Cow Fertility

Question 1

What are the 3 major factors that influence breeding productivity and performance?

Answer 1

Time taken for cows to re-conceive
Calf loss pre- and post-calving
Cow loss

Question 2

What are the 3 biggest influences of breeding productivity?

Answer 2

BCS
Grazing management
P status

Question 3

How do we measure reproductive efficiency?

Answer 3

Weaning rate

Number of calves weaned divided by the number of cows joined or retained after preg testing

Question 4

Other then a females ability to conceive what other factors can influence weaning rate?

Answer 4

Embryonic loss (prior to preg testing)
Abortions
Calf losses right through to weaning

Question 5

Factors affecting fertility and factors affecting pregnancy after 4 months?

Answer 5

Cow age class
previous calving period
BCS (July-sep)
BCS change (july-sep to feb-apr)
Protein and P status 
Brahman content
Seroprevalence of pestivirus

Question 6

What are the 3 main factors that account for cow mortality?

Answer 6

BCS interacting with dry season pasture biomass
Number of days from onset of wet season to follow up rain
BCS when entering dry season

Question 7

BCS change are influenced by?

Answer 7

Dry matter available from pasture
Dry matter digestibility of total diet
Rumen degradable protein conc of diet
Adequate mineral status, Ca, Mg, Na, P, S and trace minerals

Question 8

Protein status in primarily affected by?

Answer 8

Rumen degradable protein conc of diet (location/season)
DMD of diet (location and season)
Adequate minerals Ca, Mg, Na, P, S and trace minerals

Question 9

What diets are typically poor for livestock production?

Answer 9

<8% CP and <8MJ ME/kg DM

Question 10

When should you consider using a protein supplement at P4M?

Answer 10

When the ratio of CP:DMD drops below 0.125 you should consider a protein supplement

Question 11

When should you consider supplementation of P for P4M?

Answer 11

Indicated when P falls below 500mg P for every MJ ME/kg DM

Question 12

What are northern beef pastures usually deficient in?

Answer 12

P

Question 13

What mineral is very important for first calving heifers and what percentage does it increase P4M by?

Answer 13

> 500mg of P increases the chance of pregnancy at 4 months by 25%

Question 14

What BCS are more likely to have higher mortalities?

Answer 14

Cows with BCS < 3 much more likley to die then cows with BCS higher than 3.5