Second Oestrus Synchronization and Precocious Embryo Viability after Puberty Induction in Gilts by the Use of Gonadotrophin Treatment     

V do Lago  WL Vianna  RD Gama  A de  Campos Rosseto  ME Pinese  A de  Sant''Anna Moretti 《Reproduction in domestic animals》2005,40(2):141-144

The use of exogenous gonadotrophins in puberty inducement and ovulation synchronization is a technique that has a positive influence on the management of swine. The purpose of this study was to verify the effects of a second gonadotrophin treatment [equine chorionic gonadotrophin (eCG) and luteinizing hormone (LH), intramuscularly (i.m.)] upon the second oestrus synchronization and fertility in gilts. Seventy-one NAIMA (Pen Ar Lan) gilts had their first oestrus (puberty inducement) induced by a hormonal treatment (eCG and LH). Then, they were randomly distributed into two treatments, with (T1) and without (C) gonadotrophin treatment at the second oestrus. The animals were fed with a single ration (16% of crude protein and 3286.73 kcal ME/kg), and timed artificial insemination performed at the second oestrus. Gilts were slaughtered for embryo recovery and ovary examination about 5 days after insemination. There was no evidence of a difference in the percentage of the second oestrus expression (T1 - 90.90% and C - 86.84%), the duration of the oestrus cycle (T1 - 19.62 +/- 0.82 days and C - 19.67 +/- 4.14 days), the percentage of follicular cysts (T1 - 15.15% and C - 18.42%) and number of ovulations (T1 - 14.60 +/- 5.7 and C - 13.23 +/- 4.8) between treatments (p > 0.05). However, the hormonal treatment (T1) showed minor oestrus dispersion and embryo viability (T1 - 8.4 +/- 5.6 and C - 11.2 +/- 4.6) (p < 0.05). These results indicate that the better synchronization and expression of the second oestrus when using gonadotrophins (eCG and LH) is followed by a lower embryo viability, which is probably the consequence of the heterogeneous follicle recruitment during the injection of eCG.  相似文献   

Effect of removal and remixing of lightweight pigs on performance to slaughter weights     

Brumm MC  Ellis M  Johnston LJ  Rozeboom DW  Zimmerman DR;NCR- Committee on Swine Management 《Journal of animal science》2002,80(5):1166-1172

Two experiments were conducted to determine the effect of lightweight pig removal and remixing on performance to slaughter. Experiment 1 was a growing-finishing trial utilizing a total of 900 pigs (26.2+/-0.1 kg initial weight) that were sorted and remixed at a mean replicate BW of 72 kg. Experiment 2 was a wean-to-finish trial (17 d mean wean age; 4.8 kg +/- 0.1 BW) utilizing 225 barrows with sorting and remixing occurring 3 wk after weaning. Treatments were 15 pigs/ pen from initial weight to slaughter (15S), 20 pigs/pen from initial weight to time of sort and remix and then reduced to 15 pigs/pen (20/15), and 15 pigs/pen from time of sort and remix to slaughter comprised of the five lightest pigs from each of three 20/15 pens per replicate (15M). Space allocation was 0.56 m2/pig from 26 to 70 kg and 0.74 m2/pig thereafter in Exp. 1. In Exp. 2, pen size was fixed at 2.44 x 4.27 m. In Exp. 1, there was no effect (P > 0.20) of treatment on performance prior to 70 kg. Least squares means for ADG from time of sort and remix to first pig removal from a pen for slaughter at 113 kg were 0.93, 0.87, and 0.91 kg/d for the 20/15, 15M, and 15S treatments, respectively (P < 0.05). When comparing the population represented by the 20/15 + 15M treatments vs the 15S population, there was no difference (P > 0.20) in ADG, ADFI, feed conversion, or carcass lean content. In Exp. 2, pigs in the 20/15 treatment grew slower (P < 0.05) than 15S pigs for the first 21 d (0.20 vs 0.22 kg/d, respectively) with a lower ADFI (P = 0.06) and no difference in feed conversion. When comparing the population represented by the 20/15 + 15M treatments vs the 15S population after sorting and remixing, there was no effect (P > 0.15) of experimental treatments on ADG, ADFI, feed conversion efficiency, carcass lean content, or daily lean gain. These results suggest that removal of lightweight pigs and remixing of the removed pigs into pens of similar-weight pigs is ineffective in improving the overall performance of a population of pigs during the postweaning period.  相似文献   

