Pink Eye

Whilst Pinkeye can be tricky to see, it can certainly become an eyesore if left to brew away! Pink eye is caused by bacteria (Moraxella bovis). It becomes a pesky problem heading into the summer months as wind, heat, dust, flies and long grass can weaken the natural defences of the eye and cause an infection.

Pink eye is incredibly contagious and can rapidly move through a mob so it pays to get on top of it quickly. Signs of pink eye begin with weepy, clear discharge and squinting which then can progress to discoloured/ white eyes which can develop deep ulcers. If left untreated, it is very painful and uncomfortable. It can lead to nasty ulcers, blindness and reduced growth rates, as well as it being a significant welfare issue. Lesions quickly worsen for an animal and eye damage can be irreversible (partial or complete blindness).

Treatment of pink eye is either with Orbenin eye ointment OR injectable tetracyclines (Engemycin or Bivatop). If you are having particularly bad problems this year or it is becoming an annual problem then come talk to us to see what management factors may be of help. A single dose of Piliguard vaccine given 3-6 weeks before the risk period will significantly reduce the risk of an outbreak.

Calf Weaning

Making sure a calf is fully prepared before weaning reduces the chance that they will need preferential treatment post-weaning. Preferentially managing small groups of animals to 'catch them up' is time consuming and can be difficult to manage, so it is best avoided by good management early on.

Factors to consider before weaning calves:

1) Rumen Development - Are they consuming the desired amount of feed? Is its rumen sufficiently developed to be weaned off milk?

• The only way this can be assessed is by measuring the amount of concentrate or pasture they are readily eating, which should be at least 1kg/day of meal or 2kg/day of pasture.

2) Weight – Individual calves should reach a minimum weight prior to weaning.

• No specific weaning weight has been defined by research, however common weights used are 70kg for Jerseys, 80kg for Crossbreds, and 90kg for Friesians.

• Reaching a minimum weight is an important milestone as it indicates that they are ready to transition from individual to group management.

3) Age – A combination of weight and age is often good to use when making the weaning decision eg. a minimum of 8 weeks AND 90kg.

4) Ability to Compete Within a Group – Is the calf able to compete within the group before they are weaned? Any that aren’t should be held back until they are.

The aim is to have calves that continue to gain weight post-weaning - they should never lose weight or remain static. Some animals don’t thrive post-weaning so it is a good idea to weigh them 7-10 days post-weaning to make sure they have gained weight. Any that haven’t may need continued access to calf meal, regardless of weight or age, or examination by a vet.

Relocating Calves

Relocating calves can result in growth checks or be a trigger for other animal health issues including pneumonia, scouring and parasites. Recently weaned calves are at particular risk as they are also undergoing changes in diet, rumen development and are usually younger in age.

A few criteria to consider for relocating recently weaned calves include:

• Fully weaned and off milk for at least two weeks.

• Meet the minimum target weight for their age.

• Transitioned onto a full pasture diet or supplement provided for transition.

• Competing and coping well within the group.

• Drenched and vaccinated.

• In good health.

The First Month of Lactation - Minimising Ketosis

A good start to a cow’s season requires careful management through the springer and colostrum period to ensure that she maintains a high dry matter intake. Initial focus should be placed on prevention of metabolic disease, optimising immune function, adequate feed allocation and manipulating cow behaviour.
However, the first month of lactation beyond the colostrum mob is still very critical. Most cows will spend this period in negative energy balance – i.e. more energy is leaving their system than coming in and therefore they will lose body condition. This is why providing consistently high feed quality is imperative. We are already seeing many farms that are struggling to manage very high pre-graze covers due to good growth rates through the winter. These are impacting voluntary intakes and may have lower ME. Cows in significant negative energy balance may develop clinical or sub-clinical ketosis. Ketones are a by-product of inefficient fat break down and have a side effect of further appetite suppression.
Cows which are well fed/have a good appetite in the first month of lactation will lose less weight and have better mating performance. Try some of the following:

• Optimal pre-graze covers of 3,000 to 3,400 kgDM/ha in the first round will ensure good quality and easy harvest for the cow. You still need to maintain a residual at 1,550-1,600kgDM/ha to ensure quality in subsequent rounds.

• Aim to get your milking cows eating 4% of body weight in dry matter ASAP.

• Know what your daily cow requirement is and calculate your allocation every day - where feed deficits exist on any given day fill it with appropriate supplement.

• Use monensin (Rumenox/Rumensin TT), to increase feed conversion efficiency, by driving Proprionate production. Clinical trials show boost in milk protein production and far less BCS loss. Use strategically from calving up until end of
  mating.

• Internal parasites – the biggest impact these have is on appetite suppression. Almost all farms will have high levels of over wintered larvae this year. Aim to drench your herd by early/mid September.

• Vitamin B12 – is a requirement for energy extraction. Deficient cows will lose appetite. We see B12 levels drop at the same time as spring grass goes lush. This is partly due to rapid transit times through the gut impeding B12 absorption. A good rule of thumb is when faeces starts
  becoming loose look to give Vit B12.

Sedation and Metacam for Calves at Debudding

A large NZ trial published last year looked at the benefit of sedation and Metacam (pain relief) on calves at debudding. The results showed:

• Calves that were give Metacam and sedated along with local anaesthetic grew significantly more in the 7 days after debudding by 144grams/day compared to calves that were only given local anaesthetic.

• Sedation improved all the behavioural signs and the pain sensitivity measured in the 22 hours after debudding.

• Metacam improved some of the behavioural signs in calves that were only given local anaesthetic.

The effect of Metacam agrees with a large international study summarising 17 trials which showed NSAIDS (i.e. Metacam) reduces the signs of pain for 6 hours after debudding when used in calves that were given local anaesthetic.

• It is worth considering the use of our Vet Centre debudding teams that use sedation and/or Metacam to improve the outcomes of calves at debudding time.

Finally just a reminder that the Animal Welfare laws have changed and all calves must be given an effective local anaesthetic block prior to debudded. To be able to use local anaesthetic you have to go through an accreditation/reaccreditation process with one of our vets. Alternatively you can use our debudding service or a debudder that has a VOI to use local.

Calf Milk Replacers - Milk based vs Whey based Products

There are two main types of calf milk replacer (CMR) available on the market - milk based CMR and whey based CMR. What is the difference?

They differ on the component of the milk fraction on which they are based - i.e. casein vs whey based.

Casein Based CMR

• Are digested like whole milk, forming a 'casein curd’ in the abomasum. Failure of a curd to form can lead to nutritional scours. Good curd formation = good quality CMR. Poor curd formation = poor quality CMR.

Whey Based CMR

• Whey proteins are digested in the small intestine and do not form a curd in the abomasum. This aids in quicker digestion = more room for meal = GOOD!!! (quicker digestion encourages earlier
  dry matter intake). It also lessens the chances of nutritional scours and abomasal bloat due to the lack of a curd formation.

• A whey based product will move through a calf in only 2-3 hours, compared to 5-8 hours for traditional curding (casein) products. Globally whey based milk replacers are commonly used and lead the market in the US and Europe.

Before deciding to use a milk replacer you should weigh up the advantages and disadvantages for your calf rearing system. Ease of handling with automated calf feeding systems, high milk prices, minimal waste milk and disease control are reasons why they may be favoured on some farms. Only high quality reputable products should be used otherwise health problems and poor growth rates may result. And remember consistency is key - always mix according to the manufacturer's directions!!!