Feb. 12, 2018
Inside the Cattle report, part 2
by Derrell S. Peel, Oklahoma State University Extension livestock marketing specialist
The Cattle report issued by USDA-NASS in late January included several interesting changes in major beef cow states. Drought impacted the northern plains much of 2017 and continues to negatively impact producers in parts of Montana and North and South Dakota. However, regional drought which affected parts of those states did not result in net herd liquidation year over year. The beef cow inventory in Montana grew 0.7 percent to 1.497 million head in 2017. In North Dakota, the beef cow herd grew 3.2 percent, twice the national herd growth rate, to 984.5 thousand head, in 2017. This is the largest North Dakota beef herd level since 2002. Beef replacement heifers in both states were down sharply, 8.2 percent smaller in Montana and 7.3 percent smaller in North Dakota, and may indicate less growth potential in 2018, which could be due in part to the ongoing impacts of drought.
Most surprising is the strong herd growth in South Dakota, which added the largest number of cows of any state in 2017. The beef cow herd in South Dakota increased 8.2 percent, to 1.801 million head, also the highest state herd inventory since 2002. Beef replacement heifers in South Dakota were up 10.1 percent, suggesting that aggressive beef herd growth will continue in 2018.
The beef cow herd in Texas grew faster than the national average last year and was up 2.8 percent to a January 1, 2018 level of 4.585 million head. Nevertheless, Texas has generally recovered more slowly from the 2011-2013 drought than other states and the 2018 herd inventory is still less than the 2011 total. Beef replacement heifers were down a scant 1.2 percent in Texas, perhaps suggesting potential for additional herd growth in the coming year. Oklahoma, which had previously recovered to pre-drought levels, added another 1.7 percent to the beef cow herd inventory year over year, and at 2.131 million head was at the largest state herd level since 1983. Beef replacement heifers were down 5.7 percent in Oklahoma.
Missouri added the third largest number of beef cows to the herd (behind South Dakota and Texas) pushing the 2018 beef cow inventory up 5.4 percent to 2.166 million head. This moved Missouri slightly ahead of Oklahoma to once again rank as the second largest beef cow state in the country. Beef replacement heifers in Missouri were down a modest 1.4 percent year over year. Kansas, after jumping five percent in 2016, decreased the beef cow herd by 4.0 percent in 2017 to a January, 2018 total of 1.507 million head. Beef replacement heifers in Kansas were down 9.7 percent and may suggest additional herd decrease in 2018. Nebraska and Iowa were little changed with the Nebraska beef cow herd down 0.5 percent to 1.91 million head and Iowa up 0.5 percent to 970 thousand head. Kentucky, also a top ten beef cow state, saw a 1.0 percent herd growth in 2017 to 1.033 million head.
It is noteworthy that Florida, long a top ten beef cow state, dropped to thirteenth place with 886 thousand head on January 1, 2018; behind Arkansas with 924 thousand head and Tennessee with 910 thousand head. This is the first time Florida has had less than 900 thousand head of beef cows since 1964.
Severity of winter and impact on calf birth weights
by Glenn Selk, Oklahoma State University Emeritus Extension animal scientist
Does the severity (coldness or mildness) of the winter have an impact on spring-born calf birth weights? Ranchers have asked that question during many springs and veterinarians have speculated for years. The debate rages on! This is obviously a difficult subject to research because you cannot have a “control” group of cows to compare to a “treatment” group that is exposed to a cold winter while still running on the same pasture. Therefore research data on this subject is limited.
University of Nebraska researchers have done the next best thing. They have monitored the birth weights of genetically similar calves across three different winters and have related average winter temperatures to birth weights. A 3-year study was conducted to evaluate effects of high and low air temperatures and wind chills during winter months on subsequent calf birth weights and calving difficulty of spring-born calves. Records on approximately 400 2-year-old heifers and their calves were used. Heifer and calf genetics were the same each year. Heifers were fed similar quality hay free-choice each year before calving. High temperatures during the 1994-95 winter were 9 degrees higher than during the 1992-93 winter. The low temperatures were five degrees higher for 1994-95 compared to 1992-93. The greatest differences in monthly temperatures between years were found during December, January and February. Average temperatures for these three months increased 11 degrees F over the three years. Average calf birth weights decreased 11 pounds (81 to 70) from 1993 to 1995. A 1:1 ratio was observed. Although calving difficulty was high due to the research design, it also decreased from 57% to 35% from 1993 to 1995. Results indicate that cold temperatures influenced calf birth weight. Weather cannot be controlled; however, if we have below average winter temperatures, larger birth weight calves and more calving difficulty may be expected in the spring. (Source: Colburn, et al. 1996 Nebraska Beef Cattle Report.)
Other data that may shed some light on this subject, comes from Oklahoma State University in 1990. Birth weights of 172 fall born calves and 242 spring born calves were compared. These calves were the result of AI matings using the same bulls and bred to similar crossbred cows. The fall born calves averaged 4.5 pounds lighter at birth than their spring born counter parts (77.7 vs 82.2). Source: Selk and Buchanan, 1990 OSU Animal Science Research Report.) One possible explanation for this phenomenon, the changing of blood flow patterns of cows gestating in hot weather versus cold weather. During hot weather blood is shunted away from internal organs toward outer extremities to dissipate heat, while the opposite is the case in very cold weather with blood flow directed toward internal organs in an effort to conserve heat and maintain body temperature. This change in maternal blood flow may impact fetal growth in a small way, but result in a measurable difference.
Cow-Calf Corner is a newsletter from the Oklahoma Cooperative Extension Agency.