fertility

[Victoria]

One of the problems in the dairy industry relating to fertility is that high milking animals tend to be less fertile than lower milking animals. The dairy industry on the whole wants the higher milk producing animals of course. The trade off is shorter estrus cycles (which result in both a shorter amount of time to breed and less chance of detecting heat), and less production of both estradiol and progesterone by the cow. Can you tell I just took an AI course? :lol2:

No matter what the articles say about fertilitly/genetics over the years we have found that on average get pregnant first heat have daughters that do the same. If you find a cow that is high milking, strong cycling and high pregnancy rates I would keep her daughters before keeping the daughter of a cow that breeds back late. There is a chance that the daughter of the late catcher will be good but you have to feed for a few years to find out.

 

[TSR]

Msscamp, I'm not talking about freemartins and sterile bulls.

Say we have two hypothetical cows; one that has twins, but has her first cycle at 30 days post calving and settles to it -- and the other cow with a single calf that starts cycling at 60 days and doesn't settle for 6 services. Assuming both hypothetical cows are bred to the same bull (say he's from a herd that averages 3 services/pregnancy) and both throw heifer calves, how fertile will those calves be? Will the calves from the first, very fertile cow, be more likely to take after her, or will we sacrifice some fertility? and the calf of the second, subfertile cow, will she be more fertile than her dam? how much of a role will each parent play in the fertility level of the offspring?

To answer your question with another question...

If I told you I'll give you $ 1000 if you can throw a baseball and hit the target 30 yards away, where will you look and focus?

At the target off course!

Same principle applies to cattle breeding, if you breed for long enough (don't need to be 50 years ;-) ) you'll soon see female lines showing themselves as more fertile than the rest and typically that line will be the first to finish calving in every season.

Maternal traits and fertility's inheritance is very low (factor of 0.1 if I remember correctly), it means that its a very difficult trait to improve on and luckily also not so easy to lose it if you have it already. To get a more fertile herd you'll make much bigger strides by eliminating those with lower fertility and longer ICP than you'll ever make trying to improve those who haven't.

I agree,those female lines begin to stand out after a while with respect to fertility. Then comes the decision, especially if they are not exactly what you want phenotypically or genotypically do you cull them. I guess then it becomes a question of fertility vs genotype/phenotype.

 

[novatech]

Should not be a choice. Cows or bulls that do not produce go. First and always first priority.
Those high heritable traits can always be corrected at a later time.
This is an off the wall way of looking at this But;
If a cow progressively looses 1 month per year on rebreeding. In 12 years that is the loss if 1 calf. (I think)
Now add that up with a bulls that cannot cover the cows.

 

[milkmaid]

Knersie, so how would one go about finding semen on older bulls?

Hillsdown, I sort of agree with your thoughts on the dairy industry, but at the same time -- how can so many dairies be doing everything so wrong as to have nearly every herd with fertility problems? Esp as the larger dairies often have nutritionists on staff. :???: Thoughts?

 

[KNERSIE]

Knersie, so how would one go about finding semen on older bulls?

Hillsdown, I sort of agree with your thoughts on the dairy industry, but at the same time -- how can so many dairies be doing everything so wrong as to have nearly every herd with fertility problems? Esp as the larger dairies often have nutritionists on staff. :???: Thoughts?

One of the major USA AI studs are advertising their Golden Oldies now, they are still working on the database, but the holsteins are available already. I think its ABS, but don't quote me on that. DO a search for the major studs and you'll soon find out which one it is. Other than that contact all the studs, you'll often be surprised what they might still have.

I don't think its so much the dairies' fault as it is that they were forced by the economics of the business to try and get the maximum out of each cow. As you know maximum is seldom optimum and nature don't tolerate extremes.

 

[novatech]

Call your association. I did and to my surprise they had a lot from the bull I had been looking for. (How they ended up with it is another story)
They gave me a lot of it just to get it out of inventory as it was costing them a lot to keep it in storage. They may also know of estates that sometimes need to get rid of it, or others that have it stored and do not use it anymore.

 

[msscamp]

Msscamp, I'm not talking about freemartins and sterile bulls.

I wasn't talking about freemartins or sterile bulls, either. ;-) I was talking about basic management in order to achieve the best herd possible under any given set of circumstances. The objective of running a herd of cows is calves, first and foremost. Assuming management is what it should be, and that a bull is not being expected to take care of more cows than he can handle - any cow that does not settle on 2 services should be culled. Any bull - assuming he has passed a BSE, or is known to be fertile based on past history - who is not able to get the job done on 2 services or less, should be culled and replaced with a bull who can.

Say we have two hypothetical cows; one that has twins, but has her first cycle at 30 days post calving and settles to it -- and the other cow with a single calf that starts cycling at 60 days and doesn't settle for 6 services. Assuming both hypothetical cows are bred to the same bull (say he's from a herd that averages 3 services/pregnancy) and both throw heifer calves, how fertile will those calves be? Will the calves from the first, very fertile cow, be more likely to take after her, or will we sacrifice some fertility? and the calf of the second, subfertile cow, will she be more fertile than her dam? how much of a role will each parent play in the fertility level of the offspring?

