RESUMEN

Two experiments were conducted to examine the effect of plasma concentrations of 17ß-estradiol (E2) preceding and progesterone (P4) subsequent to ovulation on proportions of beef cows pregnant following embryo transfer. Timing of ovulation (d 0) among postpartum cows was synchronized and cows that expressed estrus were removed from each study. In Experiment 1, plasma E2 concentration on d 0 was used to classify cows (n = 353) into Low, Medium, and High E2 groups. Pregnancy rate for cows with Low, Medium, or High E2 concentrations were different (P < 0.05). In Experiment 2, there were multiple administrations of PGF2α to evaluate the independent effects of Low or High E2 before ovulation and Low or Normal (no treatment) P4 after ovulation on proportions of cows pregnant. Treatment groups in Experiment 2, therefore, were: Low E2-Low P4 (LL; n = 71), Low E2-Normal P4 (LN; n = 69), High E2-Low P4 (HL; n = 74), and High E2-Normal P4 (HN; n = 73). Concentrations of P4 on d 7 subsequent to ovulation were less (P < 0.05) in cows of the HL compared to HN, and in LL compared to LN groups. Concentrations of E2 on d -2, 0, and change in E2 (d -2 to d 0) had a positive effect (P < 0.008) on pregnancy rates. In summary, relatively greater E2 concentrations preceding ovulation; and relatively greater P4 concentrations subsequent to ovulation combined with lesser E2 concentrations preceding ovulation had a positive effect on proportions of postpartum cows pregnant.

Asunto(s)

Bovinos/fisiología , Dinoprost/farmacología , Transferencia de Embrión/veterinaria , Estradiol/sangre , Ovulación/fisiología , Progesterona/farmacología , Animales , Bovinos/sangre , Cloprostenol/farmacología , Dinoprost/administración & dosificación , Esquema de Medicación , Estradiol/administración & dosificación , Femenino , Hormona Liberadora de Gonadotropina/farmacología , Embarazo , Progesterona/administración & dosificación , Progesterona/sangre

RESUMEN

The relationship between heat stress, meat quality, and residual feed intake (RFI) is unknown in growing steers. To address this issue, high RFI (HRFI) and low RFI (LRFI) individuals were compared by assessing RFI in 48 Angus-sired steers during a 70-d feeding trial conducted during July through September to identify steers with calculated RFI at least 2 SD apart. The association of RFI with indices of meat quality and expression of genes within hypothalamic and adipose tissue was then determined in LRFI and HRFI steers. While on test, feed intake was recorded daily with BW and hip heights recorded every 14 d. Ultrasound measurements of rib eye area (REA) and backfat (BF) were recorded initially and before harvest. Carcass and growth data were analyzed using a mixed model with RFI level (LRFI and HRFI) as the independent variable. The least square means for RFI were -1.2 and 0.99 kg DMI/d, respectively, for the LRFI and HRFI cohorts (P < 0.0001). Dry matter intake was higher for the HRFI individuals versus the LRFI steers (P < 0.0001) while on-test gain was not different (P < 0.95). Marbling score was greater in LRFI than HRFI steers (P < 0.05). However, there were no differences in REA (P < 0.53), BF (P < 0.65), yield grade (P < 0.24), or objective Hunter color measures between LRFI and HRFI steers indicating there was no consistent relationship between RFI and indices of meat quality. Hypothalamic neuropeptide Y (NPY), agouti related protein (AGRP), relaxin-3 (RLN3), melanocortin 3 receptor, and relaxin/insulin-like family peptide receptor 1 (RXFP1) mRNA were expressed 280, 185, 202, 183, and 163% greater, respectively (P < 0.01), while proopiomelanocortin (POMC) mRNA was expressed 42% lower in LRFI than HRFI animals (P < 0.05). Hypothalamic GnRH mRNA expression was 67% lower while gonadotropin inhibiting hormone (GnIH) mRNA was 209% higher in LRFI than HRFI animals (P < 0.01). Pituitary expression of FSHß and LHß correlated to hypothalamic GnRH levels (P < 0.05) indicating changes in gene expression within the hypothalamus had functional consequences. Leptin mRNA expression levels were not different between adipose tissue of LRFI or HRFI steers (P < 0.84). These data indicate that animals with superior RFI evaluated during warm conditions have higher expression of orexigenic neuropeptide genes independent of the expression of adipose-derived leptin. Furthermore, the gonadotropin axis may also influence feed efficiency under these conditions.

