Dairy Flashcards
What should we consider when collecting info on a dairy farm?
Why we are looking for info. What is normal? How/Who decides what is normal? What info is available? Who is providing the info?
Which three elements are important to consider when analysing documents and records for a farm?
Data inspection (cell counts, production, milk recording), animal inspection, and farm inspection. Analyse data BEFORE going on farm.
What should we consider when looking at production data?
Average days in lactation (10 month/305d lactation ideal for one calf every 12 months).
Kg fat/protein content of cows in early lactation.
Milk fat % (
What does somatic cell count data tell us?
Amount of inflammation present within udder.
What level of somatic cells is not acceptable for heifers? And cows?
Heifers >150,000
Cows >250,000
Heifers lower as they shouldn’t have had any prior infection or wear and tear from milking.
What other factors should be considered when assessing somatic cell count data?
Count before and after parturition.
Number of new infections.
Number of chronic infections.
Comparison between previous months data.
What other factors should be considered when assessing farm data?
Payments from dairy factory.
Test results of feed and animal health service/vet.
Bills of vets - only about 4% variable costs, important for farmer to see value in it.
Management system.
What should you look for when inspecting a dairy cow?
Chewing - how many cows are grazing, number of cuts, number chewing cud.
Rumen fill - rumen score 1 (slab sided) - 5 (looks like bloat).
Faecal scoring - 1 (very liquid) to 5 (firm balls, dehydrated). 3 is optimal with porridge like appearance.
Locomotion score
Body condition score - 1 to 8 or 1 to 5.
Coat
What three elements need to be considered when undertaking a farm inspection?
Environment - surfaces, heat, shade, etc.
Feed - pasture:concentrate ratio, hay, silage, additives and byproducts.
Water - amount, head space, location, quality, source, contamination.
List some herd health goals.
What does hypo mean?
Less
What does hyper mean?
More/too much
Discuss negative energy balance in dairy cattle.
Commonly seen during late gestation and early lactation.
Occurs when output exceeds input and DM intake is compromised (only 10-12kg DM fits with calf; normally 20kg).
DM intake peaks 6wks post calving, just after peak lactation - causes energy deficit in early lactation.
What are the pregnancy and lactational energy requirements of dairy cows?
Foetal-placental unit requires 45% of maternal glucose and 72% AA supply.
During lactation the glucose requirement increases 266% and AA requirement increases by 191%.
What is acetonaemia?
Ketosis.
Creation of ketone bodies due to body fat store break down.
Occurs due to lack of energy/glucose - cows with negative energy balance. Can be increased by high protein intake.
Common in excessively fat cows and cows having twins.
Poor feed intake or very high production.
What are the signs of ketosis?
Sub clinical - reduced milk yield, reduced fertility.
Clinical - milk drop, depression, weight loss, staggering, recumbent.
Nervous ketosis - circling, blindness, tremors, hyoeraesthesia, bizarre behaviour.
How do you treat ketosis?
IV or SC glucose - prone to relapse once glucose levels drop.
Oral propylene glycol.
Corticosteroids - shouldn’t be used in cases of secondary ketosis.
What managements initiatives can be implemented to prevent ketosis?
Ensure moderate BCS at calving.
Maintain consistent BCS of 3-3.5/5 or 4.5-5/8 all year through good nutrition management.
Ensure adequate energy content in feed ration, ensure no excess protein.
Prophylactic propionate/propylene glycol/glycerine post calving as preventative.
Monensin-ionophor proven to reduce ketosis.
Discuss hypocalcaemia.
Lack of Ca. Occurs at/after calving, up to a week.
Massive demand on Ca for lactation, body is unable to immobilise enough and therefore inadequate Ca for muscle function.
Can be fatal.
What are some risk factors for hypocalcaemia?
Advancing age - clinical disease rare in heifers.
High oestrogens inhibit bone resorption.
High dietary phosphorous.
Breed - jerseys less likely to affected than Holsteins.
High dietary fat??
List the stages of clinical signs of hypocalcaemia.
- Cow standing, brief excitement, tetany, hypersensitivity, muscle tremors, ataxia, anorexia, stiff gait.
