Feeding the lactating ewe for performance

 

Reducing the quality or quantity of supplementary feeds offered to lactating ewes will reduce milk yield and quality, cut lamb growth rates and in the long run prove to be a false economy.

 

That’s the message from Trident technical manager Dr Michael Marsden, who is keen to emphasise the importance of continuing to invest in supplements for ewes after lambing. And although cereals are a temptingly cheap option this year, they must be adequately balanced with suitable sources of digestible fibre and extra protein to safeguard milk production and lamb growth.

 

“As the ewe moves from pregnancy to lactation, her nutrient requirements increase substantially,” states Dr Marsden. “Some of that energy will come from body reserves, but losing any more than half a body condition score during the first 6 weeks of lactation will significantly reduce performance.

 

“The rest of the nutrients have to come from feed, and depending on liveweight and the number of suckling lambs, ewes will need between 20-30MJ ME/day at peak lactation. Using cereals will help keep costs down, just make sure you include feeds like sugar beet pulp for the digestible fibre needed to buffer the rumen and a high quality protein source such as distillers’ pellets, soyabean meal or rumen bypass proteins like SoyPass.”

 

Since the nutrient requirements for ewes suckling multiple lambs can’t be met by forage alone, even good lush spring grass, a 75kg ewe with twins typically needs up to 1.1kg/day of supplementary feed. Where hill flocks only have access to poor quality grassland, or early lambing ewes are heavily reliant on silage, straw or hay until grass growth takes off, up to 1.6kg/day will be needed.

 

“The simplest and easiest solution is to continue feeding the same supplement used in late pregnancy, at least for the first four weeks of lactation,” continues Dr Marsden. “The lamb is entirely dependant on milk for all its nutrients during this time, so aim for at least 12.5MJ ME/kg DM, with 16-18% crude protein, rising to 20-22% crude protein for straw-based rations.”

 

Table 1 shows some simple combinations suitable for feeding to early lactation ewes. To help avoid digestive problems, feed no more than 0.5kg of supplement per meal, splitting off ewes which require higher levels and feeding them several times per day if needed. And don’t be tempted to increase the level of low-cost cereals without adding more digestible fibre, as too much starch can raise rumen acid levels (acidosis), leading to lower feed intakes, poor digestion efficiency, a drop in milk production and quality, and an increase in lameness.

 

Table 1 – Example rations for lactating ewes          

 

* Advice should be sought before feeding Scottish distillers’ feeds to ewes due to the copper content.

 

 

Digestible fibre in the ration has also been shown to be extremely important in promoting milk fat production. Research work conducted at Writtle Agricultural College, for example, demonstrated that feeding sugar beet feed as part of a lactating ewe’s ration consistently improved milk butterfat levels, and hence the energy content of the milk. Repeated on farm, the result would be higher lamb growth rates, greater weaning weights and quicker finishing.

 

“Similar work completed at ADAS Rosemaund concluded that simple 50:50 mixes of sugar beet feed and low-copper maize or barley distillers’ pellets - plus a suitable vitamin and mineral supplement - could successfully replace a barley-plus-soyabean-meal type concentrate for lactating ewes at grass,” confirms Dr Marsden. “In addition to the potential benefits in terms of ewe milk production and lamb growth, it’s an option which could become increasingly important where the traceability and GM status of feeds have to be assured.”

Table 2 – Diets used in ADAS trials*

* Advice should be sought before feeding Scottish distillers’ feeds to ewes due to the copper content.

Note that vitamins and minerals were provided

• © 2010 Trident Feeds  
• Privacy Policy
• Terms & Conditions