Milk yield and reproductive performance of brucellosis-vaccinated but seropositive Holstein cows     

Miguel Mellado  Angel M. Garcia  Beatriz Arellano-Reynoso  Efren Diaz-Aparicio  Jose E. Garcia 《Tropical animal health and production》2014,46(2):391-397

The aim of this research was to study if seropositivity for brucellosis in vaccinated cows against this disease hampers reproductive performance and milk production in high-yielding Holstein cows. For this purpose 1,026 healthy cows and 372 cows seropositive for brucellosis were enrolled in this study. Cows positive to card test and subsequently to the rivanol test were further subjected to the radial immunodiffusion (RID) test. It was found that only 11 % of the presumably infected cows by brucellosis screening tests were really infected with this disease. The reproductive performance of the group of cows with 11 % Brucella-infected animals was not impaired; overall pregnancy rate did not differ between seropositive and healthy cows (30.9 vs. 29.6 %). The abortion rates were similar between seropositive cows (5.3 %) and seronegative animals (6.9 %). Cows in the herd with 11 % Brucella-infected animals produced significantly more milk than unaffected cows over a 305-day lactation (10,684?±?1,720 vs. 10,345?±?1,736; mean ± SD; P?<?0.05). It was concluded that in dairy herds vaccinated against brucellosis with both 19 and RB51 strains, supplemental tests such as RID need to be conducted on all reactors in order to maintain diagnostic accuracy. These results also indicate that 11 % animal prevalence of brucellosis did not exert a detrimental effect on 305-day milk yield and reproductive performance in high milk-yielding Holstein cows.  相似文献   

Association between cattle herd Mycobacterium avium subsp. paratuberculosis (MAP) infection and infection of a hare population     

Miguel Salgado  Gustavo Monti  Iker Sevilla  Elizabeth Manning 《Tropical animal health and production》2014,46(7):1313-1316

Paratuberculosis has long been considered a disease of domestic and wild ruminants only. The known host range of Mycobacterium avium subsp. paratuberculosis (MAP) was recently extended to include non-ruminant wildlife species believed to be exposed to spillover of MAP from infected domestic cattle herds. The aim of the present study was to assess the association between cattle herd MAP infection pressure level and the infection level of a hare population in two dairy farms of southern Chile. Fifty hares from a herd A and 42 hares from herd B were captured and sampled for MAP culture. The results showed a statistically significant association between the cattle herds’ infection prevalence and the hare infection prevalence.  相似文献   

Neospora caninum infection as a cause of reproductive failure in a sheep flock     

Marta González-Warleta  José Antonio Castro-Hermida  Javier Regidor-Cerrillo  Julio Benavides  Gema álvarez-García  Miguel Fuertes  Luis Miguel Ortega-Mora  Mercedes Mezo 《Veterinary research》2014,45(1)

Neospora caninum has been detected only sporadically in cases of ovine abortion, and it has therefore traditionally been considered as an unimportant parasite in small ruminants. This study was carried out with the aim of identifying the pathogen causing serious reproductive problems on a commercial sheep farm. Sera from all rams and ewes tested negative for antibodies against Border disease virus, Schmallenberg virus and Coxiella burnetii, and infections by these agents were therefore ruled out. Nevertheless, seropositivity to N. caninum and/or Toxoplasma gondii was detected, although the seroprevalence was higher in the case of N. caninum. The percentage of lambings and the number of lambs per dam were significantly lower in ewes that were seropositive to N. caninum while no effect on these parameters was detected in ewes that were seropositive to T. gondii. There was also no evidence of infection by T. gondii in the foetal/lamb tissues analyzed by PCR and/or immunohistopathological techniques. On the contrary, the DNA of N. caninum was detected in 13 out of 14 foetuses/lambs descendant from dams seropositive to this parasite. Characteristic lesions caused by N. caninum and/or its antigen were also detected. Genotyping of the N. caninum DNA revealed only two closely related microsatellite multilocus genotypes. The results clearly demonstrate that infection by N. caninum was the cause of the low reproductive performance of this sheep flock.  相似文献   

