Health of dairy cows managed organically
“Organic” is a production system that is managed to respond to site-specific conditions by integrating cultural, biological and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity. To sell milk as organic, the farm must be certified and inspected to verify that an organic plan is rigorously followed. Interest in organic dairying is on the increase because of the growing organic market, premium prices for organic milk, and a preference for less intensive production systems.
For dairy operations, organic certification requires a record of:
- implementation of an Organic Livestock Plan;
- mandatory outdoor access;
- access to pasture;
- no antibiotics, growth hormones, or GMOs;
- 100% organic feed and approved feed supplements;
- organic management from last third of gestation; and
- no rotating animals between organic and non-organic management.
Many dairy farmers are leery of organic production because of concerns that restrictions on the use of antibiotics and other drugs may have a negative impact on herd health. But research indicates that a high level of herd health can be maintained in organic management systems.
Mastitis is a costly disease that is frequently treated with antibiotics in conventional production systems. Organic dairies treat mastitis with a range of tactics varying from frequent milk-out to homeopathy to utilization of a variety of organic medications such as garlic or antibody blends.
University of Wisconsin researchers Pol and Ruegg studied herd health (Journal of Dairy Science, January, 2007) on 20 organic farms and 20 conventional dairies. Results are in Table 1.
|Table 1. Reported cases/yr (% of total cows in herd)|
|Herd health problem||20 organic dairies||20 conventional dairies|
|Respiratory||0.8 (4 farms)||3.3|
|Foot infection||24.6 (12 farms)||19.7|
All the conventional farms utilized dry cow treatment for mastitis control, with penicillin and streptomycin used more often than Cephapirin. Half the organic farms medicated cows at dry-off with an ultrafiltered whey product used most often. Cephapirin was the drug most frequently used as an intramammary treatment for clinical mastitis in conventional dairy herds. Bovine whey products and garlic tincture were the most frequently used medications for clinical mastitis on organic farms. Satisfaction with treatment results were 40% on conventional farms and 74% on organic farms. The authors caution against using these results to characterize conventional and organic herds in Wisconsin as the study required that all conventional dairies make extensive use of dry cow treatment for mastitis.
An earlier Wisconsin study compared 99 conventional herds with 32 organic herds. Average production per cow per day was 68 lb for conventional farms and 50 lb on organic farms. Herds with somatic cell counts (SCC) less than 200,000 were 31.3% conventional and 9.4% organic, while SCC greater than 400,000 were 8.1% conventional and 15.6% organic. These results indicate a wider range of effectiveness in controlling mastitis in organic herds than in conventional herds.
Medication with antibiotics is strictly controlled in Scandinavia where all treatments must be done by veterinarians and recorded by the vet when treated. A Norwegian study of 93 conventional and 31 organic herds found that organic herds had longer production life (121%), and less clinical mastitis (14%), ketosis (36%) and milk fever (59%); similar SCC counts (102%); but lower production (82%) while feeding less concentrate (46%). A Danish study compared 99 conventional herds with 29 organic herds with 10 years of experience. Organic herds had fewer mastitis treatments (56%), lower SCC (87%), and less retained placenta (58%), ketosis (24%) and milk production (83%).
Scandinavian cattle may be quite different than North American cattle in their resistance to disease, thus especially well-adapted to production systems with less dependence on antibiotic therapy. Sire selection programs in Scandinavia have placed considerable emphasis on health traits for at least 25 years while North American breeding has been very focused on increased milk yields. Recent Dutch research attempted to determine if different Holstein genetics should be utilized in organic or conventional herds. This appeared to be the case for milk production, but not for somatic cell score.
The growing body of research indicates that organic production methods can be utilized while maintaining good herd health. The restrictions in use of antibiotics may be offset by beneficial effects of organic management systems. Herd health concerns should not prevent the adoption of organic production methods.
The next two articles in this series will focus on deciding if organic dairy production fits your farm and the requirements for organic certification.
Published in Dairy Star January 13, 2007