Effect of growth implant regimen on health, performance, and immunity of high-risk, newly received stocker cattle.

Growth implant efficacy may be affected when administered to nutritionally stressed calves, whereas the procedure may alter health or the humoral immune response to respiratory vaccination. The study objective was to determine the effect of different administration times (d 0, 14, or 28) of a growth implant containing 200 mg progesterone and 20 mg estradiol benzoate on health, performance, and metabolic and immunologic variables in high-risk, newly received beef calves used in a 120-d receiving/grazing stocker system. Crossbred bull and steer calves ( = 203) were weighed (initial BW = 203 ± 2.7 kg), stratified by castrate status on arrival, and randomly assigned to experimental treatments consisting of 1) negative control (no growth implant administered), 2) growth implant administered on d 0, 3) growth implant administered on d 14, and 4) growth implant administered on d 28. There were no differences ( ≥ 0.16) in BW or ADG during the 42-d receiving period. However, ADG during the subsequent grazing period and overall was greater ( ≤ 0.01) for implanted calves versus the negative control. Growth implant timing did not affect the rate of clinical bovine respiratory disease morbidity ( = 0.52; 94% morbidity overall) or bovine viral diarrhea virus type 1a antibody titer concentration ( = 0.61). Indicative of an overall negative energy balance on arrival, NEFA decreased sharply subsequent to d 0 (day effect, < 0.001), but was not affected ( = 0.47) by the timing of growth implantation. Blood urea N concentrations increased transiently (day effect, < 0.001); however, no treatment effect was observed ( = 0.72). Therefore, under conditions of this study, the timing of growth implant administration did not affect growth implant efficacy, health, or metabolic or immunologic variables in newly received, high-risk beef stocker calves. Overall, our observations suggest that there is not a clear benefit to delaying growth implantation and that a growth implant does not affect health or vaccine response in newly received beef calves.

Effect of surgical castration with or without oral meloxicam on the acute inflammatory response in yearling beef bulls.

Pain management and welfare are increasingly prevalent concerns within animal agriculture. Analgesics may alleviate pain and inflammation associated with castration of beef cattle. This study was conducted to elucidate the effects of surgical castration on the acute inflammatory response and immunomodulation and whether concurrent oral administration of meloxicam (1 mg/kg BW) would alter these responses. On d -1, crossbred bull calves ( = 30; initial BW = 227.4 ± 10.3 kg) were fitted with indwelling jugular catheters and rectal temperature (RT) recording devices, placed into individual stanchions, and randomly assigned to 1 of 3 treatments. Treatment application occurred at h 0 and consisted of 1) intact bull calves treated with sham castration (CON), 2) bulls surgically castrated without meloxicam administration (CAS), and 3) bulls surgically castrated with oral meloxicam (1 mg/kg BW) administration (MEL). Blood samples were collected at 0.5-h intervals from h -2 to 4, 1.0-h intervals from h 4 to 8, and 12-h intervals from h 12 to 72. Serum was analyzed for cortisol and haptoglobin (Hp) concentrations using ELISA. Whole blood was analyzed for complete blood counts at -2, 0, 2, 4, 6, 8, 12, 24, 36, 48, 60, and 72 h, and RT was recorded in 5-min intervals. Postcastration RT was greatest for MEL (39.04), intermediate for CAS (38.99), and least for CON (38.93°C; ≤ 0.01). Serum cortisol was increased ( < 0.001) for CAS (12.3) and MEL (11.3) compared with CON (6.7 ng/mL) during the postcastration period. At 0.5 and 1.5 h, cortisol concentration was greater in CAS and MEL than CON, whereas at 2 and 2.5 h, cortisol concentration was greatest for CAS, intermediate for MEL, and least for CON (treatment × time, < 0.001). Total white blood cell ( ≤ 0.04), lymphocyte ( ≤ 0.02), and monocyte ( ≤ 0.002) counts were greatest for CAS, intermediate for MEL, and least for CON. Administration of MEL reduced ( ≤ 0.002) eosinophil counts during the postcastration period when compared with CON and CAS. The change in serum Hp, relative to baseline values, was reduced for MEL at 36 ( < 0.01) and 60 h ( ≤ 0.03), and the overall Hp concentration was least for MEL ( < 0.001). Oral administration of meloxicam at the time of castration reduced the acute inflammatory response in castrates, as evidenced by a reduction in Hp and certain leukocyte concentrations; it also caused a delayed increase in RT. Further research is needed to determine if this reduced acute inflammatory response would equate to improved health and/or performance after castration.

