The Canadian Organic Grower www.cog.ca44 – Summer 2012

The number of organic dairy farms is on therise across Canada, coinciding with growingconsumer interest in the humane treatment

of food animals and in organic dairy products.As the Canadian organic dairy industry grows, pro-

duction and welfare challenges are being met headon. Canadian researchers are studying how produc-tion practices can affect cow health, welfare and milkquality. Welfare is connected to cow comfort and pro-duction; the physical and mental well being of dairycows is intrinsically linked to their quality of life andlongevity.

Canada’s Organic Science Cluster (OSC) hasundertaken several objectives as part of a large dairystudy led by Dr. Trevor DeVries at the University ofGuelph. One objective is to assess the health andwelfare of dairy cows. Another is aimed at identifyingcommon mastitis pathogens and their incidence. Thefindings will help farmers choose techniques thatoptimize cow health and milk production. It will alsoestablish benchmarks (points of reference) that can beused by producers and researchers to track improvingor deteriorating herd management practices.

The study has collected data from 59 dairy herdsin Southern Ontario; 41 are conventional (12 pro-viding pasture to their lactating cows, 29 having nopasture access) and 18 are certified organic. Com-parisons have been made, not only between conven-tional and organic, but also between herds havingpasture access versus no pasture access, and thosebeing housed in free-stall, tie-stall and pack barns.

Opportunities for improvementPreliminary findings presented by OSC post-doctoralresearcher Dr. Anita Tucker reveal that dairy farm-ers, including organic farmers, can improve thefollowing:1

1. Body condition of cows

Using the standard scoring system of Score 1 beingthin to Score 5 being fat, organic dairy cows had anaverage Body Condition Score (BCS) of 2.27. Idealscores range from 3 to 3.5, but the average of bothconventional and organic herds in this study wereboth below this level.

By Jane Morrigan

HEALTH AND WELFARE

ORGANIC

DAIRY COWS

A cold glass of organic milk… If this

sounds quite appealing on this Canadian

summer day, you are not alone.

Our Nature is Organicwww.cog.ca Summer 2012 – 45

2. Hock lesions

Cows housed in tie-stall barns hadmore lesions than cows in free-stall barns. Hock lesions are soreson the middle joint of a cow’s hindleg. The sores range from hair lossto open lesions and swollen joints.These can be painful and can becaused by poor stall managementand design. Features such as in-sufficient bedding, narrow lyingareas and poorly placed rails canaffect the incidence and severityof hock lesions.

3. Cleanliness of cows

Cow cleanliness or hygiene is gen-erally considered a good indica-tion of the general cleanliness of thecows’ environment. Poor hygiene isassociated with diseases such asmastitis. The study found thatcows in free-stall barns were notas clean as those in tie-stall barns.Overall, cleanliness scores couldhave been improved for cows inboth free-stall and tie-stall barns.

Once all of the data has beenanalysed, and correlations made,it is hoped that this OSC researchwill help both organic and conven-tional practitioners to improvetheir management practices.

Animal welfare

Raising heifer calves

The common conventional prac-tice is to separate the newborn calfand dam almost immediately af-ter calving. However, at the Uni-versity of British Columbia (UBC),

Dr. Dan Weary and colleaguesfound that a dairy heifer calf gainsweight three times faster if she iskept with her mother for up to twoweeks after birth. This practicedoes not affect the cow’s total milkyield. They have also demon-strated that dairy calves can besuccessfully reared in groups,without cross-sucking problemsand with no increase in disease.2 *

Pain control for disbudding and

dehorning

Another focus of Weary’s researchis pain reduction for proceduressuch as disbudding and de-horning dairy heifer calves.* Hisresearch has shown that disbud-ding/dehorning should be donebetween two and three weeks ofage. Recommended methods in-clude either a hot-iron dehorneror the application of caustic paste

to the horn bud. Pain control canbe provided by:3

1. Administering a sedative to thecalf 20 minutes before the proce-dure; followed by

2. A local anaesthetic such as lido-caine 5–10 minutes before theprocedure (not necessary for caus-tic paste method), and finally

3. A non-steroidal anti-inflamma-tory drug (NSAID), such asmeloxicam, to provide pain relieffor several hours following theprocedure.

Gentle handling at milking

Drs. Jeff Rushen, Anne-Marie dePassillé and colleagues with Ag-riculture and Agri-Food Can-ada in Quebec and B.C. havestudied animal welfare over thelast three decades. They com-pared the effects of gentle ver-sus rough handling duringmilking on milk yield. Theyfound that milk yield was higherfor cows who were handled gen-tly during milking.4 In addition,

Holsteins in tie-stalls.

