4 ways to breed your dairy cows to cut feed bills

Soaring costs of milk production and squeezed margins are turning many dairy producers’ attention to cutting input costs.

And with feed representing the largest variable cost, this bill is a substantial and obvious target.

Cutting the feed bill might be through better purchasing of ingredients, improving feeding and forage management, reducing feed rates, or introducing home-grown concentrate feeds.

But what about breeding? There is increasing evidence an animal’s genetics can have a profound influence on the amount of feed it needs to produce each litre of milk.

See also: How to assess and improve dairy herd genetics

Breeding has been proven over many decades to be the cheapest and most effective way to make permanent, long-term improvements to a wide cross-section of traits.

Below are the top four genetic indexes affecting feed efficiency that can be incorporated into any herd’s breeding strategy.

1. Feed advantage – identifies best feed converters

At the top of the target list is feed advantage, a genetic index introduced by AHDB two years ago and formulated to help producers breed animals that use the least amount of feed for their production needs.

This index accounts for the feed an animal is expected to eat given her solids-corrected milk production and the feed she needs for her maintenance.

It then compares this with her actual feed consumption, and in so doing, identifies efficient converters.

Prof Mike Coffey, who heads the animal breeding team at SRUC, explains:

“The actual feed consumption used in the calculation of this index is not measured at the herd level, as commercial milk producers don’t usually have the equipment to record precise dry matter intakes on an individual cow basis.

“However, the UK is fortunate to have the world’s longest-running trial in dairy genetic selection at the SRUC Crichton Royal Farm in Scotland.

Here, every animal in the Langhill herd has its daily feed intake recorded through its productive life, and its liveweight and body condition score recorded every week.”

This project, which has been running for about 40 years, has provided a wealth of information on animal performance, genetics and, specifically, genotype.

“It’s enabled us to translate an animal’s DNA into meaningful genomic indexes farmers can use – in this case, the feed advantage,” he says.

He emphasises the importance of both the quantity and independence of the data and the calculation of the index against a UK genomic background.

“By using this index as part of their selection criteria, farmers can expect to gradually improve the feed conversion efficiency of their cows on a permanent basis – and pass these improvements on to the next generation,” he says.

The scale of the benefits may be surprising to producers.

“The evidence indicates that the most efficient cows consume as much as 400kg less feed [dry matter] in just one lactation than the least efficient cows, given the same level of production,” he says.

“The scope for this to reduce feed bills does not need spelling out, and greenhouse gas emissions will obviously also decline as a result.”

But only Holsteins (male and female) that have a genomic index calculated will receive an index for feed advantage, which means for other dairy breeds and non-genotyped animals, producers will need to look elsewhere.

2. Maintenance – based on cow weight

Maintenance is the best genetic index for breeders without access to feed advantage. This is the case for all non-Holstein dairy breeds.

“Its calculation considers the weight of the cow – a figure that’s based on proxy traits including stature, chest width, body depth and angularity,” says Marco Winters, head of animal genetics at AHDB.

“These are used in lieu of actual cow weights, as many producers don’t routinely weigh their dairy cattle in the UK. However, we’d urge them to do so, allowing us eventually to create a database of weights to include in the calculation of this index.”

The logic to this index is that the cost of maintaining a cow is related to its weight; a cow weighing 600kg will have a lower feed requirement for its maintenance than a cow that weighs 700kg, even if they give the same amount of milk.

Figures for this index are expressed on a scale of roughly +50kg to -50kg, giving an indication of the average difference in weight expected in a bull’s daughters.

Negative figures are desirable, as they will help producers breed cattle with lower feed costs, all else being equal.

3. Lifespan – prediction of involuntary culling

The lifespan index also plays a role in reducing feed use, largely because of its favourable impact on replacement rate, which cuts heifer-rearing costs.

And since they account for about 20% of all milk production costs, mostly accounted for by feed, there is clearly scope to use far less if fewer heifers need to be reared.

The index itself gives a prediction of involuntary culling and, where available, it is calculated from actual cow survival.

Expressed as extra days of life on a scale of roughly -305 to +305, daughters of a +305 lifespan index bull are predicted to live, on average, 305 days longer than daughters of a sire whose index is zero.

As with all UK genetic indexes, zero represents the breed average for females.

4. EnviroCow – better feed conversion cuts GHGs

While the formulation of EnviroCow is designed to minimise greenhouse gas emissions for each litre of milk, most of this reduction is achieved through improving feed conversion efficiency.

Recent analysis has shown that each point of EnviroCow can cut feed intake by as much as 10% throughout a cow’s lifetime, while increasing lifetime production by 33%.

Longer lifespans, improved fertility and productivity, all built into this index, also play their part.