HFV News FEBRUARY 2023

COLOSTRUM: THE 5 Q's

Did you know? The placenta of a cow has three separate layers which totally blocks antibodies or immunity from the cow crossing over to the calf during pregnancy. This explains why newborn calves are born without an immune system and are incredibly susceptible to disease in the first few days and weeks of life.

The newborn gut of the calf is amazingly adapted to cope with this: At birth the gut has tiny holes in it, ready to let antibodies from the colostrum directly into the blood stream which then protect the calf for the first few months of life. Sadly these holes aren't selective which means bacteria and viruses can get straight into the blood stream too so the holes start closing as soon as it is born. By 12 hours old only 50% of the holes remain, with the gut being effectively closed at 24 hours old. Getting colostrum into those newborn calves at birth is critical. Colostrum feeding beyond 24 hours is still very important as the antibodies in that milk sit within the gut and block bacteria and viruses attaching to the gut lining which reduces the chance of scour.

THE 5 Q'S:

1. QUANTITY:

Target:

Calves need 2-3 litres in first 2 hours plus another 2-3 litres by 12 hours old. 2 litres = 20mins suckling if left on the mum.

2. QUICKLY:

The best absorption happens in the first 2 hours of life and reduces every hour so that by 12 hours old you'll need twice as much colostrum to get the same protection, and by 24 hours old you won't be able to get colostrum protection into the blood. Legally colostrum must be fed by 6 hours old, but the best window is by 2 hours old:

3. QUALITY:

Colostrum quality varies hugely between cows and decreases by 4% every hour after birth so again, we need to match that earliest colostrum to the open gut of a newborn to give it the best start. If you are measuring quality of colostrum - remember you need to be testing colostrum at point of calving - not first milking.

This video from AHDB explains a bit more:

The Brix refractometer:

You can also get a digital refractometer:

Target:

1st feed colostrum MUST be >22% on Brix. If you have surplus you can store and freeze in 1litre zip lock freezer bags with the cow ID, date and Brix reading on it.

4. SQUEAKY CLEAN:

We all know colostrum is a superfood for calves - but it is also a superfood for bacteria; populations of bacteria can double every 20 minutes.

This not only risks directly infecting the calf, but the antibodies in the colostrum start working on the bacteria in the bucket so there are fewer antibodies left for the calf! If you are intervening and harvesting colostrum then good hygiene is essential. Pasteurising colostrum is a great way to reduce bacterial loads which then improves the quality and absorption of colostrum.

5. QUANTIFY:

Reviewing colostrum management on farm makes sure your calves are receiving all the benefits of good quality colostrum.

We check colostrum policies in two ways:

1. We get you to monitor colostrum quality at point of calving with a refractometer

2. We check the calves immune status by taking bloods in the first week of life - if the total protein level of the calf is over 5.5 we know that the right quality colostrum has gone in at the right time and in the right amounts - "successful passive transfer" or SPT.

If levels are low but some got through this is "partial passive transfer" or PPT and if we missed the window and none got through this is "failure of passive transfer" or FPT and the highest risk status for the calf. We aim for 90% of calves to have SPT.

What about sheep and lambs??

The placenta of the sheep is no different, once again meaning lambs are born without immunity and very susceptible to disease in the first few weeks of life. The most common infection we see in lambs when colostrum intake is poor is watery mouth (E coli septicaemia) and joint ill.

Lambs need 200ml good quality colostrum within 2 hours of birth and over that first 24 hours need intakes to be 200ml/kg so a 5kg lamb needs 200ml in the first 2 hours and a further 800ml split into 4 feeds in the next day.

Ewes will often have very high quality colostrum - off the scale on the refractometers but it is still very useful to have a refractometer on farm to check your suspect ewes (triplets, first timers and ewes in poorer body condition). It can be very useful to freeze any surplus good quality colostrum in an ice-cube tray so you can quickly defrost some for triplets or lambs needing a top up - it will massively out-perform a colostrum powder.

