What does lameness in cattle cost the individual dairy farmer and the Australian Dairy Industry as a whole?
The main costs of lameness include:
1. Loss of milk production: Lame cows are less willing to walk and prefer to lie down.Time spent grazing or competing for food is reduced. Food intake declines and consequently milk production and body weight drop.
2. Reduced fertility: Reduced food intake results in negative energy balance. This can interfere with breeding performance. Reduced conception rates, delayed onset to heat post-calving and reduced visible signs of heat are common findings. Poor fertility increases the risk of cows being culled.
3. Increased risk of culling: Culling incurs costs in terms of the herd’s subsequent production and lowers genetic gain. Animals culled due to lameness itself have a reduced market value due to loss of bodyweight.
4. Treatment costs: The cost of treatment varies depending on the cause of lameness, its severity, the amount of time spent on the case by the farmer, veterinary fees, requirement for antibiotics and subsequent discarded milk. Overall costs are in the region of $200-$300 per lameness.
This does not include the extra labour costs with more time required to move cows, drafting and milking a separate treatment herd etc. This time can be quiet significant and leads to frustration! In order to determine costs, each factor is costed individually.
1. Loss of milk production
A number of studies have shown that one or more episodes of lameness significantly reduces milk production in affected cows. In one study, lame cows, on average, lost over 300 litres of milk, 13kgs of milk fat and 13kgs of milk protein over their entire lactation when compared to sound herd mates. The InCalf project demonstrated that lame cows produced about 160 litres of milk, 3.5kgs of milk fat and 6.7kgs of milk protein less over a lactation than non-lame cows. If the average price of milk paid by milk factories is 25 cents per litre, this loss ranges from $40 for the lower finding to $74 for the higher finding. The extent of the loss in individual cases will vary according to the severity of the lameness, its duration, and the stage of lactation. Some mild cases that respond to treatment in one day may not show a significant difference in production compared to unaffected herdmates, whereas cows severely lame over a long period of time may lose significant quantities of milk production.
2. Lowered fertility
a) The InCalf project demonstrated that cows becoming lame during the post-calving or mating periods had not-in-calf rates 11% higher than unaffected herd mates.
Typically, herds with higher not-in-calf rates have fewer voluntary culls (cows culled for low milk production). Every extra non-pregnant cow will result in one less voluntary cull. If a herd manager is forced to retain a low-producing pregnant cow because of one extra non-pregnant cow, herd milk production in subsequent years will be reduced, all other factors being equal.
The difference in production in subsequent years is estimated to be about 1,100 litres for every extra non-pregnant cow and the consequent retention of a low-producing cow. In addition, the “lost daughters” of involuntary culls would be genetically superior, and so would have a higher production potential compared to daughters retained from low producers. Conservative estimates place the cost of an involuntary cull caused by an event such as being empty at the end of lactation at $1500. An 11% greater risk of incurring this loss is costed at $165.
b) Another way to value the cost of a not-in-calf cow is to estimate the difference between her market value when culled, and the cost of buying her replacement. At the time of writing, this difference is estimated to be approximately $800. An 11% greater risk of incurring this loss is costed at $88.
3. Increased risk of culling
Further analysis of the InCalf data showed that, even if lame cows became pregnant, an episode of lameness caused an additional 2.5% risk of culling. This is likely to be due to low milk yield and/or poor body condition due to the lameness episode. This cost can again be expressed in terms of the difference in returns between involuntary culls, such as those animals culled because of lameness, and voluntary culls culled for low production. A 2.5% greater risk of incurring this loss is costed at $37.
4. Treatment costs
The cost of treatment will vary depending on: the type of disease causing the lameness and its severity the amount of time spent on the case by the farmer requirement for antibiotics as part of the treatment the need to discard milk because of antibiotic use requirement for veterinary examination and treatment It is estimated that a mild case of lameness costs approximately $20 to $25, a severe case $90, and on average, the financial penalty is approximately $35. The hidden costs of lower production and fertility, and an increased risk of culling far outweigh more visible costs such as treatment and discarded milk.
Add up the costs
Individual farmers can calculate their average annual cost of lameness by multiplying the estimated cost of a single cost of lameness (calculated above at $200 to $300) by the number of cases of lameness in their herd each year. Using this data and other estimates, lameness is thought to cost the Australian dairy industry over $30 to 45 million dollars per annum. Lameness in cattle also has a “human cost”.
A simple, single case of lameness is frustrating to the farmer because it takes time to treat, time that could be better used elsewhere “on the farm or off it”. In outbreaks of lameness, the financial costs and demands on time mount up.
If the farm is experiencing financial hardship, or if resources of time or patience are limited, such outbreaks can become emotionally painful. Humans also find the sight of animals in pain distressing. Seeing large numbers of animals in severe pain, such as in an outbreak of severe lameness, is very distressing.