How important is the nutrition of suckler cows in late pregnancy?

Spring-calving suckler cows and heifers are now in mid-to-late pregnancy and it’s extremely important that measures are put in place to feed these animals correctly.

Feed requirements during late pregnancy are for maintenance; some growth of the cow (especially if she is a first calver); and for the growing foetus.

According to Teagasc, the foetus gains between 75-80% of its total birth weight during the last three months of pregnancy. Therefore, it’s vital that the cow or heifer is fed appropriately.

Cows should be grouped according to body condition score (BCS). The target BCS for spring-calving suckler cows is 2.5. Animals that are in good condition (BCS of 3) can be fed a restricted diet in order to utilise fat reserves.

This will also double up as a measure to preserve silage stocks on farms. This feed energy restriction, Teagasc says, can result in a feed saving equivalent of 1-1.5t of fresh weight of grass silage. However, farmers must take care when restricting feed.

Teagasc’s advice on feed restriction:
  • When feed is restricted, farmers need to ensure that the feed space will allow all cows to eat at the same time;
  • If cows are below good BCS, they cannot be restricted and must be fed to requirements;
  • Always offer an appropriate dry cow mineral/vitamin mix;
  • When moderate or good-quality silage (65-70% DMD) is available, intake can be restricted to 30-35kg fresh silage prior to calving;
  • Good-quality straw plus 2-3kg of concentrates (including minerals and vitamins) is also suitable for dry cows in good body condition.

This year, silage quality on farms across the country may be lower than normal. Where this is the case, concentrates should be fed along with grass silage. Thinner cows with low BCS need to be fed a higher plane of nutrition.

According to Teagasc, silage with a dry matter digestibility (DMD) of 60% should be supplemented with 1.5kg of concentrates. In addition, silage with a DMD value of 55% should be fed along with 2kg of concentrates to animals falling into this category.

farm

Teagasc research shows that calving difficulty cannot be reduced by underfeeding cows. In addition, overfeeding concentrates in the last few weeks prior to calving to get cows into the required body condition will not work.

While the BCS of the cow/heifer is important at calving, so too is providing the right level of minerals. Pre-calving minerals should be fed from four-to-six weeks prior to calving.

Ways to feed pre-calving minerals:
  • Dusting on top of silage;
  • Through the water supply;
  • In boluses (not all major minerals supplied);
  • Mineral buckets;
  • Carrier rations.

Furthermore, if minerals are provided via a top dressing on silage, farmers should apply minerals twice daily and ensure that all cows have adequate space to feed.