Advice for AI on some heifers

Help Support CattleToday:

Jeanne - Simme Valley

Well-known member
Joined
Dec 9, 2004
Messages
12,165
Reaction score
920
Location
Central Upstate New York
Many people have # hours after "first" standing. I have been AI'ing for 50 years, I basically use the am / pm rule. First 2 weeks of breeding, I will try to breed as early as I dare - shooting for more heifers, but when you breed early, you take the chance of dam not releasing her egg too late. Later breeding tends to be more chance of pregnancy.
 

JKCattle

Well-known member
Joined
Mar 5, 2018
Messages
50
Reaction score
40
Just need to remember that maximum life span of semen in the cow is 24 hours and the ovulated ovum is about 18 hours, although beyond 12 hours, fertility of both declines rapidly. Ovulation occurs about 10-12 hours after end of standing heat. We try AM / PM on our cows, but keep in mind above facts and breed by what our schedule allows. If we think something is not right with a heat we either breed early with a shot of GnRH or breed twice (AM and PM).
 

Angusjohn

Member
Joined
Dec 16, 2019
Messages
14
Reaction score
5
Location
Danville, KY
Heifers tend to have a shorter cycle. Mine usually cycle average 18 days and cows 21 days. So, they generally respond faster to a PG shot (like 1-3 days and cows 2-5 days)
Heat detecting and breeding natural heats for 5-6 days, then PG shot everything not bred is the cheapest sync program and it works - IF AND ONLY IF - they are already cycling. PG will only work if they have a CL. CIDRs will make a cow cycle if she hasn't been, BUT, it is not necessarily a good viable heat.
Is your comment on CIDRs and cows based on your A.I. experience (extensive) or university research? This is a question I have asked of our extension service Agent. He tells me research indicates no difference in conception rates on natural versus synced heats. I always use CIDRs, just because of the lack of time to obreve. Some years, run 80% to the AI, other years in the mid 60s.
 

Gonz

New member
Joined
Feb 9, 2011
Messages
4
Reaction score
1
am/pm rule is fine for heifers if you are going off observed heats. If you are doing timed AI the timing makes a big difference. Ranges from 54 to 72 hours after PG depending on protocol. WB's protocol above is the best one ever for timed AI on heifers.
 
OP
J

Josher

Well-known member
Joined
Dec 10, 2018
Messages
149
Reaction score
44
Location
NW Saskatchewan, Canada
We’ve done 13 out of a group of 37 heifers. I’ve found the opening of the cervix was harder to find than on cows but not impossible. A lot less variations heifer to heifer vs cows. Hope they catch. Been using fertagyl at breeding on anything that’s questionable on timing or ones that have gotten PG. Starting to Ai cows now. Bye bye spare time lol.
 

Nkline

Well-known member
Joined
Nov 2, 2020
Messages
70
Reaction score
58
Location
Western Iowa
We’ve done 13 out of a group of 37 heifers. I’ve found the opening of the cervix was harder to find than on cows but not impossible. A lot less variations heifer to heifer vs cows. Hope they catch. Been using fertagyl at breeding on anything that’s questionable on timing or ones that have gotten PG. Starting to Ai cows now. Bye bye spare time lol.
What are you hoping to gain that a bull can’t provide. I use AI on some heifers and ET just to try out or bring in new genetics. I only do this in my purebred herd, my AI calves typically don’t sell for more than calves out of my home raised bulls.
 
OP
J

Josher

Well-known member
Joined
Dec 10, 2018
Messages
149
Reaction score
44
Location
NW Saskatchewan, Canada
W
What are you hoping to gain that a bull can’t provide. I use AI on some heifers and ET just to try out or bring in new genetics. I only do this in my purebred herd, my AI calves typically don’t sell for more than calves out of my home raised bulls.
Well to sum it up. Had a bull go down at a bad time and had to change plans where bulls went in pastures and instead of buying another heifer bull I just pulled out some heifers of the main group to AI. Most of these heifers will be sold as breds but I figure it might add some value to them. Bred to high accuracy proven calving ease bulls.
 

Nkline

Well-known member
Joined
Nov 2, 2020
Messages
70
Reaction score
58
Location
Western Iowa
W

Well to sum it up. Had a bull go down at a bad time and had to change plans where bulls went in pastures and instead of buying another heifer bull I just pulled out some heifers of the main group to AI. Most of these heifers will be sold as breds but I figure it might add some value to them. Bred to high accuracy proven calving ease bulls.
Sounds like a good reason. Especially since you’re selling breds.
 

W.B.

