Watch: Monitoring body condition score at Teagasc Grange
Suckler farmers should aim to body condition score (BCS) their cows at least three times per year, housing, pre-calving and breeding, writes Colin Byrne, Research Officer at Teagasc Grange.
This means farmers should handle their cows as per guidelines described in the video below.
Assuming that a cow has a BCS of 3.25-3.5 at housing, 65-68% dry matter digestibility (DMD) grass silage, fed ad-libitum during the dry period, is sufficient to allow for some mobilising of body reserves and aim for calving at BCS of ~3.0.
It is important to remember that 80% of the calf birth weight is grown in the last three months of the pregnancy. Where herd BCS is not uniform, group cows by BCS at housing and feed as appropriate to increase BCS to 3.0 before calving or maintain BCS if at BCS 3.0.
If cows are in good BCS (3.0+) and only better quality silage (>70% DMD) is available, farmers should restrict access to silage or incorporate straw into the silage to dilute the quality of the offered feed.
In the below video, Eddie Mulligan, Farm Manager at Teagasc Grange, demonstrates body condition scoring beef cows:
Pre-calving minerals
A pre-calving mineral should be offered to cows at least six weeks before calving to reduce the risk of health and metabolic problems around calving. Minerals and vitamins can be offered via water supply, boluses, mineral licks, dusting on silage or in concentrate feed, if offered.
Pre-calving calcium should be minimised and magnesium increased to aid calcium metabolism. Vitamins A, D and E should be fed at high levels to ensure good immune function and reduce the post-calving risk of infection and milk fever. Conducting a silage quality analysis will provide the nutritional value, preservation efficiency and mineral profile.
Body condition score at calving
Spring-calving cows should be at a BCS of ~3.0 (0-5 scale) at calving to allow for a BCS loss of 0.5 prior to breeding. Cows that are in poor body condition post-calving (BCS <2.5) will have a delayed return to heat.
The effects of low BCS at calving are only partially reversed by placing cows on a high plane of nutrition after calving and extra feeding after calving will not fully compensate for poor BCS at calving. For example, a cow with a poor BCS of 1.75 will not cycle until 71+ days after calving, whereas cows with a BCS of 3.0 will be cycling by day 55. An extended post-partum interval increases overall calving interval.
Figure 1: Target BCS for suckler cows
Teagasc Grange – suckler herd update
Calves were weaned between the 6th and 13th of October. The average weaning weight was 290kg. Cows were housed when separated from calves and have remained indoors as weather conditions meant ground was not suitable for a return to grazing. The weanlings remained outdoors until the 1st of November. Calves are currently indoors being offered 73 DMD grass silage and 1kg of concentrates.
Replacement heifers
30 weanling heifers have been purchased as replacements. Heifers are Limousin x Simmental and all in the top 20% (five star) for Eurostar Replacement Index. Heifers weighed an average of 310kg on arrival. Heifers are vaccinated for pneumonia, IBR, salmonella and BVD on arrival.
Heifers will be offered 73 DMD silage and 3kg of concentrate over the winter. These heifers will be prioritised and turned out as soon as ground conditions allow. These heifers will be AI’d to easy calving, high Replacement Index bulls in May/June 2024 to calve down at 24 months of age.
Finishing performance
Finishing of 2022-born animals is slightly behind last year. To date, eight Charolais heifers have been finished at an average age of 19 months, with a carcass weight of 294kg at R=3- grading.
Fourteen Hereford-sired heifers, from first calvers, have been finished at an average age of 18.6 months, with a carcass weight of 254 kg at R-4- grading. Ten Hereford sired steers, from first calvers also, have been finished at an average age of 19 months, with a carcass weight of 282kg at R-2+ grading.
The remaining Charolais-sired animals will be drafted for slaughter in the coming months with a target of having the heifers finished by 21 months and the steers finished by 23 months of age. The remaining animals are being offered 73 DMD grass silage ad libitum and 5kg of a high-energy, barley-based ration daily.
Cow nutrition
Calving is due to start in early February, so any corrections that are required to cow condition should be made well in advance of expected calving date. For example, if cows are in poor BCS introducing some concentrate to correct this now should have minimal impact on calf size.
Likewise, overfat cows should be restricted now. Restricting the cow closer to calving may lead to reduced colostrum quality or weaker cows at calving. Remember, you cannot starve calving difficulty out of cows and heifers!
At Grange, in-calf cows and heifers are currently indoors and being offered 69 DMD silage. At weaning, in early October, cows weighed 644kg on average with a BCS of 2.8. While the BCS average is okay, the range is 2.35 to 3.5. Cows with a BCS less than 2.5 will be grouped together and offered 0.5kg of concentrate until they reach their target BCS, this shouldn’t take longer than 4-6 weeks once the cow has been dried off.
In-calf heifers currently weigh 546kg on average with a BCS of 3, ranging from 2.75 to 3.5. At the moment, the heifers at the lower end of the range will be monitored to check BCS changes, the lower BCS in some is attributed to the wet conditions and poorer performance in animals in autumn on many farms.
This article first appeared in the Future Beef Newsletter for December. For more information on the Future Beef Programme and to sign up to subsequent newsletters, click here.
Also read: Future Beef Farm Ed Curtin demonstrates his housing and handling facilities