FOOT PROBLEMS…A NUTRITIONIST’S NIGHTMARE In the past decade I have spent as much time dealing with lameness in my dairy herds as I have with nutritional issues.Why? Cows who cannot walk do not eat, are more prone to reproductive and metabolic disorders and are likely to be prematurely culled from the herd.
FOOT PROBLEMS…A NUTRITIONIST’S NIGHTMARE Laminitis, the main non-infectious cause of lameness, is classified into 3 categories:1. Acute or subacute laminitis: Is relatively rare in dairy cattle and is due to asingle incident such as grain over load, RP’s or mastitis. It develops rapidly and causes severe signs of acute pain, but does not produce lesions that are visible in the hoof.
FOOT PROBLEMS…A NUTRITIONIST’S NIGHTMARE2. Chronic laminitis (“slipper foot”): Develops from continuous or repeated insults that cause lesions affecting the shape and function of the feet and eventually locomotion.3. Subclinical laminitis or SARA (sub acute ruminal acidosis): SARA is a multifactorial disease involving nutrition, housing and stress. It occurs when the cow’s rumen drops below 5.8 pH.
FOOT PROBLEMS…A NUTRITIONIST’S NIGHTMAREThere is a clear association between infectious causesof lameness and laminitis:Lameness due to digital/interdigital dermatitis causescows to spend less time on their feet. Once they aresettled in a stall they are reluctant to leave it even if itmeans foregoing food and water.This in turn leads to slug feeding, reduced rumen pH(acidosis) and eventually laminitis. DA’s, low BCS,compromised immune system and ketosis are alsocommon in these animals.
Nutritional InfluencesFactors such as the amount and type of grain, grain processing, forage type and quality, levels etc. influence intake patterns, energy metabolism and sub-clinical acidosis.Grain mixes containing finely ground or highly processed cereal grains have the highest rates of ruminal starch digestion.
Nutritional InfluencesGrain sources categorized by rate of ruminal starch digestion. Adapted from Stock and Britton (1993).
Nutritional InfluencesWhen formulating rations: Ensure NDF is between 28-33% for high production groups (75% of which should be coming from the forage fraction). NSC levels should be between 35-40%, although in my experience I do not like to go over 38% if possible. High production rations should contain 21-27% starch and 4 to 6% sugar. Caution should be taken to blend rapidly available and slowly available starches.
Nutritional InfluencesAt the barn level: In my experience one of the biggest reasons for laminitis in herds can be attributed to trends towards finely cut and processed forages, and a range of by-products that offer very little chemical or effective fibre.In other words there is a lack of eNDF (effective fibre).
Nutritional Influences When effective fibre is decreased or inadequate: Less chewing by animal Less salivary buffer secreted More rumen acid produced Reduced ruminal pH Shift in microbial populations & end products of fermentation (>propionic acid,<acetic acid) Milk fat depression Laminitis!
Nutritional InfluencesCaution: excessive quantities of long pieces will allow “sorting” by the cows. Ensure total ration moisture is about 50%. If too dry, add water or products such as wet brewers grains or molasses. Limit dry hay (or straw in the case of heifers and FAD cows) to 1 to 2 kg/hd/day. Limit maximum fibre length to 5 cm or less. Processed corn silage helps; the presence of husks and cobs in the TMR promotes sorting.
Nutritional InfluencesFat High fat content of TMR. Total added fat (saturated, non-saturated and by-pass) over 8% of the total ration DM can tip a fibre- marginal ration into a problem zone.Amino acids The amino acids cysteine, histidine and methionine play key roles in production of good quality horn of the hoof, providing a strong start to hoof health.
Nutritional InfluencesCalcium The onset of lactation places a large demand on mechanisms of Ca balance in the animal and most cows develop some degree of hypocalcemia at calving. Insufficient calcium supply or availability due to hypocalcemia may lead to reduced quantity and/or quality of claw horn.
Nutritional InfluencesZinc Zn is a component of over 200 enzymes, several of them involved in the processes of horn production. Many studies have shown that organic Zn improves claw integrity as well as udder health.All of the herds I work with are feeding some form of chelated or organic Zn.
Nutritional InfluencesCopper Cu activates an enzyme which is responsible for formation of the chemical bonds between keratin filaments. Cattle suffering from a subclinical Cu deficiency are more susceptible to heel cracks, foot rot and sole abscesses.Caution: NEVER feed toxic levels of any trace mineral.
Nutritional InfluencesSelenium Se may contribute to protection and maintenance of the intercellular cementing substance. I supplement Se at 7 mg/h/day and will have my clients inject Se at the start of the FAD and CUD periods if oral supplementation is not guaranteed.
