Lameness, Hoof, and Leg Issues in Dairy Cattle- Part 2
Heel horn erosion• Other ‘external factors’ – such as poor hygiene - also play a role!
Poor quality/defective sole• Discoloration (yellow, red) of sole• Poor quality sole tissue – Soft, ‘chalky’ tissue• “Interrupted” horn production – “Double sole” – Infection in damaged sole may lead to abscesses – Sole ulcers may develop
Corium of the sole Formed here… grows ‘down’/out
Discoloration Blood/serum trapped in sole tissue
So…• ‘Laminitis’ can affect all areas of the corium• Problems are often observed ~6-10 weeks after the laminitis occurred• Chronic ‘laminitis’ can be a common problem & is involved in many lameness conditions in dairy cows• Other ‘factors’ are also involved!
Internal factor: Loss of cushioning• “Prevalence of sole ulcers and white line disease was significantly associated with thickness of the digital cushion.” (Bicahlo, 2008) Images courtesy of C. Lischer, Sweden Digital cushion (“Fat pad”)
Excessive pressure on corium Lateral Medial Both Left forelimb Left hindlimb First claw(s) to contact floor of left fore and hind limbs. (n=12 cows) Left-rear foot* High-speed cinematographic evaluation of claw-groundcontact pattern of lactating cows. Schmid et al, 2009
Pressure on (“pinching”) corium • Laxity in tendons/ligaments around calving P3 P3Lischer CJ, Ossent P. “Pathogenesis of sole lesions attributed to laminitis in cattle.” 12th InternationalSymposium on Lameness in Ruminants. 2002.Knott L.,et al. “Effects of housing, parturition and diet change on the biochemistry and biomechanics of thesupport structures of the hoof of dairy heifers.” Vet Journal. 2007.
Trauma to the corium Photo: Dan McFarland, PSU
Excessive pressure on corium• Pressure reduces blood flow to corium (+/- bruising)• Shape & conformation of P3 & sole P3• Interaction with trimming, housing & cow comfort factors – flooring, excessive standing time
Healthy feet – from the outside in…• “External” factors affecting the quality/ health of the hoof: – Cow comfort – Heat stress – Walking surfaces – Handling – Hygiene & foot bathing – Trimming
Cow comfort – stall usage• Adequate lying time – 12+ hrs/day• Stall size/structure that allows ANY cow to: – enter & recline easily – rest comfortably – rise & exit easily Photo: Dan McFarland, PSU
Goal: 80-90% (or more!)of the cows in the stalls should be lying down
Effect of bedding quantityTucker and Weary, JDS Amount of sawdust on mattress Statistically87:2889 0 kg 1 kg 7.5 kg significant? Lying time (hr.) 12.3 12.5 13.8 Y Time standing 1.77 1.42 1.17 Y in stall (hr.)
Functional Claw Trimming For lame cows, and routine (maintenance) trimming “If you don’t do it (trimming) right,you can cause a lot of lame cows!!”
The soles should beflat front-to-back & side-to-side. Picture courtesy J Shearer (with modifications)
Increased weight- After trimming: ~1 bearing surface area Cow coming back from the trimming table decreased pressure
Trimming tips• Have & use good chute/table & tools• Ideally, check ‘normal’ cows twice/lactation – early dry-off & at mid-lactation• Not every cow needs (a lot of) trimming… – …but they should all be ‘put on the table’ – Too much trimming can be a disaster!• Cows should not routinely become lame 3-7 days after trimming
Treating lame cows – When?• Clinically lame cows (Locomotion score 4 & 5) – As soon as possible (within ~24 hrs) – Make it a priority…make the time necessary• Locomotion score 2 & 3 cows – When time permits – Regularly scheduled hoof trimmer visits
If they’re not a problem yet…• Untreated lameness problems usually get worse…not better! – Locomotion score 3 cows 3X more likely to be clinically lame in 4 weeks than a LS 1or 2 cow – White line separation can become an abscess – A sole abscess may become an ulcer – A sole ulcer may develop into septic arthritis
Treating lame cows – When not?• Incurable lameness – Fractures, nerve problems, etc – Septic arthritis – Very thin/weak cows• Take appropriate medical steps (eg. amputate claw) or euthanize (properly!) Work with your vet!!
Treating lame cows – How?• Have at least one trained person on the farm• Be aggressive…BUT - protect the corium!!• Use blocks / shoes