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The Potential of Suckling Systems in Calf Rearing-Dutch Research
By Jody Padgham
Organic Broadcaster issue 15.1 Jan-Feb 2007
The following has been gleaned from a paper presented at the recent “1st IFOAM International Conference on Animals in Organic Production,” held August 23-25, 2006 in St Paul, MN. The research was done by J.P.T.M. Wagenaar and J. Langhout of the Louis Bolk Institute, Department of Animal Production, Driebergen, the Netherlands. www.louisbolk.nl, j.wagenaar@louisbolk.nl. The full proceedings from the IFOAM conference can be found at http://shop.ifoam.org/bookstore/ and audio recordings of the conference may be purchased at http://www.organicvoices.com/IFOAM2006ord.html
n the Netherlands, there is little difference in calf rearing methods between organic and conventional dairy systems. Typically calves are separated from their mothers at birth, and bucket fed, isolated from calves of other age groups. The primary difference is that organic calves are fed organic milk, either fresh or organic milk replacer.
The authors state, however, that an increasing number of farmers and consumers are becoming dissatisfied with current calf rearing techniques. Early separation combined with bucket feeding results in a minimal intake of mother milk and maternal behavior, and limited cow-calf bonding and social learning. These elements are considered important for the health and well being of the calves, especially in organic systems. The authors premise that suckling systems, either from mothers or through nurse cows, offer a promising alternative. They see suckling systems as not only improving the well being of calves, but also as economically feasible and delivering healthy, well developed and easy to handle dairy cows.
In order to assess the potential of suckling systems for organic dairy farming, information has been gathered since 2002 from ten dairy farms using suckling systems for calf rearing. The following chart summarizes the thoughts of farmers that have been raising calves using a suckling system for at least five years. Statements A to E list the reasons why a suckling system might be introduced. Statements numbered 1-20 are positives that those using suckling systems have observed, and statements 21-30 show challenges or consequences of suckling systems.
Farm Observations
Four farms have been contributing in-depth observations and data from 2002 to the present, with data show here through summer 2006. The authors collected their comments into a series of observations on the most important practical issues for any farm setting up a suckling system.
1. Choice of suckling system. Most farmers leave the calves with their mothers during the first few days, significantly through the colostrum period. During this period the mother is not milked mechanically, unless needed for udder health or to draw additional milk for the calf. After this initial period there are two choices: single suckling with additional milking, or multiple suckling without additional milking. In single suckling, the calf and mother return to the dairy herd together. The mother is milked mechanically twice a day. In multiple suckling, the calf is removed from its mother and moved to a nurse cow. The nurse cow is housed separately from the milking herd, not milked mechanically but suckled by up to three calves. Cows that don’t fit well into the herd, either temporarily or permanently, are used as nurse cows. The authors found that of the ten farms studied, only a few kept calves with their mothers. Most prefer using nurse cows.
2. Housing space. Suckling systems will require extra space. Even with space available, there will need to be modifications made. In the single suckling method above, accommodations must be made for the calves to move through the milking system with their mothers. In addition, those using this system found it beneficial to provide a separate area for the calves, which the cows could not enter (“kindergarten”). In the nurse cow situation, extra pen space is needed, especially if replacement stock numbers are high. Farmers preferred to keep two to three nurse cows, with a maximum of 6-8 cows in one pen. The more nurse cows and calves in any pen, the less able to track what is going on and the higher calf mortality. It is ideal to move to seasonal calving, with calves planned for warm months. After an initial ten days inside, calves and nurse cows were allowed to graze in the pasture permanently.
3. Animal health. Diarrhea, the major cause of calf mortality in conventional rearing, is a less frequent health problem in suckling systems. Calves can drink when they want, and will choose to drink smaller portions each time. This is optimum for milk intake and digestion. Farmers who graze their calves with mothers or nurse cows did not experience serious problems with internal parasites (helminthes). Some farmers even speculate that calves have better protection against helminthes when they suckle fresh milk from grazing cows.
4. Calf development. Some farmers were concerned that suckling calves were not taking in as much roughage, causing poor growth after weaning and inferior rumen development. Several observational studies were carried out and showed that, compared to fed calves, calves which suckle do not necessarily spend less time eating roughage. Farmers concluded that suckling could even stimulate roughage intake, as calves go to the feeding rack with their mothers or nurses.
