THE Total Dairy Seminar, formerly the Large Herd Conference, attracted some 400 delegates to Gloucestershire. More veterinary surgeons attended than in previous years and a significant exhibition area covered many aspects of dairy herd management and technical improvement.
On the first day there were three streams operating together with a main talk and two workshops and on the second day a main talk and three workshops.
It was necessary to plot a course through the 23 topics, but each group had a pleasant relaxed atmosphere with plenty of opportunity for discussion. It was noticeable that the speakers continued to exchange views with the delegates during the breaks.
Overall was the realisation that difficult times exist for dairying in the UK and the speakers from the USA clearly understood the situation and were able to relate to their dairying downturn that has now changed for the better.
One of the noticeable aspects to dairy farming in the USA was the reference to “beef cows”. This caused a little confusion until it was explained that “beef cows” are cows culled from the dairy herd.
The animals are entering the beef food chain. A good price is available for beef cows so it pays the farmer to offer the beef buyers disease-free animals in good condition rather than thin, overworked, poorly beasts.
Greg Bernhard (Wisconsin) pointed out that the replacement cost of introducing a heifer is the important value, not the culling rate.
High health means high value cull cows and the financial impact of a dead or diseased cow is a high replacement cost. The aim is to sell the beef cows before serious illness or death is anticipated. Pregnant cows are valuable with day-old bull calves fetching 400-500 dollars.
This fit cow culling approach also raises questions over whether it is viable to treat a sick cow or cull her. A high culling rate (@35%) is not considered a measure of herd failure but a measure of realistic economics.
Over time the cost of replacements, less the value of the cows sold, divided by the value of milk sold, indicates herd performance.
If the difference between introducing a heifer and the salvage value of a cow is £750, then a 400- day first lactation needs to provide a margin of over £1.88 per day to justify the cull.
In assessing feed costs it is the amount served to the cows, not the amount eaten, that needs to be measured. The milk produced per cow is an outdated measure; it is the income over feed costs that is relevant.
In poor economic times it is the reproductive performance and “keeping cows right” that enables the farmer to survive and be in the best place to benefit when there is a recovery.
Dr Bernhard pointed out that when USA dairying was in recession in 2009, none of the forecasters predicted the dramatic increase in demand that came about because of the purchase of milk powder by China.
Factors in failure
Jo Leroy (Antwerp) outlined where to start to achieve good nutrition, metabolic health and fertility. Cash flow in Flemish herds is badly affected by a higher culling rate. The failure of cows due to poor reproduction, production and mastitis are significant factors.
Dairy cows are genetically engineered to utilise body reserves in order to achieve high milk production and loss of body condition is correlated with health problems and reproductive outcome. Calving problems, whatever the cause, lead to a reduction in oestrus activity.
Dry cow management is therefore crucial to pre-programme the cow for lactation, as energy imbalance cannot be adjusted once it has occurred.
The rules are: never speak about energy balance without discussing appetite first; never speak about appetite without discussing dry cow management first. Make sure the cow is eating and then consider what she is eating.
Faecal consistency is a useful indicator of adequate nutrition, with rumen fill scoring an indicator of feeding and feed intake problems. Body condition scoring is a valuable tool to recognise the amount of fat cover and therefore energy reserves.
Professor Leroy emphasised that ketosis is considered to be a symptom of a suffering metabolism and ongoing monitoring of subclinical ketosis is important for many herds.
Elanco was one of the gold sponsors and featured research results showing that cows housed all year have a lower incidence of “hidden” ketosis than cows at pasture.
The Keto-Test dipstick for milk shows a colour change, with a relative beta-hydroxybutyrate reading of 100 or more indicating ketosis. Early lactation positives, from groups of fresh calvers, indicate essential attention needed for the herd to prevent “fire-fighting” the disease.
Jon Huxley (Nottingham) openly discussed the detailed lack of knowledge about dairy herd lameness but indicated that current research is probing for answers.
Established views about the roles of rumen acidosis, laminitis and claw horn lesions are being challenged. A greater understanding of the changes within the hoof around calving, slackening of the connective tissue and the variation of the digital fat cushion are indicating areas for attention.
The relationship between body condition score and lameness is a strong one and attention to loss of body condition may be an important management development to prevent lameness.
Nick Bell (RVC) led a workshop involving three foot trimmers. Each professional (David Rowe – Devon, Tim Carter – Dorset and Steve Bradbury – Wales) utilised video to show their standard hoof trimming technique.
Initial discussion focused on the Dutch 5 Step Method but it soon became clear that although this approach was widely taught and adopted, the trimmers varied their approach.
Whether a knife or a grinder was used seemed to be a matter of personal choice but there were differences in the shaping of the inside claw (Dairyland), considered to be a likely ulcer site.
Lengthy debate
There is considerable debate around the length of the hoof. The point of measurement, from the top of the hard wall to the toe, targeting 7.5cm, is clearly in need of interpretation and that within and between herds, one size does not fit all.
The whole emphasis was on prevention and although the mobility scoring scheme has been available for some time there were doubts expressed over how many farmers effectively make use of this method.
Hoof trimmers are routinely being asked to attend to actively lame cows within a herd and there are clear situations where the cow is referred for veterinary attention.
The point was made that liaison between veterinary advisers and hoof trimmers is patchy with only some herds being closely monitored.
Hoof awareness, trimming and veterinary involvement are clearly important issues and this session was a successful informative format.
It’s in the air
The value of powered active ventilation and long day photo period lighting was explained by Michael Wolf of Country Doctors Veterinary Services, Wisconsin.
Although the extremes of temperature in his home region have specific requirements, Dr Wolf has also been involved with UK developments.
Powered fans produce dryer bedding as a secondary benefit and maintain the temperature humidity index below 68. Above this and the cows experience an increased standing time, a lower lying time and poorer milk production.
It is better to use larger, more efficient fans than more smaller fans and direct the air “where the cows are, not where the birds are”. Dust-covered fans lose half of their capacity.
Long day lighting suppresses melatonin with the effect of improving liver and other functions, leading to more substrate for milk production. Cows must experience darkness so 16 hours of lighting is arranged, concentrated on where the cow’s head is in the feeding and lying areas.
One consequence is that calves are born with a shorter hair coat as the cows think it is summer. After one week there is an increase in yield and then an increased feed uptake with the benefit being equated to “a bovine somatotrophin shot”.
Nearly 40% of semen in the UK is now selected, by farmers, following herd genetic tests, and this figure is increasing.
Andy Dodd, of AHDB Dairy, explained how herd genetic reports for milk recorded herds give the genetic potential of every breeding animal on the farm. This information is available to vets and breeding advisers and allows strengths and weaknesses to be identified.
General advice is not to breed from the bottom 10% of genetic merit and for one bull to be used on a maximum of 15% of the herd. A heifer genetic report and a TB index are anticipated.
The conclusion is that selecting for genetic merit offers significant improvements for UK herd performances.
- Next year’s seminar will be on 1st and 2nd June. See www.totaldairy.com.