Well-known member
Joined
Feb 27, 2006
Messages
452
Reaction score
39
Location
SD
I think there are a lot of reasons to ai yearlings especially if you are keeping replacements. Yes I get it that there are a lot of bulls in the studs are are not especially good but choose a proven calving ease bull that has daughters in production and your herd quality goes up. You can really focus on the little Things like udder quality and disposition.
 

Jeanne - Simme Valley

Well-known member
Joined
Dec 9, 2004
Messages
12,165
Reaction score
920
Location
Central Upstate New York
@Angusjohn sorry this slipped by me. My personal experience tells me a CIDR heat is not as reliable as a natural heat. But, I have had my vet explain it to me.
If you have ever had setting chickens, you will understand that when a hen lays so many eggs to set/hatch, they can only be so many days old. After a certain number of days, the egg gets "stale" and will not develop.
If a cow is just on the verge of cycling, her egg is ready to release, then we tell it to "hold on" until another 9-10 days. Her egg gets old and not very viable for fertilization. Whether this is FACT or not, not sure, but it explains to me why "I" have experienced lower conception with CIDR. Don't get me wrong. I use them. They definitely will get a cow cycling. But, many times, I will let her come into heat, then Lutalyse her and bring her back in 7-10 days later. I rarely am using inexpensive semen - some as much as $100-$200/unit - most at least $50. I try to make sure I'm confident on the heat we are breeding. Sometimes it's a catch 22 case, because I'm under a time limit with a 60 day breeding season.
 

kentuckyguy

Well-known member
Joined
Nov 6, 2016
Messages
623
Reaction score
153
@Angusjohn sorry this slipped by me. My personal experience tells me a CIDR heat is not as reliable as a natural heat. But, I have had my vet explain it to me.
If you have ever had setting chickens, you will understand that when a hen lays so many eggs to set/hatch, they can only be so many days old. After a certain number of days, the egg gets "stale" and will not develop.
If a cow is just on the verge of cycling, her egg is ready to release, then we tell it to "hold on" until another 9-10 days. Her egg gets old and not very viable for fertilization. Whether this is FACT or not, not sure, but it explains to me why "I" have experienced lower conception with CIDR. Don't get me wrong. I use them. They definitely will get a cow cycling. But, many times, I will let her come into heat, then Lutalyse her and bring her back in 7-10 days later. I rarely am using inexpensive semen - some as much as $100-$200/unit - most at least $50. I try to make sure I'm confident on the heat we are breeding. Sometimes it's a catch 22 case, because I'm under a time limit with a 60 day breeding season.
I definitely agree on the CIDR heats. I would hate to see my conception rate on the ones I put CIDR’s in. Seems like I always end up breeding them twice and they stick on the second heat.
 

Angusjohn

Member
Joined
Dec 16, 2019
Messages
14
Reaction score
5
Location
Danville, KY
Jeanne
Thanks for the reply. Your observation and comments make plenty of sense. I have long thought the induced heat logically was not as fertile as a natural heat. I just have not found any research results that confirmed (or not) that theory.
 

Katpau

Well-known member
Joined
Feb 28, 2009
Messages
662
Reaction score
118
Location
Roseburg, Oregon
Jeanne,
That's an interesting argument, and would seem to make sense. That could explain why the new 7 & 7 protocol works better for most people. In that protocol you are doing what Jeanne describes as her protocol.
We usually AI all of our heifers and a few cows. I tried the 7 & 7 protocol this year on just 5 cows, and had only one come in heat prior to timed AI and one that showed heat a few hours after. The worst response I have had in 12 years of AI. I don't blame the protocol however. I think there was something more going on. It might have been my minerals, or the pasture I held them in, or just poor choices in cows. With only 5 cows I did not have a statistically relevant sample. Except for the cow that first responded, I noticed that the other 4 also failed to shed out as fast as the rest of my herd. The heifers were on the 14 day protocol and all showed heat, but more than half came back in 3 weeks later. Strangely I never saw any of the cows back in heat, so maybe they settled after all.
 

GoWyo

Well-known member
Joined
Feb 16, 2019
Messages
160
Reaction score
142
Location
Southeast Wyoming
We used 7&7 heat sync protocol this year on 49 head. The extra trip through the chute was a hassle just because of the pasture rotation situation, but we got it done. Several cows had calved less than 30 days prior to placing CIDRS. Out of 49 head we had 46 show heat and 3 nonresponders. Two of the nonresponders had calved less than 45 days before the breeding date and the other was a 3-year old who calved early March and didn't really have an excuse (she did get bred by the bulll with next heat cycle). We only AI'd the cows showing heats and bred all on observed heat with no timed AI. Four cows did not come into heat until 96 hours after CIDR removal and lutelyze. It was 90*+ the week we AI'd, which was miserable for here, but the heats were strong. Cows were split to 3 different pastures for natural clean up and 2 pastures are over 40 miles from the house, so my observations 18-21 days later were not the best, but I think we are around 70% AI conception, which is typical from past years. I am sure we will lose a few like we always do and they will come back in to heat before August. Our best year was 2019 with 85% bred AI and 2020 was our worst year at about 60%.
 

