A recent study by Brian Van Doormaal and Lynsay Beavers, of Canadian Dairy Network (CDN), has raised the issue of age at first calving. Bruce Jobson considers the benefits to UK farmers based on the Canadian findings.
The cost of rearing heifers is not inconsiderable as dairy farmers ’front-load’ their businesses with a two-year lead-in before a penny is earned to cover feed, labour, insemination and vet costs.
But one way for farmers to reduce costs and receive a faster return on investment is to consider calving down heifers at an earlier age.
So CDN analysed the age at first calving records from 2006-2014, and over that time the average age of Holsteins decreased by 1.4 months to the current average of 25.8 months. This is the same age for Jersey heifers, a breed which reaches maturity one to two months earlier than the other breeds represented in the study. However, age at first calving for Ayrshire and Brown Swiss averaged 27.2 and 26.7 months respectively.
Using Dairy Herd Improvement (DHI) milk recording data, CDN calculated the profit to six years of age for a subset of 690,000 Holsteins, 17,000 Jerseys, 17,500 Ayrshires and 4000 Brown Swiss born from 2005-2008. The profit values were calculated using rearing costs, cow income and cow expenses. A cut-off of six years of age was used as a dateline for each cow’s ability to survive a multitude of cycles including reproduction, health, functional conformation and production – an imperative aspect when looking at lifetime profitability.
While Holstein cows in Canada currently average 25.8 months at first calving, the data suggests 22 months of age is the ideal time for Holstein heifers to freshen in order to maximise their future lifetime profitability. Interestingly, calving down Holstein heifers before 22 months contributes to decreased total lifetime profit.
The most profitable age at first calving differs between breeds, and while the most profitable age for Holsteins and Jerseys is 22 months, for Ayrshires and Brown Swiss it is 23 months (see table, below). Based on Canadian figures, the amount of lifetime profit lost due to calving a typical Holstein heifer at 26 months compared to 22 months is $880 (about £450).
On that basis, if a farmer calved 30 replacement heifers per year, the increased profit to six years would amount to $26,400 (£13,600). While all breeds would benefit from reducing age at first calving, the Brown Swiss would benefit most by a reduction from 27 months to 23 months. According to CDN, this could lead to an average profit gain of nearly $1400 (£720).
The main benefit of reducing age at first calving is reduced feed and rearing costs as well as reducing the amount of time a heifer takes to begin paying back a return on investment. The disadvantages include a potential reduction in first lactation milk yield, but surprisingly the data indicates production per year of herd life is typically increased by lowering age at first calving.
While first lactation may be influenced by younger calving ages, future lactations, longevity and health are not influenced as long as first lactation heifers freshen at an adequate weight. However, it is worth mentioning every dairy farm (including UK) is different and circumstances will vary including management, environmental and topography. Furthermore, cost are subjective.
Using simple UK arithmetic, if we use an example of a heifer freshening within a herd two months earlier, savings and a return on investment can be considerable.
A heifer yielding 25 litres per day – and let’s use a figure of 25ppl – will earn £6.25p per day x 60 days and provide an earlier return of £375 or £11,250 on 30 heifers.
Likewise, savings on rearing costs could be reduced, and let’s use a symbolic figure of £1 per day or £7 per week. This would reduce rearing costs by £60 per heifer or £1800 per annum on 30 replacement animals. Clearly, as milk price challenges continue for the foreseeable future, reducing age at first calving can benefit earlier cashflow, reduce costs and lead to long-term profitability.