Vet med - Farm animal

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Farm animal

Environment

Normal environment (where animal is normally kept)
Hygiene, ventilation,
feed, water, feces, urine

Group

size, consistency (age, stage of production)

Ageing by dentition

Cattle; I1 1.5-2 yrs, I2 2.5-3 yrs, I3 3-3.5 yrs, (I)4 3.5-4.5 yrs
Sheep; I1 1 yr, I2 1.5 yrs, I3 2.25 yrs, (I)4 3-3.5 yrs

History

other animals affected? - relationship (age, pen, etc)
were they diagnosed & with what.
were they treated - with what & how did they respond
Previous history of disease/problems on the farm/in the area

Considerations

implications for rest of herd
treatment (or cull) - management, withdrawal periods, cost

culling

ave 25-30% per year
reasons - infertility, mastitis, lameness, yield
want to maximize voluntary culling (enable selection)

Reproduction - basics

puberty 10-12 months, min 340 kg (380 kg better)
1st breeding 18-21 months, 350-380 kg
gestation 280 days
re-breed 2-3 months later
lactation 10 months, dry period 2 months

Reproduction - Targets

Calving interval - 370 days (ave 410)
Days to 1st service - 60 days (ave 83)
Calving to conception interval - 85 days (ave 128)
serves per conception - 1.8 (ave 2.5)
Pregnancy rate > 54% (dairy 42%, beef > 50%)
Culling for failure to conceive < 7% (ave 18%)

Reproduction - Rectal palpation

economy of effort, don't palpate against strong contractions
cervix, uterine body, horns, ovaries, middle uterine As, vagina
PD - amniotic vesicle, placentomes (≥ 3 months), fetus, membrane slip, fremitus in middle uterine As (5 months)
Palpate entire length both horns before diagnosing not pregnant

Trans-rectal ultrasound

ovaries - CL
uterus - PD (heart beat), endometritis, pyometra, mucometra (anechoic fluid)

Calving to 1st estrus

influenced by anestrus, estrus expression, heat detection
Calving to 1st service influenced by VWP & time to 1st estrus
(estrus requires P4 priming, can be simulated with a CIDR)
prolonged with - cesarean, lameness, endometritis, RFM,
dystocia, mastitis, milk fever, low BCS

Post-partum return to estrus

uterine involution takes 3 wks, endometrial restoration - 6 wks
recovery of LH pulsatility depends on severity of negative energy balance & BCS loss (dairy), suckling & maternal bond (beef)

Heat detection

observe 3-5x/day - standing to be mounted, bulling string
aids - synchronization, teaser, tail painting, k-mar heat detector, pedometers

Insemination

egg has short lifespan (4-6 hrs),
accurate heat detection is vital
Am/Pm or 12hr rule - inseminate cow 12 hrs after heat is detected/ if detected in morning inseminate in evening & vice versa

Failure to conceive

- Failure to detect estrus - cows return to estrus in 36-48 days - Poor timing or insemination technique

Female infertility

Specific problems - failure to breed, returns to service, abortion
Causes; non-detected estrus, metritis & endometritis, cystic ovarian disease, dystocia, RFM, cesarean
-> decreased annual milk yield, fewer calves/yr, more services

Failure to submit/no estrus

- no signs of estrus & no CL
Ddx - nutritional anestrus (BCS < 2.5, BCS loss ≥ 1),
calving to service interval too short,
just ovulated 1st time (sm & med follicles present),
cystic ovarian disease,
developmental abnormalities in heifers (free martins)

Failure to submit/no estrus 2

- no signs of estrus, CL on palpation
Ddx - non-detected estrus, 1st ovulation postpartum/pubertal, stress, suckler/high yield dairy cow, luteinization of dominant follicle, persistent CL (metritis/pyometra)

Failure to submit/irregular estrus

- Irregular expression of estrus, PE - CL
Ddx - inaccurate estrus detection, 1st post-partum/pubertal
ovulation, short luteal phase
- Irregular expression of estrus, no CL
Ddx - cystic ovarian disease

Metritis

history - few weeks post-partum,
CS - dullness, fever, toxemia, purulent vaginal discharge, cold extremities, collapse
Dx; ultrasound or metrocheck uterine sample
Tx; cephalosporins

Cystic ovarian disease

CS - nymphomania (mounting) or anestrus
fluid filled sac > 25 mm, no functional CL > 10 days
2 types; Follicular - thin wall, -> E2. Luteal - thick wall, -> P4
Tx - 40% self recovery from early presentation (21 days)
Follicular → GnRH, 2nd try - hCG then PMSG
Luteal → PGF2α

Failure to conceive

Ddx - Early embryo death (< 20 days post-fertilization, return to estrus at normal time), failure of fertilization, late embryo mortality (return to estrus late)