Jeanne - Simme Valley

Well-known member
Joined
Dec 9, 2004
Messages
12,165
Reaction score
920
Location
Central Upstate New York
I do want to point out that a PG (LUTALYSE/Estrumate) does NOT give you the "stale" egg syndrome. PG makes them slough their CL and drop a FRESH egg. To me, a PG heat is as good as a natural heat.
The golden advantage of CIDR is they will kick start a cow/heifer that has not started cycling yet. PG will NOT - it will only work on an animal that is already cycling.
 

Till-Hill

Well-known member
Joined
Apr 10, 2011
Messages
1,040
Reaction score
14
Location
Waterville, Iowa
I will agree with Jeanne on PG heats. We have heat detection system in dairy cows and I like to PG and sticker beef cows. Saves time and I get to breed when I want to.

On timing folks I just looked up last years breeding at dairy. We have collars on all breeding cows. We have a computer management system.

204 breedings last year 102 got pregnant. 50%
Now we break down timings on breedings.
Under 2 hours since fist sign of heat 8/13 62%
2-12 hours since first sign 28/59 47%
Greater than 12 hour 50%



Now onto breeding trigger (why I bred them)
Standing heats, either bred before collar showed up or I didn't have a collar on or maybe collar was dead
11/19 58%
Heat detection system 131/273 48%
Time Ai (ovsynch) 8/21 38%

In summary breed when you got time and breed when they are in heat.
 

Jeanne - Simme Valley

Well-known member
Joined
Dec 9, 2004
Messages
12,165
Reaction score
920
Location
Central Upstate New York
@Till-Hill , not being critical, but "in my world" those are horrible conception rates. Is that because dairy cattle are so pushed for production?
Have to admit, it sure would be nice to have a "system" that told me when they were cycling. Some cattle sure can be sneaky with their heats. LOL
With all your stats you can look at, have you tried comparing heifer vs bull calves by breeding timing? I had always been told early breeding produces more heifers - but lower conception rate. Your data had better early breeding conception.
 

Hpacres440p

Well-known member
Joined
Dec 14, 2019
Messages
297
Reaction score
179
@Till-Hill , not being critical, but "in my world" those are horrible conception rates. Is that because dairy cattle are so pushed for production?
Have to admit, it sure would be nice to have a "system" that told me when they were cycling. Some cattle sure can be sneaky with their heats. LOL
With all your stats you can look at, have you tried comparing heifer vs bull calves by breeding timing? I had always been told early breeding produces more heifers - but lower conception rate. Your data had better early breeding conception.
Also, is that sexed semen or just regular?
 

Buck Randall

Well-known member
Joined
Jun 5, 2019
Messages
1,301
Reaction score
954
@Till-Hill , not being critical, but "in my world" those are horrible conception rates. Is that because dairy cattle are so pushed for production?
Have to admit, it sure would be nice to have a "system" that told me when they were cycling. Some cattle sure can be sneaky with their heats. LOL
With all your stats you can look at, have you tried comparing heifer vs bull calves by breeding timing? I had always been told early breeding produces more heifers - but lower conception rate. Your data had better early breeding conception.
Dairy cattle will often have lower conception rates than beef cattle; high milk production is hard on fertility. Those numbers are pretty good for the collar system. A full timed AI system usually works better for dairy cattle than anything else.
 

Till-Hill

Well-known member
Joined
Apr 10, 2011
Messages
1,040
Reaction score
14
Location
Waterville, Iowa
@Till-Hill , not being critical, but "in my world" those are horrible conception rates. Is that because dairy cattle are so pushed for production?
Have to admit, it sure would be nice to have a "system" that told me when they were cycling. Some cattle sure can be sneaky with their heats. LOL
With all your stats you can look at, have you tried comparing heifer vs bull calves by breeding timing? I had always been told early breeding produces more heifers - but lower conception rate. Your data had better early breeding conception.
Sexed female semen for first 2 services than beef. Our calving interval is 13.1 months. Average 1.9 services per pregnancy. And it short yes we do push for production and there is more heat stress but Holstein's are just not known for being fertile!

When using sexed semen it's hard to tell timing anything to do with sex.
 
Top