Dairy Nutrition Flashcards
1
Q
GI Tract
A
- 50 gallon rumen
- microbes produce VFAs (butyric, acetic, propionic acid)
- microbes also produce H2 and CO2, which form methane, released thru eructation
- if no eructation, rumen pH would decrease
- can’t reduce methane to 0% (biological need for eructation); want to reduce to 30-40%
2
Q
Rumination
A
- shortens long particle length of grasses so microbes can access it
- eat for 20-30 mins
- lie down and ruminate
3
Q
Lactation Cycle Phases
A
- peak: day 60; after, lactation decreases
- dry matter intake increases with lactation increase
- when mammal first has offspring, focus goes into producing milk for offspring
- body weight decreases at beginning of lactation and slowly increases
- late lactation period: body weight increases bcs cow has another growing calf inside her
4
Q
Roughages
A
- fiber (helps w/ regular digestion in humans, can be broken down by ruminants
- 50% roughages, 50% concentrates
5
Q
Byproducts
A
- things that come from agriculture that are not the main intended purpose of producing that plant
- at least 20% of the plant material produced in CA that would otherwise be thrown away is given to cows
- high quality nutrition and why CA has so many dairy cattle
6
Q
Total Mixed Ration (TMR)
A
- formulated diet for each individual dairy
- contingent on feed availability that dairy has access to
- can be different based on yr
- diet from nutritionist
- rare to have whole herd on same diet
7
Q
Roughages
A
- primary source of food for dairy cattle
- pasture; harvested and preserved legumes and grasses
- bulky feeds, high crude fiber, low energy, protein content varies
8
Q
Preserving Roughages
A
- want to avoid spoilage caused by rains, pests, etc.
- 1000 head dairy in CA has $2M worth of feed on premises at any time
- silage and hay for feed preservation
- half of dairy feeding ration stored in hay or silage
9
Q
Alfalfa Hay
A
- legume
- high in protein due to symbiosis w/ nitrogen-fixing rhizobium microbes
- very expensive
- grown in SoCal, where water limited (but alfalfa needs a lot of water)
- chop alfalfa, let it dry until it has right DM content, then bale it, store in dry storage space (doesn’t rot bcs low moisture content)
10
Q
Silage
A
- whole (corn) plant chopped into 1-in pieces, then dumped on ground (1-2 ft thick)
- tractor drives over silage to get air out (1 ft thick)
- repeat process until pile of 40,000 tons of feed
- need to get air out (anaerobic conditions in silage prevent aerobic microbes from multiplying)
- white tarp on top, tires on top of tarp to weigh down against silage so no O2 gets in
- takes 4 days for aerobic microbes to eat all oxygen and sugars in silage, then die
- aerobic replaced by lactic acid forming microbes, which produce lactic acid and decrease silage pH from 7 to 4
- nothing else can grow in silage bcs it’s so acidic
- silage can be stored for over 10 yrs (once 500)
- # 1 silage in CA is corn silage
11
Q
Concentrates - Energy
A
- cereal grains, molasses, fats/oils, etc.
- high digestibility (roughages are low digestibility)
- low in crude fiber (roughages are high)
- moderate protein content
- high energy content, so added to TMR to incr energy intake
12
Q
Concentrates - Protein
A
- animal origin: blood meal, bone meal, fish meal, dry milk powder
- plant origin: soybean/cottonseed/canola meal; sunflower seed/cottonseed
- dried distillers grains (DDG)
13
Q
Dried Distillers Grains (DDG)
A
- most often fed
- majority of corn grown in US goes to fuel
- 5-10% of gasoline is ethanol, which comes from corn
- the solids from ethanol become DDG –> livestock feed
- 40% of corn produced goes to fuel
- 5% to cattle
14
Q
Lipids
A
- seeds (cottonseed, soybeans)
- byproducts (DDG)
- supplements (tallow, white/yellow grease, lard, veggie blends)
- energy dense (9 kcal/g vs 4 kcal/g for carbs and proteins
- not to exceed 6% of DM in diet
- ruminant vs. non-ruminant
15
Q
Vitamins
A
- organic compounds req’d in trace amts for normal metabolism
- in general, body can’t synthesize the vitamins in quantities sufficient to meet reqs
- non-ruminants obtain all vitamins from diet
- dairy cattle don’t need B vitamins from diet but need A, D, E, K from diet (fat-soluble vitamins)
16
Q
Minerals
A
- 21 minerals are nutritionally essential
- macro minerals: animal needs more intake
- micro minerals: animal needs less intake
- low absorption rate (organic trace mineral)
- ranches know what minerals they’re deficient in (soil-wise) and supplement accordingly
17
Q
Water
A
- available, convenient at all times
- clean and fresh
- at least one water space (or 2 ft of accessible tank perimeter) should be provided for every 15-20 cows
- 2+ watering locations for larger groups of animals
18
Q
Byproducts
A
- a secondary product derived from manufacturing process
- DDGs, almond/soy hulls, citrus/beet pulp, tomato pomace, etc.