Asunto(s)

Ingestión de Alimentos/fisiología , Regulación de la Expresión Génica/fisiología , Calor , Hipotálamo/metabolismo , Carne/normas , Estaciones del Año , Animales , Composición Corporal/genética , Composición Corporal/fisiología , Bovinos , Ingestión de Alimentos/genética , Masculino

RESUMEN

Mechanisms underlying variation in residual feed intake (RFI), a heritable feed efficiency measure, are poorly understood while the relationship between RFI and meat quality is uncertain. To address these issues, 2 divergent cohorts consisting of High (HRFI) and Low (LRFI) RFI individuals were created by assessing RFI in 48 Angus-sired steers during a 70 d feeding trial to identify steers with divergent RFI. The association of RFI with indices of meat quality and expression of genes within hypothalamic and adipose tissue was then determined in LRFI and HRFI steers. While on test, feed intake was recorded daily with BW and hip heights recorded at 14 d intervals. Ultrasound measurements of rib eye area (REA) and backfat (BF) were recorded initially and before harvest. Carcass and growth data were analyzed using a mixed model with RFI level (LRFI, HRFI) as the independent variable. The least-square means (lsmeans) for RFI were -1.25 and 1.51 for the LRFI and HRFI cohorts (P < .0001). Dry matter intake was higher for the HRFI individuals versus the LRFI steers (P < .0001) while on test BW gain was not different between the 2 groups (P < 0.73). There were no differences detected in marbling score (P < 0.93), BF (P < 0.61), REA (P < 0.15), yield grade (P < 0.85) or objective Hunter color measures between LRFI and HRFI steers indicating that there was no relationship between RFI and meat quality. Neuropeptide-Y (NPY), relaxin-3 (RLN3), melanocortin 4 receptor (MC4R), and GnRH mRNA expression was 64%, 59%, 58%, 86% lower (P < 0.05), respectively, while gonadotropin inhibiting hormone (GnIH) and pro-opiomelanocortin (POMC) mRNA expression was 198% and 350% higher (P < 0.01) in the arcuate nucleus of LRFI steers. Expression of agouti-related protein (AGRP), relaxin/insulin-like family peptide receptor 1 (RXFP1), and melanocortin 3 receptor mRNA was similar between LRFI and HRFI animals. Pituitary expression of FSHß (P < 0.03) and LHß (P < 0.01) was correlated to hypothalamic GnRH levels suggesting that changes in gene expression within the arcuate nucleus had functional consequences. Leptin mRNA expression was 245% higher in the adipose tissue of LRFI steers consistent with lower levels of NPY and higher expression of POMC in their hypothalami. These data support the hypothesis that differences in hypothalamic neuropeptide gene expression underlie variation in feed efficiency in steers while the gonadotropin axis may also influence feed efficiency.

Asunto(s)

Bovinos/genética , Bovinos/fisiología , Ingestión de Alimentos/genética , Regulación de la Expresión Génica/fisiología , Hipotálamo/fisiología , Tejido Adiposo , Animales , Composición Corporal , Peso Corporal , Ingestión de Alimentos/fisiología , Hormona Liberadora de Gonadotropina/genética , Hormona Liberadora de Gonadotropina/metabolismo , Masculino , Neuropéptido Y/genética , Neuropéptido Y/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor de Melanocortina Tipo 4/genética , Receptor de Melanocortina Tipo 4/metabolismo , Relaxina/genética , Relaxina/metabolismo

