Today I want to talk about a UNL research study that compared MGA and 14 day CIDR for synchronizing heifers in preparation for fixed time A.I. What they found was that there was essentially no difference in effectiveness.
MGA and CIDR estrus synchronization protocols were equally effective when used in a fixed time artificial insemination program. There was no significant difference in pregnancy rates between the two protocols.
Although there is no difference in results, there are significant differences in costs, and in management complexities.
The economic analysis part of the study showed that the MGA treatment protocol cost approximately $19 less to produce a pregnant heifer than the 14-day CIDR protocol, mainly because MGA costs less than the CIDR.
Although it is cheaper, MGA does have a disadvantage compared to the CIDR protocol:
MGA must be consumed consistently every day over a 14 day period to be effective. This easy when heifers are being fed a complete ration every day. It is harder when heifers are grazing out and are being fed a supplement containing the MGA.
An advantage for MGA is that, while it does take labor to feed the MGA every day, it takes two fewer trips through the chute than the CIDR protocol.
Although CIDRs are more expensive, there are some good reasons why might use them. When you place a CIDR in a heifer, you know that the heifer is getting the progestin dose they need. You don’t have to worry about feeding it every day, and whether or not every single heifer is getting the correct dose. This can be a big advantage when heifers are grazing and you don’t otherwise need to feed on a daily basis.
The daily labor needed for delivery of the progestin in the CIDR protocol is less than when utilizing MGA. Labor is concentrated on the day when the CIDR is placed and the day it is removed.
The disadvantages for the CIDR protocol are that it requires two more trips through the chute than the MGA protocol, and it costs more.
As you can see, whether to use MGA or a 14 day CIDR, depends a lot on how you are managing those heifers. Since they work equally well, you can simply choose which protocol best fits your budget and your management.
As always, you can call the extension office at 402-376-1850 for more information.