Dairy Flashcards
What is the dairy cow cycle?
Insemination, pregnancy, parturition, and lactation, followed by a dry period of about 2 months which allows udder tissue to regenerate
What are the main two parts of the dairy operation in regards to the cows themselves?
Milk production and calves to be reared as future replacements. Bull calves are sold at about 4 days of age or castrated and raised as steers for beef production (dry umbilical cord, in VIC they must be ear tagged)
What percent of Australian milk is exported?
55%
Where is 80% of Australian milk sent?
Asia and the Middle East
What is the avg. annual milk production per cow in AUS?
5,445 litres
When does milk production peak in Australia?
October because of seasons and rain and feed.
Why is a tight calving period important for dairy cows?
Late calving cows spend a smaller period of their time at high levels of production because cows reach a peak of production after 6-8 weeks of milking, maintaining a level of production for 2-3 months depending on feed availability.
What is split calving?
Herds that calve in two or three distinct periods each year; commonly spring and autumn. Particularly common in non-irrigation areas; production of milk year round- more efficient for manufacturers
What are the consequences of a non-pregnant cow (3)?
Culling the cow, carrying a dry cow over a whole season, milking the stale cow through
What are the benefits of year round calving in dairy cows?
Fewer cows sold as empty or late, more rapid genetic gain, less resources directed at correlating poor performance, more calves
What is the benefit of heavier heifers in dairy cows?
Reach puberty at a younger age, calve earlier, compete well, cycle earlier, and have higher peak milk yield, longer lactations and have superior lifetime production
What does colostrum provide in dairy cows? How much does the baby need in dairy cows?
Essential immunoglobulins (IgG)- immunity, excellent nutrient source, 5x protein, higher energy and vitamins than milk. 3.5-4 lit
What is the timing of colostrum? Max time and ideal time. Why?
has to be less than 12 hrs, ideally between 2-4 hours. Due to intestine failing to absorb intact macromolecules after 12-24 hours.
How do you assess adequacy of passive transfer in dairy cows?
take blood from calves 24-48 hours old and up to 7 days of age. Adequate IgG> 12 gm/L
Failure passive transfer IgG< 8 gm/L
Partial failure IgG 8 gm/L
When does the rumen develop in dairy cows?
6-8 weeks
How much protein does a calf need in dairy cows?
20-22%
How much volume of milk should a calf be fed daily?
10-12% body weight; twice daily for 1st week then once daily thereafter
When do you start feeding dairy cows grain?
From 1st week of life (small amount fresh daily), ad lib access to water, feed starter composition 18-20% crude protein
When are calves weaned in dairy cows?
1-3 days really.
6-8 weeks, weight 70-80 kg, intake 0.75-1.5 kg/day (best method)
What are the causes of calf scours?
Dietary- undigested milk in SI unclotted 1st week- E. coli 1-2 weeks- Salmonellosis 1st month- Cryptosporidosis Viral- Rotavirus causes watery yellow diarrhoea >3 weeks- Coccidiosis
What are some problems associated with undersized heifers?
Calving problems, produce less milk, and have greater problems getting back in calf during 1st lactation
When does the rumen reach mature capacity?
5 or 6 months of age.
When are foetal membranes expelled in dairy cows?
Within 12 hours of calving (sometimes 2-7 days)
What do farmers in SE Australia feed their cows?
Mostly pasture (75% of diet) of daily dry matter intake, grain, concentrates, or grain mixes
