. J., Dhanoa, M. S. and Spooner, M. C. 1986. The efficiency of energy utilisation in growing cattle consuming fresh perennial ryegrass (Lolium perenne cv. Melle) or white clover (Trifolium repens cv. Blanca). British journal of Nutrition 55: 669680.CrossRefGoogle ScholarPubMed
Gibb, M. J., Ivings, W. E., Dhanoa, M. S. and Sutton, J. D. 1992. Changes in body components of autumn-calving Holstein-Friesian cows over the first 29 weeks of lactation. Animal Production 55: 339360.Google Scholar
Givens, D. I., Everington, J. M. and Adamson, A. H. 1989. The digestibility and metabolisable energy content of grass silage and their prediction from laboratory measurements. Animal Peed Science and Technology 24: 2743.CrossRefGoogle Scholar
Hill, J. and Leaver, J. D. 1993. The intake, digestibility and rate of passage of whole-crop wheat and grass silage by growing heifers. Animal Production 56: 443 (abstr.).Google Scholar
Leaver, J. D. and Hill, J. 1992. Feeding cattle on whole-crop cereals. In Whole-crop cereals (ed. Stark, B. A., Wilkinson, J. M.), pp. 5969. Chalcombe Publications, Canterbury.Google Scholar
Leaver, J. D. and Hill, J. 1995. The performance of dairy cows offered ensiled whole-crop wheat, urea-treated whole-crop wheat or sodium hydroxide-treated wheat grain and wheat-straw in a mixture with grass silage. Animal Science 61: 481489.CrossRefGoogle Scholar
Phipps, R. H., Sutton, J. D. and Jones, B. A. 1995. Forage mixtures for dairy cows: the effect on dry-matter intake and milk production of incorporating either fermented or urea treated whole-crop wheat, brewers' grains, fodder beet or maize silage into diets based on grass silage. Animal Science 61: 491496.CrossRefGoogle Scholar
Porter, M. G., Patterson, D. C., Steen, R. W. J. and Gordon, F. J. 1984. Determination of dry matter and gross energy of grass silage. Proceedings of the seventh silage conference, The Queen's University, Belfast.Google Scholar
Sutton, J. D., Abdalla, A. L., Phipps, R. H., Cammell, S. B. and Humphries, D. J. 1997. The effect of the replacement of grass silage by increasing proportions of urea-treated whole-crop wheat on food intake and digestibility and milk production by dairy cows. Animal Science 65: 343351.CrossRefGoogle Scholar
Tilley, J. M. A. and Terry, R. A. 1963. A two-stage technique for in vitro digestion of forage. Journal of the British Grassland Society 18: 104111.CrossRefGoogle Scholar
Tyrrell, H. F. and Reid, J. T. 1965. Prediction of the energy value of cow's milk. Journal of Dairy Science 48: 12151223.CrossRefGoogle ScholarPubMed
Yan, T., Gordon, F. J., Agnew, R. E., Porter, M. G. and Patterson, D. C. 1997. The metabolisable energy requirement for maintenance and the efficiency of utilisation of metabolisable energy for lactation by dairy cows offered grass silage-based diets. Livestock Production Science 51: 141150.CrossRefGoogle Scholar
Zadoks, J. C., Cheng, T. T. and Konzak, C. F. 1974. A decimal code for the growth stages of cereals. Weed Research 14: 415421.CrossRefGoogle Scholar