The Effect of Bovine Growth Hormone on Growth,Carcass Composition and Meat Quality of Dairy Heifers

Abstract

Our objective was to examine the effects of bovine growth hormone (bGH) on growth, carcass composition and meat quality of dairy heifers. Nine monozygotic twin pairs of Friesian or Red Danish cattle were used, and pair-fed à diet consisting of grass silage, barley and soybean meal. Within each pair, one animal was given daily subcutaneous injections of 20 IU of pituitary-derived bGH (15–20 mg), while the other animal was injected with saline (excipient). Treatments started at 179±2 kg body weight and lasted for 15.6 weeks. At slaughter, carcass composition and meat quality were analyzed. bGH treatment increased gain by 8% (948 vs. 877 g/d; P <0.03). The amount of saleable meat in carcass and lean content of four main carcass cuts were on average increased by 2% (P <0.05). Concomitantly, carcass fat trim was reduced by 12% (P <0.001), fat trim of individual cuts by 4–21% (P <0.05), and kidney fat by 13% (P <0.01). Except for a 20% reduction of intramuscular fat content (P <0.001), meat quality assessed by objective as well as subjective methods was unaffected by bGH treatment. In summary, bGH treatment of dairy heifers around puberty stimulated growth and reduced carcass fattening including intramuscular fat, while eating quality of the meat was unaffected.     

Effect of a 12-Week Conditioning Period on Nitrogen Balance in Horses

Fourteen horses were used in two 12-week experiments. Horses were fed to meet crude protein needs for exercising horses and participated in light-to-moderate exercise. Total feces and urine output were measured in 4-day collections at the beginning and the end of each experiment. Fecal nitrogen (FN) and urine nitrogen (UN) were used to calculate nitrogen balance and digestibility. Nitrogen intake (NI) was higher in the end collection (P = .001). Fecal nitrogen expressed as a daily amount or as a percentage of NI was not different (P = .63 and .39, respectively). Nitrogen digestibility was not different (P = .39); however, the amount of nitrogen absorbed (NA) was lower in the initial collection (P = .001). Urine nitrogen was lower in the end collection when expressed as a total loss per day (P = .041), percent of NI (P = .001), or as a percent of NA (P = .001). Daily nitrogen retention (NR), NR expressed as a percentage of NI and as a percentage of NA, was higher in the end collection (P = .001). The improvement in NR in the end collection is due to the reduction in UN loss. This suggests more efficient use of dietary protein because there was no difference in FN loss; but without a significant change in body weight or body condition score, it cannot be concluded that the additional retained nitrogen was because of a need to support additional muscle mass.     

In vitro susceptibility testing of meticillin-resistant and meticillin-susceptible staphylococci to mupirocin and novobiocin

Antimicrobials effective against meticillin-resistant staphylococci are limited. Mupirocin is a topical antimicrobial used to treat bacterial skin infections. Novobiocin is an oral antimicrobial approved for treatment of staphylococcal upper respiratory infections in dogs. This study reports the in vitro activity of mupirocin and novobiocin on meticillin-susceptible (MSS) and resistant staphylococci (MRS) from healthy dogs and dogs with superficial pyoderma. Staphylococci were isolated from skin swabs at four sites on healthy dogs and from lesions on dogs with superficial pyoderma. Staphylococci were identified by morphology and by catalase and coagulase testing. Speciation and susceptibility testing were performed by the Dade Microscan (W. Sacramento, CA, USA). Meticillin resistance was confirmed by an oxacillin screen plate. Novobiocin and mupirocin susceptibilities were tested by disc diffusion. Staphylococci were cultured from 61 healthy dogs (17 MRS and 44 MSS) and 30 dogs with pyoderma (15 MRS and 15 MSS), with higher proportions of MRS isolates in dogs with pyoderma (P=0.038; χ(2) test). For mupirocin, 79.5% (35 of 44) MSS and 82.3% (14 of 17) MRS isolates from healthy dogs, and 100% (15 of 15) MSS and 86.6% (13 of 15) MRS isolates from dogs with pyoderma were susceptible (MSS, P=0.094; MRS, P=1.0; Fisher's exact test). For novobiocin, 95.4% (42 of 44) MSS and 52.9% (nine of 17) MRS isolates from healthy dogs and 93.3% (14 of 15) MSS and 80% (12 of 15) MRS isolates from dogs with pyoderma were susceptible (MSS, P=1.0; MRS, P=0.148; Fisher's exact test).     

