D.A. Blasi

Effect of oral meloxicam on health and performance of beef steers relative to bulls castrated on arrival at the feedlot.

Castration in weaned calves is stressful and affects profitability by reducing ADG and increasing susceptibility to disease. This study evaluated the effect of meloxicam, a nonsteroidal anti-inflammatory drug (NSAID), on performance and health of calves received as steers compared with bull calves surgically castrated on arrival at the feedlot. British × Continental bulls (n = 145) and steers (n = 113; BW = 193 to 285 kg) were transported for 12 h in 3 truckloads (d 0), weighed, and randomly assigned to receive either lactose placebo (CONT; 1 mg/kg) or meloxicam (MEL; 1 mg/kg) suspended in water and administered per os, 24 h before castration. On d 1, bulls were surgically castrated (CAST) and steers were processed without castration (STR). Combinations of CONT/MEL and CAST/STR were allocated to 24 pens (6 pens per treatment) of 8 to 14 calves each. Pen was the experimental unit. Plasma meloxicam concentrations at the time of castration (d 1) were determined by HPLC-mass spectroscopy. Pen-level ADG, DMI, and G:F were estimated using BW obtained on d 0, 14, and 28 and weigh-back of feed. Individual animals were classified as sick based on a depression score of ≥2 on a 5-point scale and a rectal temperature of ≥39.8°C. On d 0, 1, and 14, calf chute temperament was evaluated using a 4-point scale. Data were analyzed using generalized linear mixed models and survival curve analyses. Castration reduced pen ADG (P < 0.001) and G:F (P < 0.001) from d 1 to 14, yet no effects (P > 0.45) were apparent by d 28. For all treatment groups, DMI increased with days on feed (P < 0.0001) but was less in CAST compared with STR calves (P < 0.016) throughout the study. From d 15 to 28, ADG increased (P = 0.0011) in CAST but not STR calves, and G:F decreased (P = 0.0004) in STR but not CAST calves. In CAST calves only, MEL treatment reduced the pen-level first pull rate (P = 0.04) and reduced bovine respiratory disease morbidity rate (P = 0.03). The frequency of chute escape behavior was greater on arrival and at castration in CAST vs. STR calves (P < 0.01) but not significantly different at d 14 (P = 0.22). Mean MEL concentrations at castration were no different between treated STR and CAST calves (P = 0.70). Meloxicam administration before castration in postweaning calves reduced the incidence of respiratory disease at the feedlot. These findings have implications for developing NSAID protocols for use in calves at castration with respect to addressing animal health and welfare concerns.

CASE STUDY: Preconditioning Beef Calves: Are Expected Premiums Sufficient to Justify the Practice?

The concept of preconditioning calves has been around for a long time, yet adoption of the practice has been slow. Current trends in the beef industry likely will increase interest in preconditioning programs. This research estimates premiums received for preconditioned calves and the expected returns from a preconditioning program. Preconditioned calves sold in the fall received a premium of approximately

Source of dietary lipid may modify the immune response in stressed feeder cattle.

4.50-

Associations of beef calf wellness and body weight gain with internal location in a truck during transportation.

5.50/cwt relative to non-preconditioned calves. Premiums were lower for calves sold in the winter, heavier calves, and when cattle markets were strong. Based on a 45-day post-weaning preconditioning program, cow-calf producers can increase returns about

Castration and morbidity and their effects on performance, carcass quality, and price differentials for bulls and steers

14/head compared to selling calves at weaning.

Effects of corn processing and dietary wet corn gluten feed inclusion on performance and digestion of newly received growing cattle

