The development of the system to collect electronically the cow’s milking speed data was initiated in 2009. The milking speed data were collected from first lactation cows at third month.
Milking speed records of a total of 14,169 cows from 55 farms were used to evaluate the relationships between milking speed and production and functionality traits.
The effect of milking frequency on milk yield and quality traits on farms with two and three time parlour milking and different robotic milking systems was studied.
It was found that the average milking speed of 2,626 first lactation Estonian Holstein cows from 23 robotic milking farms was 2.12 kg/min and in 8,375 cows on 34 farms with parlour milking 2.14 kg/min. Genetic correlation between the milking speed in automatic milking systems and parlours was high (rgen = 0.918), so both devices can be treated as a single characteristic. However, the relationship between milking device brands with milking speed should be studied more thoroughly. This analysis showed also that milking speed is relatively highly heritable (h2 = 0.495). Genetic relationships between milking speed and milk yield and somatic cell score were positive (rgen = 0.408 and rgen = 0.271, respectively), while milk fat and protein content were negatively related (rgen = -0.248 and rgen = -0.166, respectively) to milking speed. Relationship between milking speed and udder conformation traits showed moderate or no correlation (rgen = 0.003-0.327), whereas the highest correlation was found with the rear udder height (rgen = 0.327), and the teat length (rgen = -0.202).
It was found that the changes in milk yield and quality parameters were similar throughout the lactation on farms with different milking frequencies and automatic milking systems. However, significantly more milk was received on the farms where three time milking was used, compared with those using twice a day milking (24.8 – 57.8%), while on the farms with robotic devices, milk yield was similar to that obtained on the farms with two and three time milking. Milk fat and protein content was lower in cows milked three times a day, while the fat and protein production was higher. It was found that frequent milking had a positive effect on udder health of cows as their milk somatic cell score was lower.
As of 1 June 2014, the database comprised milking speed records of 16,033 cows from 72 farms. Four milking systems were used – two or three time parlour milking (33 and 14 farms, respectively), and DeLaval and Lely milking robots (19 and 9 farms, respectively).
Recommendations for developing a methodology for evaluating bulls on the basis of milking speed data were prepared for the Estonian Animal Recording Centre.