Nutritional InfluencesBiotin A water-soluble “B” vitamin, biotin is the vitamin of greatest importance to horn production. 20 mg/cow/day supplemental dietary biotin reduced the laminitis related hoof lesions, white-line separation and sole ulcers and improved sole ulcer healing.
Nutritional InfluencesVitamin A Vitamin A plays an important role in developing the structure and quality of horn tissue.It is essential to supplement Vitamin A, the naturally occurring Vitamins A in forages and grains brakes down very quickly. I supplement rations at 200 KIU/hd/day.
Nutritional InfluencesTransition Nutrition and Management Around calving, dairy cows are introduced to a lactation diet and most often also to new housing facilities. These changes by them selves may lead to animals being at risk for acidosis/laminitis particularly in 1st calf heifers. One group short dry cow period?
Nutritional InfluencesIn my practice I have seen many herds wherecows< 90 days in milk show signs of laminitis. This is most likely due to the risk of SARA throughfailure to increase the VFA absorptive capacity of the ruminal papillae and adapt the ruminal microbial population to starch during the close-up dry period prior to the feeding of high-energy (starch) milking cow diets.
Nutritional InfluencesThis situation may be exasperated by animals moving from a “coarse” close up dry cow ration and movinginto a much “hotter”, finely chopped milk cow ration.This observation lends further support to the practice of feeding a fresh-cow ration in a separate fresh cow group.My herds that have a separate fresh cow group feedhigh or milking TMR with LIMITED long stem hay fed separately (1-2 kg).
Nutritional InfluencesHeat Stress Ruminal pH is lower in dairy cows in hot-humid conditions, this is due to decreased ruminationactivity and increased slug feeding during heat stress. Excessive sorting of long TMR particles may increase during heat stress.This can be reduced by increasing the eNDF content of the TMR and decreasing the NFC content.
Nutritional InfluencesHeat stress limits the amount of time cows spend installs which may increase risk of laminitis. Laminitisincreases in cows that spend more time standing on concrete. Remember SAAWW : shade, air exchange, airvelocity, drinking water, and water for cooling. I also reduce DMI and “dense” up the TMR prior to heat hitting.
Feeding Management PracticesEating fewer and larger meals more quickly isassociated with increased incidence of laminitis.Factors that can cause “slug feeding” of the TMR: Limited bunk space. Limited feed access time. Restricted feeding vs. feeding for 5 to 10% refusal. Inconsistent feeding schedule. Infrequent TMR push up. Bunk competition.
Feed AdditivesMonensin: Monensin and the CRC boluses are used to reduce subclinical ketosis during transition. Monensin has also been used to prevent acidosis in cattle and reduce lactic acid concentrations through inhibition of the lactic acid producer Streptococcos bovis. This suggests that monensin may have a role in controlling SARA and laminitis.
Feed Additives In my herds I use the CRC bolus 21 days pre-partum, no monensin in the dry premix, and 200 - 300 mg of monensin in the milking premix.The 200 – 300 mg of monensin is relatively low (I have seen up to 600 mg in the field) and does not affect BF% in my herds.
Feed AdditivesSodium Bicarbonate Dietary supplementation of sodium helps buffer the rumen pH, increase BF% and reduce acidosis/laminitis. In my herds I use 200-220 g/h/day in all milking groups and in some herds we also free choice sodium bicarb. (I reduce NaCl by 50%) DO NOT FEED SODIUM BICARB TO DRY COWS (MILK FEVER)!
Cow Comfort and LaminitisThis is a huge topic on to it’s self: Proper stocking density to minimize excessive standing. Free stall design and resting surface management to encourage use and minimize injury. Stall grooming, bedding addition, and regular observation of stall acceptance. Adequate air exchange to encourage moisture removal to keep stalls and alleys drier. Match group size to parlor performance.
Cow Comfort and Laminitis Alley cleaning frequency to limit manure accumulation in alleys. Convenient access to feed and feeding area for at least 21 hours per day. Installation and use of heat stress abatement methods improve cow comfort and reduce excessive standing. Periodic locomotion scoring and observation for lameness. Regular hoof trimming schedule for each cow by qualified hoof trimmer.
FOOT PROBLEMS…A NUTRITIONIST’S NIGHTMARE Take Home Messages Acidosis, laminitis and SARA : DON’T GO THERE! It will take you 1-3 years to recover and can devastate a herd.Always build for cow comfort: your cows and you will be rewarded.Foot problems affect herd nutrition, herd nutrition affects foot problems!