Analytical sensitivity of air samplers based on uniform point-source exposure to airborne Porcine reproductive and respiratory syndrome virus and swine influenza virus          下载免费PDF全文

Joseph R. Hermann  Jeffrey J. Zimmerman 《Canadian journal of veterinary research》2008,72(5):440-443

Research and surveillance activities involving airborne pathogens rely on the capture and enumeration of pathogens suspended in aerosols. The objective of this study was to estimate the analytical sensitivity (detection threshold) of each of 4 air samplers for Porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SIV). In a 5-min sampling period under controlled conditions, the analytical sensitivity of the AGI-30 (Ace Glass, Vineland, New Jersey, USA), AGI-4 (Ace Glass), SKC BioSampler (SKC, Eighty Four, Pennsylvania, USA), and Midwest Micro-Tek sampler (Midwest Micro-Tek, Brookings, South Dakota, USA) was calculated at 1 × 10^1.1, 1 × 10^1.3, 1 × 10^1.1, and 1 × 10^1.2 median tissue culture infectious dose (TCID₅₀) equivalents for PRRSV and 1 × 10^1.4, 1 × 10^1.1, 1 × 10^1.6, and 1 × 10^1.2 TCID₅₀ equivalents for SIV [per 60 L (5-min sampling period)]. Despite marked differences in sampler design, no statistically significant difference in analytical sensitivity was detected between the samplers for collection of artificially produced aerosols containing cell-culture-propagated PRRSV or SIV.  相似文献   

Aerobic soil metabolism of metsulfuron-methyl     

Yutai Li  W T Zimmerman  M K Gorman  R W Reiser  A J Fogiel  P E Haney 《Pest management science》1999,55(4):434-445

A laboratory study was conducted to determine the degradation rates and identify major metabolites of the herbicide metsulfuron-methyl in sterile and non-sterile aerobic soils in the dark at 20°C. Both [phenyl-U-¹⁴C]- and [triazine-2-¹⁴C]metsulfuron-methyl were used. The soil was treated with [¹⁴C]metsulfuron-methyl (0.1 mg kg⁻¹) and incubated in flow-through systems for one year. The degradation rate constants, DT₅₀, and DT₉₀ were obtained based on the first-order and biphasic models. The DT₅₀ (time required for 50% of applied chemical to degrade) for metsulfuron-methyl, estimated using a biphasic model, was approximately 10 days (9–11 days, 95% confidence limits) in the non-sterile soil and 20 days (12–32 days, 95% confidence limits) in the sterile soil. One-year cumulative carbon dioxide accounted for approximately 48% and 23% of the applied radioactivity in the [phenyl-U-¹⁴C] and [triazine-2-¹⁴C]metsulfuron-methyl systems, respectively. Seven metabolites were identified by HPLC or LC/MS with synthetic standards. The degradation pathways included O-demethylation, cleavage of the sulfonylurea bridge, and triazine ring opening. The triazine ring-opened products were methyl 2-[[[[[[[(acetylamino)carbohyl]amino]carbonyl]amino] carbonyl]-amino]sulfonyl]benzoate in the sterile soil and methyl 2-[[[[[amino[(aminocarbonyl)imino]methyl] amino]carbonyl]amino]sulfonyl]benzoate in the non-sterile soil, indicating that different pathways were operable. © 1999 Society of Chemical Industry  相似文献   

Prediction of Starch Amylose Content Versus Total Grain Amylose Content in Corn by Near-Infrared Transmittance Spectroscopy     

