Setting a Renewal Strategy in Dairy Farming
The renewal of a cattle herd refers per campaign to the number of heifers raised with the aim of integrating the herd.
In the short term, it constitutes one of the most costly items in the dairy operation; however, in the medium or long term, it conditions the milk production of future campaigns and allows genetic improvement of the herd.
It is therefore necessary to implement a renewal strategy consistent with the production system, in order to make it optimal from a zootechnical and economic point of view.
Initial reflection points
The basis of a renewal strategy involves three questions that must be proactively asked, 3 years before the first milking of heifers:
- What is the renewal need?
- What is the breeding rate to target on the farm?
- What are the renewal costs?
Renewal objective
In most configurations, herd renewal is defined by the number of culled cows: that is, animals that must be removed (up to 25%) for economic or health reasons (fertility, udder infections...) as well as animals that died during the campaign (5%). Generally, a safety margin of 5% is added to anticipate contingencies.
Ultimately, when the herd dynamics are stable, 35% is considered the objective not to exceed for the renewal rate.
Breeding rate
Definition
The breeding rate corresponds to the number of heifers raised as a proportion of the herd size, regardless of their fate (renewal or sale). Example: a number of 35 heifers for a herd of 50 cows corresponds to a breeding rate of 70%.
Interest of genomics
Once calvings are completed, it may be interesting to use genotyping of heifers to select the best genetically. This selection is performed via a blood or cartilage sample from the animals, whose DNA will be analyzed in a laboratory.
This process contributes positively to the genetic improvement of the herd, by inseminating the best heifers with sexed semen. It is part of a global breeding rate protocol, and allows a more informed selection of animals to inseminate by:
- Sexed semen: heifers inseminated with sexed semen will produce only female calves, thus future heifers potentially integrable into the herd. This protocol allows to optimize genetic progress, and can confer up to 8 points of ISU (Unique Synthesis Index) on average, thanks to semen from bulls with high genetic potential: this is called working on the male line. According to IDELE figures, one ISU point implies an increase in farm profitability of €5 (via improvement in milk quantities, protein content (TP), fat content (TB), somatic cell counts...), so an average gain of €40 per animal can be expected[1].
- Conventional semen: purebred and no sexing.
- Industrial crossbreeding: the less interesting females are inseminated with crossbred semen from other species (often beef breeds) aiming to produce calves better valued at sale. A Belgian Blue calf is sold on average €150 more than a Holstein calf.
Renewal cost
The third reflection point is the renewal cost: although beneficial in the long term, a high renewal rate and the use of genotyping can generate high expenses. To compensate for these, it is therefore important to rationalize the number of heifers to raise, as well as the cost of their raising.
Number of heifers to raise: case study
Example of a typical farm: 60 dairy cows - steady state - 500,000L of milk sold; renewal rate = 35% so strict need for 20 heifers per year + 5 as "safety margin" to ensure proper system functioning: 25 heifers to raise per year, the rest of the newborns are sold.
| FORAGE NEEDS | MAIZE SILAGE (14 DM/HA) | GRASSLANDS (6.5 DM/HA) |
| 1 heifer | 0.1 ha | 0.3 ha |
| 25 heifers | 2.5 ha | 7.5 ha |
| 30 heifers | 3 ha | 9 ha |
Without a predefined strategy, the farmer may decide to raise 30 heifers then sell 5 dry heifers (ready to calve), thus dedicating 2 additional hectares to them. The table below summarizes the economic consequences of this decision.
NB: the average production cost (excluding labor) of a heifer is considered €1500, including €450 fixed costs (land, insurance, mechanization...) and €1050 marginal cost (all costs related to the presence or absence of the heifer).
| 25 HEIFERS RAISED | ||
| Generated products | Details | Value |
| Sale of 5 calves | 5x100 | €500 |
| Gross margin (GM) 2 ha of wheat | 2x600 | €1200 |
| Costs saved | / | / |
| Cost of raising 5 heifers | 5x1050 | €5250 |
| Labor 5 heifers
(19h/heifer -1.25 minimum wage) |
95x1.25 minimum wage | €1128 |
| TOTAL | €8078 | |
| 30 HEIFERS RAISED (5 dry heifers sold) | ||
| Generated products | Details | Value |
| Sale of 5 dry heifers | 5x1100 | €5500 |
| Costs saved | / | / |
| Labor 2 ha
(7h/ha -1.25 minimum wage) |
14x1.25 minimum wage | €166 |
| TOTAL | €5666 | |
By choosing to raise 30 heifers, the farmer generates a loss of €2412, or €5 per 1000 liters!
It is observed that regardless of the sale price of dry heifers and the gross margin of wheat, raising only the number of heifers necessary for renewal is always more profitable (because the raising cost is always roughly close to the sale price). Moreover, depending on context and market, it may be difficult to find a buyer for 3-week-old or dry heifers, so they will have to be integrated into the herd, thus hastening the culling of productive cows.
Heifer raising cost
Once the optimal number of heifers to raise has been determined, it is possible to optimize heifer raising costs. The actual cost of raising a heifer can vary between €1100 and €1700 per head (including fixed costs), this significant range mainly depends on 2 items:
- Feed costs (forage menu, distribution) and fixed costs (heifer housing, labor…).
- Age at first calving (on average, the cost of raising a heifer calving at 25 months is €280 less than one calving at 28 months).
For information on the 2019-2020 campaign, in the 1055 farms of the Eilyps cooperative, the renewal cost averaged €24.2/1000L*. With a variation, at equal raising cost, from €11.2 to €36.5/1000L for the lower and upper quartiles.
*This renewal cost is measured by the difference between products (sale of culls, dry heifers or lactating cows) and costs (total cost of raising heifers, purchase of dry heifers, purchase of lactating cows), with heifer raising cost set at €1400, dry heifer purchase price at €1250 and lactating cow purchase price at €1100.
For further reading
Consult the website of EILYPS, a consulting and expertise company in livestock:
https://breeder-connect.com/article/definir-une-strategie-de-renouvellement-en-elevage-laitier
Summary
The renewal strategy results from a compromise between cost reduction, genetic improvement of the herd, loss limitation, and sales optimization. The diagram below summarizes the criteria developed in this article:
Appendices
References
- ↑ Delphine Scohy, Web-Agri, Renewal of the herd: Accurately calculate your need to avoid pushing too many cows to culling, 2019. https://www.web-agri.fr/genetique/article/147999/bien-calculer-son-besoin-pour-ne-pas-pousser-trop-de-vaches-a-la-reforme
