foooood Flashcards
CA26-27; CA30-32
what is the optimum rumen pH
7.0
what pH are rumen microbes depressed?
below 6.0
how is the rumen kept well buffered?
bicarbonate in saliva
name the 3 volatile fatty acids (VFA) that are end products of rumen fermentation
- acetate
- butyrate
- propionate
name 4 end products of rumen fermentation
- volatile fatty acids (VFAs)
- ammonia
- microbial cells
- gases (methane, CO2)
this the most important factor in diet formulation;
feeding of forage and concentrates;
most difficult factor to assess
Dry Matter Intake (DMI)
what is the equation for DMI (kg/day) for cattel
DMI (kg/day) = 2.5% BW + 10% milk yield
during what two stages of cows are DMI intakes reduced
- early lactation
- late pregnancy
name 7 cow factors in DMI
- body weight
- milk yield
- stage of lactation
- stage of pregnancy
- BCS
- cow comfort
- rumen health
name 5 food factors in DMI
- digestibility of foods
- concentrate feeding
- forages
- dietary deficiencies
- palatability
name 5 management factors in DMI
- TMR
- frequency of presentation of food
- restriciton of access
- water
- cow comfort
how much food should be left over at the end of 24h to ensure the cows are being fed enough?
5-10%
what is the daily maintenance energy requirement for Holstein cow?
70-80 MJ of ME
(metabolisable energy)
what is the production energy requirements for Holstein cow?
5 MJ of ME per litre of milk
(metabolisable energy)
name 2 types of non-protein nitrogen (NPN) produced by cattle
- urea
- ammonia
this is the protein (mixture of amino acids) which the animal has absorbed into its body and is available to meet the needs for maintenance and to produce protein in milk, meat and fibre
metabolisable protein
what two types of protein is metabolisable protein composed of?
- effective rumen degradable protein (ERDP)
- digestible undegradable protein (DUP)
this is an important source of energy for rumen;
essential to promote rumination;
formation of the rumen mat;
increases proportion of acetate produced in rumen (incr. butterfat levels)
fibre
name 3 types of quickly fermentable energy in the rumen
- starch
- sugars
- pectin
(creates proprionic and butyric acid)
name 3 types of slowly fermentable energy in the rumen
- hemicellulose
- cellulose
- lignin (resistant)
(creates acetate)
what length of fibre should be fed to cows
2.5-10cm long
how many litres of water does a cow need per kg of milk produced
2-3 L
what 3 things is the transition from dry cow to early lactation critical for?
- incr. dry matter intake in early lactation
- reduced disease problems in early lactation
- incr. milk production
name 4 aims for transitional cow management
- get cow ready for coming lactation
- maintain a positive energy balance
- good immune function of the cow
- prevent milk fever
what BCS should you aim for at calving
2.5-3.0
name 3 problems that can occur if a cow is too fat at calving
- excessive loss of condition score
- reduced DMI in early lactation
- health problems
name 2 problems that can occur if a cow is too thin at calving
- poor lactation yields
- health and repro problems
name 3 important reasons cattle need adequate long fibre in their diet
- to stimulate rumination
- to form floating mat in the rumen
- to promote chewing and saliva production
name 3 reasons buffer feeding of cows grazing at pasture (feeding of forage-based feeds as a supplement to grazed grass) is necessary
- decline in graass quality and availability
- inadequate grass DM intake
- support high levels of milk production
acidosis may occur if the ratio of concentrate to forage in ration exceeds what?
60:40
name 3 possible strategies to avoid drop in rumen pH
- use of third mid-day meal
- out-of-parlour feeders
- total mixed ration (TMR)
name the feeding strategy for cows
cows are fed according to requirements;
feeding to yield;
semi-TMR systems
group feeding strategies
name the feeding strategy for cows
all cows are fed the same amount of concentrates;
single TMR system
flat rate feeding strategies
name 4 factors influencing milk quality
- genetic
- age
- yield/stage of lactation
- disease
name the 3 sources of fatty acids for synthesis of butterfat
- 50% from acetate and butyrate VFAs
- 10% from adipose tissue
- 40% from dietary fat
what is the usual nutritional cause of low butterfat levels in milk?
lack of long fibre
where is the major source of milk protein from?
microbial protein
what is microbial protein synthesis (major source of milk protein) dependent on?
dietary energy
is butterfat response to correction of the dietary problem fast or slow?
rapid (days)
is milk protein response to correction of the dietary problem fast or slow?