Failure of fertilization

Causes - farm bull fertility, timing of AI/insemination technique, cervical/uterine obstructions, genetic abnormalities in oocyte, delayed ovulation

Failure in maternal recognition of pregnancy

Causes - ovulation of persistent dominant follicle, chromosomal abnormalities, impaired CL function,
specific infections (IBR, BVDV, trichomonas, Campylobacter), non-specific endometritis, nutrition, heat stress

Repeat breeder/normal returns to estrus

History - normal returns to estrus, PE - CL + NAD
Individual; Ddx - delayed ovulations, endometritis/vaginitis/cervicitis, obstruction, urovagina
Group; Ddx - management - wrong timing/poor technique of AI, endometritis, specific transmissable infections - bull

Late embryonic loss (20 days - 6 wks)

CS; late return to estrus
Causes - specific infections, endometritis, disease/trauma, nutrition, stress, iatrogenic (palpation or drugs), insemination

Fetal loss (> 6 wks)

CS; Aborted fetus/discharge at next heat
Causes - specific infections (Neospora, Leptospira, Brucella, Trichomonas, Listeria, Chlamydia), endometritis, disease/trauma, nutrition (toxins), stress, iatrogenic, fetal developmental abnormalities

Estrus synchronization - PGF2a

PGF2a - 1 or 2 injections, requires vet, cheap
1 -> estrus 2.5-7 days, requires monitoring
2 (14 days apart in cows, 11 in heifers) -> estrus 3-4 days,
fixed time AI at 48 & 72 hrs

Estrus synchronization - Progestagens

- PRID or CIDR (intravaginal device), doesn't require a vet, more expensive?, better sync
PGF2a day 7/8 & remove day 10 or long term - 12 days
-> estrus 36 hrs, inseminate 48 hrs

Estrus synchronization - GnRH + PGF2a

- costly, good sync
GnRH, PGF day 7, 2nd GnRH day 9
-> inseminate 16 hrs

Induction of estrus/ovulation

Beef - remove calf for 48 hrs on day 30 or restrict suckling, pre-post-partum nutrition
Dairy - pre/post-partum nutrition
- GnRH/hCG, progestagen, progestagen + eCG

Conception rate with natural service

45% (1st service), 90% with 3 services

Male infertility

PE - lameness, systemic disease
genital exam - penis, prepuce, testes, scrotum, epididymis
- inspection, palpation, measure scrotal circumference, US
libido (season, social dominance, mount w/i 15 min)
mating ability
semen evaluation - #s, concentration, motility, morphology
5% (> 50% of animals thought to be infertile are fertile)

Penile problems

orchitis, small/flaccid testicles/poor motility & morphology, testicular trauma, inability to erect the penis

Bulls - STDs

Campylobacter fetus, BHV-1, Leptospira hardjo, BVDV, Mycobacterium paratuberculosis, Salmonella

Bulls - Penile problems

papillomas - regress within 4 months
rupture of corpus cavernosum, drainage defect
persistent frenulum (surgical repair)
corkskrew/spiral deviation

Bulls - scrotal & testicular problems

orchitis (Brucella, Mycobacterium, A. pyogenes, Nocardia, BHV-3), spermatocele, testicular degeneration (temperature - environmental or pyrexia, infection, trauma), neoplasia
epididymitis, cysts

Rams - STDs

Maedi-visna, OPA/jaagsiekte, Border Disease virus, Salmonella, CLA, OEA
Brucella ovis, Actinobacillus seminis, Toxoplasma, Coxiella burnetti, Campylobacter fetus, Mycoplasma

Rams - Penile problems

pizzle rot (Corynebacterium renale) - ewes with blood on tail

Rams - epididymal problems

epididymitis (Brucella ovis, Actinobacillus, Haemophilus, Histophilus, Corynebacterium), cysts

Sexed semen

75-90% accurate
fertility reduced 10-15%, less choice than regular semen

Pregnancy diagnosis

no return to estrus (21 days)
milk P4 (high 21-24 days)
trans-rectal ultrasound (25-30 days)
rectal palpation (6 weeks - term)

Sheep - reproduction basics

Puberty; ewes 6-9 months, rams 4-6 months
seasonally polyestrous, short day breeders (Oct-Feb)
estrous 16 1/2 days
gestation 5 months

Sheep - prolificacy

breeds - Border leicester, Lleyn, Cambridge, Finnsheep,
Aberdale
genetics - booroola, iverdale (homozygous infertile, →
Aberdale)
nutrition/BCS - flushing/rising plain of nutrition,
NB Aberdale don't require flushing, can use grass for finishing
Lower ovulation rate - early in season, primiparous, hill breeds

