Introduction to Genomics – part 2
How much genetic improvement comes from the bulls?
Sexed semen, conventional semen, beef semen or stock bull: the choice is vast. Sometimes choosing a bull can seem a daunting experience, but needs not be. How much input you have in the type and quality of semen inside the AI tank or in the choice of bull is up to you. Some people like to go to a show to pick a prize-winning bull, or look at bull catalogues and pick their favourites. Others prefer to broadly outline the breeding aims to the AI rep and let them search the proofs. Other farmers may not have much time to make these decisions, though these are too important ones to be left to chance!
The bull is half the herd. If you use a stock bull the first step would be to choose him based on EBVs, not only on how good he looks. For a beef bull, ideally you want to be looking at improved calving ease; for a dairy bull, calving ease (direct and indirect) must be paired with improved production traits to gain any genetic improvement on the milking herd.
Using AI is often the method of choice if you want to put different cows and heifers to different bulls. This improves the overall genetics of the herd faster than using one bull only, as the replacement heifers should be an improvement on both sire and dam.
How are these bulls chosen from the AI catalogues? How do they get paired to the right cow/heifer? These are very important decisions that ought to be made with specific breeding aims in mind. Every farm is different and the “bull of the moment” may not be the best fit for your breeding strategy.
For the best chance of rearing a heifer calf from a carefully planned mating, sexed semen could be considered; this would work best alongside a tailored rearing programme, such as our Torch Youngstock Service.
It is time to take stock and check that the bulls we are using are serving the purpose, not just the cows – i.e. improving the overall herd quality, and not just a semen dispenser to produce ANY calf. If you would like to participate a bit more in the herd’s breeding choices, selecting breeding aims specific for your herd, please get in touch. We can help provide independent breeding advice starting from the requirements of your herd.
Preventing watery mouth and neonatal scours- a holistic approach
We are in an era of unpredictable, potentially challenging market conditions, along with increasing pressure from consumers and retailers on producers to produce food responsibly and ethically. This is directly relevant to sheep producers and the use of prophylactic antibiotics at lambing time, even though until now the sheep sector has largely been out of the spotlight.
At ground level, it is clear that prophylactic use of antibiotics at lambing time in animals that were not likely to be infected has led to widespread antibiotic resistance in E. coli strains commonly found on farm, making treatment in the face of an actual problem difficult.
The good news is increasing numbers of sheep farmers are finding that they have been able to reduce treatments to few or none with no increase in losses from watery mouth. This is achieved by close attention to good management.
Infectious disease is always caused by an imbalance in the threat to the animal (excess exposure to infection) and/or a reduced ability of that animal to naturally fight off that infection (insufficient immunity).
So, which areas of management can we focus on to reduce the occurrence of watery mouth?
Reducing exposure to infection
- Make sure ewes and lambs are kept on clean, dry bedding. Bedding materials need to be stored under cover and pens bedded up as often as required to achieve this. As stocking density increases, so will the bedding requirement- it is recommended to allow a ewe 1.2-1.4m2 increasing to 2.2m2 with lambs at foot.
- It is good practice to clean out the bedding between ewes in individual pens. Actually cleaning and disinfecting is not a practical solution as wet surfaces are not likely to dry out before the pen is needed again, and humidity is increased in the shed. Instead apply a thin layer of lime before replenishing the pen with a thick layer of dry straw.
- Crutching/removing belly fleece from ewes assists the lambs in finding the teats rather than sucking on dirty wool.
Increasing immunity against infection
Key to the lamb’s immunity is receiving adequate colostrum with four hours of life. Ruminants are born without any immunoglobulins of their own and are entirely reliant on colostrum to provide protection from infection, only developing their own immunoglobulins in the first few weeks of life.
- A volume of 50mls/kg lamb bodyweight of colostrum will provide enough immunoglobulins, providing the colostrum quality is good. This will be 200-300mls for an average lamb. It must be consumed early on before so that the immunoglobulins can be absorbed across the gut into the blood, and before the lamb’s limited energy supply (brown fat) is used up.
- The lamb must consume 200-250mls/kg lamb bodyweight in colostrum within 24 hours to prevent hypothermia.
- Colostrum quality is dependent on good ewe feeding both in the late pregnancy period and all the year round. Good feeding management all year round will ensure the ewe reaches late pregnancy in optimal body condition (3 out of 5 for a typical intensive lowland or upland ewe). Close attention to the late pregnancy ration will control milk and colostrum quantity and quality. In particular, adequate ‘rumen bypass’ protein must be provided. Soya meal is a good source of this.
