By Colby Elford BSc., PAg, Regional Livestock Specialist, Moose Jaw
Among the reasons many producers choose to not use fixed time artificial insemination (FTAI) is the fact that getting only 50 to 60 per cent of the animals bred is not enough benefit to justify the time and expense of this type of program. There is evidence that suggests a wide variance in occurrence of estrus and therefore, ovulation within a group of synchronized heifers. This variance, combined with the fact that the viability of frozen-thawed bull semen may be less than 24 hours, means that in a typical FTAI program, viable sperm may not be present at the time of ovulation for some animals.
Research in North Dakota attempted to address this issue by combining a typical FTAI protocol with a second insemination to increase conception rates. Their research showed a great improvement in conception to FTAI. Based on this research and through the Agricultural Demonstrations of Practices and Technologies (ADOPT) program, the Rudy Feeder Co-op, Ministry of Agriculture Livestock Specialists, and the Western College of Veterinary Medicine designed a protocol to increase FTAI conception rates in Saskatchewan.
In this ADOPT trial, there were 261 heifers at six different operations. Each herd was randomly split into two groups. The first group was bred with a typical FTAI protocol, the second group was bred with the same protocol plus a second insemination 24 hours later. Four out of the six herds saw a substantial increase in conception rates due to the second insemination treatment. Overall, a 15 per cent increase in conception rate was achieved with the double insemination protocol.
This project suggests that double insemination may be a useful tool to increase conception rates in FTAI protocols. Success with FTAI programs is generally attributed to doing a lot of little things well. Success at breeding time starts with a good winter feeding program that ensures nutrient (including mineral and vitamins) requirements are met for each class of cattle. Heifers especially, need to be on an inclining plane of nutrition and at an appropriate weight in order to be successfully bred. Semen quality and handling, AI technique, and stress level of the animals can all be factors in determining the success level of the FTAI program.
More information on this project can be found on the Government of Saskatchewan website.
For additional information on this or other local demonstration projects, contact the Agriculture Knowledge Centre at 1-866-457-2377