What do I need to feed my suckler cows in the coming weeks?

Every year at calving there is high risk of health problems. These include low calcium status, dystocia, retained placenta, low milk performance and delayed cyclicity. Catherine Egan and Joe Patton Teagasc how to manage your suckler cow’s nutrition in the crucial week’s pre calving.

Every year when calving comes around unfortunately there is high risk of health problems. There are a complex of interrelated conditions that can occur such as low calcium status, dystocia, retained placenta, low milk performance and delayed cyclicity. This is the time of year to act to reduce problems in the spring. In addition there is carryover effects on future productivity and fertility. Catherine Egan, Teagasc Cattle Specialist & Joe Patton Teagasc Nutritionist answer the key questions on how to manage your suckler cow’s nutrition in the crucial week’s pre calving.

What impact can body condition score (BCS) have?

There are a number of factors that can impact and reduce these issues at calving such as body condition score at calving. Body condition scoring works on a scale of 1-5 where 1 is extremely thin and 5 extremely fat. Condition score and group the cows in pens based on their Body Score Condition. Body condition scoring at this time of year allows you to make sure that cows will calve down in the 2.5 to 3.0 range and are "fit and not fat" before calving.  Grouping cows on body condition will allow feeding levels to be targeted to nutritional demand. The ideal situation is where cows can be split into three groups - fat cows can have fodder restricted depending on quality, cows in ideal body condition can be fed ad lib silage and thin cows will require supplementation with concentrates. Further information on how to body condition score here

What are the feed requirements of the dry cow in late pregnancy?

Cow feed requirements during late pregnancy are for maintenance of the cow, some growth of the cow particularly if she is young (especially applies to first-calvers) and for the growing foetus. The foetus gains between 75 and 80% of its total birth weight during the last 3 months of pregnancy. Where mature cows are in good BCS (~3.0) at the start of the winter their feed energy intake can be restricted such that some of the body reserves of fat are utilised to reduce winter feed requirements. This feed energy restriction can result in a feed saving equivalent to 1.0 to 1.5 tonnes fresh weight of grass silage.. The feed energy restriction can occur in various ways, such as offering moderate quality grass silage (65 DMD) to appetite, “diluting” the energy value of good quality silage with straw and offering that to appetite, or by restricting the amount of good-quality silage offered daily. Another option is feeding good-quality straw with supplementary concentrates. Where the amount of feed is restricted it is important that feeding space is adequate such that all cows can eat at the same time. If cows are below good BCS, they cannot be restricted and must be fed to requirements.

How to feed cows pre-calving?

Silage quality across farms is very variable. Unless you have your silage tested it is very difficult to guess what quality it is and what level of nutrition your cows are receiving. Once you have s silage sample result you can base your feeding practices around this as shown in table 1 below.

If moderate to good quality silage (65-70 DMD) is available, intake can be restricted to 30-35 kg fresh silage prior to calving. Assuming a BCS 2.5-3.0, cows should be fed such silage to appetite, if an adequate supply is available, while thinner cows will need concentrate before calving. Good-quality straw plus 2-3 kg of concentrates (including minerals & vitamins) is suitable for dry cows in good body condition. The crude protein content of the concentrate should be at least 18% in order to meet the dietary protein requirement. Feeding straw is not suitable for cows in poor BCS or for cows after calving.

How to avoid calving difficulty?

Many factors influence the incidence of calving difficulty but calf birth weight and internal pelvic area of the cow account for most of the variation in calving difficulty (dystocia). As cow BCS increases above a moderate level, calving difficulty can increase. Over-fat cows have increased calving difficulty because fat is deposited in the pelvic area, thereby reducing the size of the pelvic canal. Very thin cows also have increased calving problems (and increased calf mortality) due to insufficient strength to withstand the birth process and giving birth to weak, non-vigorous calves. Low levels of feeding during the last one-third of pregnancy will not result in predictable effects on calf birth weight or calving difficulty.

Fat cows can have increased difficulty at calving (fat-filled birth canal etc.). Reduced feeding during the last one-third of pregnancy may not solve this (there can still be problems calving). The problem of excess condition must be addressed earlier. Thin cows may have insufficient strength to withstand the birth process and can deliver weak non-vigorous calves

What minerals are required by suckler cows pre-calving?

Always offer an appropriate dry cow mineral/vitamin mix. It is important to feed the right type and level of pre-calver mineral (see example below Table 2). Pre-calver minerals should be fed for 4-6 weeks pre-calving. Pre-calver minerals can be fed by dusting on top of the silage, through water, trace elements can be supplied in boluses (but this will not cover for major elements), molassed mineral buckets and in a carrier ration. Ensure feeding rate is correct – weigh it out. If top dressing on silage, do it at least twice a day.  Ensure there is adequate feeding space (1.5-2.0 ft, 0.5 - 0.66m / cow). Don’t feed last year’s minerals.

To listen to this week's podcast on this topic or for more episodes and information covered on the Beef Edge, visit the show page at: www.teagasc.ie/thebeefedge