TIME4RATIONING – Rationing advice for spring calving suckler cows

TIME4RATIONING – Rationing advice for spring calving suckler cows

It’s essential that spring calving suckler cows are fed balanced diets to maintain tight calving patterns and improve the chances of calving success, which in turn impact herd profitability.

Working out daily feed requirements will help ensure target body condition scores (BCS) are met to optimise cow health and fertility, as well as improve feed efficiency.

Read on to learn what these target BCS are and how to ensure herd energy and mineral requirements are met.

Target body condition scores

Condition score for spring calvers (QMS 2020)

Ideally, suckler cows should be calving and bulling at a target BCS of 2.5 to help reduce the incidence of calving difficulties while promoting positive calving intervals. If cows are overweight at calving the assisted calving rate is more likely to increase. There is evidence to suggest that cows with a BCS of 3.5 typically have an assisted calving rate around double that of cows with a BCS of 2.5.

Aim to get pre-calving suckler cows to the correct condition score during mid-pregnancy by grouping cows with a similar BCS and feeding accordingly. Be aware that increasing the amount of energy in late pregnancy to achieve the target BCS can reduce calf vigour at birth.

Heifers and second time calvers are often the leanest cows on-farm so they, along with shy feeders, will need to be monitored more closely to make sure they reach the target pre-calving condition score.

Energy requirements

Autumn calvers require significantly more energy than spring calving beef cattle to maintain body condition while lactating throughout the colder winter months.

The energy requirements for a spring calver per day are 10% of their body weight plus 10MJ. In addition, dry matter requirements are 2% of total body weight. For example, a 600kg suckler cow would require 70MJ/energy and 12kg of dry matter per day.

It’s worth noting that genetics impact the amount of energy required to achieve target pre-calving condition scores. For example, cows put to a Charolais are likely to require more energy than those put to an Aberdeen Angus because larger breeds typically produce larger calves, meaning the cow will require more energy during pregnancy to sustain calf growth.

Generally, suckler cow energy requirements will be met through feeding forage alone and, unless cows are fed straw or have straw mixed into their diets, it’s advised to avoid feeding large amounts of concentrates.

If cows are fed a straw-based diet, aim to feed a good quality concentrate that contains 18% protein such as Lifetime Rearer or Unigold nuts. Bespoke blends can also be created by your local on-farm specialist, and also consider adding molasses to straw to encourage intakes.

Freshly calved cows will require double the energy needed by a dry cow for milk production and to promote recovery after birth. Energy is the key to ovulation and keeping a tight calving pattern, so ensuring the correct energy levels are fed during early lactation will also promote optimum fertility.

Mineral requirements

The mineral requirements of pre-and post-calving suckler cows are often overlooked, yet it is crucial the correct levels are fed to promote cow and calf health.

Consider conducting forage mineral analysis and then taking blood tests at least six weeks before calving to pinpoint any deficiencies in the following minerals:

Essential suckler cow minerals[1]

Iodine Cows that are deficient in iodine in the last four to five weeks pre-calving are more likely to have weaker calves. Consider bolusing six weeks pre-calving with a high iodine bolus to be sure requirements are met. For pregnant and lactating stock this is 0.5Mg/kg DM.
Selenium A lack of selenium can cause white muscle disease in calves and retained cleansing in cows. Selenium can be administered via a bolus. For pregnant and lactating stock, the recommended level is 0.1Mg/kg DM.
Magnesium Magnesium deficiencies can increase the risk of staggers or hypomagnesaemia post-calving. Pregnant cows require 0.12% of total ration DM while lactating cows require 0.20% of total ration DM. Consider feeding magnesium rolls to achieve this.

Providing supplementary pre-and post-calving mineral blocks such as Vitalyx super suckler or Megastart pre-calver is another option to make sure suckler cow mineral requirements are met. Megastart contains Safmannan®  which will help to increase the immunoglobulins in the colostrum by around 25% which will help to improve calf health.

If you require further advice, consider discussing historical issues with cow health around calving with a local on-farm specialist.

[1] How to manage minerals in suckler cows pre-calving – Farmers Weekly (fwi.co.uk)