RESUMEN

Animal manures, used as a nitrogen source for crop production, are often associated with negative impacts on nutrient levels in surface water. The concentrations of estrogens in streams from these manures also are of concern due to potential endocrine disruption in aquatic species. Streams associated with livestock operations were sampled by discrete samples (n = 38) or by time-integrated polar organic chemical integrative samplers (POCIS, n = 19). Samples were analyzed for estrogens by gas chromatography-tandem mass spectrometry (GC-MS(2)) and estrogenic activity was assessed by three bioassays: Yeast Estrogen Screen (YES), T47D-KBluc Assay, MCF-7 Estrogenicity Screen (E-Screen). Samples were collected from 19 streams within small (≈ 1-30 km(2)) watersheds in 12 U.S. states representing a range of hydrogeologic conditions, dominated by: dairy (3), grazing beef (3), feedlot cattle (1); swine (5); poultry (3); and 4 areas where no livestock were raised or manure was applied. Water samples were consistently below the United Kingdom proposed Lowest Observable Effect Concentration for 17ß-estradiol in fish (10 ng/L) in all watersheds, regardless of land use. Estrogenic activity was often higher in samples during runoff conditions following a period of manure application. Estrone was the most commonly detected estrogen (13 of 38 water samples, mean 1.9, maximum 8.3 ng/L). Because of the T47D-KBluc assay's sensitivity towards estrone (1.4 times 17ß-estradiol) it was the most sensitive method for detecting estrogens, followed by the E-Screen, GC-MS(2), and YES. POCIS resulted in more frequent detections of estrogens than discrete water samples across all sites, even when applying the less-sensitive YES bioassay to the POCIS extracts.

Asunto(s)

Bioensayo/métodos , Disruptores Endocrinos/análisis , Estrógenos/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Agricultura , Animales , Bovinos , Estradiol/análisis , Receptor alfa de Estrógeno/genética , Estrógenos/química , Estrógenos/toxicidad , Estrona/análisis , Peces , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Ganado , Estiércol , Aves de Corral , Porcinos , Pruebas de Toxicidad/métodos , Estados Unidos , Levaduras/efectos de los fármacos

RESUMEN

The ability to improve meat quality and production efficiency in cattle is limited by an inability to enhance marbling and simultaneously limit undesirable adipose tissue accretion. The objective of this study was to examine expression of regulatory genes in subcutaneous (SCF) adipose tissue of heifers in response to increasing days on feed (DOF) and finishing strategy. Crossbred heifers (n = 24) were allotted as follows: Group 1 = 0 d, Group 2 = 99 d on winter annual ryegrass (grass; Lolium multiflorum Lam.), Group 3 = 218 g on grass, Group 4 = 99 d on grass followed by 119 d on grain. Adipose tissue samples were collected at time of harvest and frozen. Carcass characteristics were measured 24 h postharvest. As expected, HCW (P < 0.0001), ribeye area (REA; P < 0.0002), backfat (BF; P < 0.0001), KPH (P < 0.0001), and marbling score (P < 0.0009) increased with DOF though frame score was not different (P < 0.95). Average daily gain decreased with DOF (P < 0.0001). Yield grade increased (P < 0.0014) but cook loss percentage decreased (P < 0.001) with DOF without changes in 24-h pH (P < 0.31). Interestingly, Warner-Bratzler shear force (WBS) was decreased with DOF (P < 0.0089). Meanwhile, BF (P < 0.01) and KPH (P < 0.05) were greater, whereas marbling values trended greater in grain versus grass-finished heifers. Neither ADG (P < 0.89), HCW (P < 0.26), frame score (P < 0.85), nor REA (P < 0.38) were different between these groups. Grain finishing increased yield grade (P < 0.001) but did not affect 24-h pH (P < 0.88), cook loss percentage (P < 0.98), or WBS (P < 0.44) compared with grass-finished heifers. The expression of PPARγ, bone morphogenic protein 2 (BMP2), and SMAD family member 1 (SMAD1) mRNA was upregulated in response to DOF and grain finishing, whereas sterol regulatory element binding protein 1c (SREBP-1c), sonic hedgehog (SHH), chicken ovalbumin protein transcription factor 1 (COUP-TF1), chicken ovalbumin protein transcription factor 2 (COUP-TF2), and preadipocyte factor-1 (PREF-1) mRNA was decreased in response to DOF and grain finishing. These changes were associated with increased expression of lipoprotein lipase (LPL), stearoyl-coenzyme A desaturase (SCD), and fatty acid synthase (FAS) mRNA. In summary, increasing DOF was associated with improved meat quality whereas gene expression studies suggest several novel genes are associated with subcutaneous adipose tissue development in growing and finishing cattle.

