Boosting production efficiency is vital for maximising farm profitability, comprising over 60% of Breeding Worth (BW). Milk production and liveweight, with 48% and 15% weighting in BW respectively, are key indicators. In the UK, SCI also recognises liveweight’s impact, with grazing systems favouring moderate cow size for optimal efficiency.
When breeding your next generation of calves, and determining the desired weight of future cows, it’s crucial to consider the sire’s liveweight breeding value (BV). However, it’s important to remember that the bull is only one half of the equation. The dam’s liveweight contributes the other half of the expected calf liveweight and must be factored into your mating plan. The most effective approach is to ensure accurate measurement of cow liveweight.
The impact of liveweight on feed costs
Liveweight is not only important for breeding decisions, but also in ranking your cows based on production efficiency. Larger cows require more energy for growth, maintenance, and pregnancy, all of which translates into increased feed requirements.
In New Zealand, as well as in the UK and elsewhere, there has been a significant increase in on-farm costs, which is putting more pressure on profit margins than ever before. By 2023, feed costs had escalated to 30% of total farm working expenses. This emphasises the importance of ensuring your herd’s genetics delivers the most efficient users of grass possible.
Since 1990, overall milksolids production in NZ has increased by 50%. It is estimated that 60% of this gain can be attributed to breeding or genetics as indicated by the blue arrows. Incredibly, the LIC breeding scheme has delivered a 34% increase in the milksolids BV for only a 3% increase in liveweight breeding value over that time period.
The cost of maintenance should be a consideration in any breeding program. In practical terms, maintenance cost for 100 kg of liveweight = 298 kg DM/yr*. At 11MJ ME/kg DM feed, 100 kg heavier cows require roughly 2 more bales of feed per cow, per year for maintenance. To summarise the cost, 2 silage bales at £30 per bale is £60 per cow extra just to maintain the 100 kg of liveweight. This is a significant cost for a herd of 400 cows, equating to £24,000.
High production efficiency is not breed specific to Friesian, Friesian x Jersey cross, or Jersey. Finding that sweet spot for your individual herd and farm system is key. Using liveweights and milk recording data will be insightful as to the true elite animals on your farm. There may be highly efficient and profitable cows among your herd that you haven’t yet identified or have missed serving to sexed semen in previous years.
When is the best time to weigh the whole herd?
While weighing can be done at any time when the cows are in milk, the ideal time is after mating. It’s recommended to weigh them around 60-90 days into breeding.
Do I need to weigh every cow each year?
The key is to weigh the whole contemporary group at the same time. Fully spring block = once a year. Split block = twice a year. For mature cows, obtaining their liveweights once in their lifetime is typically sufficient, if you are happy the weight is accurate. You can add more weigh events to improve accuracy, if needed. After initially weighing the whole herd, the contemporary group of newly entered cows can be weighed each year, e.g., first calving heifers.
In the catalogue, what does a bull’s breeding value of 50 kg mean when selecting a bull?
This indicates that the bull’s daughters are expected to have a mature liveweight of 25 kg heavier than the base reference of 500 kg.
How will this impact the LIC herd improvement tool?
Weighing your cows will reorganise animals on the herd improvement tool and provide more accurate data to make decisions.
Without accurate animal weights, breeding decisions on which cow to mate for maximum profitability are often based on the assumption that each cow weighs around 500 kg. Applying a flat 500 kg value can result in inaccurate results. In New Zealand herds that have weighed their cows, there can be a difference of +/- 100 kg between recorded ancestry liveweights and actual weights. Most will fluctuate +/- 30 kg from ancestry. In the UK, due to less ancestry feeding into records, this difference may be even more significant as not every animal recorded has a sire record.
Based on data from the herd improvement tool, among herds in the UK where cows average over 440 kgMS, there’s an average difference of 215 kg between the top 25% and bottom 25% within a herd. For a 400-cow herd, this represents an opportunity to have 100 cows producing an additional 215 kg of milksolids. That’s 21,500 kg more milksolids out of the same number of cows. Multiply this by your farm’s milk contract to see the increased revenue. This reiterates the importance of accurately assessing the liveweights of the top percentage of cows you are breeding from.
What are the benefits of obtaining liveweights?
• Facilitates more informed decision-making
• Improved data accuracy
• Reduces feed costs for maintenance
• Produces a more uniform-sized crossbred cow, a highly heritable trait at 60%
• Allows calculation of liveweight to milksolids percentage
Contact your local LIC farm solutions consultant for any questions about weighing cows or interpreting herd weight data.
