Sward conditions, herbage allowance and animal production: an evaluation of research results

The evidence on the influence of herbage allowance and sward characteristics upon animal performance and herbage production is reviewed briefly, with particular reference to the prediction of animal performance, the use of decision rules in grazing systems and understanding of animal/sward interrelationships. Attention is concentrated on evidence from temperate grasslands, with particular reference to New Zealand results. Simple management rules based on herbage allowance or residual dry matter indices have made a major contribution to improvement in the efficiency of grazing management. However, their use as general indices is restricted by the interdependence of the effects of variation in allowance and sward conditions upon animal performance. Furthermore, allowance-based studies make only a limited contribution to understanding of the factors influencing the links between the plant and animal components of grazing systems. It is suggested that more attention should now be concentrated on the causative effects of variation in sward characteristics upon both herbage production and animal performance.

[1]  Reardon Tf.  Effect of Herbage Per Unit Area and Herbage Allowance on Dry Matter Intake by Steers , 1977 .

[2]  J. Hodgson.  Variations in the surface characteristics of the sward and the short‐term rate of herbage intake by calves and lambs , 1981 .

[3]  A. Campbell.  Grazed pasture parameters. I. Pasture dry-matter production and availability in a stocking rate and grazing management experiment with dairy cows , 1966, The Journal of Agricultural Science.

[4]  J. McEwan,et al.  Pasture allowance and lamb growth. , 1980 .

[5]  J. Baars,et al.  The use of grazing pressure to manipulate the balance of paspalum/ryegrass-based pasture. , 1980 .

[6]  Jagusch Kt,et al.  Influence of feeding post-lambing on ewe and lamb performance at grazing , 1982 .

[7]  K. Maclean,et al.  Getting an extra 20% lambing from flushing ewes. , 1980 .

[8]  C. Scientific,et al.  Nutritional limits to animal production from pastures. Proceedings of an International Symposium held at St. Lucia, Queensland, Australia, August 24th-28th, 1981. , 1982 .

[9]  A. Bryant.  Effect of herbage allowance on dairy cow performance. , 1980 .

[10]  A. Parsons,et al.  The Physiology of Grass Production Under Grazing. II. Photosynthesis, Crop Growth and Animal Intake of Continuously-Grazed Swards , 1983 .

[11]  J. Hodgson,et al.  Herbage intake and milk production by grazing dairy cows. 2. The effects of level of winter feeding and daily herbage allowance , 1979 .

[12]  R. W. Brougham.  The Effects of Frequency and Intensity of Grazing On The Productivity of A Pasture of Short-Rotation Ryegrass and Red and White Clover , 1959, New Zealand Journal of Agricultural Research.

[13]  A. Parsons,et al.  The Physiology of Grass Production Under Grazing. I. Characteristics of Leaf and Canopy Photosynthesis of Continuously-Grazed Swards , 1983 .

[14]  C. During,et al.  The relationship of pasture parameters to liveweight gain of hoggets on North Island hill country. , 1980 .

[15]  O. Tw,et al.  The effect of herbage yield and allowance on growth and carcass characteristics of weaned lambs , 1979 .

[16]  H. K. Smith,et al.  Sward management, lamina turnover and tiller population density in continuously stocked Lolium perenne‐dominated swards , 1983 .

[17]  C. Hoogendoorn,et al.  Some effects of grazing management in early lactation, and of topping on the growth and quality of pasture , 1983 .

[18]  J. Hodgson,et al.  The influence of sward condition on rates of herbage growth and senescence in mixed swards under continuous stocking management , 1983 .