Asunto(s)

Alimentación Animal/análisis , Bovinos/fisiología , Regulación de la Expresión Génica , Genes Reguladores , Carne/análisis , Grasa Subcutánea/metabolismo , Factores de Transcripción/genética , Alabama , Animales , Bovinos/genética , Bovinos/crecimiento & desarrollo , Dieta , Grano Comestible/química , Femenino , Poaceae/química , Distribución Aleatoria , Factores de Tiempo , Factores de Transcripción/metabolismo

RESUMEN

Brucellosis is an ancient disease that still remains a significant threat to humans and is typically linked to exposure to infected animals and/or consumption of unpasteurized animal products. Despite this history, we have a relatively limited understanding of the host characteristics of this disease; consequently, further research is necessary. In this study, we examined the humoral immune response in 43 Georgian individuals that had been diagnosed with brucellosis 3-12 months before enrollment in the study, many of whom still had symptoms after the completion of antibiotic therapy. In total, 35 of 43 (83%) of the patients had antibodies that bound to Brucella lipopolysaccharide (LPS) by COMPELISA, and 34 of 38 (89%) patients had demonstrable specific antibodies to Brucellergene™ antigens; the results from the two ELISAs were highly correlated (p=0.031, r=0.851). We also studied the cellular immune responses in 15 patients. All of the patients generated interferon (IFN)-γ in response to ex vivo stimulation with Brucella protein antigens, and the majority of the patients maintained measurable humoral responses to both LPS and protein antigens. From this initial study, we conclude that measurement of antibody and of cellular (IFN-γ) responses to brucellergene OCB protein epitopes may be worthy of further investigation as an alternative or adjunct to current diagnostics.

Asunto(s)

Anticuerpos Antibacterianos/sangre , Brucella/inmunología , Brucelosis/inmunología , Interferón gamma/metabolismo , Linfocitos T/inmunología , Adulto , Animales , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Georgia (República) , Humanos , Lipopolisacáridos/inmunología , Masculino , Persona de Mediana Edad

RESUMEN

The microbial communities from three upflow anaerobic bioreactors treating purified terephthalic acid (PTA) wastewater were characterized with 16S ribosomal RNA gene sequencing surveys. Universal bacterial and archaeal primers were used to compare the bioreactor communities to each other. A total of 1,733 bacterial sequences and 383 archaeal sequences were characterized. The high number of Syntrophus spp. and Pelotomaculum spp. found within these reactors indicates efficient removal of benzoate and terephthalate. Under anaerobic conditions benzoate can be degraded through syntrophic associations between these bacteria and hydrogen-scavenging microbes, such as Desulfovibrio spp. and hydrogenotrophic methanogens, which remove H(2) to force the thermodynamically unfavourable reactions to take place. The authors did not observe a relatively high percentage of hydrogenotrophic methanogens with the archaeal gene survey because of a high acetate flux (acetate is a main component in PTA wastewater and is the main degradation product of terephthalate/benzoate fermentation), and because of the presence of Desulfovibrio spp. (a sulfate reducer that scavenges hydrogen). The high acetate flux also explains the high percentage of acetoclastic methanogens from the genus Methanosaeta among the archaeal sequences. A group of uncultured bacteria (OD1) may be involved in the degradation of p-toluate (4-methyl benzoate), which is a component of PTA wastewater.

Asunto(s)

Reactores Biológicos , Ácidos Ftálicos/química , ARN Ribosómico 16S/genética , Aguas del Alcantarillado/microbiología , Anaerobiosis , Archaea/genética , ADN de Archaea/química , ADN Bacteriano/química , ADN Ribosómico/química , Filogenia , Eliminación de Residuos Líquidos , Microbiología del Agua