- Sternal recumbancy, depressed consciousness, head turned to flank, dry muzzle, skin and extremities cool, weak pulse, pupillary light reflex incomplete, ruminal stasis, constipation, tachycardia. S shaped neck.
- Lateral recumbancy, comatose, flaccid, heart difficult to hear, bloat, death.
How do you treat hypocalcaemia?
IV Ca infusion (1g/45kg BW of Ca gluconate).
SC Ca gluconate - need to back up with oral administration of Ca chloride or Ca propionate to reduce chance of relapse.
What steps can be implemented to manage hypocalcaemia?
Short term - Ca gel orally at calving, vitamin D injection 1wk before calving, monitor herd closely and treat early.
Long term - feed anionic salts to springers (MgSO4), limit Ca intake in dry period, feed ad lib hay to springers.
Dietary Ca should be 1-1.2%, P and Mg at 0.4%, sulphur 0.25-0.4%, Na 0.1%, K 1.0%, add chloride to balance dietary cation-anion difference (not above 0.8%).
Discuss hypomagnesaemia.
Grass tetany. Multi factorial; incorporates weather, pasture growth, dietary Mg, K, Na and protein. Tends to be seasonal in Autumn and Spring.
More common in older cows grazing lush grass dominant pasture.
Can be seen in calves (2-4months age) as milk is low in Mg.
High ruminal K concentration reduces Mg uptake.
What are the clinical signs of hypomagnesaemia tetany?
In coordination, hyperaethesia, tetany, tonic-clonic muscular spasms and convulsions, high case fatality rate without treatment. Aggression.
Discuss the treatment of hypomagnesaemia tetany.
MgCl2 or MgSO4 IV, SC or enema.
IV Mg requires caution as Mg is muscle relaxant (causes heart to relax). SC and rectal safer.
Discuss short term prevention strategies for grass tetany.
Dietary supplementation with Mg - oxide, carbonate, sulfate, phosphate.
Pasture dusting, mix with molasses into hay, daily drenching, Mg rich pellets, reticulum bullets, top dress pasture (Mg fertiliser), supplement in drinking water.
What other measures can be implemented to prevent grass tetany?
Avoid grazing new, fresh pasture.
Avoid use of potash (K) fertiliser at high risk times.
Include legumes in seeder mix for crops (higher Mg levels).
Ensure adequate feed, shelter (particularly when cold).
Change calving season.
Discuss lameness in dairy cows.
Abnormal gait, resting limb, limping (body rises when affected leg placed on ground).
Most often in hoof (infectious, puncture, laminitis).
Control via ensuring laneways are in good condition, dairy yard is clean of manure, nutrition is appropriate.
Discuss displaced abomasum.
Movement of abomasum out of normal position, associated with high levels of concentrate feeding.
Post calving entrapment due to gestation elevation of the rumen allowing abomasum to move under the rumen.
Occurs immediately post calving and picked up within 6wks.
Large production losses.
(L) poor milk production, wight loss. Treat by rolling cow or surgery. Prevent via restricting heavy grain feeding, adequate fibre.
(R) less common and more severe.
Discuss calf scours.
Diarrhoea caused by bacteria, viruses, Protozoa, nutritional.
Caused by poor colostrum quality or intake, poor housing quality (drainage, bedding), ingestion from environment.
What is countdown down under?
Project funded by Dairy Australia beginning in 1998.
The aim is to improve Australia’s milk quality and quantity by establishing understanding and guidance on controlling mastitis.
Why is BMCC important?
Udder health and quality is important to farm productivity and profitability. Impacts on cow production; payments for milk, animal welfare, labour requirements, genetic gain and replacement rates, base farm costs.
What are the calving guidelines from the countdown program?
- Reduce environmental mastitis; clean and dry calving environment, milk within 24hrs, foremilk strip.
- Take care of heifers and fresh cows; time with milk let down, avoid over milking, train heifers, milk out udders with oedema.
- Milk suitable to the vat; observe WHP (particularly for dry cow therapy), colostrum.
