The performance of sheep farms is largely measured by numerical productivity, i.e. the number of lambs sold per ewe. To optimise profitability, it is crucial to pay particular attention to the ewe-lamb couple, both before and after lambing. Among the essential technical levers, nutrition plays a fundamental role, particularly during the peripartum period.
Numerical productivity, an indicator to be closely followed
Numerical production is a key indicator, as it sums up a series of technical and economic criteria on which meat sheep farmers can act to improve their profitability. The higher the number of lambs produced and sold per ewe, the greater the potential income from the farm, provided that costs are kept under control. Gross margin per ewe is positively correlated with numerical productivity, whatever the type of farming (organic or conventional, lowland or mountain).
To increase numerical productivity, action must first be taken on the ewe flock: improve fertility (>95%), prolificacy (>180% for prolific breeds) and reduce the interval between lambing and breeding (80 days for 3 lambings in 2 years, 160 for 1 lambing per year, CIIRPO 2023). Profitability will also be based on selecting the ‘best’ females, which means a high turnover and regular sorting of culls and unproductive females.
Secondly, the aim is to maximise the number of lambs sold. In France, the average mortality rate is 15-20% between 0 and 60 days, with 72% occurring in the first 10 days. The main causes are low birth weight (17%), followed by sudden death and enterotoxaemia (11%) and suckling problems (11%). To limit mortality, it is vital to prepare ewes for lambing. They need to be in good body condition when they give birth, to ensure the development of the foetus and produce quality colostrum, which will confer passive immunity on the lamb.
Higher metabolic needs in the peripartum period
While it is essential to monitor animals throughout their rearing period, the peripartum period is crucial. Ewes must arrive at lambing with an adequate body condition score (score > 3). The end of gestation is a period where nutritional problems can occur. Immune systems weaken about a month before lambing, and feed requirements increase while intake capacity decreases. Ewes may suffer from energy and nitrogen deficiencies, as well as mineral deficiencies (phosphorus, calcium, selenium). As soon as they give birth, oxidative stress in ewes will increase sharply. Ewes in good health have higher levels of superoxide dismutase, a natural antioxidant (Li et al, 2021).
Feeding ewes well at the end of pregnancy
Ewes whose nutritional needs are covered will lamb more easily and improve the performance of their lambs. These are the findings of a trial conducted by Techna on a pilot farm in 2023. Two batches of pregnant ewes were fed differently 6 weeks before lambing: one was fed exclusively a ration with 15.5% crude protein (CP), while the other was reformulated. Two products were combined: BG SUPRA, which strengthens the immune system and limits oxidation, and ELENSIS, which improves energy efficiency.
Despite a lower birth weight in the trial (4.3 kg compared with 4.7 kg in the control), linked to a higher number of multiple litters, the lambs largely made up for lost time, reaching 13.5 kg at 30 days, 200 g more than the control. The number of lambs weaned was also higher in the trial, as was the ADG. Mortality was lower thanks to easier lambing conditions. None of the triple lambs in the control survived, whereas 3 out of 4 litters were successfully born in the trial batch.
Optimising the energy efficiency of lamb diets
Techna developed nutritional solutions that improve the energy efficiency of diets. ELENSIS makes it possible to substitute certain raw materials as part of a reformulation. In a trial conducted in 2022/2023 at the Mourier experimental farm (CIIRPO), this strategy increased the feed cost margin by €5.45* per lamb. The formula of the ‘trial’ batch included a higher proportion of co-products (wheat bran) and less corn in particular, to which ELENSIS was added.
(*): Calculation based on an average heavy lamb price of €8.26/kg in 2023.
Feed influences carcass quality
Meeting the lamb's nutritional requirements not only increases carcass weight and ADG, but also improves carcass quality. Feed has a particularly strong influence on meat colour and texture. To find out more, Techna looked at the effect of ELENSIS in a trial conducted over 56 days in 2022.
The slaughter yield of lambs fed ELENSIS was 45% higher than that of the control batch (43.8%). A number of indicators showed better results: the carcass bleeding rate was lower and colour was maintained for longer. In addition, the colour of the fat is less yellow and the rancidity at 8 days is lower.
Conclusion
- Sheep production in France is dynamic and profitable, so it's important to choose the right solutions to support this industry.
- Numerical productivity, i.e. the number of lambs sold per ewe, is a direct indicator of the profitability of meat sheep farms. By monitoring it, farmers can make informed decisions that will improve the overall performance of their farm.
- Nutrition has a direct influence on fertility, foetal development, colostrum quality, lamb vigour and growth, etc. Nutritional management is therefore essential for improving numerical productivity on meat sheep farms.
- Optimum nutrition must be ensured during the critical peripartum period, otherwise technical and economic performance will be penalised.
- The programmes proposed by Techna, which include the use of ELENSIS, help to reduce lamb mortality, increase the feed cost margin and improve meat quality.
To find out more
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