Fragmentation patterns and systematic transitions of the forested landscape in the upper Amazon region,Ecuador 1990–2008     

Santiago Bonilla-Bedoya  Juan R. Molina  José E. Macedo-Pezzopane  Miguel A. Herrera-Machuca 《林业研究》2014,25(2):301-309

The analysis of the systematic transitions in the forested landscape and the study of the forest fragmentation patterns allow us to deepen our understanding of the changes in the vegetation ground cover. The importance of knowing the intricate patterns of the land usage of the upper basin of the Amazon region is widely recognized. This zone is one of the most diverse biological areas in the world, is home to large areas of mature tropical cloud forest and demonstrates high probabilities of stable climatic conditions in light of global warming. The research quan- tiffed systematic transitions through the ＂loss＂ and ＂gain＂ of the different categories of landscape during the eighteen-year study period of the Ecuadorian Amazon Region （EAR）, the forest fragmentation patterns were also analyzed based on a set of indicators. Therefore, with respect to the entirety of the landscape, the results registered for the ground coverage in forested areas during the first period （1990-2000）, show a decrease of 6.99% and an increase of 0.68%; and during the second period （2000-2008）, show a decrease of 3.99% and an increase of 2.14%. It demonstrated that forest and agricultural areas tended to replace or be replaced by herbaceous vegetation faster than expected fortuitously. Finally, the indices of fragmentation signaled intense changes during the 1990-2000 period with a reduction during the period 2000-2008. Per- centages registered in the Largest Patch Index （LPI） were between 79.58%; 52.39% and 49.99% respectively; while the Patch Density （PD） varied between 0.04; 0.06 and 0.07. This suggests the propensity of for- est cover to remain intact. The results of this investigation suggest a tendency towards stability in Ecuador＇s Amazon landscape. Within the framework for development and management of this area, the tendency is natural regeneration. This permits a consolidation of the conservation, reforestation, forestation and agricultural forestry plans, programs and systems for the protected areas in EAR.  相似文献   

Effects of antiproteolytic agents on corneal epithelial viability and matrix metalloproteinase‐2 and metalloproteinase‐9 activity in alkali‐burned corneas of rats     

Dunia Y. Trujillo Piso  Alexandre P. Ribeiro  Miguel L. Silva  Patrícia J. Guimarães  Adriana Morales  Bianca C. Martins  Ivan M. Padua  Roberta Renzo  Alexandre L. Andrade  Ricardo R. Uscátegui  José L. Laus 《Veterinary ophthalmology》2014,17(1):23-31

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Effect of increasing levels of seven tree species extracts added to a high concentrate diet on in vitro rumen gas output     

Abdelfattah Z. M. Salem  Ahmed E. Kholif  Mona M. Y. Elghandour  Saul R. Hernandez  Ignacio A. Domínguez‐Vara  Miguel Mellado 《Animal Science Journal》2014,85(9):853-860

This study was conducted to investigate the effects of increasing levels of extracts of Byrsonima crassifolia, Celtis pallida, Enterolobium cyclocarpum, Fraxinus excelsior, Ficus trigonata, Phoradendrom brevifolium and Prunus domestica on in vitro gas production (GP) and ruminal fermentation of a high concentrate diet. Plant extracts were prepared at 1 g dry matter (DM)/8 mL of solvent mixture (methanol : ethanol : water, 1:1:8) and added at levels of 0, 0.6, 1.2 and 1.8 mL/g DM of a high concentrate diet. In vitro GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48 and 72 h of incubation. Increasing addition of extracts linearly increased (P < 0.001), the GP₂₄, GP₄₈ and GP₇₂ (mL/g DM), and linearly decreased (P < 0.001), the discrete GP lag time. Moreover, increasing extract doses linearly increased (P < 0.001) the asymptotic GP and decreased (P < 0.001) the rate of GP. GP₆ was not impacted by treatments and GP₁₂ increased linearly (P = 0.01) with increasing addition of extracts. Rumen pH declined linearly (P < 0.05) with increasing doses of extracts added. As no interactions (P > 0.05) occurred between the extracts and doses, it could be conclude that all extracts positively modified rumen fermentation at doses of 1.2 to 1.8 mL extract/g diet DM.  相似文献   

