Dairy Cattle

annual production of dairy cow

some cows produce more than over 34,000 lbs milk annually (over 4200 gal)

how much protein and energy are needed at peak production

3-10x as much

hunger and nutrient requirements

hunger usually lags behind nutrient requirements

goals of feeding programs

meeting nutrient needs, while minimizing body weight loss, GI upsets, and maintaining cow health

milk production and peak production

milk production increases rapidly and reaches peak production6-9 weeks after calving

when does maximum daily dry matter intake occur

12-15 weeks post partum

when are cows in a negative energy balance

for weeks 8-10

how do cows make up nutrient deficits

by borrowing from her body stores

how much do cows lose during early lactation

often lose 90-135 kg of body weight

what happens after optimal dry matter intake increases

• Intake follows production requirements and decreases as production decreases

• Tends to consume more than she needs during later lactation

• Allows her to regain body weight lost in early lactation

what is weight gain during dry period due to

fetal growth

what should happen during late lactation

should regain most of lost body weight

bovine somatotropin

• For cows injected with bovine somatotropin (bST), there may be a second increase in production within a few days of initial injections

  • May again experience a short time of negative energy balance

• Production typically increases about 10% as a result of bST injections

  • Dry matter intake needs to increase 2% to 3% to supply nutrients needed for increased production

how many phases are the feeding cycle

the lactation and gestation cycle can be divided into 5 phases based on nutritional consideration

phase 1 of feeding

the first 10 weeks of lactation, when peak production occurs, and body stores are used to make up for nutrient intake deficits

phase 2 of feeding

about 10 weeks postpartum for most cows, continuing for 10-20 weeks. maximum dry matter intake, and intake is in balance with requirements

phase 3 of feeding

intake exceeds nutrient requirements for production, restoring body reserves

phase 4 of feeding

period for any final regain of body weight, and involution following by regeneration of secretory tissue in the udder for the next lactation

phase 5 of feeding

the last 1-3 weeks pre-partum, increase grain intake to help prepare for increased nutritional intake after cows give birth

what occurs during the dry period

regenerate new secretory tissue and replace lost body condition

• changes occur in the udder

  • active involution; steady-state involution

    • lactogenesis plus colostrogenesis

length of dry period

• 6-8 weeks long

• Dry periods shorter than 40 days do not allow enough time for udder regeneration, which may cause a decrease in production during the next lactation

how to feed dry-cows

• Dry-cow feeding emphasizes maintaining body condition that a cow carries when she is dried off

  • USDA research demonstrated that cows convert feed energy to body tissue more efficiency in late lactation than during the dry period

  • If still thin at drying off, need to replenish body stores as well as provide for fetal growth

what are the 3 stages of involution

active involution, steady state involution, lactogenesis plus colostrogenesis

what occurs during active involution

completed by 30 days into the dry period, milk-secreting tissue is reabsorbed

what occurs during steady state involution

can exist indefinitely, and the mammary gland remains in a collapsed state

what occurs during lactogenesis plus colostrogenesis

begins 15 to 20 days pre-partum, involves onset of lactation and the secretion of colostrum

body condition at calving

• Body condition score of 3.5 at calving

  • On a scale of 1-5

    • 1 being thin and 5 being excessively fat

  • Ideal for high milk yield, fat test, and reproductive performance

    • Thus the cow should be in ideal calving condition when she goes dry and weight when she goes dry is accounted for by the fetus

rations for dry-cows

• Dry cow’s nutrient requirements can often be met with only forages

  • Legume-grass hay and corn silage combination needs only vitamins and a small amount of Phosphorus

  • Dry-cow ration can be simple but should include the following considerations:

    • 1% of body weight as long-stem, dry forage

      • Pref grass hay

    • Free-choice feeding of corn silage should be avoided

      • Leads to excessive energy intake and increase likelihood of a displaced abomasum and fat cow syndrome

    • Grain should be limited to energy and protein needs

fat cows

• Consuming excess energy from grain and/or corn silage likely to develop a disorder called fat cow syndrome

