The goal of our study was to document whether different methods of calf raising (bottle- vs. mother-raised) resulted in observable differences in weight and body condition, grazing behavior, ease of calving, ease of integration into the milking herd, and milk production in two groups of approximately two-year old heifers. The results from our study are limited due to an unexpected variation in conception dates in the study heifers which led to their calving dates being spread out over a six month period and resulted in over-riding seasonal differences in herd management and grazing conditions which made some direct comparisons between bottle- and mother-raised heifers and their calves impossible. However, the stress level of the entire herd (as measured by the somatic cell count in the bulk tank) was significantly reduced since the calves were mother-raised. The benefit for the calves themselves, although not documented in this study, has been obvious. They grow faster, have stronger legs, and are overall more alert and capable, than our bottle-fed calves ever were. The initial problem of a deterioration of some the calves condition after weaning has been rectified by leaving them longer with their mother (on average 3 months, now), a more gradual weaning process using nose rings, and improved housing of the weaned calves. We did not experience a drop in milk volume in the bulk tank after mother-raising the calves. We suspect that the increase in herd health associated with the change in method of raising the calves made up for the milk “lost” to the nursing calves. We also feel that the work associated with managing the calves has become less than when they were bottle-fed. As a consequence, we are committed to continue raising the calves with their mothers. We are considering experimenting with a system that involves nurse cows, but have not yet worked out the logistic details.
This study takes advantage of the fact that, in the Spring of 2007, Hawthorne Valley Farm gradually transitioned from raising calves in pens to raising them with their mothers. Pen-raised and mother-raised calves will both be entering the milking herd in early 2010. We propose to compare these two cohorts in terms of their health and grazing efficiency as heifers during 2009, their behavior as first-time mothers, and their productivity as milk-producers during their first lactation. This will allow us to estimate the costs and benefits associated with this important modification in standard dairy herd management. The results will shape our own practices and contribute to those of others. Hawthorne Valley Farm is an established institution in Hudson Valley alternative agriculture. As such it has participated frequent meetings and regional agricultural gatherings, and is an effective location for sharing the results of this study. Dr. Darrell Emmick, our technical advisor, is NRCS’s New York State Grazing Land Management Specialist and so is in frequent contact with graziers throughout the Northeast and is well able to share our results.
Grazing Rates: In order to assess the question, whether mother-raised heifers are more efficient grazers than bottle-fed heifers (at an age of 2+ years), we compiled the average grazing rates (sec/20bites) of our study animals throughout the grazing season. Figure 2 compares the grazing rates of study heifers during several periods when a number of study animals grazed within the same herd under presumably identical conditions. The columns representing grazing rates of bottle-fed animals are in shades of blue, those of mother-fed animals in shades of red/yellow. Shorter columns represent more efficient grazing (=less seconds per 20 bites). At a first glance, there seemed to be an overall seasonal trend in all animals towards more efficient grazing later in the season or as they get older. Alternatively, the higher grazing rate later in the season might simply be a reflection of lower forage density on the fall pastures. During the periods when at least some bottle- and mother-raised animals were in the same herd, there was definitely no indication of a more efficient grazing rate of the group of mother-raised heifers. If anything, the bottle-raised heifers were feeding on average at a slightly more efficient rate than the mother-raised heifers. However, the interpretation of these results has to consider the average age difference between the animals in the two groups. The bottle-raised heifers were on average 2 ½ months older than the mother-raised heifers and further along in their gestation. During the Sept./October period, the average grazing rate of the mother-fed heifers was more efficient than that of the bottle-fed heifers three months before. But the nature of our data limits substantially the conclusions we can draw from our results. The study animals were within the same herd and grazing under the same environmental conditions for only a period of two weeks during June/July. And even then, there was an age difference of 3 months between the youngest and the oldest study animal and they were between 0 and 10 months into their gestation. Environmental conditions obviously changed during the grazing season and therefore don’t allow for valid comparisons of grazing rates at comparable ages.
Time spent Grazing: Another way to look at grazing efficiency is to compare the percent of time spent grazing and with other feeding-related behavior. Figure 3 shows the percentage of instantaneous observations during which the six study animals were exhibiting feeding-related behavior. Again, our data give no clear indication of any significant difference between the two groups. The percent of time spent grazing varied between 47% and 52% in the bottle-raised group and between 47% and 50% in the mother-raised group. The time spent ruminating varied more within the bottle-fed group (15%-22%), than between that group and the other (17%-18%). Feeding-related behavior was exhibited between 68% and 69% of the time in the bottle-fed group and between 66% and 69% in the mother-fed group. We consider these differences non-significant.
- Figure 2: Comparison of grazing rates throughout the growing season
- Figure 3: Comparison of time allocated to grazing and other feeding-related behavior
- 5 calves are released to find their mothers in barn yard on a winter morning
- 6 calves explore farm yard in winter
- 10 calf meeting mother on winter morning
- 2 calf w mother on pasture
- 9 calves with mothers in barn yard in winter
Education & Outreach Activities and Participation Summary
Steffen Schneider’s article “Raising Calves the Old Modern Way” was published in the in the Biodynamics Journal (Winter 2008) and has subsequently also appeared in the Stockmans Grass Farmer. Beyond showing the calves with their mothers to visitors on the farm and explaining to them what we are doing, we don’t quite feel ready to provide a “recipe for success” to other farmers. We feel that we are still fine-tuning our method for raising calves. However, we are committed to this system of calf rearing, and are happy to exchange our experience with others who are reconsidering their way of raising calves. We are considering writing a follow up article describing our learnings to date.
We found the method of mother-raising the calves very beneficial to the calves, the overall herd health, and less work than bottle-raising the calves. At the same time, it did not seem to result in any lost income from less milk volume. Therefore, we are committed to continue to raise calves either on their mothers, as we have been doing for three years, now or on nurse cows. The latter would allow the calves to be with the cow 24 hours a day. However, we have not yet worked out the logistical details of such an arrangement. Generally we could observe that within our herd size and grazing system the optimum number of calves on their mothers at any particular time was 8 to 10.
While we are committed to continue to raise calves on their mother, we might experiment with a system where the calves go onto pasture with their mothers for the first 6 weeks and then become assigned to a foster mother, together with two other calves. The hope is, that by that time, the mother has benefited from having the calf (increased oxytosin levels; reduced somatic cell count), the calf has physically benefited from being with the mother, learned her grazing behavior and gotten to know the herd and the farm. Joining the calves at 6 weeks with a foster mother (a cow late in her lactation who will dry off within 3-4? months) on a high quality 24 hour pasture with low stocking density will hopefully allow the calves to continue their fast growth and development and to more gradually go through the process of weaning themselves of milk and shifting their diet to forage. In the meantime, their mother will contribute to the bulktank. Herd management stays “manageable”, because there is a smaller number of calves that have to walk to and from pasture with the milking herd and stay contained within the rotating paddocks.