Performance by spring and fall-calving cows grazing with full, limited, or no access to toxic Neotyphodium coenophialum-infected tall fescue.

Replacing toxic, wild-type Neotyphodium coenophialum-infected tall fescue (E+) with nontoxic, N. coenophialum-infected tall fescue (NE+) has improved cow performance, but producer acceptance of NE+ has been slow. The objective was to compare performance by spring- and fall-calving cows grazing either E+ or NE+ at different percentages of the total pasture area. Gelbvieh×Angus crossbred cows (n=178) were stratified by BW and age within calving season and allocated randomly to 1 of 14 groups representing 5 treatments for a 3-yr study: i) Fall-calving on 100% E+ (F100); ii) Spring-calving on 100% E+ (S100); iii) Fall-calving on 75% E+ and 25% NE+ (F75); iv) Spring-calving on 75% E+ and 25% NE+ (S75); and v) Spring-calving on 100% NE+ (SNE100). Groups allocated to F75 and S75 grazed E+ until approximately 28 d before breeding and weaning, then were then moved to their respective NE+ pasture area for 4 to 6 wk; those allocated to F100, S100, and SNE100 grazed their pastures throughout the entire year. Samples of tall fescue were gathered from specific cells within each pasture at the time cows were moved into that particular cell (∼1 sample/mo). Blood samples were collected from the cows at the start and end of the breeding season. Stocking rate for each treatment was 1 cow/ha. Forage IVDMD, CP, and total ergot alkaloid concentrations were affected (P<0.05) by the treatment×sampling date interaction. Hay offered, cow BW, and BCS at breeding, end of breeding, and at weaning were greater (P<0.05) from fall-calving vs. spring-calving. Cow BW at weaning was greater (P<0.05) from F75 and S75 vs. F100 and S100. The calving season×NE+ % interaction affected (P<0.05) calving rates. Preweaning calf BW gain, actual and adjusted weaning BW, ADG, sale price, and calf value at weaning were greater (P<0.05) from fall-calving vs. spring-calving and from SNE100 vs. S75 except for sale price which was greater (P<0.05) from S75 vs. SNE100. Cow concentrations of serum prolactin at breeding and serum NEFA at the end of breeding were affected (P<0.05) by the calving season×NE+ % interaction. Serum Zn and Cu concentrations from cows were affected (P<0.05) by calving season. A fall-calving season may be more desirable for cows grazing E+, resulting in greater calving rates, cow performance, and calf BW at weaning, whereas limited access to NE+ may increase calving rates, serum prolactin, and NEFA concentrations during certain times in the production cycle, particularly in spring-calving cows.

Effects of establishment method and fall stocking rate of wheat pasture on forage mass, forage chemical composition, and performance of growing steers.

Stocking rate is a fundamental variable for managing pastures, and there is a distinct relationship between stocking rate and animal performance for each forage type. This research was conducted to determine the effects of fall stocking rate (SR) and method of establishment of wheat pasture planted into dedicated crop fields on animal performance during the fall and subsequent spring. There was a factorial arrangement of tillage methods used in the establishment of wheat pasture and fall stocking rates. Tillage treatments included 1) CT, seed sown into a prepared seedbed, 2) RT, a single pass with a light disk followed by broadcasting of seed, or 3) NT, direct seeding into the undisturbed stubble of the grazed-out wheat pasture from the previous year. The fixed SR during the fall were 1.9, 2.5, and 3.7 growing beef steers (Bos taurus L.)/ha. In the spring all pastures were grazed at the same fixed SR by steers for graze out. Data were analyzed using the mixed procedure of SAS as a randomized complete block design with field as the experimental unit and year as the block. Forage mass, forage nutritive composition, and animal performance during the fall or spring were not affected (P ≥ 0.14) by tillage method. During the fall grazing season, with increasing SR there were linear (P < 0.01) decreases in BW of steers upon removal from pasture, BW gain per steer, and ADG, whereas grazing-day per hectare and BW gain per hectare increased linearly (P < 0.01) with increasing SR. The carryover effects of fall SR into the spring grazing season decreased (P< 0.01) grazing-day per hectare and tended (P ≤ 0.09) to produce quadratic changes in BW upon removal from pasture and BW gain per hectare. Across the fall and spring grazing seasons, grazing-day per hectare increased linearly (P < 0.01) with greater SR, and BW gain per hectare increased quadratically (P = 0.02) with increased fall SR. A tillage treatment by fall SR interaction (P = 0.10) indicates that although there was no difference (P ≥ 0.12) due to tillage treatment in BW gain per hectare at 1.9 or 2.5 SR, NT fields produced (P ≤ 0.04) more BW gain per hectare than CT or RT at the 3.7 SR. Although increasing SR of growing steers leads to reduced animal performance in the fall and reduced carrying capacity in the spring, NT appears to be capable of withstanding greater fall SR with less impact on total production per hectare than CT or RT.