- Find, treat, record fresh cow clinical mastitis quickly; look for symptoms, milk samples for culture, antibiotic selection, mark treated cows, minimise spread.
What are the lactation guidelines of the countdown program?
- Good milking technique; calm cows, foremilk strip all cows in first month lactation, teat cups on clean and dry teats, cups on when teats plump, avoid over milking, cut vacuum and minimise air entering teat cups.
- Monitor and maintain milking machine; daily checks (air, vacuum, pulsators, check teats), weekly checks (liners, airlines, listen to regulator), monthly checks (reserve and regulator function, completeness of milking, cup squawks and slips).
- Post-milking teat disinfection; mix fresh everyday, use high quality water, use emollients, dipping/spray technique, clean out dipper when low.
- Practice good hygiene; avoid milk splashes or sprays, use disinfectant to remove infected milk from gloves and liners.
- Manage teat sores and cracks; assess each milking, clean surfaces (laneways, troughs, etc), ensure cows can’t access creeks/dams, single use applicators for ointments.
- Find, treat and record clinicals; monitor BMCC, check swelling and clots, fore milk strip, ICCC (>6000cells/mL), cultures, treatment.
- Monitor BMCC; if high check for undetected clinicals,
How often should treat liners be changed?
2000-2500 milkings.
5000-10,000 for silicone.
4-6 months.
What are the late lactation guidelines of the countdown program?
- Drying off strategy; use expected calving dates to create lists, dry high ICCC earlier, plan dry cow treatment strategy.
- Cull persistently infected cows; 3+ clinical cases in lactation, high ICCC cows with dry cow therapy in 2 lactations.
What are the drying-off guidelines of the countdown program?
- Dry-off abruptly; 5-12L/d, put into clean paddocks, feed to maintenance for 3-4d, illegal to restrict water.
- Administer dry cow therapy as recommended; correct procedure, sanitation procedures, dip teat with fresh solutions, ID treated cows, minimise leakage.
- Check udders daily for a week; check swelling (don’t touch as could stimulate milk let down), treat if suspicious.
- Observe weekly
- Selling cows; check WHP
- Buying cows; check BMCC, ICCC, history.
What should you consider when conducting an investigation involving mastitis?
Define the problem; nature, occurrence, clients definition versus yours.
Consider risk factors; human resources, equipment, environment, cows.
Why is lameness important in dairy herds?
Third most economically important disease of dairy cattle (1. Repro failure, 2. Mastitis).
Incidence has increased with confinement to concrete floors.
Major cause of culling.
Hooves only grow 5mm per month.
High producers often larger, more wear and tear on their feet.
Important from economic and welfare perspective.
Discuss economic losses due to lameness.
Decreased fertility; decreased heat display, increased metritis.
Decreased milk production; sit down more, eat less, increased mastitis (think losses in lactation curve).
Increased labour requirements; trimming and treatment.
Increased culling; decreased slaughter value due to decreased BCS, loss of genetics.
Increased vet costs.
Name 6 economic losses due to lameness and rank them from most, to least important.
Reproduction 34%, low milk production 25%, mastitis and reduced yield 13%, labour 13%, veterinary costs 8%, weight loss 7%.
What are the economic losses of lameness, per case.
Loss of milk production $96, treatment (20% cases) $20, extended calving-conception period $70, forced culling $35.
Total for each individual average lameness case $221 (average).
Apart from economic and welfare lameness issues, what are its other effects?
Come into milking shed later, increased labour costs and time.
Restless when milked so poor milk letdown, increased kicking, possible teat damage, incomplete milking, droplet impacts.
Lie in unusual positions and get pressure sores.
What are the welfare implications of lameness?
Body condition score
Hock lesions
Locomotion score
Competition for feed and water
What are the two most common sites of disease which cause lameness in dairy cattle and briefly describe the primary causes of each site.
90% claw; cows 80% hindlimb, 75% outer claw due to increased weight on lateral claw. Heifers 56% hindlimb, 55% outer claw. 38% of ALL lesions in heifers are inner fore claw-more weight and increased resistance heading into dairy.
10% upper limb.
What percentage of lameness is traumatic in grazing systems?
