Effect of stocking rate on pasture and sheep production in winter and spring lambing systems

A 2-year study was conducted to quantify the effect of stocking rate on pasture and sheep production in winter and spring lambing systems. Pastures were set-stocked with ewes and their winter-born single lambs at low (20 ewes + lamb ha 1), medium (28 ewes + lamb ha 1), and high (36 ewes + lamb ha 1) stocking rates in spring 2012 and by ewes and their spring-born lambs at low (16 ewes + lamb ha 1), medium (24 ewes + lamb ha 1), and high (32 ewes + lamb ha 1) stocking rates in spring 2013. Annual pasture dry matter production ranged from 8.9 to 10.2 t ha 1 but was not affected by the spring stocking rates. The average live weight gains of the winter-born lambs were 73 and 10 g head 1 day 1 for low and medium stocking rates, respectively, while the lambs at the high stocking rate lost 10 g head 1 day 1 in spring 2012. The spring-born lambs grew at 245, 189, and 133 g head 1 day 1 for low, medium, and high stocking rates, respectively, in spring 2013. High stocking rates did not have any negative effects on the pasture production or botanical composition but they resulted in poor sheep performance, particularly in the winter lambing system.

PDF

___

1. Deak A, Hall MH, Sanderson MA. Grazing schedule effect on forage production and nutritive value of diverse forage mixtures. Agron J 2009; 101: 408-414.
2. Foster A, Vera CL, Malhi SS, Clarke FR. Forage yield of simple and complex grasslegume mixtures under two management strategies. Can J Plant Sci 2014; 94: 41-50.
3. Thompson AN, Doyle PT, Grimm M. Effects of stocking rate in spring on liveweight and wool production of sheep grazing annual pastures Aust J Agric Res 1994; 45: 367-389.
4. Ates S, Lucas RJ, Edwards GR. Stocking rate effects on liveweight gain of ewes and their twin lambs when grazing subterranean clover-perennial grass pastures. Grass Forage Sci 2015; 70: 418-427.
5. Jones RJ, Sandland RL. The relation between animal gain and stocking rate: derivation of the relation from the results of grazing trials. J Agr Sci 1974; 83: 335-34.
6. Ceyhan A, Serbester U, Çınar M, Ünalan A, Akyol E, Şekeroğlu A. Current condition and directions of livestock breeding in the Central Anatolia Region. Turkish Journal of Agriculture - Food Science and Technology 2013; 1: 62-66 (in Turkish with abstract in English).
7. Yılmaz O, Denk H, Bayram D. Effects of lambing season, sex and birth type on growth performance in Norduz lambs. Small Ruminant Res 2007; 68: 336-339.
8. Norouzian MA. Effects of lambing season, birth type and sex on early performance of lambs. New Zeal J Agr Res 2015; 58: 84-88.
9. Jenkinson CMC, Peterson SW, Mackenzie DDS, McDonald MF, McCutcheon SN. Seasonal effects on birth weight in sheep are associated with changes in placental development. New Zeal J Agr Res 1995; 38: 337-345.
10. French P, Stanton C, Lawless F, ORiordan EG, Monahan FJ, Caffrey PJ, Moloney AP. Fatty acid composition, including conjugated linoleic acid, of intramuscular fat from steers offered grazed grass, grass silage, or concentrate-based diets. J Anim Sci 2000; 78: 2849-2855.
11. Penning PD, Parsons AJ, Orr RJ, Treacher TT. Intake and behaviour responses by sheep to changes in sward characteristics under continuous stocking. Grass Forage Sci 1991; 46, 15-28.
12. AOAC. Official Methods of Analysis of AOAC International. 17th ed., 2nd rev. Gaithersburg, MD, USA: AOAC; 2003.
13. Van Soest PJ. Robertson JB, Lewis BA. Method for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J Dairy Sci 1991; 74: 3583-3597.
14. Payne RW. The Guide to GenStat Release 12 Part 2: Statistics. Harpenden, UK: Lawes Agricultural Trust, Rothamsted Experimental Station; 2009.
15. Ates S, Lucas RJ, Edwards GR. Effects of stocking rate and closing date on subterranean clover populations and dry matter production in dryland sheep farms. New Zeal J Agr Res 2013; 56: 1-15.
16. Volaire F, Norton M. Summer dormancy in perennial temperate grasses. Ann Bot 2006; 98: 927-933.
17. Moot DJ, Scott WR, Roy AM, Nicholls AC. Base temperature and thermal time requirements for germination and emergence of temperate pasture species. New Zeal J Agr Res 2000; 43: 15-26.
18. Moot DJ, Brown HE, Pollock K, Mills A. Yield and water use of temperate pastures in summer dry conditions. Proceedings of the New Zealand Grassland Association 2008; 70: 51-59.
19. Lowe K, Bowdler TM. Growth, persistence, and rust sensitivity of irrigated, perennial temperate grasses in the Queensland subtropics. Aust J Exp Agric 1995; 35: 571-578.
20. Neal JS, Fulkerson WJ, Lawrie R, Barchia I. Difference in yield and persistence among perennial forages used by the dairy industry under optimum and deficit irrigation. Crop Pasture Sci 2009; 60: 1071-1087.
21. Davies A. White clover. Biologist 1992; 39:129-133.
22. Nolan T, Connolly J, Wachendorf M. Mixed grazing and climatic determinants of white clover (Trifolium repens L.) content in a permanent pasture. Ann Bot 2001; 88: 713-724.
23. Stevens DR, Hickey MJ. Effects of binary seed mixtures of ryegrass, cocksfoot and tall fescue on pasture production. Proceedings of the New Zealand Grassland Association 2000; 62: 141-146.
24. Ates S, Isik S, Keles G, Aktas AH, Louhaichi M, Nangia V. Evaluation of deficit irrigation for efficient sheep production from permanent sown pastures in a dry continental climate. Agric Water Manage 2013; 119: 135-143.
25. Nicol AM, Bryant RH, Ridgway MJ, Edwards GR. Liveweight gain per head and per ha throughout the year of lambs grazing conventional pastures and those that switch from grass to clover. Proceedings of the New Zealand Grassland Association 2010; 72: 211-216.
26. Marai IFM, El-Darawany AA, Fadiel A, Abdel-Hafez MAM. Physiological traits as affected by heat stress in sheep A review. Small Rumin Res 2007; 71: 1-12.
27. Litherland AJ, Lambert MG. Herbage quality and growth rate of single and twin lambs at foot. Proceedings of the New Zealand Society of Animal Production 2000; 60: 55-57.
28. Blanc F, Bocquier F, Agabriel J, Dhour P, Chilliard Y. Adaptive abilities of the females and sustainability of ruminant livestock systems. A review. Anim Res 2006; 55: 489-510.
29. Rattray PV, Thompson KF, Hawker H, Sumner RMW. Pastures for sheep production. In:Nicol AM, editor. Livestock Feeding on Pasture. Occasional Publication No. 10. Christchurch, New Zealand: New Zealand Society of Animal Production; 1987. pp. 89-105.
30. Beef + Lamb New Zealand. Ewe Body Condition Scoring (BCS) Handbook. Auckland, New Zealand: Beef and Lamb; 2013.