Animal performance and economic comparison of novel and toxic endophyte tall fescues to cool-season annuals.

Increased costs of annual establishment of small grain pasture associated with fuel, machinery, and labor are eroding the profitability of stocker cattle enterprises. Interest has therefore increased in development of cool-season perennial grasses that are persistent and high quality. This study occurred on 24 ha (divided into thirty 0.81-ha paddocks) located at the University of Arkansas Division of Agriculture Livestock and Forestry Branch Station, near Batesville. Two tall fescue (Festuca arundinacea Schreb.) cultivars infected with novel endophytes (NE), Jesup infected with AR542 endophyte (Jesup AR542), and HiMag infected with Number 11 endophyte (HM11) were established in September 2002. Jesup AR542 and HM11 were compared with endemic endophyte Kentucky 31 (KY-31) tall fescue; wheat (Triticum aestivum L.) and cereal rye (WR, Secale cereale L.) planted in September 2003, 2004, and 2005; and annual ryegrass [RG, Lolium perenne L. ssp. multiflorum (Lam.) Husnot] planted in September 2004 and 2005. Each year, 3 steers (3.7 steers/ha) were placed on each pasture for fall and winter grazing, and 5 steers (6.2 steers/ha) were placed on each pasture for spring grazing. Animal performance is presented by year in the presence of a year x treatment interaction (P < 0.01). Body weight gain per hectare of steers grazing NE tall fescue was greater (P < 0.01) than those of KY-31 and WR during 2003 to 2004, whereas in 2004 to 2005, BW gain per hectare of steers grazing NE and RG did not differ (P < or = 0.29) and was greater (P < 0.01) than that of WR, which was greater (P < 0.01) than that of KY-31. During 2005 to 2006, BW gain per hectare was greater (P < 0.01) for steers grazing RG than those of NE and WR, which did not differ (P > or = 0.14). Body weight gain per hectare was least (P < 0.01) for steers grazing KY-31. Average net return of NE tall fescue was greater (P < 0.01) than KY-31, but profitability of NE did not consistently differ from cool-season annuals. Across the 3-yr study, NE tall fescue produced net returns per hectare of $219; this level of profitability would require 4 yr for a new planting of NE tall fescue to break even. Novel endophyte tall fescues offer potential benefits related to decreased risk of stand establishment of annual forage crops, longer growing season, and acceptable animal performance.

Effects of on-arrival versus delayed modified live virus vaccination on health, performance, and serum infectious bovine rhinotracheitis titers of newly received beef calves.

