70% of lamb growth occurs in the final six to seven weeks of pregnancy.
The ewe’s daily nutrient requirements increase during this period and can no longer be met by a forage-based diet alone. Getting late pregnancy nutrition correct will aid in:
1. Achieving optimum birth weights; 2. Ensuring a plentiful supply of high-quality colostrum; 3. Reducing lambing difficulty and metabolic issues; 4. Reducing ewe and lamb mortality rates
It is important to scan ewes and group accordingly, as this allows for adequate supplementation pre-lambing according to litter size. For housed ewes, it is crucial to have sufficient trough space to enable them to eat comfortably at the same time. On average, a 70-kilogram ewe requires 50 centimetres of feed space.
So, for a standard bay that is 4.8 metres wide, there is enough feed space for around 10 ewes.
Clean, dry bedding is vital. Damp, dirty bedding will lead to increased lameness issues, along with lamb mortality, as it harbours bacteria that can easily infect the newborn lamb.
Reducing stocking rates at housing and feeding dryer forages can aid in lowering straw requirements for bedding. Ideally, allow 1.2–1.4 square metres of pen space per ewe in straw-bedded sheds.
Having ewes at the correct body condition score is essential in helping prevent twin lamb disease and milk fever. Ewes should be at a condition score of 3–3.5 at lambing or, as the saying goes, they should be “fit, not fat.” Ewes in poor body condition should be grouped accordingly to allow extra feeding (i.e. thin singles grouped with twins and thin twins grouped with triplets, etc).
Supplementation of ewes should start six to eight weeks pre-lambing, when energy requirements increase. The level of supplementation required will depend on forage quality, which is why a forage analysis is essential.
The ewe’s protein requirements increase dramatically in the last three to four weeks of pregnancy and are vital for producing a plentiful supply of high-quality colostrum. Lambs require 50 millilitres of colostrum per kilogram of body weight every six hours, amounting to 200 millilitres per kilogram of body weight in the first 24 hours of life. Feeding a 19–20% crude-protein concentrate is recommended.
Useful guidelines to consider when supplementing concentrates to ewes include: Increasing concentrate feeding levels gradually, with a maximum increase of 0.2 kilograms every three days (see Table 1); Splitting concentrates between two feeds when feeding rates rise above 0.5 kilograms per head, reducing digestive upsets and maximising forage intake; Ensuring clean, fresh drinking water, as ewes can require up to six litres of water per day.
Mineral supplementation is a vital part of late-pregnancy nutrition that is often overlooked in sheep. Ewes should be fed a suitable mineral premix, usually included in the concentrate, continually for six to eight weeks pre-lambing to ensure a good reserve of minerals and trace elements for when the ewe lambs.
Lambing is one of the most stressful stages of the ewe’s production cycle, which is why a good reserve of trace minerals to draw from is critical to boosting both ewe and lamb immunity, fertility and performance.
These important trace minerals include zinc, copper, manganese and selenium. Offering these minerals in their standard inorganic forms, such as copper sulphate or zinc oxide, will have little effect due to the ewe’s low absorption levels.
Research has proven that feeding these trace minerals in their chelated form, such as Bioplex® Copper, Bioplex® Zinc, Bioplex® Manganese and Sel-Plex® (an organic form of selenium), leads to better absorption, storage and utilisation by the animal.
This helps support the ewe’s and lamb’s natural immunity, colostrum quality and reduce lambing difficulties. This reduces the workload around lambing and improves profitability.
Using proven technologies as part of late-pregnancy and early-lactation ewe nutrition generates a greater return on investment. Many farmers are experiencing positive responses using Bioplex® and Sel-Plex® in their ewe mineral premix.