Cow basics: housing, breeding, and nutrition
Do you want to be a dairy farmer? Here’s what you need to know...
Continuing here this week and next week, answers to the 50 Frequently Asked Questions of new entrants to dairying, compiled as part of the Teagasc Animal & Grassland Research & Innovation Programme.
WINTER FACILITIES
How much slurry storage is needed for a cow?
0.33 cubic metres required per week per cow, where no rainfall is included.
How much silage does a cow need over winter?
A cow will need 10kg of silage dry matter per day, which is equivalent to about 50 kg of fresh weight.
For a 3-month winter, 0.9t of DM (4.5t fresh wt) is required; for a 4-month winter, 1.2t of DM (6t); for a 5-month winter, 1.5t of DM (7.5t).
What are the dimensions of a cubicle?
Cubicle width is 1.2m and depth is 2.3-2.6 metres.
BREEDING
What are the main breeding targets?
90% submission rate in the first three weeks of the breeding season, six-week calving rate of 90%, and empty rate of less than 10% for a 12-week breeding season.
How many inseminations does it take to get a heifer milking in three years time?
Approximately 5.5 straws are required to result in a heifer milking in three years’ time (because conception rate is about 50%, the male to female ratio is about 50%, and there will be some heifer losses).
What is the target breeding weight for heifers?
The objective is to have heifers calving at two years of age; the target mating weight for Holstein Friesian is 330kg, and 295kg for Jersey cross.
To achieve these gains, heifers must gain 0.7 kg/day up to two years of age.
What heat detection aids work with dairy cows?
Farmers use all heat detection aids, they all work as an aid to identifying cows in heat. Teaser bulls are being used more widely now.
NUTRITION
For 100 cows, how much land do I need?
It depends on how much grass your farm can grow.
A cow needs about five tonnes of grass dry matter for grazing and silage for a full year.
On a farm growing 10 t of grass, 50 ha is required (stocking rate of 2.0 Livestock Units/ha).
On a farm growing 12 t of grass, 42 ha is required (stocking rate 2.4 LU/ha).
On a farm growing 14 t of grass, 36 ha is required (stocking rate 2.75 LU/ ha).
How much does a milking cow eat?
About 17 kg of dry matter per day.
How much meal does a cow need?
Cows will be in negative energy balance after calving, and need meal to try and minimise this body loss after calving. Where adequate grass is available, approximately 250 kg of meal would be sufficient.
Meal fed for the remainder of the lactation is usually to fill for grass deficits, and to extend the grazing rotation in autumn.
What is the ideal grass for cows in summer?
Grazing low covers in summer will restrict cow intake, grazing high covers in summer will limit energy intake because this grass contains more stemmy material. The optimum cover is about 1,400 kg, as this contains mostly leaf, which is highly digestible.
To see the 50 questions and answers in full, go to the http://www.teagasc.ie/publications/2014/3242/New_Entrants_to_Dairying-50Q&As.pdf website.
Basics of dairy farming
