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1.
J Dairy Sci ; 107(6): 3688-3699, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38135042

RESUMO

The objective of the study was to quantify the association between the birth weight of a calf and the subsequent performance of its dairy dam in the absence of any recorded calving assistance. A total of 11,592 lactation records from 4,549 spring-calving dairy cows were used. The association between a series of quantitative cow performance metrics (dependent variable) and calf birth weight (independent variable) was determined using linear mixed models; logistic regression was used where the dependent variable was binary. Nuisance factors in the models were calf sex, heterosis coefficient of both the cow and calf, dry period length immediately before the birth of the calf, cow age at calving relative to the median cow age per parity, breed proportion of the cow, cow live weight between 100 and 200 d of lactation relative to the mean cow weight per parity, and contemporary group. Calf birth weight was included in the model as either a continuous or a categorical variable. Primiparous and multiparous cows were analyzed separately. Mean (SD) calf birth weight was 36.2 (6.8) kg. In primiparous cows, calf birth weight was associated with milk yield in the first 60 d of lactation, calving to first service interval, calving body weight (BW), and both nadir BW and body condition score (BCS). In multiparous cows, calf birth weight was associated with total milk, fat, and protein yield in the first 60 and 305 d of lactation, peak milk yield, total milk solids, both calving and nadir BW, and BCS loss from calving to nadir. Relative to primiparous cows that gave birth to calves weighing 34 to 37 kg (i.e., population mean), their contemporaries who gave birth to calves that weighed 15 to 29 kg produced 9.82 kg more milk in the first 60 d of lactation, had a 2-d shorter interval to first service, and were 8.08 kg and 5.51 kg lighter at calving and nadir BW, respectively; the former was also 0.05 units lower in BCS (5-point scale, 1 = emaciated and 5 = obese) at nadir. Relative to multiparous cows that gave birth to calves that were 34 to 37 kg birth weight, multiparous cows that gave birth to calves that were 15 to 29 kg yielded 59.63 kg, 2.44 kg, and 1.76 kg less milk, fat, and protein, respectively, in the first 60 d of lactation; produced 17.69 kg less milk solids throughout the 305-d lactation; and were also 10.49 kg lighter at nadir and lost 0.01 units more BCS to nadir. In a separate series of analyses, sire breed was added to the model as a fixed effect with and without calf birth weight. When calf birth weight was not adjusted for, 60-d milk yield for multiparous cows who gave birth to calves sired by a traditional beef breed (i.e., Angus, Hereford) produced 59.63 kg more milk than multiparous cows who gave birth to calves sired by a Holstein-Friesian. Hence, calf birth weight is associated with some subsequent dam performance measures; however, where associations do exist, the effect is biologically small.


Assuntos
Peso ao Nascer , Distocia , Lactação , Leite , Animais , Bovinos , Feminino , Leite/metabolismo , Distocia/veterinária , Gravidez , Paridade , Indústria de Laticínios
2.
J Dairy Sci ; 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38825095

RESUMO

As the proportion of prime carcasses originating from dairy herds increases, the focus is shifting to the beef merit of the progeny from dairy herds. Several dairy cow total merit indexes include a negative weight on measures of cow size. However, there is a lack of knowledge on the impact of genetic selection, solely for lighter or smaller-sized dairy cows, on the beef performance of their progeny. Therefore, the objective of this study was to quantify the genetic correlations among cow size traits (i.e., cow body weight (BW), cow carcass weight (CW)), cow body condition score (BCS), cow carcass conformation (CC), and cow carcass fat cover (CF), as well as the correlations between these cow traits and a series of beef performance slaughter-related traits (i.e., CW, CC, CF, and age at slaughter (AS)) in their progeny. After data editing, there were 52,950 cow BW and BCS records, along with 57,509 cow carcass traits (i.e., CW, CC, and CF); carcass records from 346,350 prime animals along with AS records from 316,073 prime animals were also used. Heritability estimates ranged from moderate to high (0.18 to 0.62) for all cow and prime animal traits. The same carcass trait in cows and prime animals were strongly genetically correlated with each other (0.76 to 0.85), implying that they are influenced by very similar genomic variants. Selecting exclusively for cows with higher BCS (i.e., fatter) will, on average, produce more conformed prime animals carcasses, owing to a moderate genetic correlation (0.30) between both traits. Genetic correlations revealed that selecting exclusively for lighter BW or CW cows will, on average, result in lighter prime animal carcasses of poor CC, while also delaying slaughter age. Nonetheless, selective breeding through total merit indexes should be successful in breeding for smaller dairy cows, and desirable prime animal carcass traits concurrently, because of the non-unity genetic correlations between the cow and prime animal traits; this will help to achieve a more ethical, environmentally sustainable, and economically viable dairy-beef industry.