- If in doubt that a lamb has received adequate colostrum, do not hesitate to milk off the ewe, or another ewe with a good supply, and stomach tube the lamb. This can be done routinely in all at risk lambs such as triplets, undersized lambs and those from thin ewes.
- Cow colostrum is also an option providing it is pooled from a number of cows and not from one individual (seek advice on the risk of Johne’s disease first). Some large enterprises use cow colostrum routinely in all lambs.
- The routine administration of an enema (warm water mixed with obstetrical lubricant) helps protect against the stagnation of meconium in the gut allowing overgrowth of E. coli. This could also be routinely carried out in high risk lambs. A soft stomach tube is ideal for the job, just make sure it remains dedicated to this task!
Our vets will very happy to discuss strategies particular to your farm and in the event of watery mouth or scour problems please do contact us for further advice.
We are also keen to hear of more success stories!
Selective Dry Cow Therapy
Intramammary tubes are the main form in which antibiotics are used in the dairy industry and their actual need should be reviewed.
Public health, economic reasons and animal welfare must be the crucial focus when choosing a dry cow management protocol:
- What is dry cow therapy?
Dry cow therapy was introduced to clear any suspected infections that had developed in the udder during the lactation. Not all cows will need it and treating cows unnecessarily may increase clinical cases of mastitis around the time of calving.
- Where can it be implemented?
There is room to implement the protocol on every farm however, herds with a high percentage of chronic cows should address this issue first.
- How does it work?
Selection criteria vary from farm to farm. As a general rule cows with consistent low cell counts during lactation and no clinical episodes of mastitis are the best candidates for the use of sealant alone. Parameters do change and the protocol should always be discussed with a vet.
- The role of teat sealants
Some dairy cows are not quick or effective enough in forming a natural teat plug to prevent bacterial access to the udder. Teat sealants make up for this and they extend their activity until the time of calving, when the udder starts producing milk and can become susceptible to environmental infections again.
Internal sealants infusion must be completely sterile to avoid any contamination that could lead to clinical mastitis. It is crucial to ensure that the sealant sits in the teat canal only and does not spread throughout the udder as this would impair its efficacy.
Sub-optimal sealant infusion can potentially lead to severe consequences. Any doubt should be promptly referred to a vet.
- Data used for selection
Individual somatic cell counts and accurate recording of clinical mastitis are the best data. Bacteriology results also play an important role, because strong evidence of contagious pathogens such as Staph. aureus or Strep. agalactiae on farm may affect the criteria of selection.
Individual and bulk tank bacteriology, together with the history of the farm can also indicate which type of dry cow tube would be more suitable.
- Non milk-recording herds.
It is, admittedly, more difficult to draw a consistent protocol in the absence of data. However, individual monthly recording over a period of 3 months prior to drying off, together with accurate recording of clinical episodes throughout the lactation do offer a starting point for the implementations of selective dry cow therapy. This should only be done after consulting a vet.
Individual somatic cell count can also be a useful tool, prior to drying off, in the absence of a recent individual milk recording.
CMT (California milk test) can identify high cell count cows. However, it can only detect cows with a cell count between 300 and 400 or above. This means that a proportion of cows needing treatment will be missed.
- The environment
Dry cow environment should always be designed to reflect the needs of the animals as it is widely known that many issues developing in this stage can affect health and productivity of the herd.
This applies to udder health as well. High infectious pressure on dry cows, overstocking or any other form of stress can potentially affect the outcome of the dry period, whether intramammary antibiotics have been administered or not.
Torch Farm Vets are very pleased to now stock Immucol Lamb Colostrum.
Trial work published in 2016 showed this product to have the highest (by far) level of antibody of any colostrum replacer on the market.
Lambs rely on getting a good dose from mum’s colostrum. Weakly lambs, multiples and lambs from maidens all benefit from a top up dose of colostrum.
Why risk using the equivalent of skimmed milk when you can top up your lambs with gold top?
Saturday 8th April
Torch Farm Vets are pleased to invite you to join us on the 8th April to watch Barnstaple RFC vs Cinderford RFC at Barnstaple Rugby Club.
Please join us from 12:30pm onwards for refreshments and lunch Kindly provided by Ceva Animal Health . Kick-off is at 2pm.
If you would like to book a space please contact either Fiona or Jemma on 01769 610000.
We look forward to seeing you there!