Stress commonly associated with weaning, marketing, and shipment of feeder cattle can temporarily compromise immune function, thereby reducing the effective response to vaccination intended to control bovine respiratory disease (BRD). Two vaccination timing treatments were used to evaluate the effect of timing of a multivalent modified live virus (MLV) BRD vaccine on health, performance, and infectious bovine rhinotracheitis (IBR) antibody titers of newly received stocker cattle. Crossbred bull and steer calves (n = 528) were weighed (197 +/- 2.4 kg) and randomly assigned to MLV vaccination treatment: 1) MLV vaccination upon arrival (AMLV), or 2) delayed (14 d) MLV vaccination (DMLV). All cattle were processed similarly according to routine procedures, with the exception of the initial MLV vaccination timing. Subsequently, BW were recorded on d 14, 28, and 42. Blood samples were collected on d 0, 14, 28, and 42 to determine serum IBR titers, and comparisons were made between treatments on a receiving-day basis and an equivalent postvaccination day basis. Daily BW gains were greater (P < or = 0.05) for DMLV calves from d 0 to 14 (1.16 vs. 0.88 +/- 0.22 kg/d) and from d 0 to 42 (0.75 vs. 0.65 +/- 0.09 kg/d). Days to first treatment, total treatment cost, percentage death loss, and pasture ADG after the 42-d receiving period did not differ (P > or = 0.15). Morbidity rates for BRD were high for both AMLV and DMLV (71.5 and 63.5%, respectively) and did not differ (P = 0.12). Positive IBR titer seroconversion was greater (P < or = 0.03) for DMLV calves on d 42 of the study, and for the 28- and 42-d equivalent postvaccination basis. Delaying vaccination by 14 d may increase ADG during the receiving period compared with AMLV, and seroconversion to IBR was greater in DMLV calves, indicating a possible improvement in acquired immune response when MLV vaccination is delayed.

Effect of rotation frequency and weaning date on forage measurements and growth performance by cows and calves grazing endophyte-infected tall fescue pastures overseeded with crabgrass and legumes.

A grazing study was initiated in April 2000 and continued through three calving and weaning cycles (ending July 2003) to investigate the effects of rotational grazing management (twice monthly [2M] vs. twice weekly [2W]) and weaning date (mid-April [EARLY] vs. early June [LATE]) on production of fall-calving cow-calf pairs (495 +/- 9.6 kg initial BW) grazing Neotyphodium coenophialum-infected tall fescue (Festuca arundinacea Schreb.) overseeded with legumes and crabgrass. Secondary objectives of the experiment were to monitor differences in quantity and quality of available forage and to evaluate changes in forage species composition. Pastures were dominated by tall fescue throughout the study, and the proportion of basal cover was greater (P < 0.05) in 2M than in 2W pastures. The percentage of legumes was very low across all treatment combinations, but the percentage of crabgrass continued to increase (P < 0.05) linearly and quadratically across years for both summer and fall sampling periods, regardless of rotation or weaning program. In vitro DM disappearance and mineral concentrations varied minimally because of rotation frequency or weaning date. Rotation frequency did not substantially affect (P = 0.11 to 0.97) cow BW, hay offered, milk production, calving interval, calf birth weight, or actual or adjusted weaning weights; however, 2M cows had 0.3 units higher (P < 0.05) BCS at the time of breeding than 2W cows. Calves weaned late had greater (P < 0.05) actual weaning weight and weighed more (P < 0.05) on the LATE weaning date than on the EARLY weaning date, but 205-d adjusted weaning weights did not differ (P = 0.74) across weaning dates. Therefore, rotation frequency and/or weaning date had little effect on forage species composition or forage quality. In addition, the rapid rotation program offered little advantage with respect to animal performance, and weaning fall-born calves grazing endophyte-infected tall fescue pastures at approximately 189 d of age seemed to be detrimental to calf performance compared with delaying weaning until 243 d of age.

Teaching gross anatomy using living tissue.

Embalmed cadaver tissues and organs that are dissected in gross anatomy laboratories lack many characteristics of fresh or living tissues. The purpose of this study was to assess the educational value of allowing first-year medical students to experience first-hand the color, texture, delicacy and other qualities of living porcine tissues and organs that are similar to those of human tissues. Guided by a laboratory protocol, medical students palpated and inspected organs of the opened thorax, abdomen and pelvis of anesthetized pigs on pulmonary ventilators. The learning experience was rated highly by the students as well as by the participating faculty. A further review of the medical students' later experiences at autopsies and in surgical clerkships showed that the living-tissue experience in their gross anatomy course represented a large part of their medical school exposure to unembalmed tissues.

Effect of maturity on degradation kinetics of sod-seeded cereal grain forage grown in northern Arkansas.

