ANSC 3120 Lecture Notes - Lecture 4: Dairy Cattle, Bran, Dicalcium Phosphate
19 Nov 2016
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RUMINANT
- rumen microorganisms hydrogenate USFA = convert USFA to →SFA
* exceptions = EPA and DHA (once thought to be the case, not true anymore)
~ if diet very high in FA [], cannot convert them all, some will be SFA deposited in tissues and milk etc.
~adding hydrogen atoms and removing the C=C of the USFA and convert to a SFA
~ detoxification strategy to get rid of the C=C bonds
RUMINANT: BYPASS FAT
~ alter dietary fat so rumen microbes can not digest it
- to change FA composition in adipose tissue and milk
- rumen biohydrogenation produces FA that may be considered unhealthy for humans
- can partially overcome this with bypass fat
- additional benefit it to provide extra energy for high producing ruminants (lactating dairy cow)
- fat is concentrated form of energy
- too much fat bad for rumen microbes
- feed a fat unavailable for rumen microbes but available in SI to add energy
~ would be healthier consumer option to put more USFA into tissue and milk
Effect of Rumen Biohydrogenation on Qualitative FA Composition → convert very high amounts of SFAs
Classification of Minerals in Animal Nutrition
Basis of classification = Concentrations in body
- amounts required in diet (based on metabolic roles)
- in past, fed purified diets (highly refined expensive ingredients) w. specific mineral absent
- determined if any deficiency symptoms developed when mineral was absent from diet
- then determined if deficiency was eliminated when mineral was added back to diet
- proving essentiality may be difficult due to presence in water or air or via contamination
MACRO (major) = - > 100 ppm in body
- Calcium (Ca), Phosphorus (P), Chlorine (Cl), Magnesium (Mg), Potassium (K), Sodium (Na), Sulfur (S)
MICRO (trace)= - < 50 to 100 ppm in body or feed
- Chromium (Cr), Cobalt (Co), Copper (Cu), Flourine (F), Iron (Fe), Iodine (I), Manganese (Mn), Molybdenum (Mo), Selenium (Se), Silicon (Si),
Zinc (Zn) * Mineral/mineral interactions (Antagonisms) will affect how well feed minerals are used
MINERAL NUTRITION
- goal is to meet species requirements for major and trace minerals, not simple due to:
- mineral []s of feed stuffs
- high []s of specific minerals
- excess pollute environment
- may cause mineral antagonisms
- bioavailability of minerals in feeds affected by:
- phytates and phytic acid
- oxalates
CALCIUM
- most abundant mineral in body w. 99% in bones and teeth
- what are other roles for Ca?
- enzyme action as a cofactor for many enzymes
- nerve impulse transmission
- muscle contraction
- blood coagulation
Calcium Deficiency
RICKETS (spongy, poorly mineralized bones)
- Young, growing animals
- impacts bone formation and animal mobility – stiffness, lameness, misshapen bones, fractures
OSTEOMALACIA (Bone Demineralization/Mobilization)
- Adult animals = bone strength and egg shell quality
~ bones become weak and break easily bc body counts on bones when it becomes deficient
Ca:P RATIO & others
- causes not a simple nutritional problem
- Ca deficiency, P deficiency
- Vitamin D deficiency
- Abnormal Ca/P Ratio
MILK FEVER – Parturient paresis, Hypocalcemia in dairy cattle
~ lots of Ca going into colostrum, can cause upset in cow
~ Ca needed for muscle function, NS affected first, don’t have adequate Ca to release and stimulate
- Symptoms = muscle spasms, paralysis, and unconsciousness
- Treatment
= IV Ca Gluconate
= Vit D….
Ca Absorption
or excretion via
intestines
Bone: Ca
Deposition into
or resorption
from
Large amounts
of Ca deposited
into milk
Think of the dairy
cow before and
after she calves
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find more resources at oneclass.com
find more resources at oneclass.com
= in past, fed cow low Ca in dry period prime the cow but practical problem now because..