3.
J Dairy Sci ; 105(9): 7550-7563, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35879159

RESUMO

The cumulative improvement achieved in the genetic merit for reproductive performance in dairy populations will likely improve dairy cow longevity; therefore, it is time to reassess whether linear type traits are still suitable predictors of survival in an aging dairy cow population. The objective of the present study was therefore to estimate the genetic correlations between linear type traits and survival from one parity to the next and, in doing so, evaluate if those genetic correlations change with advancing parity. After edits, 152,894 lactation survival records (first to ninth parity) were available from 52,447 Holstein-Friesian cows, along with linear type trait records from 52,121 Holstein-Friesian cows. A series of bivariate random regression models were used to estimate the genetic covariances between survival in different parities and each linear type trait. Heritability estimates for survival per parity ranged from 0.02 (SE = 0.004; first parity) to 0.05 (SE = 0.01; ninth parity). Pairwise genetic correlations between survival among different parities varied from 0.42 (first and ninth parity) to 1.00 (eighth to ninth parity), with the strength of these genetic correlations being inversely related to the interval between the compared parities. The genetic correlations between survival and the individual linear type traits varied across parities for 9 of the 20 linear type traits examined, but the correlations with only 3 of these linear type traits strengthened as the cows aged; these 3 traits were rear udder height, teat length, and udder depth. Given that linear type traits are frequently scored in first parity and are genetically correlated with survival in older parities, they may be suitable early predictors of survival, especially for later parity cows. Additionally, the direction of the genetic correlations between survival and rear udder height, teat length, and udder depth did not change between parities; hence, selection for survival in older parities using these linear type traits should not hinder genetic improvement for survival in younger parities.


Assuntos
Lactação , Glândulas Mamárias Animais , Animais , Bovinos , Feminino , Lactação/genética , Longevidade/genética , Leite , Paridade , Fenótipo , Gravidez
4.
J Dairy Sci ; 105(4): 3341-3354, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35123785

RESUMO

The inclusion of reproductive performance in dairy cow breeding schemes has resulted in a cumulative improvement in genetic merit for reproductive performance; this improvement should manifest in longer productive lives through a reduced requirement for involuntary culling. Nonetheless, the average length of dairy cow productive life has not changed in most populations, suggesting that risk factors for culling, especially in older cows, are possibly more associated with lower yield or high somatic cell score (SCS) than compromised reproductive performance. The objective of the present study was to understand the dynamics of lactation yields and SCS in dairy cows across parities and, in doing so, quantify the potential to alter this trajectory through breeding. After edits, 3,470,520 305-d milk, fat, and protein yields, as well as milk fat and protein percentage and somatic cell count records from 1,162,473 dairy cows were available for analysis. Random regression animal models were used to identify the parity in which individual cows reached their maximum lactation yields, and highest average milk composition and SCS; also estimated from these models were the (co)variance components for yield, composition, and SCS per parity across parities. Estimated breeding values for all traits per parity were calculated for cows reaching ≥fifth parity. Of the cows included in the analyses, 91.0%, 92.2%, and 83.4% reached maximum milk, fat, and protein yield in fifth parity, respectively. Conversely, 95.9% of cows reached their highest average fat percentage in first parity and 62.9% of cows reached their highest average protein percentage in third parity. In contrast to both milk yield and composition traits, 98.4% of cows reached their highest average SCS in eighth parity. Individual parity estimates of heritability for milk yield traits, milk composition, and SCS ranged from 0.28 to 0.44, 0.47 to 0.69, and 0.13 to 0.23, respectively. The strength of the genetic correlations per trait among parities was inversely related to the interval between the parities compared; the weakest genetic correlation was 0.67 (standard error = 0.02) between milk yield in parities 1 and 8. Eigenvalues and eigenfunctions of the additive genetic covariance matrices for all investigated traits revealed potential to alter the trajectory of parity profiles for milk yield, milk composition, and SCS. This was further demonstrated when evaluating the trajectories of animal estimated breeding values per parity.


