Feedlot Bulls and Steers Treated With Diethylstilbestrol and Zeranol

This experiment is one of a series to study effects of castration, growth stimulating compounds and various feeding and management systems on performance and carcass characteristics of feedlot male and female cattle. It involved a comparison of bulls with steers and their response to diethylstilbestrol or zeranol (a resorcyclic acid lactone compound shown to have growth stimulating properties) implants when fed high-concentrate diets

Reactions of Reduced Glutathione with Some Methylated Selenium Compounds

Selenium biochemistry has been of general interest since the discovery of selenium as the toxic agent in certain plants, which when ingested by animals causes a definite disease syndrome and even death. Early scientists suggested that the logical place in the body for toxic selenium compounds to attack was at the various sites occupied by sulfur. In 1939 a study was published which indicated that reduced glutathione (GSH), a thiol, protected rats against death from a minimum fatal dose of selenium given as sodium selenite. Since this discovery, the reaction of GSH with various selenium containing compounds has been the subject of much research. Improved technology has led to new insights about the reaction of GSH with selenium compounds. This, coupled with recent advances in metabolite and toxicity studies, has led to the proposal of a pathway for the metabolism of selenium which involves the reaction of GSH with several methylated selenium compounds. The studies reported here have been done in an attempt to investigate those proposed reactions. Specifically, the reactions under investigation are: 1) The reaction of GSH with methylseleninic acid (CH3SeO2H), 2) The reaction of GSH with dimethyl diselenide (CH3SeSeCH3), 3) The reaction of GSH with dimethyl selenoxideCH3)2SeO]

Take an Accurate Forage Sample

Successful livestock production depends largely on the feeding program; and what you should feed depends on an accurate analysis of the forage portion of your ration. The accuracy of forage analysis depends on the sample that you send to the lab. Samples must be representative of the feeds being fed. Poor sampling will result in misleading values, higher feed costs, and reduced performance. In many feeding programs, the sample is the weak link. The results of the lab tests will be useful only if the sample accurately represents what your animals will be eating. Keep in mind that every field and every cutting will be different

Growing and Fishing Bulls, Heifers and Steers

Growth rate of an animal depends upon energy consumed in excess of that for maintenance, and the requirements increase as the animal grows and fattens. Male and female cattle differ in rates of growth and fattening, but changes may be brought about by castration. There still is some concern as to the effects of market weight and energy content of rations on weight gain, feed efficiency and carcass characteristics of feedlot bulls, heifers and steers. This experiment was conducted to study these factors. Bulls ( calves and yearlings), heifers and steers were fed to one of two final weight groups. Rations with about 50% or 9 0 % concentrates were used for each weight and sex group. This report is concerned with the feedlot performance data. Results of the study on carcass data are presented in another report (A.S. Series 73-37)

How to Evaluate a Forage Testing Laboratory

Can you be sure that the results that come back from your forage testing lab are accurate? To help you evaluate your lab, ask the questions in this publication. Accurate laboratory analysis requires an organized, plan in the laboratory and properly trained technicians to assure quality data. Concern over laboratory accuracy and repeatability is frequently focused on results generated by near infrared reflectance spectroscopy (NIRS). However, NIRS is just one of the methods used by laboratories to test forage samples for nutrient levels. Your concern as a user of laboratory analysis is not in the type of method used but in the accuracy of the information you receive. Answers to these questions will reveal if your laboratory is following proper quality control procedures

Interpretation of Water Analysis for Livestock Suitability

This article contains a summary that analyzes the purpose of water for livestock suitability

Feedlot Performance of Bulls and the Response to Diethylstilbestrol or Zeranol

The objective of this experiment was to determine the response by feedlot bulls to DES and zeranol when administered at a younger age (about 10 months) and a lighter weight (about 500 lb.)

Performance of Calves Fed Chlortetracycline-Sulfamethazine During Feedlot Adaptation Followed by Chlortetracycline

This experiment was conducted to determine the effects of supplementing calves with a chlortetracycline-sulfamethazine combination for 4 weeks following weaning. Chlortetracycline was then fed at 70 mg. daily during a growing phase when the calves were fed a high-roughage diet

Interpretation of Water Analysis for Livestock Suitability

Good quality water is essential for the production of livestock and poultry. In South Dakota, many water supplies have naturally occurring al that may limit their use. Livestock producers that test their water supply can make informed decisions about the stability of their water for different classes of livestock. The purpose of this guide is to assist livestock producers in the interpretation of their water analysis

Diethylstilbestrol, Melengestrol Acetate and Zeranol During Growing and Finishing of Feedlot Heifers

Hormone and hormone-like compounds are commonly used for feedlot heifers. Effects on feedlot performance and carcass characteristics appear to vary depending on compounds used, levels administered including frequency of implanting, stage of growth and fattening, and dietary conditions. This experiment was one in a series to study the effects of melengestrol acetate (MGA) and implants of diethylstilbestrol (DES) or zeranol administered to heifers during growing and finishing or during finishing only