M. R. Campbell  S. R. Mannis  H. A. Port  A. M. Zimmerman  D. V. Glover 《Cereal Chemistry》1999,76(4):552-557

A study was conducted to investigate methods of improving a near-infrared transmittance spectroscopy (NITS) amylose calibration that could serve as a rapid, nondestructive alternative to traditional methods for determining amylose content in corn. Calibrations were developed using a set of genotypes possessing endosperm mutations in single- and double-mutant combinations ranging in starch-amylose content (SAC) from -8.5 to 76%, relative to a standard curve. The influence of three factors were examined including comparing calibrations made against SAC versus grain amylose content (GAC), developing calibrations using partial least squares (PLS) analysis versus artificial neural networking (ANN), and using all samples in the calibrations set versus using progressively narrower ranges of SAC or GAC in the calibration set. Grain samples were divided into calibration and validation sets for PLS analysis while samples used in ANN were assigned to a training set, test set, and validation set. Performance statistics of the validation sets that were considered were the coefficient of determination (R), the standard error of prediction (SEP), and the ratio of the standard deviation of amylose values to the SEP (RPD), which were used to compare all NITS models. The study revealed an NITS prediction model for SAC (R = 0.96, SEP = 5.1%, RDP = 3.8) of similar precision to the best GAC model (R = 0.96, SEP = 2.7%, RPD = 3.5). Narrowing the amylose range of the calibration set generally did not improve performance statistics except for PLS models for SAC in which a decrease in SEP values was observed. In one model, the SEP improved while R and RPD remained constant (R = 0.94, SEP = 4.2%, RPD = 2.8) when samples with SAC values <20% were removed from the calibration set. Although the NITS amylose calibrations in this study are of limited precision, they may be useful when a rough screening method is needed for SAC. For example, NITS may be useful to detect severe contamination during transport and storage of specialty grains or to aid breeders when selecting for amylose content from large numbers of grain samples.  相似文献   

Vegetation diversity in an interconnected ephemeral riparian system of north-central Arizona, USA   总被引：15，自引：0，他引：15  

Julie Crawford Zimmerman  Laura E. DeWald  Peter G. Rowlands 《Biological conservation》1999,90(3):721-228

A vegetation survey was conducted in the Pumphouse Wash canyon system, south of Flagstaff, Arizona. Plant species distribution, abundance, and diversity were quantified within and among canyons in this sensitive ephemeral riparian area. Abiotic variables were examined to see if they could predict vegetation diversity. Results of stand ordination and cluster analysis suggested that variation in vegetation distribution and composition was best explained by a complex temperature/moisture - substrate gradient. Understory diversity in general was related to changes in slope and sand/gravel substrate. Each tributary canyon supported unique plant species and the riparian vegetation in one tributary canyon was significantly less diverse than in each of the other canyons. The two canyons with the lowest understory diversity contained rare plant species not found in the other, more diverse canyons. Thus, overall diversity was demonstrated to be a poor predictor of the presence of rare species. Similarly, abiotic variation was useful at predicting diversity levels but was not useful at predicting species occurrence or ecological quality. In summary, attributes frequently considered of use for predicting conservation value of one type (e.g., diversity) were not good at predicting other conservation values (e.g., rarity).  相似文献   

Chaotic stirring in a tidal system     

Ridderinkhof H  Zimmerman JT 《Science (New York, N.Y.)》1992,258(5085):1107-1111

An analysis of a two-dimensional tidal model of the Wadden Sea reveals Lagrangian chaos in the trajectories of water parcels. The associated chaotic stirring results from the transverse intersection of the stable and unstable curves of hyperbolic fixed points in the Lagrangian residual displacement field (the tidal Poincaré map). This tidal dispersion mechanism produces rapid water exchange along the channel axis and could be representative of many shallow tidal seas.  相似文献   

Milk Progesterone Profile at and after Artificial Insemination in Repeat-Breeding Cows: Effects on Conception Rate and Embryonic Death     

ME Ghanem  T Nakao  K Nakatani  M Akita  T Suzuki 《Reproduction in domestic animals》2006,41(2):180-183