Sheep - reproduction targets

Conception rate - 75-80% ewes, 99% by 3rd service
Lambing rate - 183 Lowland, 166 Upland, 112 Hill
Lambing % = # lambs born/# ewes put to tup x 100
% weaned/reared = # lambs weaned or reared/#ewes put
to tup x 100
168 Lowland, 150 Upland, 100 Hill

Sheep - reproduction problems

↓ ovulation rate - more singles than usual
→ nutrition, age, stress/weather
↓ conception/pregnancy rate - more barren than usual
→ rams, nutrition, stress/weather, disease
barren ≠ infertile
↑ abortion rate - ↓ lambing rate, normal conception rate
↑ perinatal losses (> 8-10%) - ↓% weaned, normal lambing %

Sheep - rams

Teeth, toes (mobility), tone (BCS 3.5-4 pre-season), testicles (large, firm)
ram: ewe ratio; Hill 1:30, Lowland 1:50, ram lamb 1:20,
synchronized 1:10-15

Sheep - ewes

Teeth, toes (mobility), teats (mastitis), tone (BCS 2.5 hill, 3
upland, 3,5 lowland)
Flushing - lush pasture from 6 weeks pre-mating (avoid
brassicas - kale or forage rape, clover & alfalfa - estrogenic)

Sheep - PD

US 60-90 days, fetal count (single, twin, triplet)
no return to estrus (marking harness on ram, change crayon
color q 2 weeks)
Ballotement from 100 days

Sheep - advancing the breeding season

Ram effect - within 4 weeks of season, isolate from males (>1
mile for > 1 wk), introduce ram -> 50% ovulate within 6 days
Progestagen priming - within 6 weeks of season, sponge or
CIDR, eCG at removal -> estrus within 2-3 days, compact
lambing period
[Melatonin (suffolks), lighting]

Sheep - synchronization of estrus

Progestagen - sponge or CIDR for 14 days, +/- eCG at
removal, ovulation within 2 days, 1 ram: 10-15 ewes
-> compact lambing period

Goats - reproduction basics

Puberty; does 5-7 months, bucks 4-6 months
estrous 21 days

Goats - PD

US
may show signs of estrus early in pregnancy
pseudopregnancy - persistent CL, treat with PGF

Abortion

expulsion of a fetus incapable of independent life
Brucellosis order definition < 271 days, requires investigation
> 2% is abnormal
- ID & isolate affected animal, retain products of abortion
NB don't use aborter as foster mother

Abortion investigation

Fetal exam - weight, size (crown-rump length), appearance
estimate fetal stage, NB incisors erupt 8-9 months
gross pathology
bacteriology of fetal stomach contents
serology - fetal fluids & blood, BVD, BD, Lepto, Neospora,
Toxoplasma, Coxiella
(Virology - culture liver)
Maternal blood screen - BVD, IBR, Lepto, Neo, Toxo, Coxiella

Non-infectious causes of abortion

stress
Uterine damage
Nutrition, Iodine deficiency - goiter in fetus
Nitrate/nitrite poisoning - roots, brassicas, grass silage
→ methemoglobinemia
genetic/congenital factors (chromosomal abnormalities)
Induced - vet pd/treatment (PG or corticosteroids)

Infectious causes of abortion

BVDV, BD, IBR/BHV-1, Neospora, Leptospira, Toxoplasma, Coxiella
Campylobacter fetus ssp venerealis, Trichomonas fetus,
Salmonella, Arcanobacterium, Listeria
(Brucella, Blue tongue)
non-specific metritis or endometritis

Campylobacter fetus ssp venerealis

STD - natural service, bulls are asymptomatic carriers
Cows - temporary infection - endometritis, usually clears after
abortion (EED)
test bull

Trichomonas fetus

STD - natural service, bulls are asymptomatic carriers
Cows - self-limiting infection, endometritis, abortion
cull infected bulls?

Neospora caninum

horizontal entry to farm, then transmitted vertically & via dogs
Causes abortion storms, calves with neurological signs
(weakness, ataxia), infected but normal calves
can reactivate in subsequent pregnancies, cull repeat aborters
test farm dog

Systemic illness abortions

Salmonellosis - systemically unwell, scour
Listeriosis - systemically unwell, metritis/retained placenta,
+/- neurological signs.
Focal necrosis of cotyledonary villi, miliary necrosis of fetal
liver & spleen
IBR/BHV-1 - multifocal necrosis of fetal liver, spleen, kidneys
& lungs

Brucellosis abortions

eradication in UK, cases - imported cattle
placentitis, fibrinous serositis

Leptospira abortions

Transmission - urine, semen, vertical, water-borne
CS; sporadic abortions, milk drop, flabby bag
Pathology - icterus, edema, renal degeneration & inflammation
(small gray spots)
vaccination, antibiotics, isolation zoonotic