slow (months)
name 5 diseases associated with subacute rumen acidosis (SARA)
- negative energy balance
- LDA
- lameness
- poor fertility
- other peri-parturient diseases
name the term
reduction in body stores
depletion
name the term
subnormal concentrations in body
deficiency
name the term
malfunction of body processes (sub-clinical disease)
disorder / dysfunction
name the type of deficiency
levels of mineral in diet are inadequate
primary (simple)
name the type of deficiency
levels if mineral in the diet are normal;
absorption and uptake from the diet inadequate
secondary (conditioned)
name 3 indirect methods of correcting deficiency problems
- application of fertilisers to pasture
- minimising antagonists
- genetic selection
what breed is more susceptible to copper deficiency? (cattle or sheep?)
cattle
name 4 important functions in the body that copper plays an important role in (and would therefore become a clinical sign with copper deficiency)
- haemoglobin synthesis
- demyelination
- skeletal and connective tissue abnormalities
- melanin production
where is 70% of body copper reserves stored?
liver
name 3 chemical elements that have an effect on copper absorption in the rumen - they all bind copper and reduce it (create insoluble copper complexes)
- iron
- sulphur
- molybdenum
name 3 coat and hair changes that may be seen with copper deficiency in cattle
- dry, sparse hair coat
- loss of coat colour
- ‘spectacles’
name 4 skeletal abnormalities that may be seen with copper deficiency in cattle
- thickening of epiphysis (fetlock)
- spontaneous fractures
- joint stiffness
- lameness
is neurological dysfunction a feature of copper deficiency in cattle?
no
name the common neurological sign of copper deficiency in sheep
congenital;
hind-limb weakness and paresis;
ataxia and incoordination;
usually bright and alert otherwise;
usually apparent at birth or soon after
swayback (enzootic ataxia)
is there treatment for swayback (enzootic ataxia) in sheep due to copper toxicity?
no, irreversible
name 3 ways to diagnose copper deficiency
- dietary molybdenum levels
- serum/plasma copper levels
- liver copper levels
what copper-dependent enzyme can be used for a longer term measure of copper status;
measures dysfunction ;
expensive
superoxide dismutase (SOD)
name 3 methods of copper supplementation with oral compounds
- copper oxide needles
- boluses
- oral drenching with copper sulphate
what element is required for the synthesis of vitamin B12 by rumen microbes?
cobalt
what two things is vitamin B12 required for?
- energy metabolism (propionic acid)
- methionine synthesis
what 2 specific clinical signs are seen in lambs with cobalt deficiency
- ovine white liver disease
- hepatic encephalopathy
what is the main role of selenium and vitamin E in the bod?
prevent oxidative damage / cell membrane destruction
what is the usual cause of selenium deficiency
low soil content
what is the main clinical disease caused by selenium/vitamin E deficiency
white muscle disease
(nutritional muscular dystrophy)
name 3 clinical signs of selenium/vitamin E deficiency
- stiffness
- discomfort
- reluctance to move
name 2 markers of muscle damage in the blood that can be used to diagnose white muscle disease
- creatinine kinase (CK)
- AST
what is iodine essential for the production of?
thyroxine
is selenium a primary or secondary deficiency?
primary
is iodine a primary or secondary deficiency?
both (can be either)
what is the classic sign of iodine deficiency?
enlarged thyroid gland (goitre)
what is the classic cause of secondary iodine deficiency
feeding brassicas to pregnant dam
what is the best way to definitively diagnose iodine deficiency?
thyroid histopathology (PM)
name 2 levels to measure to help diagnose iodine deficiency in the live animal
- plasma inorganic iodine
- thyroxine (T4)
what is the major source of vitamin A for the newborn calf?
colostrum
name 3 clinical signs of vitamin A deficiency in calves
- night blindness
- neurological signs
- opacity and thickening of cornea
name 2 clinical signs of vitamin A deficiency in adult and growing cattle
- reduced growth rates
- bran-like scales on coat
name 4 outputs we can use to assess if a diet for cattle is working properly
- milk production
- milk quality
- body condition score
- poor fertility
what 3 biochemical parameters can be tested in blood to look at energy balance in a cow
- beta-OH butyrate
- NEFA
- glucose
what 4 biochemical parameters can be tested in blood to look at protein levels in a cow
- urea
- total protein
- albumin
- globulin
what 4 minerals might be routinely measured to look at diet balance for a cow
- magnesium
- phosphorous
- copper
- selenium (GSH-Px)
how long after major diet changes should you wait before blood sampling?
2 weeks
how many cows in the group should you blood sample to look at nutrition
5-12 cows in the group
