Dairy cow and beef cattle production systems (subproject 1)

Mastitis (and to a lesser extent foot diseases/lameness) remain the main health and animal welfare problems in organic and other ‘low input’ production systems.

Mastitis is a particular challenge and often causes significant economic losses for organic producers, because organic standards and/or certification bodies

• restrict the use of antibiotic treatments (e.g. prophylactic treatments for dry cows),
• encourage producers to use complementary remedies (e.g. homeopathy, nosodes) before resorting to veterinary medicine use and
• prescribe longer withdrawal periods after veterinary medicine use.

It has been estimated that more than 60% of veterinary antibiotic use in organic farming is for mastitis control. There are reports for lower levels of antibiotic use in organic and other ‘low input’ cattle production systems. However, other studies showed no significant differences in udder and foot health and antibiotic use between organic, ‘low input’ and high input production systems. The continuing high level of veterinary antibiotic use has resulted in consumers concerns about welfare standards, antibiotic residues in dairy products and the risk of ‘low input’ dairy systems contributing significantly to increasing problems with antibiotic resistant pathogens in human medicine. 

Fertility problems as a result of metabolic disorders are also a main issue in ‘low input’ and organic systems. They are often caused by imbalances between protein and energy supply in the total ration. Cows with high genetic potential for milk production may be at a greater risk of energy deficiencies in early lactation which could lead to metabolic disorders and fertility problems. In the organic sector

(a) the withdrawal of derogations on the use of non-organic concentrate feeds and

(b) the limited availability and increasing cost of organic concentrate feeds is expected to lead to reduction of concentrate and increase in forages in dairy rations. In organic farms with high yielding cows (e.g. Holstein Friesian genotypes) this may result in an increased incidence of metabolic disorders and fertility problems.

However, the composition of milk from ‘low input’ systems was also shown to be more variable throughout the year and organic milk was reported to have higher somatic cell count levels. Also, the higher level of polyunsaturated fatty acids may result in a reduced oxidative stability and shelf life of milk. Nutritional quality is likely to become a key driver for increasing demand and maintaining price premiums for milk and dairy products from organic and ‘low input’ systems in the future, especially if recent reports linking human health benefits to organic milk consumption are confirmed.

Environmental impacts (greenhouse gas especially methane emissions, N-leaching, P-run-off) of ruminant production systems are also a major societal concern. Animal breeding and production system development must therefore attempt to provide a balance between animal health and welfare, product quality and environmental gains.

The development of more ‘robust’ genotypes via traditional and marker-assisted assisted breeding strategies is thought to be one of the most promising approaches to address the issues listed above. Genetic improvement is also thought to provide more sustainable/stable solutions compared to other measures (e.g. management strategies, veterinary treatments). However, there are currently no ‘within breed’ selection/breeding programmes targeting the needs (see above) of ‘low input’ and organic production systems.