AbstractFollowing the evolution of the “Two Pasture System” of hill sheep management by the Hill Farming Research Organisation (HFRO) at their Sourhope and Lephinmore stations, the model was adopted by the Agricultural Development and Advisory Service at Redesdale experimental husbandry farm (EHF) and by the Scottish Agricultural Colleges at the West College Hill Farm of Kirkton in West Perthshire. At the time, the ADAS Pwllpeiran EHF in mid-Wales was engaged in an exercise based on the traditional Welsh management system in which ewes are kept on enclosed better grazings from tupping until after lambing and then ewes and lambs are summered on the hill.The paper describes the developments at Sourhope, Redesdale, Kirkton and Pwllpeiran from the mid/late 1960's until the present time (1980 for Kirkton). The four farms differ considerably in climate, topography, soil type, vegetation and size. In all cases, however, between 20-30% of the total resource was subjected to some degree of pasture improvement over the course of the development. In the case of Kirkton and Sourhope, 9% of the resource was reseeded, whilst at Redesdale the corresponding figure was 17%. At Pwllpeiran, most of the improvement involved surface treatment but of a fairly costly nature almost equal to that of reseeding.In all cases, the improved pasture was used to provide ewe and lamb grazing during lactation and ewe grazing around mating and lambing. Supplementary feed inputs per ewe during late pregnancy increased significantly on all farms. There was an increase in ewe numbers carried, being 99, 139, 42 and 3% greater for Sourhope, Redesdale, Kirkton and Pwllpeiran, respectively. Weaning percentages (lambs weaned per 100 ewes put to the ram) also increased, by 26, 48, 48 and 36% for Sourhope, Redesdale, Kirkton and Pwllpeiran, respectively. Taken together, there was a significant corresponding increase in the number of lambs weaned of the order of 121, 297, 129 and 47%.Lamb weaning weights were improved in all cases in spite of increased twinning. This weight increase was most significant at Pwllpeiran where a major effort had been made to change breed type with the specific purpose of producing a heavier lamb.Gross margin data were available for Sourhope, Redesdale and Kirkton and when plotted on a per ewe and per hectare basis follow remarkably similar pathways over the development for the three centres. The gross margin figures per ewe, when discounted to base, show no significant increase and in some cases were reduced up until the introduction of the EEC sheep meat regime in 1981, after which time significant real increases occurred for those developments still in progress (Sourhope and Redesdale). The real increase there occurred as a result of increased stocking rate. On Pwllpeiran, however, where stocking rate increase was low, it is still considered that the exercise was profitable as measured by Internal Rate of Return.The various increases confirm that investment in land improvement, coupled with an enlightened approach to sheep management, has improved the overall efficiency of pasture utilisation and economic viability.
Effect of stocking rate on milk and pasture productivity and supplementary feed use for spring calving pasture fed dairy systems