* See www.oacc.info/AnimalWelfare/aw_awtf_factsheets.asp

The physical and mentalwell being of dairy

cows is intrinsically linkedto their quality

of life and longevity.

The Canadian Organic Grower www.cog.ca46 – Summer 2012

cows handled gently had signifi-cantly lower heart rates and therewas less milk left in the udder atthe end of milking.

Housing design and behaviour

At UBC, Dr. Nina von Keyserlingkhas been designing better environ-ments for dairy cows for severalyears. She has expanded our under-standing of cow behaviour andhelped producers design suitablehousing and management systems.Her research has shown thatbecause cows synchronize thebehaviours of feeding and lyingdown, there must be sufficientspace for all cows to feed and/or liedown at the same time. Keyserlingkhas also shown that (1) providingmore space per cow at the feedingbunk reduces aggressiveness andincreases feeding activity, and (2)providing a rubber floor surfacemay reduce lameness.5

Lameness in dairy herds†Lameness in dairy cows occurs atan average rate of 25% in Cana-dian dairy herds, and is a majorwelfare issue.† Lameness causespain (sometimes severe), and con-tributes to reproductive infertility,a loss of milk yield, high vet billsand more culling. Dr. Rushen andhis team have shown that lame-ness can be caused by:6

• stalls being too small;

• concrete floors being rough orbroken;

• poor drainage of water on floorsin the barn and milking parlour;

• manure on floors;• rough handling of nervouscows;• feeding too much grain (as op-posed to more forage) in cow ra-tions; and• poor hoof health as a result ofinadequate trimming.

Heat stress†Dr. Tina Widowski from theCampbell Centre for the Study ofAnimal Welfare at the University ofGuelph studies heat stress. Sheemphasizes that heat stress in lac-tating dairy cows can occur at tem-peratures above 23OC, and thathumidity, direct sun and low air-flowincrease the risk of heat stress. Shecautions that heat stress can reducemilk production by 10–25%, espe-cially in high-producing cows.

Signs of heat stress in dairy cowsinclude reduced feed intake, rapidshallow breathing, panting, a re-luctance to move, lack of coordi-nation, trembling, and increasedwater intake. A lactating dairy cowrequires at least 10 gallons of fresh,clean water per day when the tem-perature is 20OC, and 32 gallonsper day at a temperature of 35OC.

Preventing heat stress can beaccomplished first and foremostby providing shade, and a supplyof cool, clean water provided in ashaded location. There should beone watering station for everytwenty cows, with a minimum fillrate of 3–5 gallons per minute.7 Inaddition, Widowski recommendsincreasing air flow; installing sprin-klers in waiting areas; avoidingstressful handling; reducingpopulations of biting flies; and pro-viding high quality forage in shadedbunks on a free choice basis.7†

Dealing with diseaseManaging mastitis

Dr. Léna Levison, a veterinarianwho has temporarily left her clini-cal practice to obtain a Master’sDegree at the University of Guelph,is participating in the OSC studyled by Dr. DeVries. Her focus is onpreventing mastitis, specifically in-tra-mammary infection.

Mastitis in lactating cows canlower milk production, reducemilk quality and affect cow welfareby causing pain and discomfortfor the infected cow. Mastitis is asignificant problem and is one ofthe main reasons that dairy cowsare culled from herds. Becauseorganic dairy producers arerestricted in their use of antibiot-ics, it is very important for farm-ers to know which managementpractices help prevent or mini-mize mastitis.

Levison’s research involvesidentifying common pathogens inmastitis samples collected frominfected cows. She is investigatingthe connection between thesepathogens and management prac-tices, including the type of hous-ing (i.e., free-stall, tie-stall or packbarns). So far, the three top masti-tis pathogens that have been iden-tified from the samples collectedby farmer participants at levelssufficient to cause intra-mammarinfections are Staphylococcus aureus,Streptococcal spp., and Coliforms(such as E. coli).8

Johne’s disease

Johne’s disease is a chronic, debili-tating intestinal disease affectingcattle and other ruminants. It hasbecome more prevalent in dairyherds in Canada during the lastdecade. Newborn calves are espe-cially susceptible and can becomeinfected by ingesting feces, milk

† See www.oacc.info/AnimalWelfare/aw_awtf_factsheets.asp

There must be sufficient

space for all cows to feedand/or lie down at the

same time.