Reduced milking frequency: Milk production and management implications.

Discipline: lactation management; Keywords: once-a-day milking, extensive dairy production systems, labour requirements, pasture deficit.

Reduced frequency of milking such as once-a-day remains controversial and will do so for some time to come. As it may reduce milk yield by 20-25% and may adversely affect lactation length and persistency, the practice does not appear to make economic sense. However, there may be other advantages as reviewed by Dr K. Stelwagen and co-workers. The review was published in the Journal of Dairy Science, Volume 96 of 2013, pages 3401 to 3413, with the title: Reduced milking frequency: Milk production and management implications.

Reducing milking frequency is not common. However, once-a-day milking has been practised either strategically during the lactation period or less often during the entire lactation in prominent dairying countries where less emphasis is put on milk yield per cow. The practise fits well with more extensive dairy production systems, particularly those based on grazed pasture such as in New Zealand and seasonal milking. The negatives are associated with the reduced production and persistency. On the positive side it can offer several farm management options associated with labour requirements and farm working expenses. It also allows better management of the metabolism and energy balance of cows during early lactation or during periods of pasture deficit: (1) High-producing cows are prone to metabolic problems such as ketosis, sub-acute acidosis, lameness, laminitis and impaired udder health, the latter three reflecting on animal welfare. These are associated with high energy demands and the concentrate diets necessary to cope with the demand, specific nutrient imbalances and housing. (2) On pasture less concentrates are supplemented than with total mixed rations and because once-a-day milked cows produce less milk, even less resulting in better pasture intake and digestion. (3) With pasture deficit once-a-day milking should reduce pasture intake by the cow, thereby assisting to overcome the period of shortage. Once-a-day milking may improve reproductive performance, because cows remain in positive energy balance to the benefit of re-conception and inter-calving period. Some results suggest also positives to mammary physiological function.

The question is then could there be a place for once-a-day milking in South Africa? Many of us are sceptical. However, labour cost with over-time has become a factor in the conventional twice or three times daily milking, which can be avoided in once-a-day systems. Feed costs and other inputs are further concerns affecting the sustainability of dairy farms, so are the requirements of intensive management 365 days of the year. These problems escalate for the small scale and emerging farmers, making it almost impossible to enter the dairy industry. Once-a-day milking will allow these farmers to come by with less management skills, less labour and in some instances they should be able to raise calves comparatively cheaply, allowing in income from meat in addition to milk.

There currently is a long term experiment on pasture run at Döhne, Stutterheim by Dr Jean Rust and co-workers, comparing once-a-day milking with the conventional twice daily system. Some preliminary results apparently support some of the findings in the review by Dr Stelwagen and co-authors. I think the dairy industry should be positive to this initiative; the project is expected to run until 2017 and since measurements will be conducted over a wide spectrum of influencing factors, the outcomes should provide valuable directives as the experiment progresses.