BVDV abortions

Causes abortions & infected but normal (PI) calves
anomalies of skeletal, nervous, CV, respiratory systems, etc

Sheep - abortion, infectious causes

BD, Toxoplasma, Leptospira, Coxiella, BVDV?
Chalmydophila abortus/EAE, Campylobacter fetus ssp fetus,
Salmonella, Listeria, Tick borne fever (Anaplasma)
(Brucella, Blue tongue)

Sheep = abortion, non-infectious causes

Inadequate nutrition - need high quality fiber, rumen
compressed
Pregnancy toxemia - late pregnancy, twins & triplets, older
ewes, fat ewes
less than adequate nutrition in last 2 months of pregnancy
Stress
Concurrent disease

EAE/Chlamydophila abortus

pathology - necrotizing placentitis
ZN stain
control - tetracyclines, vaccinate, cull aborted ewes,
buy EAE-free accredited stock zoonotic

Toxoplasmosis

oocysts shed in feces of young cats, contaminated feed
CS - abortion, still born or weak lamb + brown mummified fetus, normal but infected lambs
pathology - focal necrosis & calcificaiton (white spots) on cotyledons (placenta)
Control - retain aborted ewes, control cats, cat-proof feed, decoquinate, vaccine zoonotic

Campylobacter fetus ssp fetus

contaminated water & feed, reservoir - pigs & poultry
pathology - brown muco-purulent vaginal discharge, enlarged necrotic cotyledons
Control - isolate, tetracycline, retain aborted ewes zoonotic

Brucella melitensis

Mediteranean basin, notifiable zoonotic
orchitis, abortion storms

Border disease

'Hairy shakers' - wobbly lambs with thick wooly coat
Pathology - dysplasia of skeleton, CNS & fleece

Tick borne fever/Anaplasma phagocytophilum

Sheep tick - Ixodes ricinus
sporadic abortion in non-immune flocks
Control - tick control, tetracyclines

Hematuria

(RBCs, separates with centrifugation)
→ enzootic hematuria (bracken fern), pyelonephritis, purulent metastatic nephritis, urolithiasis

Hemaglobinuria

(no RBCs, doesn't separate)
→ babesiosis, post-partum hemoglobinuria, rape/kale poisoning, bacillary hemoglobinuria (Clostridium haemolyticum), Acute Cu poisoning, water intoxication

Bracken fern toxicity

causes enzootic hematuria (bladder tumors, bleed), bright
blindness in sheep, oral/esophageal/reticular carcinomas,
aplastic anemia

Sheep - Urethral obstruction in rams

Risk factors - dietary P: Ca > 2, ↑concentrate/↓roughage
diets, insufficient water
group problem
CS - anorexia, pain, crystals at prepuce, anuria, dripping urine
Cull, ensure adequate water supply & evaluate diet of other
animals in group - Ca:P > 2.5, sufficient roughage

Babesiosis

tick-borne, naive animals in tick areas (bought in)
CS; pyrexia, anorexia, depression, weakness, hemoglobinuria, anemia, jaundice, diarrhea, muscle wasting
Tx; Imidocarb, notify animal health of use

Post-parturient hemaglobinuria

associated with hypophophatemia, possible subclinical ketosis pre-partum
CS - CS; Hemaglobinuria, inappetance, milk drop,
dehydration, +/- pyrexia, jaundice, high mortality
test Ca, P, Mg, +/- BHB
Tx - blood transfusion + phosphate

Pyelonephritis

ascending infection with Corynebacterium renale (unilateral)
CS; acute - abdominal pain, dull, anorexic, dysuria, pollakiuria with blood and/or pus
enlarged painful left kidney on rectal palpation, dipstick, US
Tx - Pennicillin for 21 days + NSAIDs, guarded prognosis

Renal amyloidosis

chronic disease, bilateral
CS - massive non-painful left kidney, frothy urine, weight loss
dipstick (+++++protein), US - large kidney w/ normal structure
cull

Renal failure

uncommon, culled
pre-renal - severe scour in calves
renal - plant toxins eg Oak/acorn poisoning, infections
post-renal - urolithiasis

BVDV - Bovine Viral Diarrhea Virus

transmission - vertical (naive infected cow or PI cow), sexual
CS - subtle, poor herd performance, ill thrift in calves,
abortion, fetal stunting, cerebellar hypoplasia,
diarrhea in adults in naive herd
Mucosal disease - oral & feet lesions - ulcers

BVDV diagnosis & control

Dx - bulk milk ELISA or PCR 4x/yr, individual blood samples from bulls & herd replacements ELISA or PCR, ear tag sample calves PCR
PIs - Ag+/Ab-
False + -> border disease virus, acute infection
False - -> colostral Abs (< 9 months)
control - ID & cull PIs, vaccinate
Scottish BVDV eradication scheme - mandatory screening of breeding herds

