Bio-economic efficiency of creep supplementation of forage legumes or concentrate in pasture-based lamb production system
Supplemental feeding of lambs with forage legumes or grains provides a potential option to increase proportion of prime lambs and profitability in intensive pasture-based lamb production systems. A two-year study in the Central Anatolian Region of Turkey compared the effects of creep grazing/supplementary feeding of either alfalfa, birdsfoot trefoil (BFT), or a feed concentrate on the performance of pasture-fed suckling lambs and their dams. The lambs that grazed the base pastures alone without access to any supplemental feeding served as the control group. In both years, creep feeding/grazing commenced in early June following a 42-day pasture grazing period (Period 1) and continued until mid-summer for two separate periods of 21 days each (Periods 2 and 3). Creep supplemented lambs grew faster than those that grazed pasture alone, with no significant difference across all creep supplementation treatments. Across the years, the lambs grew at 229, 222, 219 and 161 g per head d-1 for alfalfa, BFT, concentrate and control groups respectively. None of the lamb feeding strategies affected the performance of ewes. Results from a bio-economic optimization model however showed that supplementing the pasture with BFT and alfalfa in Periods 2 and 3 respectively, maximized economic returns with an extra profit of US$82.22 per lamb above those that grazed the pasture alone.