Is your bull pulling his weight?
We all spend a large amount of our time and efforts making sure your herds fertility is as good as possible - but it’s easy to forget about the other 50% of the herd!
It is often assumed that the bull is fully fertile and capable of getting the job done, but up to 20% of bulls are found to be sub-fertile once tested (NADIS). This can clearly have a massive knock-on effect on the number of cows becoming pregnant. Every extra day that an individual cow remains open can cost £3-4 so the costs can quickly rack up. The implications in a block-calving herd can be even more stark.
There are a number of things that we can do to ensure that stock bulls are performing to the best of their ability before we set them to work:
1. Assess body condition score (BCS) - bulls should be score 3/3.5 for optimum performance with both under and over conditioning leading to a decrease in fertility
2. Nutrition - is the bull getting enough high quality nutrition to give him the energy he needs. Any dietary changes should be made well before the breeding period as changes during that time can affect semen quality
3. Trace elements - some trace elements such as Zinc are crucial for maintenance of semen quality so make sure that your bull is supplemented correctly
4. Legs and feet - A lame bull cannot work effectively so it is paramount that any lameness issues are resolved well before the bull needs to go in
5. Infectious disease - any new animal entering the herd should be quarantined for at least 14 days and tested for infectious diseases such as BVD and Leptospirosis as these pathogens can cause serious harm to your cows and their fertility. All bulls should be treated for Lepto on arrival as a precaution
6. Semen quality - both the quantity and quality of the semen a bull produces are very important: This is where we can help by carrying out a Bull Breeding Soundness Examination
Bull Breeding Soundness Examination:
This examination assesses whether a bull is capable of producing a large enough volume of high-quality sperm so he can be considered fertile enough to get the required number of cows in calf as quickly as possible. We will assess your bulls overall health including BCS, heart, lungs and feet as well as taking more specific measurements such as scrotal circumference that are key indicators of fertility. Both the internal and external genitalia will be checked to ensure that there are no abnormalities preventing normal function, and we will obtain a semen sample by electro-ejaculation (EEJ). This allows us to examine the sperm under a microscope to check that all are swimming as they should be.
Having passed all of these examinations your bull can be certified fully fit and fertile and ready to get to work.
Facilities: There are a few requirements that will enable us to test your bull safely and efficiently - a crush (that your bull will be able to fit in to!) with side access doors is crucial, as is a source of electricity to power the necessary equipment. A table or bench also comes in handy to put everything on, and some lighting helps too if possible.
Please get in touch if you would like any more information about bull breeding soundness examinations or to book in a bull for his check-up. Discounted rates apply for multiple bulls tested together.
Johne's and whole milk feeding - what is the risk?
There are benefits to whole milk feeding calves in terms of consistency, constituents and antibodies but there is a risk of spreading Johne's disease too. Sometimes it's the bull calves that are fed on whole milk, whilst the heifers are fed on powdered milk replacer, and it is always interesting to compare growth rates and health traits between these two groups.
80% of Johne's infections happen in that calf's first month of life - the vast majority of those infections are from the calf having access to adult cow muck in a calving yard or in that first week of life so limiting this contact must be the top priority. Over time, as the number of infected cows reduce, Johne's control changes and we can focus in on the smaller risks.
When feeding whole milk, the biggest risk is feeding milk that has been contaminated with infected muck before it is fed to the calves as muck is by far the biggest source of Johne's bacteria. Up to 1 in 10 high risk cows will be shedding bacteria directly into her milk, and 25% shed into colostrum - and that risk increases over time as the disease progresses which is why test positives must NEVER contribute to milk fed to replacements.
If you are pooling unpasteurised milk to feed to replacements there are some golden rules to follow to avoid the accidental spread of Johne's via milk:
- Test all cows quarterly to pick up as many positives as possible so we can start to believe the repeat negative results are truly negative - these true negatives can contribute to the pool
- Clearly identify all known positive cows and these never contribute to the pool
- Strict pre-milking teat disinfection in the parlour so there is no accidental contamination of the pool with muck from dirty teats
- Collect pooled milk in a lidded dump bucket or direct to line so there is no chance of muck contamination from passing cows
Is there Johne's bacteria in the milk fed on your farm?
Most of the testing for Johne's is looking at immunity to the bacteria in the form of antibodies, but we can also test for live bacteria in the milk.
For those of you who are feeding whole milk to replacement heifers and have put control plans in place to limit this risk, testing for live Johne's bacteria is a way of checking how effective your protocols are. This testing can be done regularly throughout the year, or strategically in block or seasonal herds.
JOHNE'S DECLARATIONS:
All dairy farms must have a Johne's plan in place which needs to be reviewed each year and your declaration signed off for your milk purchaser. Usually the declaration is due by 31st October but due to Covid there is an extension until 31st December so we will be getting these sorted over the next few months.
New Mastitis Treatments:
Mastitis treatment has historically been centred on broad spectrum intramammary tubes but as we collect culture results and identify the bacterial patterns on farm we can narrow the spectrum to increase cure rates for a better outcome.
Ubropen is a new narrow spectrum mastitis tube which is licensed for once daily treatment for up to 5 days. Narrow spectrum tubes need to be used carefully alongside culture results rather than a first line tube - Ubropen will be particularly useful in herds struggling with cell counts and a confirmed pattern of Staphs and Streps from cultures.
Broad spectrum tubes still have a role in treating 1st line mastitis cases, and choice and supply of these drugs have been under pressure this last 12 months.
Albiotic is a broad spectrum mastitis tube - one tube to be given each milking for 3 milkings, and is effective against E coli as well as Staphs and Streps. We have secured good supplies of this going forward to minimise disruptions to treatment protocols and withdrawals at your end.
VACCINES: closing the gaps
Did you know?
A study in 2014 found:
- less than half of farms got the second dose of a primary course in correctly
- 14% were vaccinating outside the age-range
- 32% were vaccinating by the wrong route
Vaccines are an important part of disease control at the herd level but need to be considered, stored and used correctly to be effective. Remembering boosters, scheduling in different heifer groups to get their primary doses on time, and to fit vaccinations in with management tasks can be tricky - and can create windows of opportunity for disease to get into the herd.
This month we are focusing on getting vaccine plans completed for all HFV herds - these can be laminated for you and your staff, or put on your shared client folder or entered into your client calendar so incoming heifers, annual boosters and disease monitoring won't get forgotten.
GET IN TOUCH:
Paula: 07764 747855 paula@haywoodfarmvets.com
Tom: 07837 291097 tom@haywoodfarmvets.com
Enquiries: mail@haywoodfarmvets.com
Website: haywoodfarmvets.com
Open hours: M-F 08:30 - 16:30
Out of Hours: 07398 743095