A review of interactions between cetaceans and fisheries in the Azores     

Mónica A. Silva  Miguel Machete  Dália Reis  Marco Santos  Rui Prieto  Carla Dâmaso  João Gil Pereira  Ricardo S. Santos 《水产资源保护:海洋与淡水生态系统》2011,21(1):17-27

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Sunflower seed meal as a protein source in diets for Tilapia rendalli (Boulanger, 1896) fingerlings     

Miguel A Olvera-Novoa  Leticia Olivera-Castillo  & Carlos A Martínez-Palacios 《Aquaculture Research》2002,33(3):223-229

This study tested the use of sunflower seed meal as a dietary protein replacement for fishmeal in practical diets for tilapia fingerlings. In order to determine the optimum substitution level for this species, sunflower seed meal was used to replace 10%, 20%, 30%, 40% and 50% of the fishmeal protein in diets containing 40% protein overall. During a 70‐day feeding period, diets containing 10% and 20% plant protein provided the best growth and feeding efficiency results, with values statistically similar to those of the control diet based on fishmeal as the sole protein. The unitary feeding cost index showed the highest profit with diets containing 20% sunflower seed meal. Growth depletion observed with diets containing higher sunflower seed meal percentages is explained by increasing Phe and Met deficiencies, and high non‐digestible fibre content. It was concluded that sunflower seed meal is a suitable feed ingredient for tilapia complete diets when it constitutes up to 20% of the dietary protein.  相似文献   

Amino acid profile of the quinoa (Chenopodium quinoa Willd.) using near infrared spectroscopy and chemometric techniques     

Olga Escuredo  M. Inmaculada González Martín  Guillermo Wells Moncada  Susana Fischer  José Miguel Hernández Hierro 《Journal of Cereal Science》2014

The high content of amino acids of the quinoa, especially essential amino acids (higher than other cereals) makes a food increasingly demanded by consumers. A total of twelve amino acids (arginine, cystine, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) were analyzed in quinoa samples from Chile by near infrared spectroscopy (NIR) with direct application to the samples of a remote fiber-optic reflectance probe. The calibration results using modified partial least squares (MPLS) regression satisfactorily allowed the determination of the concentrations of this amino acid group with high multiple correlation coefficients (RSQ = 0.97–0.71) and low standard prediction errors (SEPC = 0.07–0.20). The prediction capacity (RPD) for the arginine, the cystine, the isoleucine, the lysine, the serine, the threonine, the tryptophan, the tyrosine and the valine ranged between 2.6 and 5.2, for the rest of amino acids were higher to 1.8, indicating that the NIRS equations obtained were applicable to unknown samples. It has confirmed that NIRS technology is a method that may be useful to replace the traditional methods for routine analysis of some amino acids.  相似文献   

Antimicrobial and Antibiofilm Effect of Inulin-Type Fructans,Used in Synbiotic Combination with Lactobacillus spp. Against Candida albicans     

García-Gamboa  Ricardo  Domínguez-Simi  Miguel Ángel  Gradilla-Hernández  Misael Sebastián  Bravo-Madrigal  Jorge  Moya  Andrés  González-Avila  Marisela 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(2):212-219

Plant Foods for Human Nutrition - There is great interest in the search for new alternatives to antimicrobial drugs, and the use of prebiotics and probiotics is a promising approach to this...  相似文献