I would say the cow that twinned would have the more fertile calves due to the fact that she cycled and bred back in 30 days. Why would twinning have any negative effect on fertility? True, twins could possibly have an effect on the cow breeding back, depending on management, but I would think that could be easily remedied with a little adjustment in feeding. No, I do not believe a calf from a subfertile cow will be more fertile than her mother. How could it be when fertility is an inherited trait? The bull might possibly influence that fertility a little bit, but I believe that mitochondrial DNA will prevent him from influencing it enough to make any kind of significant difference from this particular mating.

 

[TSR]

Should not be a choice. Cows or bulls that do not produce go. First and always first priority.
Those high heritable traits can always be corrected at a later time.
This is an off the wall way of looking at this But;
If a cow progressively looses 1 month per year on rebreeding. In 12 years that is the loss if 1 calf. (I think)
Now add that up with a bulls that cannot cover the cows.

Been gone awhile. My point was that if all your cows are say calving in an 11-12 mo. window what do you start selecting for next now that fertility is no problem. Personally, I look at each cow individually to see what specific improvement can be made and now with ultrasound data on these cows' heifers it requires even more thought. I also make it a point to retain heifers out of my most fertile cows. I have one bloodline that I don't ever remember ai'ing but one time each yr.-very fertile. So far the daughters have been the same but I wonder, as you keep selecting bulls to ai to if at some time in the future fertility won't be affected. I guess I'm gonna find out.

 

[novatech]

Should not be a choice. Cows or bulls that do not produce go. First and always first priority.
Those high heritable traits can always be corrected at a later time.
This is an off the wall way of looking at this But;
If a cow progressively looses 1 month per year on rebreeding. In 12 years that is the loss if 1 calf. (I think)
Now add that up with a bulls that cannot cover the cows.

Been gone awhile. My point was that if all your cows are say calving in an 11-12 mo. window what do you start selecting for next now that fertility is no problem. Personally, I look at each cow individually to see what specific improvement can be made and now with ultrasound data on these cows' heifers it requires even more thought. I also make it a point to retain heifers out of my most fertile cows. I have one bloodline that I don't ever remember ai'ing but one time each yr.-very fertile. So far the daughters have been the same but I wonder, as you keep selecting bulls to ai to if at some time in the future fertility won't be affected. I guess I'm gonna find out.

After fertility what to breed for next is up to the breeder in trying to improve specific traits with individual cows or maybe the entire herd. These things or goals will be up to the individual. Some want to improve on meat quality and some want to improve on phenotype. I really do not do the individual improvement for the individual cow. I have a list of bulls that I AI to. I will usually stick with only 2 of these bulls for the year. It is simply to hard for me to select a bull based on the limited amount of information given in an AI catalogue. You rarely get a picture from the back or front and I have never seen a bull with an udder. :lol: I have never seen a fertility EPD. There is only one way to get the info needed so that you do not end up breeding something in that you do not want. That is looking at progeny and talking to other people that have used these bulls in the past.
The smaller your operation, the more selective you must be, because you simply do not produce enough progeny to cull as you should. It is human nature to be biased when developing your own cattle. Consequently the slower herd improvement will be.

 

[pdfangus]

I don't think you can select fertility on an individual basis.
It is a herd trait. You select for it by disposing of the under achievers.

We have a cow that is about 14 years old.
Pathfinder angus.
always raises a good calf
Bulls usually sold as yearling bulls or used as cleanup and sold as two year old.
Heifers usually retained as replacement heifers.
But she has never had a daughter able to match her in terms of total production. We are talking AI daughters of industry leading bulls.
We flushed her a few years ago to Fame and have two daughters from that flush that have survived the yearly fertility test and one has a really attractive bull calf on her this year. but to date she has been unable to match her dams production.

Cattle must be bred to perform within their environment. when we began to stack the good cows in our herd thru use of their superior sons we began to make progress. This was inadvertant as we strived to get those good cows bred AI. But when the cleanup bulls from one good cow managed to breed other good cows the selection for adaptation to the environment made itself manifest.

Now I quit obsessing over AI. I service once, wait two weeks and expose to the cleanup bull. All cleanup bulls originate in our herd. then we sell as two or three year old bulls.
cull cows not bred in 60 day season.

 

[TSR]

Generally speaking I believe you are right-fertility is a herd trait but you still see certain bloodlines exhibiting greater fertility than other bloodlines,or at least I do in my cattle.
I too had a high performance cow as you mentioned. I was beginning to wonder if I would ever have a daughter from her that would outperform her. She is now 13 yrs old. As her oldest daughter reached 8 yrs. of age she finally had a bull calf that surpassed her dam's progeny. Sometimes it takes time. Now I have a grandaughter of the ol' gal that has a bull calf that just might outdo them both. But after ai'ing all these years it has taken until now for this occurrence. I guess maybe age is finally catching up on the 13 yr old. I also used her son out of EXT as a cleanup bull to concentrate her genetics in my herd as much as possible and I haven't been disappointed. But I don't want to over do it. This is one of the things that makes breeding cattle fun isn't it?