Technical and economic performances in sheep for meat production. Key factor for success. Comparison of 2 systems in experimental farm.

Summary in the original language of the document

Two sheep for meat flocks on OF are compared in experimental farm, carried out according two contrasted managements of the reproduction: 3 lambings over 2 years or one lambing per year (“grass system”). The first system is in coherence with OF principles (1 lambing per ewe per year) whereas the second one tries to be much more productive and is much more confronted to the respect of standards.The aim is to study the global balance with a systemic approach, the technical (animal) and economic performances, the ways to have a good mastery of sanitary problem with as few chemical treatments as possible, the quality of the lambs, the management of the forage system and the soil fertility, the biodiversity. A specific work is made about the reproduction of ewes (how to have good fertility for spring mating) and the limitation of concentrates for the lambs. The economic performances are compared with private organic and conventional farms.
Two 100 ewes flocks are compared, each managed with their own lands (pastures, crops…: 24ha by system) and shed. Recorded data are concerning grass production, animals (fertiliy, prolificacy, mortality, growing rates, body scores, concentrate use, faecal analysis for worms), economics (production costs, products, calculation of gross margin), quality of carcass (conformation, color and firmness of subcutaneous fat), biodiversity (flora, insects, birds).
The economical advantage of increasing lambing frequency was not demonstrated, whereas this strategy complexified management and resulted in higher internal parasitic infection of the lambs, and finally showed a lower stability. In the accelerated system, the numerical productivity is slightly higher (+6%: 161 vs 152 on average over 3 years 2001-2002-2003) but, even when the difference is high (year 2002: 193 vs 152), the gross margin per ewe is not much higher (90€ vs 86) because of high production costs: the concentrates achieve 178kg/ewe (+58%) with a price 60% higher than on conventional farming. Moreover, the results are much tended and irregular in this system. The “grass system”, less intensive for the animal, is the illustration of a compromise between high level of animal performances and the mastery of feeding costs with the maximisation of fodder resources use.There were difficulties in establishing a very high feed self-sufficiency in both systems, especially the more intensive system (4 points lower), due to harsh climatic conditions. Fodder production (quantity and quality) is one of the most basic points (with the special importance or nitrogen supply). There was no major sanitary problem and 77% of the lambs had not any chemical treatment ; the ewe mortality rate decreased and achieved only 2,3 and 3,6% (respectively grass system and intensive system, average 2002-2003).