Squaric esters as peptide stapling reagents.

We report that squaric esters can serve as bifunctional reagents for selective peptide stapling reactions. Formation of the squaric amide staple occurs under mild conditions with amine-containing side chains. We show that short resin-bound peptides are readily stapled on solid phase and that stapling can occur at various relative positions along the peptide and with various amine tether lengths (e.

Effect of rotating monensin plus tylosin and lasalocid on performance, ruminal fermentation, and site and extent of digestion in feedlot cattle.

Two trials were conducted to evaluate the effects of ionophore rotation programs on performance and digestion by feedlot cattle. A 90% concentrate diet was fed with treatments of no ionophore (C), 33 mg lasalocid/kg diet daily (L), 29 mg monensin plus 11 mg tylosin/kg diet daily (MT), and daily (D) and weekly (W) rotation of L and MT. In Trial 1, feedlot performance of 200 crossbred steers (average initial BW 296 kg) was evaluated during a 133-d period.

Nutrition and management of stressed beef calves. An update.

In an earlier report in the Veterinary Clinics: Large Animal Practice, the author discussed some basic principles upon which receiving programs for stressed calves should be based. Additional information has been developed in some of the areas covered in that report and in certain other areas. It is the purpose of this article to discuss some of this new information, after a brief review of the basics.

Effects of receiving and growing diets on compensatory gains of stressed calves.

Three hundred seventy-seven male stocker calves were used to study the effects of three receiving diets, two growing-finishing diets and two levels of shipping shrink on compensatory gains during the post-receiving feeding period. Calves received on a 75% concentrate diet gained 19 kg more during the first 42 d than those received on hay plus .91 kg daily of protein supplement (P less than .

Influence of steam-flaked, steamed-whole or whole shelled corn on performance and digestion in beef steers.

Three trials were conducted to evaluate finishing diets containing 67% steam-flaked corn (SFC), steamed-whole corn (SWC) or whole corn (WC). In a feeding trial, steers fed SWC consumed more (P less than .05) dry matter per day (7.

Mass medication in reducing shipping fever-bovine respiratory disease complex in highly stressed calves.

One thousand and eighty-five newly received, stressed calves were used in studies to determine the effectiveness of certain mass medication procedures for reducing morbidity from shipping fever-bovine respiratory disease complex. In two experiments, im injections of oxytetracycline at 11 mg/kg body wt for 3 successive days reduced treatment days/calf purchased 21 (P less then .05) and 31% (P less than .

Millet and alfalfa hays alone and in combination with high-energy diet for receiving stressed calves.

Calves subjected to stresses of weaning, marketing, shipping and processing ate more feed, gained more weight and gained more efficiently when fed a 75% concentrate receiving diet, alone or with free choice hay, than when fed hay alone (P less than .01). Diets with greater bulk or lower energy densities did not promote higher feed intake in these stressed calves, as would be the case in unstressed animals.

Effects of dietary energy, free choice alfalfa hay and mass medication on calves subjected to marketing and shipping stresses.

Five-hundred and fourteen calves subjected to the stresses of marketing and shipping from Florida to New Mexico were used to study performance after arrival at the feedlot. Flaked milo diets containing 50 and 75% concentrates promoted more rapid recovery of purchase weight and more efficient gains than a diet containing 25% concentrates. Free-choice alfalfa hay with the flaked milo diets reduced death loss, number of calves requiring medication and number of treatments per medicated calf.

Metabolic and cellular profile testing in calves uncer feedlot conditions: blood cellular components--reference values and changes over time in feedlot.

The cellular components of the blood of 114 calves were measured under feedlot conditions. The results suggest that certain cellular components of the blood of a group of crossbred feedlot-type calves which are homogeneous only with regard to weight are reasonably uniform. More specifically, all red blood cell components have coefficients of variation of less than 10%.

Metabolic and cellular profile testing in calves under feedlot conditions: minerals, electrolytes and biochemical components--changes over time in feedlot.

The concentration of 19 mineral, electrolyte, and biochemical components in blood serum of 114 calves under feedlot conditions were measured or calculated over a 58-day period (2 days before and 56 days during a feed trail). The purpose was to evaluate the variability in the concentration of these components over time. The blood was collected on 7 sampling dates and analyzed on the day following sampling.

Metabolic and cellular profile testing in calves under feedlot conditions: minerals, electrolytes, and biochemical components--reference values.

Blood serum samples were obtained from 114 crossbred calves on a feed trial under feedlot conditions at the end of a 56-day feeding period. Average values for 19 blood components were determined. The effects of the 3 trial rations and 2 electrolyte treatments were analyzed.