  • High blood lipids and fatty livers

  • Calving difficulties, displaced abomasums, ketosis, and other health problems

• Cows fed hay and/or haylage are less likely to have problems than cows receiving free-choice corn silage

  • Limit corn silage for dry cows to 9.5 to 11 kg/day

    • Plus a protein and ca-P supplement

nutrient requirements for bred heifers during late gestation

• Nutrient requirements of bred heifers during late gestation are slightly greater than of dry cows

  • Bred heifers will likely need some grain along with forages during the last 3-4 months of gestation (still growing)

  • Good-quality forages can provide all the nutrient needs

  • If forages are not of good quality

    • Additional grain may be needed to maintain optimal growth (not fat)

  • Usually fed in groups of similar age or size

transition period in the last weeks before parturition

• In the last weeks before parturition:

  • Aimed at adapting rumen microflora to higher-energy diets needed postpartum

  • Adjustment often achieved by including small amounts of all ingredients of the lactating ration

    • Gradually increasing concentrates

    • Minimize the chances for milk fever and ketosis during lactation

transition period before calving

• Minimize the chances for milk fever and ketosis during lactation

• Most cows experience a sharp decrease in total dry matter intake 24-48 hours before calving:

  • Stabilizing the rumen is important to avoid displaced abomasum, acidosis, and off-feed

what are the objectives following calving

• Parturition until peak milk production is period when appetite lags behind nutritional requirements so peak milk production (phase 1) is negative nutrient balance period

  • 1. Increase feed intake as rapidly as possible, but not to cause digestive upsets and off-feed

  • 2. Once the stress of calving has passed, concentrate intake can increase 0.5 to 0.7 kg/day

  • 3. If total mixed rations are fed, this equates to a forage-to-concentrate ratio of 55:45 or 50:50

how to have successful phase 1 feeding

• Maximizes peak milk yield

• Utilizes some body weight as an energy source

• Minimizes ketosis

• Returns cows to a positive energy balance by 8-10 weeks postpartum

how do cows compensate for their deficit in energy intake

• Cows can compensate for much of their deficit in energy intake

  • Borrow remaining needed energy from body fat

  • Cannot borrow very much protein, so protein must be supplied in the diet

  • Early lactation cows will benefit from rumen bypass (escape) proteins

    • Allows to bypass microbes and go to abomasum

how to help maintain normal rumination during early lactation

by feeding at least 2.25 kg dry hay in the daily ration

what diets cause acidosis during peak milk production

• Higher starch, lower fiber diets are more apt to cause acidosis, digestive upsets, and milk fat depression

what should cows be fed during peak milk production to limit acidosis

• Non-structural carbohydrate (starches and sugars) should be limited to 30-40% of diet and dry matter

• Feeds such as distiller’s grains can replace a sizable amount of high starch feeds, providing more energy and decreasing rumen acidosis 

maximum dry matter intake

• Should be achieved as early in lactation as possible

• Conception rates are greater for cows in positive energy balance

• Body weights should stabilize, and weight gains should actually start occurring during this phase

• Maximum dry matter intake will reach 3.5% to 4.5% of body weight

• Dry matter intakes are usually higher for higher producing cows

  • Not unusual for some cows to consume more than 5% of their body weight

how to feed cows during late lactation

• Easiest phase to manage

  • Cow is pregnant, nutrient intake exceeds requirements and milk production is declining

• Replace the weight that was lost during early lactation

• Minimize feed cost by increasing forage-to-concentrate ratio

• Lower protein content

  • Protein-to-energy ratio needed for weight gain is less than the ratio needed for milk protein

  • NPN sources may be well utilized, where bypass proteins will be less cost effective than in earlier lactation, when production was higher

energy for lactating cows

• Challenge is to get cows to consume sufficient amounts of energy, especially during early lactation

• Energy intake may be increased by:

  • Increasing the energy density of the diet

  • Increasing the readily fermentable carbohydrates

  • Increasing dry matter intake

    • Higher in fiber is better for GIT

why is fat added to the diet

• Energy density can be increased by replacing portions of the carbohydrates in the diet with fat

