Cornstalk Strip Grazing Demonstration with Beef Cows

In the fall of 2012, the ISU McNay Research Farm, Chariton, Iowa, conducted a trial on strip grazing of cornstalks to extend the normal 40–60 grazing days per cornstalk acre. The goal was to delay feeding hay as long as possible due to limited hay supplies and high costs caused by drought

Bovine Respiratory Syncytial Virus Infection in McNay Farm Calves

Clinical respiratory disease occurs almost every year in fall calves in the McNay Farm herd. Diagnostic procedures have implicated Haemophilus somnus (H. somnus) and bovine respiratory syncyial virus (BRSV) as the infectious agents primarily associated with this disease. Therefore, the 1995 calves were closely monitored after weaning and during the course of a respiratory disease. Serologic evidence indicated the involvement of the same two agents in the pathogenesis of the disease. Also, experimental evidence suggested a role for a preexisting immediate hypersensitivity to H. somnus and the development of this type of response to BRSV. We theorize that the pathogenesis of the clinical disease involved infection with H. somnus, establishment of immediate hypersensitivity in the lungs, viral infection with associated pathologic lesions, and viral exacerbation of the immediate hypersensitivity reaction with resultant clinical signs and tissue damage

Antibody Response to Inactivated Viral Vaccines Administered to Calves at Weaning

Respiratory disease in beef calves has been associated with the stress of weaning. Management practices commonly delay vaccination of calves to this time, and weaning stress could potentially suppress the immune response. To reduce this stress we have been experimenting with a procedure termed “pasture weaning” in which the dams are removed and the calves remain on pasture. Observation suggests that calves weaned with this approach adapt to the weaned state much better than those held in drylot. Consequently, one would expect less stress-mediated effects including those on the immune system. Calves were weaned and assigned to groups that were pasture or drylot weaned, and calves within the groups were vaccinated with one of two inactivated virus vaccines by either the intramuscular or subcutaneous route. Weaning placement did not affect antibody responses to the viruses included in the vaccines. The route of administration did not influence responses with subcutaneous injection inducing responses equivalent to the intramuscular site. Utilization of this route for vaccination could be advantageous because it precludes the tissue damage and hidden abscessation that sometimes results from intramuscular injections. A distinct difference was noted in the immunogenicity of the vaccines with the Vira Shield product yielding significantly better responses to all viral entities

Beef Cow Feeding Demonstration

Pregnant mature beef cows were fed one of five rations: tub ground hay, low corn supplementation plus hay, high corn plus hay, low corn gluten feed (CGF) pellets plus hay, and high CGF plus hay. All treatments resulted in weight gains and limited body condition score changes. The hay and high CGF pellet diet resulted in statistically different weight gains compared with the other supplementation programs

Prebreeding Immunization of Beef Cows

A number of infectious agents are potential threats to the fetus of a pregnant cow and may result in abortion. These agents include Leptospira sp., Campylobacter fetus and viruses such as infectious bovine rhinotracheitis (IBR) and bovine virus diarrhea (BVD). Maintenance in the cow of a high level of immunity to these agents during pregnancy can insure protection of the fetus. In particular, vaccines against BVD and IBR viruses can establish protective immunity throughout gestation. An appropriate vaccination regimen prior to breeding is required to establish this protective immunity. This can be achieved with a single dose of certain modified live virus vaccines, but those vaccines must be administered at least 30 days prior to breeding to avoid interference with conception. We have evaluated an oil-adjuvanted inactivated virus vaccine in cattle with differing immunological histories. Two doses of the vaccine administered 30 days apart to serologically negative animals induced appreciable levels of BVD and IBR anti-viral antibodies with persisting titers throughout gestation. In other experiments a single dose of the vaccine was administered to: (1) animals given two doses of the vaccine several months earlier, (2) animals previously vaccinated with other inactivated virus vaccines, or (3) animals previously vaccinated with modified live virus vaccine. The vaccine consistently induced marked anamnestic responses in these animals. Not only did mean titers rise, but a vast majority of individual animals responded. This contrasts with efforts to boost titers with modified live virus vaccines where the effect may be erratic among animals. The safety and efficacy of selected inactivated viral vaccines argues for their use in prebreeding immunization of beef cows

Teaching Self-Control Procedures to Learning Disabled Youths

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.This study developed and evaluated a self-instructional booklet that teaches adolescents to change their behaviors with minimal intervention from other individuals. The subjects, to varying degrees, learned the principles of self-control and applied the principles to their own behaviors. The application of the sett-control procedures produced inconsistent results both within and across subjects

Effect of Early Weaning of Beef Calves on Performance and Carcass Quality

A study was conducted to evaluate early weaning of beef calves at 60-70 days of age on feedlot performance and carcass characteristics. One hundred twenty steer calves sired by either Simmental or Angus sires were weaned at an average age of 67 (early weaned, EW) or 147 (late weaned, LW) days. Calves were allotted to 16 feedlot pens by weaning treatment and sire breed at approximately 750-800 lb. EW calves were heavier (P \u3c .05) in initial feedlot weight. There were no differences due to weaning age on daily gain, dry matter intake, feed efficiency or slaughter weights. Simmental steers required more days on feed than Angus steers (P \u3c .05). Early-weaned calves had a higher percent intramuscular fat (5.7 vs. 5.1%), higher average marbling scores (Small78 vs. Small20, P \u3c .05), a higher percentage of cattle grading average USDA Choice and higher (38% vs. 14%, P \u3c .05) and a higher percentage of USDA Prime (10% vs. 0%, P \u3c .05). These data confirm observations in previous studies that early weaning and placing calves on a higher grain diet improves marbling at slaughter. In this study, the effect was shown in calves weaned at an average of 67 days

A Project to Produce Calves from Selected Historical Angus Bulls

As part of the 50th anniversary of the McNay Research Farm, cows were inseminated with semen from Angus bulls of the 1950s and the 1970/1980s. The goal was to produce calves from Angus bulls that were popular 50 years ago and 25 years ago for viewing at the McNay Research Farm’s 50th Anniversary celebration in September 2006

Organic Beef Cattle Grazing Demonstration

There is growing interest in grass-fed organic beef. The objective of this study was to compare the performance of conventional feedlot-based cattle finishing with organic beef cattle finishing