Area-wide management of Aedes albopictus: choice of study sites based on geospatial characteristics, socioeconomic factors and mosquito populations

BACKGROUND: Aedes (Stegomyia) albopictus (Skuse), the Asian tiger mosquito, is an introduced invasive species in the United States that is responsible for a significant proportion of service requests to local mosquito control programs. This container‐utilizing mosquito is refractory to standard mosquito abatement measures in the United States. This study is part of a USDA‐ARS project to develop an area‐wide management strategy for Ae. albopictus. The goal was to identify three study sites, similar in socioeconomic parameters, geography and Ae. albopictus abundance, in urban and suburban areas in Mercer and Monmouth counties in New Jersey. Prior service requests and light trap counts and also detailed county maps were used to chose nine preliminary sites (four in Mercer and five in Monmouth) where weekly surveillance for Ae. albopictus was performed throughout the 2008 active season. RESULTS: Although outliers were detected, socioeconomic variables in the study sites within each county were fairly consistent. Ae. albopictus abundance was associated with poverty levels and had the highest maxima in Mercer, although average mosquito abundance was similar in urban Mercer and suburban Monmouth. CONCLUSION: Three study sites in each county were identified for future studies. The summer‐long surveillance also revealed socioeconomic variables critical for the development of integrated mosquito management. Copyright © 2011 Society of Chemical Industry     

The use of oral transmucosal detomidine hydrochloride gel to facilitate handling in dogs

Safe and humane handling in the veterinary clinic can be challenging when dealing with fearful or anxious dogs. Historically, alpha-2 adrenergic agonists have been used via parenteral routes to facilitate handling of difficult canine subjects. Detomidine hydrochloride is an alpha-2 agonist sedative commercially available in an oral transmucosal (OTM) formulation (Dormosedan Gel; Pfizer Animal Health, Madison, NJ) approved for sedation and restraint in horses. The usefulness of this detomidine formulation has not been previously reported in dogs. This study evaluated the behavioral and physiological effects of OTM detomidine gel administration in dogs to assess its efficacy and safety for facilitation of handling canine subjects. Six healthy institution-owned adult dogs were administered detomidine gel at a dose of 0.35 mg/m² via OTM route. Behavioral and physiological assessments were performed pretreatment and repeated every 15–30 minutes for 5 hours after administration. Behavioral assessments included global sedation (GS), composite sedation (CS), global anxiolysis (GA), and ease of handling (EH) scores. Physiological assessments included heart rate and rhythm, respiratory rate, mucous membrane color, indirect blood pressure, rectal temperature, oxygen saturation, and capillary refill time. Posttreatment GS, CS, GA, and EH scores were improved for all 6 subjects as compared with pretreatment. For 4 of 6 dogs, maximal GS scores occurred at 45 minutes posttreatment, and duration of maximal GS scores was 30 minutes. Five of 6 dogs achieved adequate GS scores. EH scores were significantly higher during time points of adequate GS scores as compared with time points when adequate GS scores were not achieved. The physiological measures revealed transient bradycardia in 5 of 6 dogs and intermittent second-degree atrioventricular block in 1 dog. No other significant adverse events were noted, and all dogs recovered uneventfully. OTM detomidine gel was safely administered to 6 dogs at a dose of 0.35 mg/m² and resulted in measurable sedation, anxiolysis, and improved EH in all subjects. Although further evaluation is warranted for use in client-owned dogs, OTM detomidine gel offers a novel sedative and anxiolytic option to facilitate handling of canine subjects.     

Evaluation of an enzyme-linked immunosorbent assay for serological surveillance of infection with Actinobacillus pleuropneumoniae serotype 5 in pig herds

An indirect enzyme-linked immunoassay for serological surveillance of infection of pigs with Actinobacillus pleuropneumoniae (Ap) serotype 5 was developed. The antigen used was prepared from Ap serotype 5b strain L20. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the antigen contained high molecular weight lipopolysaccharide (LPS) and presumably also capsular polysaccharide (CP). The Ap serotype 5 ELISA was tested using sera from pigs experimentally infected with the 12 different Ap serotypes of biotype 1 and with sera from herds naturally infected with Ap serotypes 5, 6, 7 and 12. Cross-reactions were shown in one pig from a herd naturally infected with Ap serotype 7 and in one pig from a herd naturally infected with Ap serotype 12. The herd sensitivities of the Ap5 ELISA and a complement fixation test (CFT) were both estimated to 1.0, on the basis of serum samples from six herds naturally infected with Ap serotype 5. The herd specificities of both tests were estimated to 0.98, based on serum samples from 123 pig herds (10 samples from each herd) from the Danish specific pathogen-free (SPF) programme for pig production.     

Redwood/tanoak stand development and response to tanoak mortality caused by Phytophthora ramorum

Coast redwood (Sequoia sempervirens) and tanoak (Lithocarpus densiflorus) form mixed-evergreen forests along the northern California coast. In the mid-1990s, an introduced pathogen (Phytophthora ramorum) began causing extensive mortality of tanoak in these forests. This research reconstructed stand development patterns occurring in stands with and without the pathogen, measured stand responses to tanoak mortality, and developed projections of future stand development and structure in the presence of P. ramorum. Redwood forms an upper canopy layer while tanoak forms a multicohort lower canopy, resulting in distinct vertical stratification patterns. Individual redwood tree response patterns to tanoak mortality included crown expansion, increased basal sprouting, and increased basal area growth. Future stand structures will likely have greater proportions of redwood relative to tanoak.