Pre-partum problems

(Pregnancy Toxemia - sheep), (Hypocalcemia - sheep),
Trauma, Dietary disturbances, vaginal prolapse, Hydrallantois,

vaginal prolapse

late gestation
Herefords, fat?, estrogenic pastures
Surgery - epidural, lubricate, replace, Buhner's suture - umbilical tape
highly repeatable -> cull

Hydrallantois

Cs - severely swollen abdomen, weakness, inappetance, ↓BCS, impaired respiration
prognosis guarded consider culling
Tx; give fluids, induce parturition - corticosteroids

Parturient problems

Dystocia, Trauma, Obstetric paralysis, hemorrhage, uterine prolapse, Retained fetal membranes, Mastitis, Hypocalcemia

Dystocia

Failure of one of the components of the birthing process;
expulsive forces - weak abdominal straining, uterine inertia
adequacy of birth canal - incomplete dilation or constriction,
inadequate pelvis
size & disposition of fetus - relative & absolute, congenital
monsters, fetal pathology, faulty disposition (presentation,
position & posture)
1/3 of fetal & calf losses occur at parturition

Dystocia - history

Full term?, sire, breeding history (if cow),
when did straining begin - force & frequency, (Is she still straining?), appearance of water bag?, appearance of any parts of fetus,
has she been examined, what has she been given

Dystocia - assessment

quick general PE on cow - appearance, size, anxiety
Epidural & clenbuterol
clean & disinfect cow & self, lube, examine - dilated? damaged birth canal?, calf viable (movement, pulse), calf size, uterus contracting?
Options; fetotomy (if dead), assisted delivery, cesarean
NB cows pelvis widest at diagonal

Uterine torsion

Determine direction & degree of rotation
- 180 most common
consider cesarean

Malformations

schistosome - acute vertebral angulation, viscera exposed
hydrocephalus - big head
double headed calf, twin malformations
anasarca - swollen edematous carcass

Dystocia - assisted delivery

If no progress then stop pulling, re-assess
After calf delivered check cow for 2nd calf, tears or bleeding

episiotomy

= cutting open vulva, 2 incisions (at 10 and 2 o'clock)
when vulva is open restriction to passage of calf
give epidural & suture after delivery of calf

Calf resuscitation

clean off fetal membranes,
stimulate breathing - swing, massage chest, straw in nose
If not breathing within 2 minutes then intubate & ventilate, Doxapram under tongue or etamiphylline gel

Neonatal calf care

ensure calf receives adequate colostrum, must be able to get up & suckle

Cesarean section - indications

fetal oversize, failure of cervix to dilate, irreducible malposture, irreducible uterine torsion, fetal emphysema, and stage labor began > 24 hrs ago
elective - pelvic deformity, uterine rupture, severe hemorrhage

Cesarean section

Premed - line or para-veretbral block, epidural if straining a lot, Clenbuterol, antibiotics if suspect infection
Clip & scrub
Post - clean, give oxytocin

Cesarean section - surgery

Flank incision - diagonally through skin, EAO, blunt dissect IAO, incise transverse abdominus, peritoneum
incise uterus - long enough to remove calf
remove & hand-off calf
Suture uterus - double layered cushing chromic catgut 6-8,
suture peritoneum & each muscle layer chromic catgut 5 or 6,
suture hypodermis & skin - nylon

Dystocia - prevention

breed for calving ease - sire
monitor heifer pelvic size & breed at apt stage of maturity
NB Dystocia causes chronic problems - reduced milk production, weak calves

Recumbent peri-parturient cow

milk fever, mastitis & metritis, obstetric paralysis, sacroiliac luxation, femoral fracture, coxofemoral luxation, gastrocnemius rupture, 2o ischemic necrosis

Obstetric paralysis

Damage to obturator N, ischiatic N
CS; paresis, ataxia, lateral deviation of hind legs (splay)
Dx; history, appearance, absence of other abnormalities
prognosis ↓ with time (< 12 hrs), can cause fractures and muscle tears
Tx; NSAIDs, hobbles, supportive care - bedding, turning
Rapid improvement within few days & complete recovery,
recovery unlikely if not markedly improved within fortnight

Uterine prolapse

risk of ruptured uterine A - can exsanguinate, emergency!
Assess circulation, hemorrhage, herniation
Tx; epidural, Clenbuterol, replace & give oxytocin or resect
can occur within minutes - hours of calving
- dairy cattle, milk fever, dystocia

Retained fetal membranes (RFM > 6-12 hrs)

- failure of separation and/or expulsion
CS; putrefaction (smell), metritis, pyrexia, inappetance, tenesmus, diarrhea, mastitis, death
Tx; oxytocin (in 1st 6-12 hrs), Ca, gentle traction, trim dirty membranes level with vulva, monitor T & appetite daily, antibiotics if pyrexic
predisposes to metritis & endometritis