  • One kilogram of fat contains approximately 2.25 times as much energy as 1 kg of carbs

  • Energy density can be increased by replacing carbs with fats, avoids excessive starch

how much fat can you add to the diet

• Forages and grains contain 2% to 4% fat

  • Fat can be increased to 5% to 7% of total dry matter

  • More than 8%-10% may reduce feed intake, fiber digestibility, and cause digestive upsets

what sources of fat are good/bad for the diet

• Not all sources of fat are suitable feeds for milking cows

  • Free oils such as soybean, sunflower, cottonseed, corn, and fish oils often affect rumen fermentation adversely

• COTTONSEED > COTTONSEED OILS

feeding groups at dairies

• Some dairies group cows by reproductive status, keeping cows that need to be bred in one pen

  • May make it easier for heat detection

• When moving cows from one group to another make sure shift does not cause undue stress

  • Recommended to move groups of cows rather than individual cows to minimize stress when social hierarchy is determined

the first critical days for calves

• Health and vigor of calves at birth depends on the nutrition of the cow during the last 60 days before freshening

• Cows fed properly and immunized against locally prevalent pathogens during this period develop colostrum of good antibody quality

  • Calves are born without a functioning immune system

    • Colostrum

calves and colostrum

• Calves should receive a minimum of 2 quarts of colostrum in two feedings in their first 12 hours

  • Dairy calves rarely receive from mothers in commercial conditions, good colostrum is fed fresh or frozen and saved

newborn calves

• Digestive processes are similar to monogastric animals

  • Rumen is not fully developed until the calf reaches a weight of 200 kh

• Rumen does not start to be populated with microbes until the calf is approximately 60 days old

  • Calf must be supplied with whole milk or milk replacer

the first 60 days for calves

• Calf must elevate its heat to nurse using a nipple to activate the esophageal groove

  • Milk flows directly to the omasum and abomasum and bypasses the rumen

    • The more nearly they are fed to approximate natural conditions, the more efficient their performance

    • The more frequently they are fed, the more efficient their performance is

• Calves fed by lowering their heads to drink from a bucket do not activate this esophageal groove as well as bottle fed calves

milk replacers for calves

• First 3 weeks

• Milk source protein (dried whey, dried skim milk, casein) is superior to plant protein sources or to animal protein, such as fish protein concentrate

• Many milk replacers contain antibiotics

• Tetracycline is the most common

• Vitamin E has been recommended at levels as high as 135 IU per day for calves during the time prior to weaning

starter diets for calves

• About 1 week of age

  • Standard ingredients used in dairy feeds can be used for starter rations, but fine ground feeds are not acceptable

• Good-quality alfalfa hay should be offered in small amounts

  • Consumption of starter feed is critical to development of an active, functioning rumen

weaning calves

• Wean when calves are consuming approximately 2 kg starter feed in addition to hay and milk replacer

• Two approaches to weaning

  • Abruptly remove the milk replacer so calves have to utilize the starter ration

  • Gradually adds increasing amounts of water to the milk replacer, until it is only water

• Before weaning, calves should be moved from hutches to small group pens

  • 100 ft^2 of space per calf and a maximum of 10 calvesper pen

• Weaned calves can be moved to larger group pens and offered growing rations

  • Sort calves by size

heifers and solid feeds

• If heifers were properly introduced to solid feeds before weaning, growing ration can be gradually changed so they reach puberty at 15 months

  • Goal is maximum growth/minimum fat deposition

what are the two nutritional phases of gestation

• breed to 60 days before calving

• the last 60 days of gestation (late gestation)

what happens during 1st phase of gestation (breed to 60 days before calving)

• Rations should be designed for growth, with fat deposition avoided

• If fed high energy, low protein rations tend to deposit fat in the udder, limiting future production capability

what happens during 2nd phase of gestation (late gestation, last 60 days)

• Grain mix similar to that used when they enter lactation

• Adjust the rumen population to increase microbes that ferment lactation ration feeds

• Increase nutrient intake for storage to support early lactation plus growth

• Provide for the increased demand for nutrients by the rapidly developing fetus