Dairy Cattle Flashcards
What percent of cattle herds in the US are used as dairy cows?
10% - cows have increased productivity, so fewer cows are needed to meet demand
How often are dairy cows milked
2-3 times/day
Tie-stall barns
-low-cost investment
-individual cow care
-labor intensive and difficult for workers
-poor stall design can lead to lameness, broken tails, swollen hocks, and decreased cow cleanliness
-uncommon now
Free-stall barns
-give cows comfortable place to lie down and rest
-not restrained in the stalls
-able to enter and leave as they like
-cows must walk to another area of the barn for water
-milked in a different location
How many hours do dairy cows typically rest per day?
10-14 hours/day
Compost-bedded pack barns
-loose housing system
-no stalls or alleys
-bedded pack area to rest instead
-wood shavings or sawdust are used for bedding
-needs to be aerated twice daily
-milked in a different location
-cheaper to build
-cows can get lost (sick cows overlooked)
Parallel parlor
-cows stand on an elevated platform facing away from the operator area
-udder access is between the rear legs (reduces visibility and can make unit attachment and udder sanitation difficult)
-cows stand parallel to each other
-released from parlor one at a time
-fairly common
Herringbone parlor
-most popular in the US for “small” farms
-cows stand on an elevated platform at an angle facing away from the operator area
-milk is accessed from the side and there is room for an arm type attacher and associated equiptment
-cows stand at 45 degree angle
-all cows are released at once
Tandem parlor (side opening)
-cows handled one at a time
-slow milking cows do not delay the completion of milking and release of other cows
-cows stand nose to tail in individual stalls
-milker gets a side-on vantage of udder
-cows can be released one at a time
-take up a lot of space
Rotary parlors (carousel or turnstile)
-cow movement is largely automated
-frees operators for tasks more directly associated with milking
-more difficult to provide special cow care
-stalls arranged in a large circle on a platform that rotates slowly
-cows usually finish milking after a lap or two
-milker stays in one place and cows come to them
What are the 4 phases of the lactation cycle
- early lactation
- mid lactation
- late lactation
- dry period
Negative energy balance
not consuming enough feed to offset milk production
Early lactation (stage 1)
-day 0-100
-production begins at a high rate and increases for 3-6 weeks after calving (peak milk production)
-feed intake starts to lag and cows lose weight due to a negative energy balance
-cows stop losing weight at peak dry matter intake is achieved
-cows should be rebred withing 60-70 days in milk
-grain > 60% diet
-constant access to feed and protein is a critical nutrient
Mid Lactation (stage 2)
-day 100-200
-maintain peak production for as long as possible
-maximize dry matter intake
-should be eating 4% of their body weight
-protein requirements are reduced
-important to feed high quality forage
-cows maintain or increase body weight
Late Lactation (stage 3)
-day 200-305
-milk production continues to decline
-feed intake declines
-cows rapidly gain weight to support pregnancy and replenish tissues lost in early lactation
-calves weaned ~288 days
-feed consumed is going to weight gain not milk production
Dry period (stage 4)
-305 days to calving time
-dry period should last 45-60 days
-prepping for calving
-monitor salt, calcium, and phosphorus levels
-dry matter intake = 2% of body weight
Subclinical mastitis
-undetectable to human eye
-only detected with the California Mastitis Test (CMT) = a reagent is added to small wells with milk, if a reaction occurs the relative degree of subclinical mastitis can be determined
-measures somatic cells count
-high levels is an infection
Mastitis treatment
antibiotic - but the milk cannot be kept from that cow
Clinical mastitis
-easily observed
-small white clots appear in milk
-strip cup can be used = a fine screen on a dark background so white flakes, strings, or blood can be seen
-milk shows more clots and is watery as mastitis progresses
-udder is swollen, red, and hot
Ketosis
-occurs when fatty acids are transported to the liver in greater quantities than can be metabolized = negative energy balance created
-10 days to 6 weeks after calving
-occurs during stage 1 of lactation cycle
-can test urine for ketone bodies (using pH strips)
Ketosis symptoms
-depressed appetite
-decreased milk production
-rapid weight loss
-listless behavior
-constipation
-increased milk fat percent
-low blood glucose levels
Ketosis treatment
dextrose or glucose
Milk fever (hypocalcemia)
-occurs in fresh cows
-metabolic disease that occurs when a cow’s blood serum calcium drops below normal levels
-muscles are weak-lacking calcium for muscle contraction
-occurs during stage 1 of lactation
Milk fever symptoms
-dull eyes
-cold ears
-trembling
-weakness
-eventually coma
-eventually death if not treated
Milk fever treatment
-calcium administered either orally or an IV for an immediate response
-IV given first, then oral a few hours later
-may have to continue this for several days
How are the majority of the dairy cattle bred in the US?
artificial insemination