Comparison of NSAIDs:

Some points to consider:

If you need anti-inflammatory QUICKLY eg pneumonia or toxic mastitis then use the MUSCLE OR VEIN route - uptake from under the skin will be even slower in a sick animal as blood flow reduces to the extremities - you'll often tell us "she's cold to touch"

If the animal is dehydrated you MUST make sure they receive fluids too - NSAIDs can cause kidney problems in dehydrated animals so make sure they are drinking, if not then drench them at the same time

All of the NSAIDs come with warnings about use in very young calves as their kidneys are slower to clear the drug so always make sure they are well hydrated, and ideally choose a short acting option, and at a lower dose

Allevinix seems particularly good for TOXIC disease eg E. coli mastitis

Ketofen/Kelaprofen has ZERO MILK WITHDRAWAL so useful for slips, falls, lameness, assisted calvings or down cows where antibiotics aren't needed

MANAGING THE HEAVILY PREGNANT EWE: top tips from Amy

This article touches on a broad topic but I have tried to concentrate on the major considerations for pregnant ewes as we approach lambing time. I appreciate many of you are lambing at different times!

Nutrition

Day 90-145 of pregnancy is a very important time to get feeding right. Pregnant ewes have an increased energy and protein demand for growth of the lambs. Too much or too little energy can lead to metabolic problems such as twin lamb disease which in turn can lead to dead/weak lambs or even death of the ewe, and prolapses. An excess of energy can also cause lambing difficulties. Too little protein can mean an underdeveloped lamb and poor colostrum quality which has implications for lamb immunity and growth.

The most important feed for pregnant ewes is ad-lib excellent quality forage. This is what maintains rumen throughput. The ewe nut is just a supplement to provide the extra energy and protein that the forage can't supply as the pregnancy progresses and the growing lambs take up more space in the abdomen. Minimum protein content of a concentrate feed should be 16-18% but the quality of protein is also important. Make sure you get your forage analysed so your concentrate feed can be tailored to fill in the shortfalls.

Fodder beet and other forage crops can be a useful feedstuff at this time of year. They often lack in protein so have to be fed in combination with concentrates and forage. They also contain substances such as nitrates which can be harmful so it is important to introduce ewes to them gradually and always provide forage alongside.

Adequate feed space is essential for ewes to access the food you are actually providing. Trough space should be 50cm per ewe for concentrate feeding and 15-25cm per ewe for forage depending on the size of the ewes and frequency of feeding (less space required if ad lib).

EWE METABOLIC TESTING:

We have some subsidised testing available for ewes 2-3 weeks before lambing - these tests give an overview of nutritional status of the ewes, are a predictor of twin lamb risk, colostrum quality and future milk supply. Get in touch if you want to book in:

Housing

Lambing outside is fantastic if the weather is on your side, there's good natural shelter, and the ewes nutritional demands can be at least partly met by spring grass. 1.5kg DM of grass per ewe per day would be a rough* guide to an average ewe’s energy requirement in late pregnancy. Grazing would need to be carefully planned with sward heights measured etc.

Grouping pregnant ewes is useful to manage nutrition regardless if the ewes are lambing in or out; group according to body condition score in combination with the number of lambs they have scanned for to make sure ewes carrying multiples have protected feed space and availability. Ewe lambs should also be managed separately to mature ewes.

If lambing inside then the minimum space requirements are 1.2m2 per pregnant ewe, increasing to 1.8m2 once lamb(s) are at foot. Overstocking can lead to diseases such as lameness, twin lamb disease and hypocalcaemia in the ewes and many diseases of newborn lambs: Scour, watery mouth, joint ill etc.

The lambing shed needs to have been cleaned, disinfected and rested before you start and then mucked out between batches to control the rise in bacteria as your lambing season progresses. Bedding needs to be clean and dry at all times so ewes teats are as clean as possible for that first feed. Individual lambing pens should ideally be mucked out between ewes and lime applied to the flooring before fresh bedding is applied and the next ewe and lamb(s) come in.

Lime is great for keeping bacterial load at bay. Use in between different ewes using lambing pens and around communal areas such as feed and water troughs as a minimum. Make sure you collect and bag any afterbirths from the lambing pens.

Water supply is just as important as feed trough space. Water should be kept clean and fresh at all times: pregnant ewes can drink 6L per day!

Abortion management

If you have any ewes produce stillborn lambs or abort before time, it is essential to isolate these ewes from the main flock and not use them as foster mothers or use their colostrum/milk to prevent spread of diseases such as enzootic abortion/toxoplasmosis.

If you are having more than one or two ewes lamb early or lamb unexpectedly dead please get in touch to investigate possible causes.

Vaccinations

4-6 weeks pre-lambing is the time for clostridial/pasteurella boosters. This is appropriate for ewes that are already on a programme ie. have had a previous booster or a primary course of 2 injections within the last 12 months.

There have been some supply issues with Heptavac P so please get in touch if you are needing some this season.