Wheat (Triticum aestivum L.), oat (Avena sativa L.), and rye (Secale cereale L.) were overseeded into a dormant bermudagrass (Cynodon dactylon (L.) Pers.) sod and harvested at 3-wk intervals throughout March, April, May, and early June. Plant growth stage was documented for each forage on each harvest date, and harvested forages were evaluated for forage quality characteristics. Degradation kinetics of DM and NDF for these forages were evaluated by the in situ method. Fractional degradation rates for DM and NDF in all three species were relatively rapid for vegetative forage (> or =0.086 h(-1)) but declined rapidly by the heading stage of development and stabilized thereafter. Forage quality declined and forages were more resistant to ruminal degradation as plants entered the reproductive stages of growth. Based on these findings, growth stage is an effective predictor of most characteristics of in situ DM and NDF disappearance. The relationships between these degradation parameters and growth stage were typically explained with quadratic or cubic models. Clearly, forage quality characteristics of overseeded rye deteriorated more rapidly with phenological development and growth stage than quality characteristics of overseeded wheat and oat grown in the same environment. For rye, this problem is further complicated by its accelerated phenological development. These factors combine to permit a very narrow harvest window in early spring, relative to the other cereal grains evaluated. Acceptable forage quality may persist for an extended period in wheat and oat; this suggests that producers wishing to utilize these forages may lengthen the harvest window by planting more than one species, either as a mixture or preferably in independent stands.

Intraoperative gamma probe-directed biopsy of asymptomatic suspected bone metastases.

BACKGROUND: Radioisotope bone scanning is frequently used in staging malignancies. However, false-positive results are common, and biopsy is usually required. In the absence of plain radiographic abnormalities or local symptoms, localization of the area of abnormal tracer activity at the time of open rib or sternum biopsy may be difficult. It often requires resection of a large portion of one or more ribs or the sternum to assure that biopsy of the target area was performed. In this setting, a small gamma probe underwent evaluation as an aid to precise intraoperative localization of increased tracer activity in the target bone. METHODS: Ten patients with asymptomatic suspected osseous chest metastases by radioisotope bone scanning but with normal plain radiographs underwent open biopsy of 13 ribs and 1 sternum. Six to 12 hours before operation, each received an intravenous injection of 28 mCi of technetium-99m oxidronate. The hand-held, pencil-sized gamma probe in a sterile sleeve was used to localize the area of greatest activity in the target bone, once the bone was exposed through a small incision. Biopsy of a 3-cm length of rib or portion of sternum was performed. In the first two rib biopsies, an intraoperative radiograph with a radiopaque marker on the rib confirmed that the correct rib was selected for biopsy. Intraoperative radiographs were not done on later cases. RESULTS: The mean ratio of hot spot activity on the targeted rib to background counts on adjacent ribs was 1.65 +/- 0.22 (range, 1.35 to 2.05), and the difference was easily discernible intraoperatively. The ratio of hot spot activity on the sternum was somewhat lower (1.22), but the target area was still easy to detect. An abnormal diagnosis to account for the increased tracer activity was found in each of the 13 ribs and 1 sternal biopsy in all 10 patients: metastatic squamous cell carcinoma (1 rib), metastatic prostatic adenocarcinoma (1 rib), lymphoma (2 ribs), localized hypercellular marrow (1 rib), medullary fibrosis/Paget's disease of the bone (2 ribs), localized fibrosis/granulation tissue (1 rib), enchondroma (3 ribs), and chondroma (2 ribs, 1 sternum). The difference in background counts to hot spot activity was best with injection of the tracer 6 hours before operation. CONCLUSIONS: The intraoperative use of gamma counting is an easy, highly accurate aid (100% sensitivity) to localize areas of abnormal radioisotope uptake in suspected asymptomatic rib and sternal metastases. Use of this technique obviates the need to obtain intraoperative localizing radiographs to confirm accurate rib identification, thereby decreasing operative time.

Clinical anatomy instruction in the operating room.

Instruction in regional gross anatomy is facilitated by a series of illustrations projected in the operating room and viewed sequentially during major operations. This teaching method is described, and the evaluations by the medical students confirm the efficacy of the method.

Costal osteomyelitis after pectoralis major myocutaneous flap use in head and neck reconstruction.

