New methods of calf rearing give farmers many options
Based on available data, dairy cow numbers are expected to increase by 2.5% this year and over 4% in 2013 despite heavy culling. (See table below)
This trend is likely to continue and cause severe over quota problems until after 2015. So many farmers will be forced to feed whole milk to calves. In the process they may feed excessive quantities and exacerbate bloat or scour problems.
The current over quota problem is encouraging milk producers to retain calves on farm longer to consume surplus milk and/or to buy additional calves. In many cases farmers do not have adequate space for extra calves so additional problems may arise from overcrowding.
Insufficient labour or time at this very busy period is another headache. Options to consider are contract calf rearing off farm or maybe hire some extra help from the local Farm Relief Service. Another good idea is the Hi-tech camera in the calving shed and the TV monitor in your home which enables you to monitor the births of your valuable calves.
Using an automated system to feed the calves is also a good long term investment. One saves a lot of time while successfully rearing lots of healthy calves in a cost effective manner. Dairymaster, Volac etc all have excellent computerised calf rearing systems available.
Depending on the brand and model, weaning can be done automatically according to concentrate intake. Information from the milk consumption makes it easy to detect health problems early. These automated systems also allow you to feed cow’s milk or milk-replacer or both.
The availability of over-quota milk is leading to large numbers of calves being imported for feeding. Farmers need to be aware that imported calves could cause future health problems.
Anyway you look at it we have a record number of valuable dairy calves to be reared with 1.09 million dairy births per year according to the Dept. of Agriculture. Not to mention the 884,000 beef calves from suckler cows which are even more valuable.
Good colostrum management is the most important factor in calf health and survival. The quality of colostrum in beef breeds is generally good, so that adequate passive transfer can be assumed as long as the calf is suckling early on.
In dairy cows, the quality of colostrum is poorer and rapidly diluted with every hour that passes between calving and first milking. So use the first milk from the cow and feed the calf three litres within two hours of birth.
Colostrum is rich in antibodies that provide protection from diseases until the immune system of the calf becomes functional. However the older the calf gets the fewer antibodies it absorbs.
Only clean colostrum from the first milking post-calving is suitable for calves as the quality of the colostrum halves between the first and second milking. Colostrum from heifers is of poorer quality than older cows. The highest quality colostrum in a Teagasc Moorepark trial was from cows in their fifth lactation.
The key to rearing quality calves is getting the basics right. While this takes time and effort it pays dividends. After all sick calves are very time consuming, cost a lot extra in veterinary expenses and may never reach their adult potential.
Mortality levels within the first year of life are approx. 1.5% lower for heifer than bull calves. Mortality rates of heifer calves average 6.5%. Half of these deaths occur within the first six weeks so clearly this is the critical time for calf care and management.
Frozen colostrum can safely be stored for at least a year. Slow thawing at below 50 degrees does not affect colostrum, while temperatures above 50 degrees reduce quality and lower the available antibodies (i.e. do not use a microwave to defrost colostrum).
Colostrum replacement products are available however, the efficacy and quality of these products is variable so only purchase a reputable brand.
Farmers may be tempted to feed waste milk — however this milk is usually high in bacteria, especially if it has high cell counts. It will deteriorate further if left at room temperature until it is fed.
Apparently healthy cows may, in fact, be transmitting disease to the calves. A good example is Johne’s disease, others include Salmonella and E. coli. A safe strategy is to pasteurise and chill waste milk to prevent fermentation and bacterial growth.
If you do not have a quota problem feeding milk replacers is a good policy. However with any brand of milk replacer you generally get what you pay for. Good quality milk replacer should be easily dissolved and leave no sediment. It should be a cream colour, have a pleasant odour and milk-derived proteins are preferable.
Always check the label for the ingredients and product specifications. The crude protein in many milk replacers is only 20%. However to promote muscle growth, milk replacers should have a crude protein content of at least 25%. Always mix carefully according to the manufacturer’s guidelines.
The intake of calf starter concentrates is the single most important factor for the development of the rumen. So it is important that calves have access to clean and palatable starter concentrates from early on, even though they will only eat small amounts in the first 3 weeks. Calves need small amounts of hay or straw. In particular, if fine ground pelleted rations are fed, additional roughage will be necessary for the development of the rumen. Calves with free access to water eat more starter concentrates and have enhanced rumen development.
Calves fed coarse starter mix eat more and have higher weight gains than calves fed pellets or nuts. The coarseness also benefits growth of the muscle layers in the rumen wall. Calves only begin to eat considerable amounts from 3 weeks onwards. However, the higher the amount of milk fed the less starter concentrates they will consume. Thus, the time of weaning is dependent on the feeding regime.
Scouring calves are unable to maintain a correct balance between fluid intake (absorption) and fluid loss. The inevitable effect is dehydration Electrolytes (e.g. sodium, potassium, bicarbonate) are also lost in large quantities. In severe cases of scour, dehydration and electrolyte loss leads to a reduction in blood circulation, acidosis, impaired kidney function, and even death.
Even with the best management it may not always be possible to prevent diarrhoea. It is now recognised that milk feeding does not worsen, or prolong, the course of diarrhoea, despite a somewhat lowered digestive capacity.
Continued milk feeding not only provides the energy required for weight gain and growth throughout the period of diarrhoea, but also provides the nutrients that are necessary for the recovery of the intestinal mucosa.
According to Animal Health Ireland good quality oral electrolyte solutions should be given to counteract the fluid and electrolyte losses caused by the diarrhoea.
Incidentally the majority of scours are caused by viruses or cryptosporidia. However, vaccines are available to prevent scours caused by rotavirus, coronavirus, E.coli and Salmonella spp.
The vaccines are normally administered to the cow between 12 and 3 weeks prior to calving. In the case of Salmonella vaccines, these can also be administered to healthy calves from 3 weeks of age. As yet it is not possible to prevent scours caused by cryptosporidia, which, because of the success of vaccination against the viruses, has now become the biggest cause of calf scour.
It’s a good investment to ask your vet to do a herd health check. He or she can advise on best hygiene practices, a vaccination programme, dosing strategies, most cost effective animal health products etc. This visit by your vet could save you a lot of time and money later not to mention the benefits of improved calf thrive.
Sometimes the potential problems are less obvious so a second and professional opinion is well worthwhile. Calves need clean water, good ventilation, a dry and comfortable bed, suitable penning, no overcrowding and adequate feeding space.
Expanding dairy herds often do not adequate accommodation for calf rearing during expansion. Respiratory diseases (pneumonia etc) often occur in non weaned calves and are associated with the housing system. Factors include the number of animals/group, animal density, housing facilities and the ventilation.
Respiratory diseases are the second most important cause of death and ill thrift in calves. The main environmental factor predisposing calves is poor ventilation. Cold, humid conditions, sudden changes in air temperature, stress due to different causes and change in the environment have also been associated with outbreaks.
Large, shared air spaces, calves from different age groups and poor hygiene between batches often make calves more vulnerable. Calves that have suffered from diarrhoea are also more likely to suffer from respiratory disease. The stress associated with dehorning and castration may also increase disease levels.