19
Q
3 Months Before Calving
A
- roughage
- group feeding
- starter should be high in energy and 15-18% CP
- hay, hay and grain, or all grain + protein pellet mix
20
Q
Heifers 3 Months Before Calving
A
- heifers make satisfactory growth on good to high quality roughage alone
- w/ low quality roughage, add some concentrate
- feeding goal is for sufficient size at 14-15 mo of age to allow breeding (so 1st calves are at 2 years)
- concentrates fed prior to calving to meet fetus needs and heifer development/growth to continue
21
Q
Last Few Weeks Before Calving
A
- add concentrates in 2-3 weeks pre-calving (5-8 lbs per cow per day)
- want to accustom heifers and cows to lactating diet
- benefits: adjust microbial population to fresh cow diet and reduce incidence of ketosis
- reduce Ca in diet so that cow mobilizes Ca from her own body reserves –> reduces milk fever
22
Q
Springer
A
- heifers w/in 2-3 mo of calving
23
Q
Milk Fever
A
- cows can’t mobilize enough Ca at calving for milk production
24
Q
Feeding Lactating Cows
A
- cows should have good body condition score of about 3.75
- lose 1 BCS after calving/during milk production
- body fat mobilization
- loss of body weight must be restored prior to next lactation
- losing body structure because they’re mobilizing fat – need to compensate for that
- energy intake deficiency is the main concern, as that will cause the animal to mobilize too much of her own body reserves
25
Feeding Early Lactation Cows
- fresh cows should receive high quality forage
- 40-50% concentrates to supply high energy intake
- problems: milk fat depression and off feed problems
26
Feeding Mid Lactation Cows
- 100-200 days of lactation
- peak DMI occur in this period
- main goal: maintain peak milk production as long as possible and minimize decrease trend in milk curve (bcs no longer using rbST)
- high quality forage and concentrates
27
Feeding Late Lactation Cows
- fed slightly above requirements for milk production
- restore body condition by dry period
- replace weight loss
- replenish Ca and P reserves for milk and bone production (otherwise, deficient animals use Ca and P from their own bones)
28
First and Second Lactating Cows
- feed 1st and 2nd lactating cows differently than mature cows
- increase requirements by 20% for 1st and 10% for 2nd lactation to allow for body growth
- nutritional requirements increase for increasing maturity of cows
- 2.5 lactations per cow in CA because many dairies replace cows before 3rd lactation
- doesn't make sense bcs they're not fully developed
- other dairy cows have 5-6 lactations before replaced
29
Dry Period
- rest before next lactation
- repair and regeneration of secretory cells of udder
- development of unborn calf
- results in more milk yield in succeeding lactations
- recommended length is 45-60 days
- done through complete cessation of milking or incomplete milking
30
Early Dry Period
- fed mainly roughage
- watch energy intake to avoid fat cows and dystocia
- good mix: 30% legume and 70% non-legume w/ added trace minerals
- an all-legume diet is high in Ca and protein
- non-legume diet is low in protein and minerals
31
Feeding the Calf
- consistency is key to establish gut microbiome
- colostrum w/in 5 hrs of birth and from days 1-3 at 6% of body weight
- keep consistent feeding frequency and milk temperature (warm or cold, but not both)
- clean water available at all times (if unclean, can get scours)
- individual feeding for health and management reasons
- choice of milk or milk replacer
- protein: 20% CP if milk-based or 22% CP if soy-based
- 10-20% fat (esp animal fat)
- carbohydrate (lactose or dextrose, not starch
32
Bloat
- excessive gas in the rumen
33
Hardware Disease
- less nutritional than it is bcs animals ingest things they shouldn't
- nails, screws, plastic -- esp metal pieces that accumulate in the rumen
- metal pieces can pierce thru rumen wall and possibly hit the heart
- prevention: put magnet in cow and attract all the metal to keep the metal together
34
Ketosis/Acidosis
- most common metabolic disease in high-performance dairy cows during the first 6-8 weeks of lactation
- energy demands exceed energy intake and result in production of toxic ketones
- keep up energy intake to prevent ketosis
35
Lactic Acid Acidosis
- ingestion of large amounts of highly fermentable, carbohydrate-rich feeds, which result in the excessive production and accumulation of acids in the rumen
36
Displaced Abomasum (LDA or RDA)
- LDA: the abomasum moves to the left of its normal position, becoming trapped between the rumen and the left abdominal wall
- RDA: abomasum moves to the right of its normal position
37
Hypocalcemia (Milk Fever)
- sudden decrease in serum calcium levels that occurs in the production of colostrum and milk in early stages of lactation
38
Free Stall Barn
- 98% of lagoon is water, 2% is manure
- lactating cows in free stall barn
39
Dry Lot Corrals
- dry lot corrals for dry cows and heifers; manure dried out and sanitized for cow bedding
- advantage of dry lot corrals; can see estrus behaviors (mounting) easier than in free stall barn
40
Covered Lagoon
- costs in the millions to make
- biogas bulging out
- 60-70% is methane
- biogas is cleaned and made into transportation fuels
- people say they don't like anaerobic digesters/covered lagoons because only 2000+ cow dairies can afford them
- but good way to deal with large dairy emissions
- farmers incentivized to reduce emissions
- half of dairies in CA will produce biogas and continue to replace diesel in 5 yrs
- digester company puts in covered lagoon, maintains it, and gets big % of sales from biogas; dairies give manure and get some money (takes dairies 4-5 yrs to break even and start making profits)
41
Methane Reduction in CA
- 2% of all taxpayer dollars used to reduce methane goes into dairy sector
- leads to 30% of all methane reductions in the state
