Automated measurement of milk yield in suckler cows
Abstract
The productivity of suckler cow farms depends on the number of calves weaned per cow and of their weights at
weaning, as these are the criteria used for selling them. To ensure calf weight gain, supplementation with concentrates
has become the preferred method, therefore, it is essential to maintain and develop the dairy potential of
suckler cows (SC) to reduce feed costs. The aim of this project is to develop a validated reference model for predicting
milk production (MP) in SC. The standard method for quantifying MP involves weighing the calf before
and after suckling. This method is time-consuming and requires significant manpower, and is therefore only used
in a few experimental stations. The development of automated weighing and electronic animal identification has
led to the emergence of an alternative method that could become the reference. The concept is to allow the calf
to suckle its mother freely, with a compulsory weighting between its pen and mother one. The software processes
the weights collected automatically to estimate MP. INRAE’s Herbipôle unit designed and tested a prototype 7
winters on 117 cows, 71 Charolais (CH) and 46 Salers (SA). Each winter was divided in 6 periods of 14 days.
Each period alternated between 4 days of standard method (2 sucklings/day) and 10 days of free suckling with the
device based on automatic weighing at each pen change. An algorithm transform calf weights into MP. The calves
suckled 3.1 ± 1.5 times/day during the first period compared to 4.5 ± 1.7 during the last. The free device estimated
that MP was 8.3 ± 2.1 kg/d for SA, 6.9 ± 1.3 for CH, with a good correlation with the reference method (r² from
0.86 to 0.66 from period 1 to 6). The free device has been validated and will be extended to various suckler cattle
experimental stations to measure MP of other breeds in various breeding conditions.