Oklahoma Farm Report masthead graphic with wheat on the left and cattle on the right.
Howdy Neighbors!
Ron Hays, Director of Farm and Ranch Programming, Radio Oklahoma Ag Network  |  2401 Exchange Ave, Suite F, Oklahoma City, Ok 73108  |  (405) 601-9211

advertisements
   
   
   
   
   
   
   
   
   
   

Agricultural News


Severity of Winter and Calf Birth Weights

Tue, 10 Jan 2012 18:00:50 CST

Severity of Winter and Calf Birth Weights 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. According to Glenn Selk, Oklahoma State University Emeritus Extension Animal Scientist, 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 grazing 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. This research is reported in detail in the 1996 University of Nebraska Animal Science Research Report (Coburn, et al.)   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.


Other data that may shed some light on this subject, comes from OSU 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 pounds versus 82.2 pounds). 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.


Weather cannot be controlled; however, with (thus far) above average winter temperatures, normal to slightly lower birth weights hopefully will bring less calving difficulty this spring. If the colder temperatures arrive during late gestation, that may be a clue that birth weights may be slightly increased and require a watchful eye for calving difficulty.


Our thanks to Dr. Selk for these comments- a part of his weekly electronic newsletter Cow Calf Corner that is published in conjunction with Dr. Derrell Peel of the Ag Economics Department.




   

 

 

WebReadyTM Powered by WireReady® NSI

 


Top Agricultural News

  • Soybean Harvest Ramps Up Finally with Favorable Weather, South Plains Wheat Planting Continues  Mon, 22 Oct 2018 16:52:42 CDT
  • New Crop Canola Acreage in OK Comparable to Last Year - Specialist Josh Lofton Offers This Advice  Mon, 22 Oct 2018 16:16:07 CDT
  • Oklahoma Grain Elevator Cash Bids as of 2:00 p.m. Monday, October 22, 2018  Mon, 22 Oct 2018 15:25:06 CDT
  • Ag Secretary Sonny Perdue Announces Receipt of 136 Expressions of Interest in Hosting ERS, NIFA  Mon, 22 Oct 2018 15:19:56 CDT
  • Monday Market Wrap-Up with Justin Lewis  Mon, 22 Oct 2018 15:01:27 CDT
  • Stillwater FFA's Agriscience Star Finalist Adrienne Blakey in Indy to Compete for National Honors  Mon, 22 Oct 2018 14:42:15 CDT
  • Monday Afternoon Market Wrap-Up with Carson Horn  Mon, 22 Oct 2018 14:07:48 CDT
  • Foreign Feed Grain Importers Visit Southern States to Forge Relationships with US Sorghum Suppliers  Mon, 22 Oct 2018 13:12:08 CDT

  • More Headlines...

       

    Ron salutes our daily email sponsors!

    Livestock Exchange Oklahoma Ag Credit Oklahoma Farm Bureau National Livestock Credit P&K Equipment Tulsa Farm Show Stillwater Milling KIS FUTURES, INC. Oklahoma Cattlemen's Association

    Search OklahomaFarmReport.com

    Find more about Weather in Oklahoma City, OK

       
       
    © 2008-2018 Oklahoma Farm Report
    Email Ron   |   Newsletter Signup   |    Current Spots   |    Program Links

    WebReady powered by WireReady® Inc.