Guarding against a dip in butterfat, typically seen when cows go out to graze and continuing through the summer months, is high on the agenda for dairy farmers keen to maximise the milk cheque and protect margins.
Spring 2023 sees milk prices easing but no let-up in input prices. Riding alongside these factors is the increased focus on milk quality, with significant emphasis on constituents – fat and protein.
Degree of the dip
In Ireland, a typical seasonal pattern sees a reduction in milk fat throughout the grazing season, with the most noticeable drop in late-spring and early summer.
According to Irish Cattle Breeding Federation (ICBF), 10% of dairy herds in Ireland have butterfats lower than 3.3% and 40% of farms average below 3.6% during this period.
“Drops of 0.5% in milk fat are typical, and usually occur during the second and third grazing rotations – between three and nine weeks after turnout,” Cargill’s ruminant technology manager, Philip Ingram said.
“An average reduction of 0.35% is often seen between April and August.”
Figure 1 (below) shows the seasonal butterfat profile for a typical 120-cow herd managed on an automatic milking system and producing 7,450L of milk, at 4.49% butterfat and 3.65% protein, on 1.2t of concentrates.
Between March and October butterfat fell by 0.35%, with a low of 0.48% in May. In financial terms this equates to 70c/cow/day in May and 50c/cow/day on average throughout the season, based on an average yield of 25L/cow on a typical milk contract.
“This dip in butterfat ‘costs’ the business €75/cow, or €9,000 for the herd during the summer period, from May to September,” Dr. Ingram commented.
Why the butterfat dip
The greatest risk of reduced butterfat is seen where cows are grazing young, green, leafy grass.
“This grass has lower structural fibre, so digests quicker, as well as having higher sugar content, which can create acidic rumen conditions,” Dr. Ingram explained.
Also, it is higher in oil than more mature, later-season grass. In spring and early summer, the oil content in grass is 50% richer in unsaturated fats than a typical winter ration.
“The combination of the acidic conditions and the high oil content in fresh grass creates a ‘perfect storm’ in the cow’s rumen and disrupts the usual pathways used by the cow to produce milk fat,” added Ingram.
“Under these conditions, dietary oil is converted to conjugated linoleic acid (CLA). This oil disrupts the fat production pathways and causes a depression in milk fat.”
Mitigating the butterfat dip
Farmers can protect the butterfat content of their milk and their milk cheque by adding the specialised rumen buffer Equaliser Cream to buffer diets or concentrate feeds.
“Prevention is better than waiting for the problem to occur and then tackling it,” said Dr. Ingram.
“A dip in butterfat at turnout and through summer is inevitable, and the effects will soon bite into the milk cheque.”
Equaliser Cream is proven to mitigate a drop in butterfat. It targets the causes of milk fat depression.
“Most buffers tackle rumen pH as a means of helping to prevent milk fat depression, but they are not consistently effective,” said Dr. Ingram.
“Instead, [Equaliser] Cream has key ingredients to help reduce the impact of the high oil content of grass on milk fat.”
Equaliser Cream is in widespread use across Ireland and UK.
Cargill has monitored its effect on 25 dairy farms in 2021 and 2022. The response has been positive and consistent on all farms.
Of the 25 farms, 13 farms introduced the Equaliser Cream early, before the usual dip in butterfat, and 12 farms introduced it after experiencing low milk fat. Rates used were between 75-150g/cow/day. The proportion of grazed grass in the diet ranged from 0-75%.
Early users
The 13 farms adopting Equaliser Cream early had the best response with an average improvement in butterfat of 0.4% in May, compared with the same month in the previous year.
They pre-empted the dip in butterfat, avoided the stress of reduced milk quality and protected their milk cheque.
The 12 testimonial farms started feeding Equaliser Cream when they experienced low milk fat and saw an uplift of 0.33%, which continued during the next few weeks with an average increase in one month of 0.51%.
The benefit was rapid, with butterfat improving within a week of adding the buffer, and any drop in the milk cheque was minimised.
“The results show a positive response in both groups of farms but adding Equaliser Cream ahead of the predicted butterfat dip is more beneficial,” said Dr. Ingram.
“Responding after a fall in butterfat, making a dietary change and waiting for production to get back on track takes time, during which the milk cheque could well have taken a hit.”
The average financial benefit of adding Equaliser Cream to diets of the 25 commercial dairy herds monitored in 2021 and 2022 was 80c/cow/day, or €2,422/month based on a 100-cow herd on a typical milk contract.
For more information on Equaliser Cream contact:
- Michael Luttrell (southern Ireland) – +353 86 254 8827;
- Gordon Richardson (Northern Ireland) – +353 87 619 1616.
Or read up online by clicking here.