5. Weaning. Because suckling systems result in mother-calf bonding, weaning can be a stressful time. For some farmers, this is an important reason to use nurse cows. Calves can be weaned in a more gradual way by moving a calf from its mother to a nurse cow after two months. Milk intake decreases and roughage intake increases. Sometimes nurse cows are used from birth onwards and sometimes from one or two months before weaning. Nurse cows are also used to avoid problems around milking and to prevent unrest in the milking herd in general.
6. Cost. In a suckling system in which a calf suckles its mother for two months and a nurse cow for one month, total milk consumptions is estimated to be 1065 kg (2,343 lbs), compared to 840 kg (1,848 lbs) with a nurse cow only and 540 (1,188 lbs) with a bucket fed system. This is a considerable difference. However, if a nurse cow is used that otherwise doesn’t fit into the system, the cost of the milk will be relatively low. Also, it should be noted that suckled calves have an average extra 30-40 kg (66-88 lbs) of extra live-weight at 90 days of age. So far trial results indicate that the live-weight difference remains through one year of age.
7. Herd dynamics. Suckling systems result in increased natural behavior. Several cows, not only the mothers, keep an active eye on the calves. A lot of caretaking behavior can be observed.
Research Trial Results
Up to the age of weaning (90 days), suckling calves had a higher growth rate compared to calves bucket fed with tank milk or milk replacer. Average live-weight at weaning was 136 kg, 101 kg and 95 kg (299, 222, 209 lbs) for suckling, bucket fed milk and bucket fed replacer, respectively. Average pre-weaning growth rate of suckled calves was 1.080 kg (2.38 lb) per day vs. 0.658 kg (1.45 lb) for bucket fed calves (milk) and 0.630 kg (1.39 lb) per day (replacer). Results show that the rearing method, as well as individual farm management, had a significant effect on the pre-weaning growth and live-weight at 90 days. The rearing method had no clear significant effect on the growth between 90 and 365 days. However, the live-weight at one year did differ significantly between rearing methods: the calves maintained the early growth benefit of the suckling system.
Conclusions
In order for a suckling system to be successful, changes need to be made to the farm set-up and the farm manager’s attitude. A suckling system will not work in all farm set-ups, and not every farmer is capable of using a suckling system. Farmers partly hand over the care of their calves to the cows, and by doing so have to accept a different level of control over an important part of farm operations.
Calves in a suckling system optimize conditions for early growth- suckled calves grow faster. It is possible that these higher weaning weight calves will have a lower age at first calving or a higher live-weight at calving. This research will continue to study these criteria, and the possibility of higher milk production at first lactation for these suckled calves.
Suckling systems have the potential to improve welfare and natural conditions by restoring maternal and social behavior. Suckling systems would be attractive to consumers, in assuring them that organic dairy farmers make an effort to increase the wellbeing of their animals. However, increased natural behavior can have some negative consequences, in poor milk letdown and animals becoming less easy to handle. Farmers indicate that these negatives can be overcome with the right attention.
In general suckled calves show no additional health problems. Farmers must stay attentive to both cows and calves for the first ten days after birth to see that both are doing well and the calf is receiving enough milk. However, cows with good mothering skills are very capable of rearing their young. There is no indication that suckled calves suckle other calves.
The risks of increasing the number of animals infected with Para tuberculosis is higher when suckling systems are used, owners of herds that have tested positive are advised to not rear calves with a suckling system.
Critics emphasize that suckling systems are not compatible with modern dairy farming because of its focus on quantities of salable milk for human consumption. They also point out the increased risk of transmitting a variety of infectious diseases, which are thought to be declining as a result of ever increasing hygiene regulations. The authors point out that obvious risks of transmitting infectious diseases should be avoided at all times, but that this should not discourage farmers from developing suckling systems.
The results of this study show that the advantages of a suckling system outweigh the extra costs. If there are no indications that animal health or food safety are at risk, a suckling system should be considered. Introducing suckling systems can play an important role in living up to the image that the organic sector has set out for itself: sound safe and animal-friendly production methods resulting in high-quality food.
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