Over 66%
What percentage of dairy cows on large farms have thin soles?
30-75%
What are the main causes of lameness lesions?
Laminitis/trauma-sole ulcer/haemorrage 20-40%, white line disease 20-40%.
Infectious-septic pododermatitis 20-30%, interdigital necrobacillosis (footrot) 10%, digital dermatitis, heel erosion.
Which lesions of the hoof are characteristic of laminitis?
Sole bleeding, sole ulcers, white line defects.
What is the pathogenesis of solar bruising?
Ration and environment, Feeding CHO, Trauma.
Solar bruising can lead to ulcers, white line defects.
Cause a change in fat cushions and suspensory ligaments (relaxing at calving causes increase in water in collagen allowing it to stretch). Reduced fat cushions are replaced by connective tissue.
What are the 5 steps to trimming hooves?
- Length-cut toe to 8.5cm on both claws.
- Height-pare claw down, keep 5-7mm thickness at tip of toe, keep sole flat and heel high.
- Shape the claw-cut slope into cleft of both claws.
- Any lesions, lower this part-if outer claw bruised, than make it lower than heel so inner claw can take weight.
- Trim loose parts-remove loose horn from heel.
List some risk factors which could predispose a cow to lameness.
Property and herd size, age (increased age=increased weight), bail feeding, voluntary entry into bails, features of farm track (length, surface), presence of steep slopes, surface material.
Discuss the link between nutrition and laminitis.
Sudden changes in nutrition have been associated with laminitis.
Laminitis causes vascular laminae damage, poor horn quality and deterioration of the horn.
Multi factorial and not well understood.
Draw a diagram representing the interaction between feed and animal health.
Feed in centre, arrows to reproduction, mastitis, milk production and lameness. All arrows go forwards and backwards and link between each quarter.
Describe the environmental and behavioural risk factors which predispose to lameness.
Stoney, rutted, muddy laneways and walking areas.
Confinement to concrete floors.
Laying time - cubicle comfort.
Congestion and crowding of cows - laneways narrow, yards small, cows turning corners.
Level of patience in herding/moving cattle.
Which risk factors at the herd level predispose to lameness?
Farmer knowledge - attitude, economic importance
Concentrate and fibre levels in diet - excess energy can cause laminitis.
Comfort of walking surfaces - standing too much means lying is uncomfortable (should lay @12hrs/d). Surfaces should be non-abrasive and fine to ensure drainage.
Foot trimming - hoof wall short and steep at toe, regular trimming, excess length at toe means increased pressure on pedal bone.
Discuss the risk factors for lameness in individual cows.
Adult, first 3-4months of lactation, have been previously treated, increased body weight, low body condition score, excessive growth rate as heifer, genetics (dorsal claw angle, rear legs and rump width).
Farmer awareness, diagnosis and treatment (early), heifers joining main herd, rough walking surfaces (wood chips or grass are ideal, softer surfaces increase walking speed, high risk areas are around troughs and gateways).
Discuss methods for the prevention of lameness.
Differs per lesion, identify important risk factors for the specific farm.
Foot bathing may reduce incidence however feet need to be clean for this to work (CuSO4, formaldehyde).
Regular foot trimming (once or twice a year).
Balanced ration.
Give an overview of the objectives and information of herd health programs.
Herd, not individual cows is important.
Lameness in one cow is just indicator of the herd.
Which lesions are most prevalent.
Which risk factors for an individual farm.
How to cure and prevent.
General management cycle.
What are the three areas to identify in terms of risk in a herd health program?
Environment
Animals
Period
Discuss factors for animals at risk in herd health management.
Heifers
0-60d lactation
Poorly trimmed hooves
Discuss factors for period at risk in herd health management.
Purchase of new cows
Introduction in the herd
Udder oedema (chaffing inside legs from udder-weight will be transferred to medial hind claw)
Calving
Summer period (competition for shade, more standing)
Discuss factors for environment at risk in herd health management.
Walking path Walking distance Feeding Milking parlour Cows are not designed to walk on concrete!
What are the goals of a dairy heifer program?
Raise healthy calves with 575kg.
Produce productive animals cost effectively.