Costal osteomyelitis and chondritis are rare complications of PMMF usage. They probably represent a secondary complication of a donor-site infection. This diagnosis must be considered in cases of PMMF donor-site infections, which fail to resolve with local wound care and antibiotics. Antibiotic coverage in these cases should be taylored to culture results, while having broad gram-positive activity. Workup of these patients should include CT and biopsy to rule out a neoplastic process.

Thoracoscopic lung biopsy.

Progress in instrumentation and techniques developed for laparoscopic surgery have paved the way for a resurgent interest in thoracoscopic procedures. Traditional thoracoscopy was limited by access, restricted visualization, and surgical devices. Recent cases provided an opportunity to successfully perform thoracoscopic pulmonary wedge excisions using state-of-the-art technology and instruments adapted from laparoscopy. These preliminary cases provided an opportunity to modify and adapt these techniques to thoracic procedures. Video thoracoscopy is rapidly evolving in both methods and instrumentation.

Digestion and performance responses to lasalocid and concentrate supplements by beef cattle fed bermudagrass hay.

Beef cattle consuming bermudagrass hay were not supplemented or received a limited amount of ground corn alone or with a mix of protein meals to determine influences of concentrate supplementation on digestion and performance when the ionophore lasalocid (200 mg daily) was given. With limited feed intake, supplement treatment did not change the acetate to propionate shift in beef cows occurring with lasalocid (P < 0.06). Lasalocid did not affect sites of digestion of organic matter or nitrogen with any supplement treatment. However, lasalocid decreased (P < 0.10) ruminal digestion of neutral and acid detergent fibre. Live-weight gain by growing beef calves ingesting bermudagrass hay ad libitum was higher (P < 0.05) with than without supplementation and tended (P < 0.12) to be greater for corn plus protein meals than for corn alone. Lasalocid did not affect or interact with supplement treatment in feed intake or live-weight gain of heifers (236 kg; no growth stimulant) or steers (237 kg; treated with 200 mg progesterone and 20 mg estradiol benzoate). Lasalocid at 200 mg daily did not improve digestion characteristics or influence performance by beef cattle consuming a Basal diet of bermudagrass hay. Further, effects of lasalocid were not modulated by supplementation with concentrate, concentrate type or sex or growth stimulant usage.

Digestion in steers and lactational performance of Jersey cows fed diets varying in natural protein level continuously or on alternate days.

Five crossbred beef steers (515 kg) were used in a Latin square experiment and 36 lactating Jersey cows (12 primiparous, 310 kg; 24 multiparous, 365 kg) were used in a completely randomized design study to determine effects on characteristics of digestion and lactational performance of daily alternation of the dietary level of natural protein (NP). In Experiment 1, steers were fed diets of 50% bermudagrass hay and 50% concentrate. Concentrate was approximately 18% crude protein (CP), formulated to be 60, 80 or 100% NP (varying proportions of soybean meal, urea and ground corn), and was fed at 1.5% body weight (dry matter basis). These concentrates were fed daily or ones with 60 and 100% NP were fed on alternate days. Alternate day feeding did not markedly affect characteristics of digestion, including ruminal escape of feed protein, and NP level of concentrate fed continuously had no effects either. In Experiment 2, cows were subjected to treatments similar to those in Experiment 1, and performance on d 20-40 of lactation was measured. Concentrate was given at 1 kg (as fed)/2.15 kg milk produced, yielding a dietary concentrate level of approximately 40% (dry matter basis). Alternate feeding depressed (P less than 0.05) overall milk fat percentage. Alternate feeding increased production of milk and protein and body weight of primiparous cows but caused little change with multiparous cows. Besides increasing the dietary level of concentrate, perhaps alternate feeding regimes have utility to lower milk fat level without impairing milk production. Level of NP in concentrate fed continuously did not affect performance by multiparous cows though primiparous cow performance was generally enhanced, possibly because CP intake was adequate for multiparous cows but marginal for primiparous cows. However, overall, efficiency of production of solids-corrected milk rose slightly with increasing NP.

Polyurethane sheath disintegration causing impaction of pacer lead and shock during attempted removal.

Steady traction to remove a lead whose polyurethane sheath had disintegrated caused displacement of the heart and caused hypotension; the bared lead uncoiled and impacted in the wall of the subclavian vein. The tension on the intrathoracic lead was relieved via immediate anterior thoracotomy and compartmentalization of the superior vena cava.