Fertility

[Ebenezer]

Question:

I have a few donors. 2 donors provide an average number of embryos.

1 donor is exceptionally high. 15-22 with 20 being the average. Very lucky.

Would it be safer to assume that a line of pathfinders is a good indicator or do you think it's just luck? Since HP doesn't actually indicate "fertility".

Do you suppose that is heritable? Would it be fair to assume that one of her daughters would also provide a good number of embryos?

Pathfinder is defined at 5 YO and 3 calves which excel in growth to weaning. A pathfinder is fertile to do that but you or I do not know how they are fed to be able to pull it off. It is a comparative within the herd and how the herd is fed and which sires are used on what cows.

# embryos per cow is a heritable trait to daughters just as low #s of embryos is also heritable to daughters according to the Vet and folks who have done a lot of it. That is one reason some donors stay in programs as they are successful and other cows are as good or better but cannot be manipulated to deliver enough embryos to make it worthwhile.

SC and fertility of the bull. EXT was not known for the high SC EPDs. So it is not all correlated as tightly as we hope.

If fertility is only heritable at 11% per individual but we cull the worst of females do we not have odds to speed the process if we save daughters of the right cows, use short breeding windows on yearling heifers and do our homework on the bull selections?

Bonsma selection can also help. He also discussed cattle that have system problems earlier in life than others so that they quit functioning too soon. It's good not to set that up in a herd.

 

[W.B.]

I agree with above post. Crossbreeding can fix the problems in the f1 generation but be prepared for rapid regression in subsequent generations if bred back to either of the f1 breeds. The rash of open cows in the local commercial herds tells me lack of fertility selection in the seedstock herds is woefully inadequate. The generational turnover and lack of selection pressure for a low heritability trait is catching up to the commercial cowherds.

 

[Stocker Steve]

What is an example of an early "systems problem", and how could ID it before it happens?

 

[Ebenezer]

What is an example of an early "systems problem", and how could ID it before it happens?

Quickly, the Bonsma issue uses visuals. He related it to glandular or such failures. The fastest example to me to mention is the line of cattle that get pudgier with each calf and the cows go into menopause before their full life should be over (reproductive system) . There is a major source herd with that type of issue.

There are other signs that he mentions for other failures.

 

[Stocker Steve]

How do you ID pudgy prone females early on ?

 

[Ebenezer]

How do you ID pudgy prone females early on ?

Bonsma selected for more than I will ever remember. But the overall type was to be a feminine cow and a masculine bull. The reverse wedge discussion goes into this more. He also selected for early rapid growth. Hair and skin were big "reads" for him. And when he was interested in endocrine gland functions and such he keyed in on whorls, whorl sizes and locations. If the cow is functioning properly in a normal environment she will gain and lose weight on a cyclic pattern due to weaning, late gestation, calving, milk production and a repeat. But she will not be prone to the pones of fat at the tailhead, the ball in the brisket, the heavy jaw and steer look that is somewhat accepted today as the average cow. So, not 1,2,3 answer. More of a type issue and then fine tuned. Others may can give this a better discussion.