Suckling systems improve natural living in organic dairy calves
by Jan-Paul Wagenaar and Jos Langhout, Louis Bolk Institute, NL
Organic farmers in the present study successfully implemented suckling systems in calf rearing. The consumption of mothers’ milk resulted in higher weaning weights at 3 months of age. Moreover, suckling systems offered increased opportunities for natural behaviour of the calves.
Increased natural living through suckling systems
Animal welfare through 'natural living' is a main goal of organic farming systems. Yet, the lives of calves in current organic dairy herds can still be considered to be very ’un-natural’.
Like with conventional systems, organic calves are separated from their mothers shortly after birth, they are bucket fed and raised according to a housing concept that reduces contact with animals of other age groups.
To comply with the principles of organic farming, but wary of the practical constraints, some farmers seek to make changes to the existing calf rearing method. They experiment with a calf rearing system in which calves are allowed to suckle up to an age of 3 months.
The suckling method practised is either single suckling of the own mother with additional machine milking, or multiple suckling of a nurse cow without additional machine milking. Both systems increase the 'natural living' among the calves (>> Table 1), with the higest potential in the single suckling system.
In the present study (Wagenaar and Langhout, 2008), we examined the practical implications and the extent to which suckling systems affect technical results in a practical organic dairy context.
Comparison of calf rearing methods at three farmsAs part of a four-year study (Wagenaar and Langhout, 2007) three calf rearing methods were tested in 2004-2006 at three farms (farm 2, 3 and 4 in >> Table 2). The rearing methods tested were:
- bucket feeding with milk from milk powder (milk replacer)
- bucket feeding with bulk farm cow milk (tank milk)
- feeding by a suckling system
Both bucket fed groups were single housed between birth and 90 days of age. Calves suckled in the same period stayed with their mother in the milking herd or in a group with 3 nurse cows and up to 8 calves. Each rearing group involved 58 calves per farm, and all calves were weaned at 90 days of age.
During the on-farm rearing data were recorded on live weight, milk production, bacteriology and somatic cell count (SCC). Additionally, data on calf and cow health were recorded in individual logbooks. Further details of data recording is presented in >> Box 1.
Increased and persistent gain in liveweightCalves reared in suckling systems, even if their mother was being milked twice a day, had the potential to grow very fast. Live weight monitoring indicated that more than 1 kilogram growth per calf per day was possible.
Figure 1 shows the average liveweight gain of calves raised with the 3 different rearing methods. Average live weight at weaning (90 days) was 136 kg, 101 kg and 95 kg for suckling, bucket fed tank milk and bucket fed milk replacer groups, respectively.
Figure 1. Average pre-weaning liveweights during the period 090 days of age of calves reared in the three calf rearing groups. Adapted from Wagenaar & Langhout, 2006.
Rearing method (P<0.001) and farm (P< 0.01) had a statistically significant effect on pre-weaning growth and live weight at 90 days of age, but had no statistically significant effect on growth between 90 and 365 days. The live weights at 365 days were 343, 316 and 288 kg for suckling, bucket-fed tank milk and bucket-fed milk replacer groups, respectively, and differed significantly (P < 0.001) from each other. This shows that the higher average live weight of the suckling group at weaning could be sustained until the age of 1 year.
Similar milk quality, but lower initial production
Because data on milk production and somatic cell counts (SCC) were incomplete for farm 3 and 4, only the results for farm 2 are presented. Although milk production in the first 3 months of lactation was significantly lower for cows suckling calves, there was no statistically significant difference in milk production between rearing groups from the fourth month onwards.
No statistically significant difference was found in SCC between the rearing groups up to 6 months post-partum. SCC levels for the three groups were always below the upper critical value of 400,000.
Weaning stress is unavoidable
In addition to the postive effects on liveweigt and 'natural living', the single suckling also had negative implications.
Stress around weaning was one of the most important ones. Because modern dairy cows produce large quantities of milk and milk consumption by calves is unrestricted, the result is high growth rates. Weaning is a moment at which calves are not only separated from their mother, but also from their feed (milk) and from their housing environment.
Although farmers tried to adapt their suckling system in such a way that stress around weaning was avoided, they did not find a satisfactory solution. To some extent weaning stress is unavoidable: it is part of the suckling systems.
Multiple suckling as a compromise
For some farmers it is difficult to accept the weaning stress and to step back from trying to control every aspect of their calf rearing system. Thus, although a single suckling system was seen as the most natural suckling system, three out of the four farmers finally chose to switch to a multiple suckling system.
Multiple suckling can be considered a compromise between increased ‘natural living’ and practical and economical implications. However, as calves are raised with nurse cows instead of their own mother, this compromise results in lower levels of ‘natural living’
In the case of increasing ‘natural living’ through implementation of a suckling system, farmers should be encouraged to take enough time to step back from control and to give calf and cow a chance.
Wagenaar, J.P. & J. Langhout, 2006. The potential of suckling systems in calf rearing in Dutch organic dairy farming, practical implementation and liveweight development. In: Proceedings 1st IFOAM Conference on Animals in Organic Production, 2325 August 2006, St. Paul, Minnesota. International Federation of Organic Agriculture Movements (IFOAM), Bonn, pp. 6471.
Wagenaar, J.P. & J. Langhout, 2007. Practical implications of increasing 'natural' living’ through suckling systems in organic dairy calf rearing. Netherlands Journal of Agricultural Science 54-4, 375-386.