RESUMEN

The protective antigen (PA) of Bacillus anthracis and the V antigen of Yersinia pestis are potent immunogens and candidate vaccine sub-units. When plasmid DNA encoding either PA or V antigen was used to immunise the Balb/c mouse, a low serum IgG titre was detected (log (10)1.0 or less) which was slightly increased by boosting with plasmid DNA. However, when mice immunised with plasmid DNA were later boosted with the respective recombinant protein, a significant increase in titre (up to 100-fold) was observed. Mice primed with a combination of each plasmid and boosted with a combination of the recombinant proteins, were fully protected (6/6) against challenge with Y. pestis. This compared favourably with mice primed only with plasmid DNA encoding the V antigen and boosted with rV, which were partially protected (3/6) against homologous challenge or with mice primed and boosted with plasmid DNA encoding the V antigen which were poorly protected (1/6). Combined immunisation with the two plasmid DNA constructs followed by boosting with a combination of the encoded recombinant proteins enhanced the protective immune response to Y. pestis compared with priming only with plasmid DNA encoding the V antigen and boosting with rV. This enhancement may be due to the effect of CpG motifs known to be present in the plasmid DNA construct encoding PA.

Asunto(s)

Vacunas contra el Carbunco/agonistas , Vacuna contra la Peste/administración & dosificación , Vacunas de ADN/administración & dosificación , Animales , Carbunco/inmunología , Carbunco/prevención & control , Vacunas contra el Carbunco/genética , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/genética , Bacillus anthracis/genética , Bacillus anthracis/inmunología , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Femenino , Inmunización Secundaria , Inmunoglobulina G/sangre , Técnicas In Vitro , Ratones , Ratones Endogámicos BALB C , Peste/inmunología , Peste/prevención & control , Vacuna contra la Peste/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Linfocitos T/inmunología , Vacunas Combinadas/administración & dosificación , Vacunas Combinadas/genética , Vacunas de ADN/genética , Yersinia pestis/genética , Yersinia pestis/inmunología

RESUMEN

Plasmids expressing the V antigen of Yersinia pestis or the E2 glycoprotein of Venezuelan Equine Encephalitis (VEE) virus were used to vaccinate mice by intra-dermal or intra-muscular injection, or by particle-mediated bombardment using the Helios gene gun. After two immunizations, groups of mice which had received 4 microg doses of plasmid DNA using the gene gun had IgG levels which were higher than in other groups manually immunised with 12-fold more plasmid DNA. The immunoglobulin isotype profile was predominantly IgG1 following inoculation with either plasmid. Our results indicate that gene gun mediated vaccination can be used to increase the magnitude of the immune response to both bacterial and viral antigens expressed by plasmid DNA.

Asunto(s)

Antígenos Bacterianos/inmunología , Vacunas Bacterianas/administración & dosificación , Biolística/métodos , Virus de la Encefalitis Equina Venezolana/inmunología , Vacunas de ADN/administración & dosificación , Proteínas del Envoltorio Viral/inmunología , Vacunas Virales/administración & dosificación , Yersinia pestis/inmunología , Animales , Antígenos Bacterianos/genética , Vacunas Bacterianas/genética , Vacunas Bacterianas/inmunología , Preescolar , ADN/administración & dosificación , ADN/genética , Virus de la Encefalitis Equina Venezolana/genética , Femenino , Oro , Humanos , Inyecciones Intradérmicas , Inyecciones Intramusculares , Ratones , Ratones Endogámicos BALB C , Plásmidos/administración & dosificación , Plásmidos/genética , Proteínas Citotóxicas Formadoras de Poros , Vacunas de ADN/genética , Vacunas de ADN/inmunología , Proteínas del Envoltorio Viral/genética , Vacunas Virales/genética , Vacunas Virales/inmunología , Yersinia pestis/genética

RESUMEN

Protective antigen (PA), the major protective component of the existing vaccine, is a potent immunogen. Protective antigen in alhydrogel induced a high serum IgG titre (> log10 4) in both the C57B16 and Balb/c mouse and the predominant subclass of antibody induced was IgG1, indicating that the response to PA was predominantly Th2 directed. When plasmid DNA encoding PA was used to immunize the Balb/c mouse, a low serum IgG titre was detected (

Asunto(s)

Carbunco/inmunología , Antígenos Bacterianos/inmunología , Bacillus anthracis/inmunología , Toxinas Bacterianas/inmunología , Vacunas , Animales , Carbunco/prevención & control , Humanos , Inmunidad , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Vacunación