Five studies were conducted to evaluate the effects of lipid source on performance and health of stressed feeder cattle. A total of 332 heifers (195 +/- 2.37 kg initial BW) in trial 1 and 336 heifers (206 +/- 1.70 kg initial BW) in trial 2 were fed diets containing ground flaxseed (FLAX), rolled full-fat soybeans (SOY), or tallow (TAL) at 13, 20, or 4%, respectively (DM basis). All diets were formulated to be isonitrogenous and isocaloric. The ADG and G:F for the first 7 d and for the entire feeding period were greater (P < 0.05) for TAL and FLAX than for SOY. Percentage of animals treated and retreated for bovine respiratory disease did not differ among dietary treatments. The FLAX treatment increased (P < 0.05) total n-3 PUFA concentrations in the plasma, whereas SOY increased (P < 0.05) plasma concentrations of total n-6 PUFA. In trial 3, 18 steers were individually fed diets containing TAL and 18 steers were fed a diet containing SOY (20% of DM). In trials 4 and 5, 18 steers were individually fed diets containing TAL and 18 steers were fed diets containing FLAX (12.9% of DM). On d 14 and 17 of study 3, 4, and 5, 16 steers from each dietary treatment were injected i.v. with Escherichia coli O55:B5 lipopolysaccharide (LPS), and 2 steers from each diet were injected with saline. Rectal temperatures after LPS challenge were lower (P < 0.05) for SOY and FLAX than for TAL, and plasma TNF was greater (P < 0.05) for SOY than for TAL. Serum haptoglobin and blood fibrinogen increased and white blood cell count decreased in response to LPS, but none of these variables was affected by treatment. Although this research failed to measure an effect of lipid source on feedlot morbidity or mortality, these studies indicate that altering the source and type of dietary fatty acids may modify the immune response in stressed feeder cattle and that performance may be hindered by feeding full-fat soybeans to receiving cattle.

A field study evaluating health, performance, and behavior differences in crossbred beef calves administered different vaccine-parasiticide product combinations.

Cattle transportation by commercial truck carrier is common in the United States, and often cattle are placed within 1 of 8 potential compartments within the truck for the journey. The objective of this research was to determine potential associations between animal wellness (as measured by ADG and health outcomes) during a relatively short backgrounding phase (46.6 +/- 8.5 d) and location within the truck during transit. Data from 21 loads (average calves per load = 101.5; average BW = 210.1 +/- 19.4 kg) were included in the analysis. For each shipment, calves were divided among 8 compartments within the trailer: nose on top deck (NOT), nose on bottom deck (NOB), bottom deck middle forward (BDF), bottom deck middle rear (BDR), rear on the bottom (ROB), top deck middle forward (TDF), top deck middle rear (TDR), and rear on the top deck (ROT). General logistic (health outcomes) and mixed (ADG) models were employed to analyze the data accounting for effects due to truck section as well as the hierarchical data structure of multiple arrival times, loads, and pens. Cattle in the ROT section had less short-term BW gains compared with NOT and tended (P < 0.10) to be less than NOB. Cattle in the forward sections (NOT, NOB) were less (P = 0.02) likely [odds ratio (OR): 0.67, 95% confidence limits (CL): 0.50, 0.94] to be treated at least once compared with cattle in the middle sections (TDF, TDR, TOP, BDF, BDR, BOT). Calves in compartments with 15 head or less tended (P < 0.10) to have reduced odds of being treated compared with cattle in compartments with 16 to 30 head (OR: 0.79, 95% CL: 0.60, 1.0) or greater than 31 head (OR: 0.73, 95% CL: 0.53, 1.0). Our current project reveals that the location within the truck may affect calf health and performance.

Read distance performance and variation of 5 low-frequency radio frequency identification panel transceiver manufacturers.

When purchasing feeder calves, bulls are typically discounted relative to steers. Determining the appropriate discount is difficult. Being able to calculate this discount under varying conditions would help stocker operators maintain a greater level of profitability or recognize opportunities to make more profit when excessive discounts are being applied. The objectives of this study were to determine how castration timing affects performance, morbidity, and carcass quality and how morbidity affects performance and carcass quality. Ordinary least squares and logit models were estimated to quantify the effects of various management and environmental factors on performance, morbidity, and carcass quality. These estimates were used to calculate price discounts for bulls relative to steers, for both a short backgrounding period and when ownership is retained until slaughter. Results confirm that late-castrated bulls exhibit diminished performance and increased morbidity probabilities relative to early-castrated bulls. Increased morbidity also decreases ADG. However, castration timing and morbidity during the backgrounding period have minimal effects on carcass quality, with morbidity only affecting hot carcass weight, whereas castration timing only affects days to market and hot carcass weight. Based on 2009 market conditions, bulls should be discounted at feeder calf sales compared with steers. The average calf arrived at 209 kg. At this BW, bulls should be discounted (P < 0.01)

Serum Steroid Concentrations at Different Phases of Production and Brain Monoamine Oxidase Type A Messenger Ribonucleic Acid in Buller Steers1

0.11/ kg relative to the same BW steers. The discount increases (P < 0.01) to

Effects of dietary energy level and intake of corn by-product-based diets on newly received growing cattle: antibody production, acute phase protein response, stress, and immunocompetency of healthy and morbid animals.

0.12/ kg for 170-kg calves and decreases (P < 0.01) to