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The effect of season and level of concentrate on the voluntary intake and digestibility of herbage by outdoor sows

  • M. G. Rivera Ferre (a1) (a2), S. A. Edwards (a1) (a2), R. W. Mayes (a3), I. Riddoch (a2) and F. D. DeB. Hovell (a1)...


The intake and the digestibility of herbage, and the effect of level of supplementary concentrate food, were measured in late spring and late summer in two studies, each with eight multiparous, pregnant sows. In the spring study sows were nose rung to prevent rooting but only four nose-rung sows were available for the summer study; the remaining four were unrung. In both cases, sows had access to a plentiful (>2·5 t organic matter (OM) per ha) ryegrass/clover sward in a paddock of 1922 m2. After a week of adaptation to the herbage in the experimental paddock, sows were offered 1·5 or 3·0 kg/day concentrate for consecutive 2-week periods in a change-over experimental design with four sows on each treatment in each period. Samples of herbage were also taken to measure the sward density, chemical composition and n-alkane content. Herbage intake and digestibility estimates were calculated using the n-alkanes technique, with the marker dosed on small food pellets. In the spring study, the herbage intake ranged from 0·9 to 1·8 kg OM per day in the first period (herbage neutral-detergent fibre(NDF) content 439 (s.e.41·6) g/kg OM) and 0·2 to 1·4 kg in the second (475 (s.e.29·3) g NDF per kg OM). The intake was affected by the level of concentrate only in the second period. The results obtained during the summer study with the rung and unrung sows showed an intake between 0·9 and 2·4 kg OM per day in the first period (524 (s.e. 16·0) g NDF per kg OM) and between 1·3 and 4·8 kg in the second (526 (s.e. 21·8) g NDF per kg OM). A high intake estimation for certain unrung individuals appeared to reflect their frenzied feeding behaviour and possible loss of some marker pellets. There were no differences between level of concentrate treatments in either period. Digestibility of the diet was affected by the intake of herbage and the level of fibre consumed (P < 0·01). These herbage intakes equated to proportionately 0·50 (s.e. 0·05) and 0·66 (s.e. 0·1) (or 0·49 (s.e. 0·07) excluding problem sows) of the maintenance energy requirement in each season. Faeces of unrung sows indicated a high ingestion of soil or stones by some individuals: one of the sows produced a bulked faeces sample containing 450 g/kg fresh weight of stones, whilst another sow had a faecal ash content of 937 g/kg DM. The results indicate that the intake of nutrients from herbage by grazing sows is highly variable between seasons and individuals.



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Agricultural Research Council. 1981. The nutrient requirements of pigs. Commonwealth Agricultural Bureaux, Slough.
Agricultural Research Council. 1984. The nutrient requirements of ruminant livestock. CAB, Farnham Royal, Slough.
Boaz, T. G. 1962. The significance of level of protein in the nutrition of the pregnant sow. Veterinary Record 74: 14821489.
Brouns, F., Edwards, S. A. and English, P. R. 1995. Influence of fibrous feed ingredients on voluntary intake of dry sows. Animal Feed Science and Technology 54: 301313.
Brown, J. M. E., Edwards, S. A., Smith, W. J., Thompson, E. and Duncan, J. 1996. Welfare and production implications of teeth clipping and iron injection of piglets in outdoor systems in Scotland. Preventive Veterinary Medicine 27: 95105.
Buckner, L. J., Bruce, J. M. and Edwards, S. A. 1994. Modelling the energy system of outdoor sows. Pig News and Information 15: 125N128N.
Close, W. H. and Poornan, P. K. 1993. Outdoor pigs: their nutrient requirements, appetite and environmental responses. In Recent advances in animal nutrition-1993 (ed. Haresign, W. and Cole, D.J. A.), pp. 175196. Nottingham University Press.
Cole, D. J. A. and Chadd, S. A. 1989. Voluntary food intake of growing pigs. In The voluntary food intake of pigs (ed. Forbes, J. M., Varley, M. A. and Lawrence, T.L. J.), British Society of Animal Production occasional publication no 13, pp. 6170.
Crowther, C. 1934. Pig breeding annual no. 14. 6170.
Davidson, H. R. 1930. The value of grazing for fattening pigs. Scottish Journal of Agriculture XIII: 3.
Dove, H. and Mayes, R. W. 1991. The use of plant wax alkanes as marker substances in studies of the nutrition of herbivores: a review. Australian Journal of Agricultural Research 42: 913952.
Edwards, S. A. 1994. Outdoor pig production: the European perspective. Pig News and Information 15: 111N-112N.
Edwards, S. A. and Zanella, A. 1996 [Pig production in outdoor systems in Europe: production, welfare and environmental considerations.] A Hora Veterinara 92: 8693.
Ellis, J. C. B. 1937. The feeding of farm livestock. Crosby Lockwood and Son, London.
Gannon, M. A. 1996. The energy balance of pigs outdoors. Ph.D. thesis. University of Nottingham.
Livingstone, R. M. 1985. The advantages and limitations of fibrous feedingstuffs. Proceedings of the 36th annual meeting of the European Association for Animal Production.
Livingstone, R. M. and Fowler, V. R. 1984. Pig feeding in the future: back to nature? Span 27: 3.
Livingstone, R. M. and Fowler, V. R. 1987. The correction of digestible energy for fermentative losses: a simple concept for the evaluation of unusual feed sources for pigs. Proceedings of the 38th annual meeting of the European Association for Animal Production, Lisboa, Portugal 5·10.
Low, A. G. 1993. Role of dietary fibre in pig diets. In Recent developments in pig nutrition — 1 (ed. D. J. A. Cole, , Haresign, W. and Garnsworthy, P. C.), pp. 137162. Nottingham University Press.
Mayes, R. W., Lamb, C. S. and Colgrove, P. M. 1986. The use of dosed and herbage n-alkanes as markers for the determination of herbage intake. Journal of Agricultural Science, Cambridge 107: 161170.
Minson, D. J. 1990. Forage in ruminant nutrition. Academic Press, London.
Nappan Experimental Farm. 1964. Sows fed with grass. Department of Agriculture, Nova Scotia.
Salt, C. A., Mayes, R. W. and Elston, D. A. 1992. Effects of season, grazing intensity and diet composition on the radiocaesium intake by sheep on re-seeded hill pasture. Journal of Applied Ecology 29: 378387.
Stephen, T. G. 1976. A preliminary evaluation of the value of grass and grass pulp to non lactating sows. M.Sc. thesis, University of Aberdeen.
Van Soest, P. J., Robertson, J. B. and Lewis, B. A. 1991. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science 74: 35833597.
Wilson, H., Sinclair, A. G., Hovell, F. D., Mayes, R. W. and Edwards, S. A. 1999. Validation of the n-alkane technique for measuring herbage intake in sows. Proceedings of the British Society of Animal Science, 1999, p. 177.


The effect of season and level of concentrate on the voluntary intake and digestibility of herbage by outdoor sows

  • M. G. Rivera Ferre (a1) (a2), S. A. Edwards (a1) (a2), R. W. Mayes (a3), I. Riddoch (a2) and F. D. DeB. Hovell (a1)...


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