Effects of suckling on milk yield and milk composition of dairy cows in cow-calf contact systems
Kerstin Barth; Germany
The study investigated the effect of various cow–with-calf systems on milk yield and milk composition, during periods when calves where allowed to suckle their dams and after calves were separated, in comparison to cows that were only machine milked throughout their lactation. Nursing dams had contact to their calves during the whole day, during night-time or only twice per day shortly before milking. A control group of cows that had no contact to their offspring was part of every experiment.
Results showed a significant effect of the suckling system on the machine milk yield over the whole lactation. While cows with night-time contact reached the milk production level of the control cows, cows with whole day or short-time contact still produced less milk after the calves were separated.
Fat content was always lower during the suckling period but not afterwards. The significantly higher milk protein content in dams with calf contact requires further investigation. Somatic cell count in milk of nursing dams was slightly increased, probably due to the exposure of the teats to frequent suckling in addition to machine milkings.
Cow–calf contact systems influenced the performance of cows during and after the suckling period but to varying degrees, depending on the system adopted.