A Steak in Genomics™

Darrh Bullock University of Kentucky Crossbreeding should always be a consideration for commercial cattlemen. Crossbreeding has the greatest benefit for reproduction and other lowly heritable breeds. Practical Guide to Bull Buying Determine marketing strategy. Will heifers be retained? Make breeding decisions based on specific marketing plan. But, change marketing plan based on current situations. It's pretty easy to find a bull that will give you great feeder calves and market animals. When we are keeping replacement females, we are now asking a bull to create females and feeder calves. We've given him a new job. Determine your management level. What is your labor? How frequently do you visit your cattle? How much attention do you give to them? What is your level of nutritional management? Assure that bulls are reproductively sound with a BSE. Check for structural soundness. This is doubly important if you are retaining females. The tough one is to set performa...

Brandon Smythe New Mexico State University Three species Smythe works on: Horn flies Stable flies House flies House flies become an issue when we upset our neighbors. Dairy in New Mexico dealt with litigation from their neighbors. Everyone knows that flies are horrible. Both horn fly males and females feed on blood. Horn flies feed 30 to 40 times a day. Stable flies feed once or twice and then find a place to rest. Horn flies almost never leave a cow. Only time they leave is to lay eggs on a manure patch. There can be 200 to 1000 flies per animal. Flies are reproductively efficient. Flies lay 10 to 200 viable eggs per female. This reproduction efficiency allows for population surges. Horn flies are a warm weather pest, thus during cattle breeding and growing. Flies go dormant in winter months. Horn flies reduce performance in feed efficiency, growth and milk production. Horn flies are number one in causing production losses. We see a $5 to $8 return for every $1 ...

Jordan Thomas University of Missouri Bos indicus cattle are different from Bos taurus cattle. They were domesticated at a different time, in a different location from a different population than Bos taurus cattle. The big difference between Bos indicus cattle and Bos taurus is the attainment of puberty. Bos indicus cattle reach puberty later on average. Nutrition does not cause earlier puberty, but adequate nutrition is necessary to express potential for puberty. Brahman influenced animals are very sensitive to lower target weights and their ability to reach puberty. Modern compound bows have multiple sights for different distances. Even if we use perfect form, but use the 20 yard sight to shot a target at 60 yards, we will miss the target. We often make this same mistake when trying to hit mature cow weight targets. Cull cow weights can help us better identify the mature cow weight target. Reproductive tract scores are a helpful tool in managing Bos indicus- influenced...

George Perry South Dakota State University Criteria that heifers should meet: What has the pregnancy rate in your heifers been over the past few years? Have your heifer received growth promoting implants? Have your heifers reached the target weight? Typically 65%. What are the Reproductive Tract Scores of the heifers? Heifers have to reach 55% of their mature weight to start reaching puberty. However, how well can we know what the mature weight will be? When targeting 55% at breeding, we are really walking on the knife's edge. By targeting 65%, we are hedging for uncertainty. Heifers with Reproductive Tract Scores that are 1 or 2 not only have lower conception rates as heifers, they also have lower conception rates at 2-year olds. Criteria that Cows Should Meet What was the body condition score of your cows at calving? Should be greater than 5. What is the current body condition score of your cows? How many days postpartum will your bows be when estrus synchronizat...

Sandy Johnson Kansas State University There are 365 days in a year. There are 283 days of gestation, plus or minus. We have 82 days to get a cow cycling and breed. Kansas State University and Iowa Beef Center have put together 3 versions of the Estrus Synchronization Planner, Excel, mobile, and multi-group. The sync planner is freely available at http://www.iowabeefcenter.org/estrussynch.html . In the tool, you select the type of protocol you are using (estrus detection, estrus detection with clean up AI, and fixed-time AI). The mobile version is available at www.estrussynch.com . They also have a multi-group version of the Excel estrus synchronization planner. It is important to enable macros within the Excel program so the sheet can work. This allows you to have two groups of heifers, or a group of heifers and a group of cows. This allows you to print out a calendar. The estrus planner also produces a supply list. The estrus planner is focused on the few weeks of br...

David Patterson University of Missouri The goals of developing FTAI protocols: Easy to schedule and administer Reduce animal handling Result in a highly synchronized and fertile estrus and ovulation Protocols in Heifers Make sure you are using the protocols for the current year. Don't use protocol sheets that are several years old, as the protocols are changed and improved. "With an MGA program, intake is key" Patterson said. He does not recommend top dressing the MGA, but mixing it into a 3 to 5 lbs carrier. MGA has a much broader distribution of the timing of estrus expression compared to a 14-day CIDR protocol. With a MGA protocol, you AI 72 hours after PGF2 administration. With a CIDR protocol, heifers are AI'ed 66 hours after PGF2 administration. You should not see any estrus expression during MGA feeding periods. If you do see heifers in heat, then there is a problem with MGA intake. Prior to the first breeding season, there needs to be he...

Michael Smith University of Missouri The estrous cycle averages 21 days, with a range of 17 to 24 days.  There is variation in how long cows express estrus. Most cows express estrus for more than 11 hours. However, there is a significant number of cows who express estrus for less than 10 hours. These cows are often the ones that are missed in heat check programs. The success of artificial insemination programs is a function of both estrus detection and pregnancy rate. The presence of progestorone prevents ovulations and the expression of estrus. We use this principle in estrus synchronization procotols to synchronize estrus and ovulation. There are three catagories of horomones used in estrus synchronization: Progestins/Progesterone Prosteglandins GnRH Progesterone blocks estrus, blocks ovulation, preserves oocyte quality, and prepares for pregnancy. The two progestorone products used in the US are MGA and CIDR. MGA feeding for 14 days syncs heifers...