- National Importance
The dairy industry not only provides milk and milk products but also beef animals for the beef industry. - National Importance
At the end of 2003 there were 1.1 million dairy cows in Ireland
Milk deliveries per cow averaged 4,808kg in the year 2003
Approximately 10% of Irish milk output is consumed domestically in liquid form.
The rest is used in the manufacture of dairy products (butter, cheese, yoghurt, etc.), of which about 84% is exported at a value of €1.543 billion per annum. - Breeds -Dairy breed-produce milk only :hole stein, Jersey
Dual purpose breed -produce milk and beef animal:
Friesein
Dairy shorthorn
Beef breed-produce beef animal:
Hereford
Limousin
Begian blue
- Most Irish dairy cows are Friesian because they have high milk yield and supply reasonable beef calves.
More and more dairy farmers are using Holstein bulls because of their very high milk yields - Dairy Breeds
Holstein-Friesian:
highest milkproducing
cow.
Large animal that
originates from
the Netherlands.
Ayrshire:
Scottish breed.
Easy calving - Jersey: originates
from the Channel
Islands. Produces a
lower milk yield but
high butterfat
content.
Jersey x Holstein-
Friesian cross:
demonstrates hybrid
vigour. - Composition of Milk
Water 87.5%
Fat 3.5% – 4.0%
Solids non fat (SNF)
oProteins (casein, albumin, globulin) 3.3% - 3.6%
oSugars (lactose, glucose) 4.6%
oMinerals (mainly calcium and phosphorus) - The Cow’s Udder
The milk-producing cells are called the alveolus. These cells have a duct that allows milk to drain out.
These ducts empty milk into the gland cistern.
The gland cistern is connected to the teat cistern.
The udder has a rich blood supply to help it synthesise milk. - Milking
‘Milk let-down’ is triggered by the hormone oxytocin.
Any disruption during the milking routine can trigger the release of the hormone adrenaline in the cow. Adrenaline works against oxytocin by blocking the release of it and preventing it reaching the udder. - Lactation
Lactation means “milking period” and it begins as soon as a cow has a calf.
The aim is to have a calf/cow/year.
A cow will go dry and stop giving milk 2 months before calving. This means that cows milk for 10 months of the year and are dry for 2 months.
Therefore the standard lactation of dairy cows is 305 days (10 months). - Colostrum
After the birth the cow produces colostrum.
Colostrum is darker in colour and much creamier than normal milk.
Feeding colostrum to a newborn calf (or any newborn animal) has a number of benefits:
oAntibodies in the colostrum protect the newborn against disease.
oThe ability of the calf to absorb these antibodies is greatest in the first 24 hours.
oColostrum is high in easily digestible nutrients.
oIt has a laxative effect, helping clean out the digestive system of the calf. - Lactation Yield
Lactation yield is the amount of milk a cow gives in 305 days.
It is measured in kgs not litres because it is the solids in milk that we are interested not the water.
Lactation yield of individual cows can vary greatly but in general yields are increasing in Ireland due to selection within the breed.
This means picking the best cows and breeding replacements heifers from them. - Lactation curve
Plots the milk production of a dairy cow over the course of her lactation.
Milk production increases from the start of lactation until the peak yield 4–6 weeks after calving.
Peak yield will depend on lactation number and the diet of the cow.
After peak yield is reached her milk yield will decline. - Factors Affecting Milk Yield
Age: milk yield rises with age of cow.
Frequency of milking: increasing frequency of milking increases milk yield.
Drying off: milk yield is reduced if drying off period is less than 40–60 days - Factors Affecting Milk Composition
Breed: milk composition varies greatly between purebred and crossbred dairy breeds.
Animal feed: good grassland increases fat and protein yields in milk.
Stage of lactation: the percentage of fat, lactose and protein of milk varies with stage of lactation. The percentage of fat and protein is highest immediately after calving. - Age: the percentage of fat and protein content of milk decreases with the dairy cow’s age.
Disease: infections of the udder, particularly mastitis, affect milk composition. The percentages of fat, protein and lactose all decrease. - Frequency of Milking
Milking empties the udder and stimulates the milk secreting cells (alveoli) to produce more milk.
Cows milked 3 times a day will give more milk than cows milked twice.
Cows are milked twice a day because the extra milk you get from milking them more often is not worth the labour of getting them in. - Milking Interval
Ideally cows should be milked every 12 hours because this puts less stress on the animal.
This means a very long working day for the farmer so cows are generally milked at 14 and 10 hour periods.
Whatever the interval it is important to keep it regular as cows are creatures of habit. - Factors affecting Yield and Composition of Milk
Breed ( SNF lower in lower genetic animals)
Stage of lactation (SNF lower at end of lactation)
Age of cow
Feeding levels and quality of food (SNF lower in underfed cows)
The efficiency of milking (a definite programme)
The length of time between milkings (regularity)
Time of year (lower in winter time) - Milk Hygiene and Milk Testing
Total bacterial count (TBC): Used as an indicator of hygiene on a farm. TBC can be high as a result of mastitis, dirty milking machinery or failure to properly cool the milk.
Somatic cell count (SCC): A measure of the health of the udder. Somatic cells are white blood cells. These increase if the udder has mastitis. - Milk Hygiene and Milk Testing
Antibiotics: Must be absent from milk at all times as antibiotics interfere with the processing of the milk. Delvo test is carried out on raw milk to identify the presence of antibiotics.
Sediment: Milk must be free from sediment and particles. The udder and the teat should be cleaned prior to milking and the milk filters must be changed regularly. - Testing of Milk
Creameries test milk for a number of different things.
Total bacteria count (TBC) is a measure of the amount of bacteria in a ml of milk.
Somatic Cell Count (SCC) is a measure of the amount cells that fight infection.
The milk is tested for antibiotics.
The percentage of fat and protein are measured.
The litmus and delvo tests are used by creameries - Husbandry and Management to Maintain High Hygiene Standards
Maintain clean housing, cubicles and dairy parlour.
Wash cow’s udder and teat.
Check for mastitis.
Use dry-cow treatment at drying off.
Filter milk.
Wash bulk tank and milk line regularly.
Ensure proper cooling of milk. - Typical Dairy Cow
Weighs 40kg at birth
Reaches puberty at 1 year old when she is 250kg
Oestrus Cycle (reproductive cycle) is 21 days and oestrus (heat) lasts for 18 hours
Gestation period (length of pregnancy) is 283 days
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