Factors affecting calving difficulty
up the calf in front of a heater. I don’t think anyone cared since the snow was coming down so hard, the sledding was not going to be too much fun.
In Gordon County, we estimate we have easily more than 10,000 head of brood cows. Just like it was important to save that little calf back in 1993, it is just as important to have as close to 100 percent calf crop as possible on your farm. A farmer becomes attached to their livestock and wants to see a healthy herd, but in the end it is important to have a high percentage calf crop to give you a better chance at making a profit.
Today, I will be sharing information from a UGA publication on calving difficulty and the factors that can lead to calving problems. The original publication was by former UGA staff, Tim Wilson and Johnny Rossi, but was revised by my good friend, Mr. Ted Dyer, former UGA Beef Specialist.
Sire selection is the first factor we need to discuss in terms of calving difficulty or dystocia. Many times people will want to blame a particular breed of cattle for calving problems. The truth is, every breed of cattle can have bulls that can cause calving difficulty when they are bred to certain females. You should try to match the correct sire to the correct female. In general, you would not want to breed a large framed bull to a group of small framed heifers. If breeding heifers, you would want to find a sire that is known for producing low birth weight calves. As the heifers become mature cows, you can then breed them to larger framed bulls since the cows should be more able to deliver heavier birth weight calves. It is said that the dystocia potential of a bull can’t be visually determined. Cattle producers should look at past calving records or the Expected Progeny Differences ( EPDs) that are available for registered bulls.
The UGA- Calhoun HERD program is in full swing. In this heifer development program, the goal is to develop the heifers and have them all confirmed bred by sale day in late May. We artificially breed the heifers to nationally known calving ease bulls, but we also use low birth weight calving ease bulls as clean- up bulls, too. There was one Montana study that took place over a 15 year period. During this time they autopsied nearly 800 calves that died in a disease- free herd. The study determined that twice as many calves were lost around time of calving than any other time from birth to weaning. Of the calves that died at or around calving, 51 percent of those calves died from dystocia. The second most common cause of death was from disease such as scours or pneumonia.
Temperature at the time of calving is a major factor in calving problems in a herd. This is where environmental factors come into play. Our information states that calf birth weights can vary from year to year, even though the same genetics and management are used. Studies have shown that calves born in the fall weigh less than calves born in the winter and spring months. Calf birth weights can increase in cooler months, likely because of the increased nutrition due to supplemental feeding. If the cow in winter is getting the added nutrition of good hay or feed, the nutrient flow to the unborn calf increases so you can get a larger calf at birth. To get more specific, the greatest fetal growth happens in the last three months prior to calving. Thus, the temperature during this time period will have a greater effect on calf birth weight.
One factor in regards to calving problems on the farm is abnormal presentations of the unborn calf. Many cattle producers will, over time, gain experience and can help deliver a calf when needed. I will add that it is important to have an expert large animal veterinarian that you can call on in some abnormal calf presentation situations. Remember, being prepared for unexpected calving problems can save many calves and increase your calving percentage.
Also, having a controlled breeding season will result in a shorter calving seasons. You can be more observant and on hand to assist in difficult births when you know calving times. For more information, contact UGA Extension-Gordon County at 706- 629- 8685 or email gbowman@ uga. edu.