The aim of this study was to investigate whether the skim milk progesterone concentrations at artificial insemination (AI) and day of rise of post-ovulatory progesterone concentration thereafter affect the conception and embryonic death rates in repeat-breeding cows. Milk samples were obtained from 96 repeat-breeding cows that failed to conceive to three or more AIs. The samples were taken from the cows at the day of AI and three times/week until day 45 post-AI. Skim milk was obtained after centrifugation and used for progesterone assay. The cows with a progesterone concentration more than 0.5 ng/ml at AI showed a significantly higher incidence of late embryonic death than those having a progesterone concentration<0.5 ng/ml at AI (p<0.01). As the progesterone level at insemination rose, conception rate declined. A negative correlation was shown between conception rate and skim milk progesterone level at AI. Of 56 cows showing a rise of progesterone to 1 ng/ml or more within 6 days after AI, 28 cows (50%) conceived. On the contrary, only eight of 39 cows (20.5%) conceived when the progesterone rose up to 1 ng/ml after day 6 post-AI. We concluded that increased progesterone concentration at the time of AI and delayed rise of progesterone post-AI might lead to decrease in fertility in repeat-breeding cows.  相似文献   

Pathological Conditions of the Reproductive Organs of Male Stray Dogs in the Tropics: Prevalence, Risk Factors, Morphological Findings and Testosterone Concentrations     

A Ortega-Pacheco  JC Rodríguez-Buenfil  JC Segura-Correa  ME Bolio-Gonzalez  M Jiménez-Coello  C Linde Forsberg 《Reproduction in domestic animals》2006,41(5):429-437

The objective of this study was to estimate the prevalence of and risk factors for pathological conditions of the reproductive organs in stray dogs under tropical conditions. Three hundred and eighteen dogs were examined post-mortem in the period from 1 July 2002 to 30 June 2003. Before killing, a blood sample (from the cephalic vein) for testosterone assay was taken. Pathological conditions of the reproductive organs were found in 135 of the dogs (42.5%) and in 175 of the testes (64.8%). The most frequent pathologies found were testicular degeneration, cryptorchidism, testicular hypoplasia and testicular tumours (in 15.1%, 6.6%, 6.6% and 5.4% of the dogs and 15.1, 4.6, 6.0 and 3.5 of the testes, respectively). Transmissible venereal tumour (TVT) was seen in 5.4% of the dogs. Testicular degeneration was more common in old dogs and underweight dogs (p < 0.05). Testicular tumours were 14.3 times more common in cryptorchid dogs. Age was another important factor for the development of testicular tumours (p < 0.05). Lower levels of testosterone concentration (p < 0.05) were observed in dogs with advanced testicular degeneration (0.7 +/- 0.8 nM), dogs with hypoplastic testicles (0.8 +/- 0.9 nM) and dogs with one degenerated and one retained testis or with bilateral cryptorchidism (1.2 +/- 0.9 nM) compared to dogs with one or two normal testes (7.0 +/- 5.5 nM). Testicular volume and weight were significantly lower in degenerated, hypoplastic and retained testes compared with the contralateral normal testis. Some spermatogenic activity was found in three of the retained testes, producing oligozoospermic smears with a high percentage of sperm abnormalities. No comparable epidemiological data about male pathological conditions of the reproductive organs in the dog is available. The prevalence found in this study, yet, appears high.  相似文献   

Porcine toxoplasmosis in Indiana.     

J P Dubey  S E Weisbrode  S P Sharma  N W Al-Khalidi  J L Zimmerman  S M Gaafar 《Journal of the American Veterinary Medical Association》1979,174(6):604-609

Toxoplasmosis was diagnosed at necropsy in a 4-week-old pig from a litter of 16 born to a clinically normal sow. Multifocal acute necrosis of blood vessels and parenchyma was found in the small intestine, mesenteric lymph nodes, liver, lungs, and brain. Numerous tachyzoites, ultrastructurally indistinguishable from Toxoplasma gondii, were found in lesions. The affected pig and seven other littermates died after diarrhea had developed within 1 to 2 weeks of birth. The most likely source of infection was oocysts from cats on the farm.  相似文献