RFM 2

Risk factors - premature birth, infectious placentitis, induced calving, over-stretching of myometrium (twins, dystocia, hydrallantois), hypocalcemia
Prevention - breeding management,
transition management - BCS, vit ADE, Se

Post-partum problems

Metritis, Endometritis, pyometra,
trauma, obstetric paralysis, hemorrhage, uterine prolapse, peritonitis, septicemia, mastitis, hypocalcemia,
post-parturient Hemoglobinuria, LDA

Metritis

post-partum
CS; acute (24-48 hrs), depression, inappetance, agalactia, pyrexia or hypothermia, recumbent, homogeneous red-brown vaginal discharge, uterus distended, death
Tx; Uterine lavage, systemic antibiotics, NSAIDs, fluids PO/IV

Endometritis

post-partum
CS; chronic, discharge on tail, palpation - , no systemic signs
regular return to estrus, irregular return to estrus or no discernible effect → pyometra
Tx; Antibiotic infusion?, PGF2a?, estrogens?

Pyometra

- thin walled fluid filled uterus, no fetal membranes, no placentomes
Tx; PGF2a (associated with luteal cysts)

Transition period

Important time, from 3 weeks pre - 3 weeks post-partum
sudden ↑ in nutrient demands, ↓ in dry matter intake (last week of pregnancy, estradiol & space taken up by fetus)
inadequate management → metabolic disorders (RFM, milk fever, LDA, ketosis, poor production, poor fertility)
management - diet, BCS

Transition period - BCS

Important to maintain apt BCS
fat cows are predisposed to ketosis, hepatic lipidosis, dystocia, LDA, mastitis

Transition diet

ensure adequate DMI around calving, condition rumen for lactation diet → good fiber, restricted energy, good quality protein, restricted Ca
- increased digestible CHO

Energy

greatest demand 3-4 weeks post-partum in cow
high demand + insufficient intake -> range of syndromes
fatty liver (mild) → subclinical ketosis → clinical ketosis → fat cow syndrome (severe, fatal)
- fat breakdown -> FFAs in liver (exceeds livers metabolic capacity), exhaustion of glucogenic precursors stalls krebs cycle

Ketosis

Risk factors - LDA, metritis, etc (Often 2o), high production heifers, winter housing/silage feeding, fat cows, previous occ
CS; inappetance, milk drop, depression, recumbency, neurologic signs (licking & chewing manias), acetone breath, ketonuria (dipstix or diagnostic tablet)
(no pain, T, CV & respiratory normal, no ping)

Ketosis - treatment

Tx: 500mLs 50% dextrose IV, oral glucose precursors eg propylene glycol (Ketol, Forketos) for 3-4 days (200mLs BID 1st day, 100mLs BID next 3 days) - maintain blood glucose prevent relapse → somnolence, milk taint
B vit supplement - niacin anti-lipolytic, ↑blood glu & insulin

Pregnancy toxemia (beef cattle & sheep)

high fetal Glu requirements (twins & triplets) + declining/poor nutrition last 1-2 months of pregnancy (bad teeth, lameness, adverse weather)
CS; dull, weak, lethargic, depressed, neurologic signs, recumbency, death PM - hepatic & renal fat infiltration
poor prognosis, consider salvage cesarean section or induction with dexamethasone & PG
Tx; Dextrose iv, glucogenic precursors PO

Pregnancy toxemia - prevention

Prevention; scan ewes, feed concentrates from 6 weeks pre-lambing, supplement ewes with twins & triplets, condition score regularly and adjust feeding as needed

LDA/Left Displaced Abomasum

= abomasum displaced & trapped between rumen & left abdominal wall, often within 6 weeks post-partum
- over conditioned cows, negative E balance, stress (inapt management) → decreased abomasal motility & emptying
Risk factors; poor transitional nutrition, fat cows, twins, poor weather, other problems - Hypocalcemia, ketosis, acidosis, RFM, metritis (illness → ↓intake)
taller cows - elliptical shaped abdomens (deep)

LDA - CS & Tx

CS; ↓milk yield, ↓appetite, ping over left ribs 9-13, Ddx ketosis
good prognosis with surgery, treat concurrent disease
- right flank laparotomy + caudoventral omentopexy,
left flank laparotomy + ventral abomasopexy or omentopexy, laparoscopic

LDA - prevention

maximize DMI in peri-parturient cow - palatable forage, ad lib, min competition, separate management group,
ensure adequate fiber of sufficient length, introduce rapidly fermentable CHOs slowly (concentrates & silage), +/- antioxidant supplements
supply plenty of water
dry off at optimum BCS (2.5-3) & maintain until calving, monitor for signs of GI upset, ketosis & hypocalcemia

