Assessment of fertility Flashcards
How can dairy cow infertility cause financial loss?
Less milk per yer (low yield or longer dry period) Unnecessary culling - replacement cost Fewer calves per year More semen costs More labour costs
What needs to be monitored on cattle farms?
Calving fates
Culls
(Abortion, service dates)
What are primary indices?
Factors affecting losses
E.g. calving interval, abortion, reproductive culling
What are secondary indices
Factors directly affecting primary indices but can be monitored earlier
E.g. timing of first service, heat detection
Why is timing of first service important?
Too early = decreased fertility
Too late = prolonged calving interval
Why is 1st service pregnancy rate important?
Waste of semen
Later calving interval
What is submission rate?
Heat detection rate
What are alternative terms for pregnancy rate?
Conception rate
Conception risk
What should be the normal inter-service interval? Why?
Multiples of 18-24
Normal cycle length in a cow (18-24, avg 21)
What is the weaning % in beef herds?
Calves weaned / cows to bull
What are the advantages of a compact calving period?
Homogenous group at sale Favourable environment Management procedures done at same time Disease control Strategic nutrition
What is meant by lambing percentage? Does this include non-fertility reasons?
Number of lambs reared per 100 ewes to ram
Yes
What are empty days in pigs?
Any day that falls outside of the production cycle
Days that aren’t spent gestating, weaning, servicing or lactating (Day off)
What can be measured with laying poultry?
Age at 1st laying
No eggs/year
Egg size
Mortality/culling
What can be measured at a hatching farm?
No eggs/year
Viable chicks/100 eggs
