Sexed heifer semen and timed A.I. ?

[jd720]

I`ve got 4 heifers to breed around May and I plan on setting them up with cidrs and possibly using sexed heifer semen from Select Sires on Grandmaster and Optimizer. What works best between the 7 day cidr and timed A.I. and the 14 day cidr protocol ? I have heard some say you need to wait a little longer to breed them when using the sexed semen. What has worked well for those of you that have tried this before ? Thanks

 

[bse]

The 14 day works good on hefiers, it does take a little more planning. Unless I already had the sexed semen I wouldnt use it, conception rate is lower its a little better on hefiers but not enough to make me want to use it, and theres no guarantee it will be a hefier because theres still some male in there, so I just take my chances on conventional.

 

[cow pollinater]

If you're bound and determined to use sexed semen on sync cattle then wait longer. In the past I'd have said DON'T DO IT at all but within the last year I'm seeing results similar to what they originally told us it would do. It's not as good as they say it is now but it's better than it was. ;-) You're still going to want to follow it with conventional to get decent results.

 

[Craig]

You might want to consider putting a second straw in them 8-12 hours after the first one. Less chance of repeats this way in my experience. Using one straw per heat cycle I'm averaging 2.3 straws of sexed per conception. I have not used any yet this year though, so maybe as CP said, it's getting better.

 

[jd720]

I think I may try using a second straw later. I asked my vet about it and he said he has pretty good results using sexed semen on virgin heifers with 2 straws. These 4 heifers are my best so I really don`t mind the added expense and labor.

 

[cow pollinater]

I tried using a second straw later in dairy cattle and couldn't get the conception anywhere near better enough to justify the extra cost. I think you're better off with just the one straw timed properly.

 

[cow pollinater]

I have not used any yet this year though, so maybe as CP said, it's getting better.

Craig, I was told last year that improvements were made. I spoke to the guys from sexing technologies in person at the farm show in Tulare last year and they told me when the changes were made. I did a direct comparison with a couple of hundred straws from two bulls before they made changes and the same two bulls from later batches and the conception is quite a bit better. It's not the same as conventional semen but it's now a viable option for getting things pregnant instead of being a shot in the dark.

 

[toughntender]

CP- What's your opinion of the 5 day Co- Synch with CIDR and TAI? I was using the seven day and switched to the 5 day with very positive results. Yes, you have to run them through for the 2nd shot of pgf2a but it seems to line everybody up very nicely. We watch for heats and breed off of that. Anybody who won't show, we breed TAI. We had one group where 9 out of the 10 cows stuck, I was shocked! I've even used it on heifers with good results. Maybe my herd is an anomaly, but I don't use anything else anymore.

 

[cow pollinater]

CP- What's your opinion of the 5 day Co- Synch with CIDR and TAI?

I don't have an opinion as I haven't tried it.

 

[toughntender]

Dang, I figured you had run across it before. I wonder why more guys don't try it.

 

[bse]

I have tried it and didnt get along very well at all, the 7 day works for me, if the 5 day works then id stick with whatever worked.
I do have a question for the gurus on the 5 day. I dont know all the technical terms for the question. The pg is given then 6 to 10 hours later again. Its I think a half life drug meaning absorbed immediately, so its in going to do what it does, then with the later shot your asking a drug to do something its already supposedly done. The pg is given with X amount no matter if its a 800lb hefier or a 1600lb cow. Is it because the cidr didnt do its job in 5 days and the extra 8 hours or so gives them another chance?

 

[toughntender]

I have tried it and didnt get along very well at all, the 7 day works for me, if the 5 day works then id stick with whatever worked.
I do have a question for the gurus on the 5 day. I dont know all the technical terms for the question. The pg is given then 6 to 10 hours later again. Its I think a half life drug meaning absorbed immediately, so its in going to do what it does, then with the later shot your asking a drug to do something its already supposedly done. The pg is given with X amount no matter if its a 800lb hefier or a 1600lb cow. Is it because the cidr didnt do its job in 5 days and the extra 8 hours or so gives them another chance?

Yes the pg does act immediately. It starts working to regress the Corpus luteum within a matter of minutes of being injected. At least that's what my vet has told me when we were flushing cows. The reason you have to give the second shot is that all of the animals receiving the treatment may not have a CL to regress at the time the first shot is given. PGf2a is very potent, so potent, that pregnant women aren't even supposed to touch the bottle. That's why the same shot amount works on large and small animals. The 5 day was recommended to us by our vet because there is research that it works better on heifers, due to the fact that they have more sporadic cycle times. Some will cycle faster, and it's easier to get a group of heifers synced up. From what I've seen, the cows/heifers are much closer together, and not as strung out as when I did the 7 day. The final reason I like the 5 day is that it is that much less time for the CIDR to be lost, and there is that much less vaginitis.