Mineral elements

Interactions between mineral elements
eg Cu depends on Fe, Mo, S
Functions - structural, physiological, enzymes, regulatory
Measures of adequacy - minimum, ave
Production traits can reflect mineral deficiencies - milk
production, growth, reproductive performance
different traits → different measures of adequacy

Macrominerals

Ca, Mg, P, Na, Cl, K

Hypocalcemia/milk fever/Bovine parturient paraparesis

= insufficient available circulating Ca
(normal plasma Ca > 2 mmol/L, ionized Ca > 1.1 mmol/L)
- sudden increase in demand (for milk) + decreased supply (intake), shift to mobilization from body stores takes time
few days before - week after calving, mature cows, acute
Risk factors; fat, chronic ↓Mg intake, genetics (mod heritable - Jerseys), high production, late summer & autumn

Hypocalcemia - CS & assessment

CS; weak, tremor, cold ears, ↓GI motility, rumen tympany, hypothermia, weak fluttery heart beat, recumbency, death
Assessment; Is death imminent? Calving? Live calf? Hemorrhage? Uterine prolapse? Evisceration? Mastitis? Bloat? fractures/luxations?
Treat more significant ailments 1st, then Ca

Hypocalcemia - Tx

Tx; position in sternal recumbency & point up-hill, restrain, slow IV Ca +/- Glu/dextrose & Mg (calciject 20 or 40, over 10-15 min) & auscultate heart (slow infusion if dropped beats), AE - cardiac arrest, Mg reduces risk
follow up with SC or oral preparation eg Calcoral or Enercal gel, Phosphorus IV, remove calf for 12-48 hrs
Evidence of response to treatment; sweat on muzzle, steam rising from coat, eructation, tremor, standing

Hypocalcemia - prevention

DCAD (Dietary Cation Anion Difference) diet last 2-3 weeks of gestation - mix with highly palatable ration
Limit Ca & P pre-partum - min 30 g/day Ca, < 80 g/day P
Normal Ca + binding agent - phytates eg calfix
Prophylactic Ca - high risk animals, oral gel or SC injection eg BoviKalc

Hypocalcemia in sheep

6 weeks pre to 1 week post-partum
Risk factors - recent movement, reduced intake - bad weather, oxalates or green cereal crops
CS; tremor, weakness - flaccid paralysis, staggering gait, recumbency, death no ketonuria (dipstick, Ddx preg tox)
Tx; Calcium Borogluconate (CBG) IV or SC eg calciject 20
Prevention; avoid transport late gestation, supplement aptly

Hypomagnesemia/Grass staggers/Lactational tetany

= < 0.4 mmol/L + trigger (- ↓intake - bad weather, transport stress, concurrent disease, etc → hypocalcemia) → CS
Daily nutritional requirement 30 g/day
low Mg diet - rye grass, pastures with ↑K fertilizers or slurry, wet pasture, lush grass, ↑N, ↑K, ↓E -> ↓Mg absorption
- ↑demand (milk) + ↓intake → inhibits neuro-muscular function, tetanic muscle spasms, convulsions

Hypomagnesemia

Spring & Autumn, recent turn-out
Post-partum Dairy cattle ( < 2 months), milk fed calves (3-6 months), adult store beef cattle, sheep post-partum
CS; stop grazing, discomfort, hyperaesthesia, twitching, ears pricked, jaw chomping, pyrexia, staggering, recumbency, paddling, sudden death, sudden death of healthy calf

Hypomagnesemia - Tx

Tx - approach quietly, +/- sedation (xylazine), MgSO4 SC, Ca borogluconate (CBG) slowly IV, supplementary feed & water prognosis poor if not up within 2 hrs
Prevention - pasture management - limit use of fertilizers, herd management - turnout timing, supplement in risk period - Mg salt in feed, Mg bullets, MgCl in water, mineral blocks, hay
supplement calves with hay (adequate Mg in milk replacer)

Trace elements

Fe, Co, Cu, Mo, Zn, Se, I, B, F, Si, Cr, Mn

Plant Mineral content

Soil - pH (lime → ↑pH - ↑Mo availability,
sulphate fertilizers - ↓pH - ↑Co & Mn availability),
fertilizers
water logging → ↑Co, Mo, Mn
soil ingestion - Co, I, Se
climate & season - atmospheric - S, I, N (↓away from coast)
plant stage & maturity (Zn, Cu, Co, Mn ↓with age - stem <
seed, straw poor source, oil seed < cereal)

