Synchronizing heats

[JeffNY]

Asked this on another site, however I received a bunch of different answers. So here goes. What is the best method to synchronizing heifers? Mainly using PGF (Lutalyce). How many days in from a heat do you inject? I read somewhere 5-15 days in. I plan on synchronizing 5 at a time, makes it worth while for the AI tech, and makes it easier for when they calve (around the same date, vs sporadic). Also it helps with timing. If I went all natural with breeding, I would have some odd dates. Some are cycling on the same day, however it would be nice to do bunches. The Jerseys id synch for a different time. The holsteins would be for a different time. More or less the Jerseys for the beginning of October, and the holstens late Sept. If I went with the natural heats, they get later in the month. What I mean is their calving period.


Thanks!

Jeff

[willow_girl]

JEff, here is a schedule I found online:

Basic OvSynch Schedule:

Day 0 2ml Cystorelin/GnRH given IM

Day 7 5ml Lutalyse given IM after 4pm

Day 9 2ml Cystorelin given IM after 4pm

Day 10 Inseminate by 8am

Example used often: Start 1st GnRH on a Monday and end up breeding following Thursday.

Basic HeatSynch Schedule:

Day 0 2ml Cystorelin/GnRH given IM

Day 7 5ml Lutalyse given IM after 4pm

Day 8 1/4ml ECP heifers IM 1/2 ml ECP cows IM

Day 10 Inseminate by 8am unless seen standing earlier(then use AM/PM rule)

This is a better plan for heifers and also allows the animal to exhibit more signs of heat, which for some people is preferred allowing them better ability to palpate the reproductive tract on AI.

http://www.acornemb.com/ovsynch.htm

I did the Ovsynch cycle on the girls last year and the results were Boo and Little Man! It is interesting to note that Teeny was clearly in heat at the time she was bred, while Twist did not display obvious signs yet she settled anyway!

Also, they were AI'ed on the same day, but calved a week apart -- Twist 2 weeks, and Teeny 1 week, before their due date. Teeny's calf was so big, though, that I suspect she would have split right down the sides had she carried him to term!

Good luck with your girls, and I hope you get lots of heifers!

Oh, here is something my boss swears by ... if you breed early in the heat (i.e., while they're mounting rather than waiting until they're standing ... ignore the AM/PM rule) you will have a lower conception rate, but get more heifer calves than bulls out of the ones who do conceive. (Something about the 'female' sperm surviving longer than the 'male' ones ... ?!)

I also talked to a farmer who uses a bull, and says he gets 60-70 percent heifer calves ... we speculated as to whether it's because the bull is covering the cows earlier in their heat? Which would have the same effect ... and it seems that in nature, where the survival of the species requires many females, but not as many males, this would be advantageous. I don't know if this holds true, though ... whether among wild animals, the gender ratio would be 50-50, or there would be more females born than males. Anybody know?!

[DaleK]

I use OVSynch, just gave 21 head the 1st shot yesterday. Different protocols work differently depending on diet etc., I'd try OVsynch first and if it doesn't work your AI tech should have a list. I've seen at least 10 different programs.

[JeffNY]

That is interesting willow, however our beef cattle are bull bred and last year we had 2 heifers and the rest were males (2 out of 12). He was with them all the time, so he would breed them whenever they were ready. Hard to say what truely makes a bull or a heifer, or atleast what determines it. Perhaps it happens depending on the animals temperature, acidity, diet etc etc. I know of someone that has an 87% heifer rate, I have no idea how he gets it. But there must be some sort of trick!

I hope they are heifers, however the one I bred recently hopefully has a heifer. Bred her to Ladino Park Talent, maybe she will become the A family on the farm . Since her name is Amnesty, and I will go from there. Pending she took!


Jeff

[unioncreek]

JeffNY,

I give 5ml of Lutalyze between 5 and 18 days in the cycle. That will usually bring them into standy heat in 36 hours. If some don't come into heat in that time give them a second injection seven days after the first.

Bobg