-- it may be hard to find low Ca forages
- by feeding low Ca forages, induce the following changes in metabolism:
- mobilize bone stores (action of parathyroid hormone or PTH and Vit D3)
- increase Ca absorption from 2 places (action of Vit D3 mediated w. PTH): GIT & Kidneys
- feeding high levels of Ca ineffective as it won’t increase Ca absorption
Calcium Sources
Good = legumes, green leafy crops, milk, meat and fish, bone meal
Poor = cereals & roots – normal diet high in grain, if not feeding forage high in Ca need to add supplement
Choice of supplement dependent on mineral needs
- Limestone (Ca only): CaCO3 ~ only supplying Ca
- Dicalcium phosphate (28% Ca, 18% P)
- Oyster Shell ~ good source of Ca (seen in laying hen diets, due to increased demand for Ca)
Calcium Ratios
→need proper Ca:P ratio
- Red meat species (lamb, pork, beef)
- 1:1 (1:2) to 2:1 often recommended
~ bone generally have 2 Ca: 1 P, good ratio to work w.
- ruminants tolerant to a wide ratio when it favors Ca …
~ dairy producer feeding a lot of alfalfa have high Ca:P ratio and ruminant can handle
- Poultry - Laying hen = % Ca in diet, broilers don’t need this
~ every egg laid hen looses 2g of Ca, diet can only supply 1g
** Fat can depress Ca absorption (Mineral Antagonism)
→ Low Ca:P Ratio = diet high in P and low in Ca
- Nutritional Secondary HYPERPARATHYROIDISM
- diet induced problem from high blood P
- parathyroid gland is just doing it job: want to excrete P via kidney
* horses fed wheat bran (low in Ca, high P) – consumed large amounts of wheat bran
- developed M)LLER’s D)SEASE or B)G (EAD
- demineralization of the frontal bones of the head (Ca and P affected)
~ high P stimulating parathyroid gland to start breaking down bone – causing Ca deficiency
PHOSPHORUS
- has most functions in the body of any mineral element (~ and most deficiency uses, greatest payback)
- associated w. Ca in bone and teeth
- found in Phosphoproteins, Nucleic Acids, Phospholipids
- Energy Metabolism – intermediates in pathways, ADP, ATP
Phosphorus Deficiency
- most widespread and economically important mineral deficiency P deficient soils around world
- Rickets and Osteomalacia: importance of Ca and P in bones and teeth (99%-Ca, 80-85%-P)
- Pica in cattle
- Reproductive Problems (calving every 2-3 years)
- estrus and fertility problems
- ovarian dysfunction
- low conception rates
- depressed production
~ PICA: eating random things to cover up mineral deficiency – leads to hardware disease in cows
Phosphorus Sources
Good = milk, meat and fish, bonemeal
- Grains (~low in Ca but high in P) but problem w. phyates
- see differences in availability btw monos and rums and w. in classes also
- important to know available P content of feedstuffs for monogastrics
Poor = forages, pasture, crop residues (straw, stover)
Incorporation in diet = meet animals need, limit cost (P expensive), prevent pollution (promotes algal growth)
Grains VS Forages
Grains = Low in Ca, High in P but tied up by phytates
~problem for non-rum VS. phytate-P handled by ruminant microbes
Forages = High in Ca, Low in P
~ grazing animals will get Ca, but need to supplement P on pasture
POTASSIUM DEFICIENCY
Roles = Acid/base balance, nerve and muscle excitability, CHO metabolism
- not common since quite prevalent in soils and seeds w. some exceptions:
- effect of stress: Double D’s diarrhea and dehydration) depress K
- high grain feedlots: diets low in high K forages
- consumption levels VS other minerals
DEFICIENCY SYMPTOMS = depressed growth, weakness, tetany, severe paralysis and death
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
~ detoxification strategy to get rid of the c=c bonds. Can partially overcome this with bypass fat. * exceptions = epa and dha (once thought to be the case, not true anymore) Rumen biohydrogenation produces fa that may be considered unhealthy for humans. In past, fed purified diets (highly refined expensive ingredients) w. specific mineral absent. Determined if any deficiency symptoms developed when mineral was absent from diet. Then determined if deficiency was eliminated when mineral was added back to diet. Too much fat bad for rumen microbes. Feed a fat unavailable for rumen microbes but available in si to add energy. Rumen microorganisms hydrogenate usfa = convert usfa to sfa. ~ if diet very high in fa [], cannot convert them all, some will be sfa deposited in tissues and milk etc. ~adding hydrogen atoms and removing the c=c of the usfa and convert to a sfa. ~ alter dietary fat so rumen microbes can not digest it.