Causes of Deficiency

- low intake, low availability/absorption, increased requirement

Selenium deficiency/white muscle disease

- ↓Se (granite derived soils), ↓availability (↑S), ↑requirement (↑PUFAs or heavy metals, legumes, season/cold, ↓vit E)
CS; muscle degeneration, still births, sudden death after exertion, stiff lamb disease, ill thrift, ↓growth rate, reproductive failure, mastitis, RFM, post-parturient heamoglobinuria?, Heinz body anemia
2o/induced I deficiency (deiodinase converts T4→ T3)

White muscle disease

Dx; GSH-peroxidase (GSH-PX or GPX), PM
individual - ↑LDH, CPK, SGOT
Tx; injectable Se/vit E (repeated injections can be toxic; acute - dyspnea, pulmonary edema, diarrhea, death. Chronic - severe lameness & pain)
Prevention - supplementation in feed, boluses, injectable Se/vit E

Selenium toxicity

→ Blind staggers - blindness, abdominal pain, shedding hooves, paralysis, respiratory failure
- accumulator plants eg Astragalus

Copper deficiency

- ↓availability - ↑Mo, S, Fe, ↑pH
CS; depigmentation - 'spectacles', anemia, diarrhea, fetal death
steely wool (straight - loses crimp, weak), pathological epiphyseal fractures
Swayback in lambs - small weak lambs, head tremor, poor coordination (myelin aplasia & motor N degeneration)

Copper deficiency 2

PM - aortic rupture, cardiac enlargement, swollen epiphyses
Dx; CS + liver [Cu] - biopsy or PM, response to supplementation
NB plasma [Cu] can be normal in deficiency
Tx; Cu supplementation - in feed, bolus, lick blocks
injectable - risk of local reaction → abscess

Copper toxicity

Chronic → hepatotoxicosis, acute hemolytic anemia
Acute → abdominal pain, convulsions, collapse & death

Cobalt deficiency/Pine

Cobalt is part of Vit B12 - cofactor for conversion of proprionate to succinate in Energy metabolism
- Wasting disease - inappetance, poor growth, weight loss, pale MM
Dx; regional history, FIGLU in urine, Liver Co, serum B12
Tx; parenteral B12, bolus or in feed for others at risk

Iodine deficiency/Iodine-associated thyroid deficiency - Goiter

Cause; gross environmental I deficiency, ↓uptake - goitrogens eg thiouracils (cruciferae, rape seed), cyanogenic glycosides (brassicacea, clover, rape seed), ↑requirement - cold stress,
↓Thyroid hormone metabolism - Se deficiency (T4→T3)
CS; goiter pathognomonic, stillbirths, weak calves
Dx; PM, plasma [T4], plasma inorganic Iodine
Prevention; Supplement - in feed, salt licks, kelp, drenching, boluses → no effect if thiouracils

Milk Legislation

EC hygiene regulations 853 & 854 - microorganisms & SCC standards (bulk tank SSC geometric mean over 3 months < 400,000, TBC geometric mean over 2 months < 100,000),
no residues, conditions for hygiene & welfare, HACCP - pasteurization & antibiotic residues, traceability back to farm
antibiotics - Veterinary medicines regulations 2008
Council directive 92/46/EEC

Microbes in milk

Raw milk - MAP (paratuberculosis), antibiotics, E. coli, rBST (GH), Tb, FMD, Bluetongue, Salmonella, S. aureus, Listeria, Leptospira, Q fever
- all are killed by pasteurization (71.7oC for 25 seconds)

Milk wages

Payments based on bactoscan, SCC, antibiotics, added H2O - FPD, fat & protein, volume

Milk safety

Farm; Herd - Tuberculosis-free, Brucellosis-free
Cow - not ill, no zoonoses, not under treatment (residues)
Hygienic premises, equipment & tools, staff hygiene
Cooled to 8oC before collection by tanker
Transported by tanker (cleaned & disinfected before re-use)
Tested for antibiotics, accepted by dairy (or farm pays for entire tanker)

Pasteurization

Pasteurization - at least 71.7oC for 15 seconds (25 seconds preferred - paratuberculosis) kills most pathogenic organisms
UHT (ultra heat treated) - 135oC for 1 second, doesn't require refrigeration, alters taste

Mastitis

= Infection/inflammation of 1 or more quarters of the mammary gland, usually caused by bacteria which enter via teat canal (occasionally hematogenous spread - Tb, Lepto)
Dynamic process; subclinical infection → recovery or persistence → clinical infection, acute mastitis, illness and/or loss of quarter, peracute mastitis, death
affects milk quality - ↓yield, ↑SCC, ↑bacteria, ↑residues

Subclinical mastitis

↑SCC (WBCs & sloughed epithelial cells)
individual cow SCC varies with stage of lactation

Clinical mastitis

CS; hot, swollen, painful quarter(s), ↓yield, ↑SCC
Dx; California mastitis test - determine affected quarters, then culture milk (bacteriology) - ID bacteria often *S. aureus
Herd picture - sample 10+ cows

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