To have animals performing at their best technically, to take advantage of genetic progress, it is normal to cull certain cows and introduce heifers into the herd. We speak of voluntary culling when the farmer decides to cull a cow that does not meet their expectations, in terms of milk quantity or rate, or calving period. We will speak of involuntary culling, when the farmer is forced to cull a cow that has health problems. The top three most frequent causes of involuntary culling are mastitis, infertility and lameness.
Several causes are behind this lameness. In 90% of cases, they are injuries or infections of the claws (sole ulcer, whitlow, interdigital dermatitis). Lameness can also be caused by joint problems or poor horn wear. On a hard and abrasive floor, such as concrete, leg problems are more frequent because the horn is weakened and sole injuries are more frequent. Humidity and stagnant excrement are aggravating factors by promoting the development of bacteria.
Lameness increases the risk of culling
Lameness triples the risk of premature culling. Indeed, a lame cow will move less to eat and drink, and its production level will suffer. The Institut de l’élevage estimates that in the event of severe lameness, milk production may decrease by up to 36%. In addition, a cow with foot pain will express her heats less. It will therefore be more difficult to identify the right time to inseminate her. This gives a non-pregnant cow rate multiplied by 15 for cows with a recurring lameness problem. In addition to these production losses, there is the time spent treating lameness and its direct cost estimated at around €250. Enough to explain an early retirement.
The financial impact of this early culling is all the heavier if we take into account the cost of raising the heifer, which is around €1,500. It will take 2.5 lactations to amortize this rearing cost through the sale of her milk. If we are forced to cull her before, we lose money because the price of the cull will not compensate for the rearing cost.
Investing in Magellan mats to reduce the cull rate due to lameness
Before the installation of Magellan mats in the barn of Gaec Etang de la Roche, located in Marsac sur Don (44), the scarification of the concrete had an abrasive effect on the sole of the hooves, causing numerous lesions. « All the first-calf heifers started to limp. Half of the herd experienced more or less severe lameness and about twenty cows out of 180 were culled for this reason », recalls Stéphane Roué, one of the partners of the Gaec. « With the installation of the mats, in 6 months, we went from 25% of cows with lameness to only 2 or 3%. The cull rate for lameness is almost 0 ».