Assuntos
Lactação , Leite , Animais , Bovinos/genética , Contagem de Células/veterinária , Feminino , Lactação/genética , Leite/metabolismo , Paridade , Fenótipo , Gravidez
5.
J Dairy Sci ; 105(2): 1346-1356, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34955265

RESUMO

Measuring dry matter intake (DMI) in grazing dairy cows using currently available techniques is invasive, time consuming, and expensive. An alternative to directly measuring DMI for use in genetic evaluations is to identify a set of readily available animal features that can be used in a multitrait genetic evaluation for DMI. The objectives of the present study were thus to estimate the genetic correlations between readily available body-related linear type traits and DMI in grazing lactating Holstein-Friesian cows, but importantly also estimate the partial genetic correlations between these linear traits and DMI, after adjusting for differences in genetic merit for body weight. Also of interest was whether the predictive ability derived from the estimated genetic correlations materialized upon validation. After edits, a total of 8,055 test-day records of DMI, body weight, and milk yield from 1,331 Holstein-Friesian cows were available, as were chest width, body depth, and stature from 47,141 first lactation Holstein-Friesian cows. In addition to considering the routinely recorded linear type traits individually, novel composite traits were defined as the product of the linear type traits as an approximation of rumen volume. All linear type traits were moderately heritable, with heritability estimates ranging from 0.27 (standard error = 0.14) to 0.49 (standard error = 0.15); furthermore, all linear type traits were genetically correlated (0.29 to 0.63, standard error 0.14 to 0.12) with DMI. The genetic correlations between the individual linear type traits and DMI, when adjusted for genetic differences in body weight, varied from -0.51 (stature) to 0.48 (chest width). These genetic correlations between DMI and linear type traits suggest linear type traits may be useful predictors of DMI, even when body weight information is available. Nonetheless, estimated genetic merit of DMI derived from a multitrait genetic evaluation of linear type traits did not correlate strongly with actual DMI in a set of validation animals; the benefit was even less if body weight data were also available.


Assuntos
Lactação , Leite , Ração Animal/análise , Animais , Peso Corporal/genética , Bovinos/genética , Ingestão de Alimentos , Feminino , Lactação/genética , Fenótipo
6.
J Dairy Sci ; 104(1): 561-574, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33189261

RESUMO

Lactation yield estimates standardized to common lactation lengths of 270-d or 305-d equivalents are commonly used in management decision support tools and dairy cow genetic evaluations. The use of such measurements to quantify the (genetic) merit of individual cows fails to penalize cows that do not reach the standardized lactation length, or indeed reward cows that lactate for more than the standardized lactation length. The objective of the present study was to quantify the genetic and nongenetic factors associated with lactation length in seasonal-calving, pasture-based dairy cows. A total of 616,350 lactation length records from 285,598 Irish cows were used. Linear mixed models were used to quantify the associations between lactation length and calving month, parity, age at calving, previous dry period length, calving difficulty score, heterosis, recombination loss, breed, and herd size, as well as to estimate the genetic and residual variance components of lactation length. The median lactation length in the edited data set was 288 d, with 27% of cows achieving lactations of at least 305 d. Relative to cows calving in January, the lactations of cow calving in February, March, or April was, on average, 4.2, 12.7, and 21.9 d shorter, respectively. The lactation length of a first parity cow was, on average, 7.8, 8.6, and 8.4 d shorter than that of second, third, and fourth parity cows, respectively. Norwegian Red and Montbéliarde cows had, on average, a 4.7- and 1.6-d shorter lactation than Holstein-Friesian cows, respectively. The heritability estimate, coefficient of genetic variation, and repeatability estimate of lactation length were 0.02, 1.2%, and 0.04, respectively. Based on the genetic standard deviation for lactation length estimated in the present study (3.3 d), cows ranked in the top 20% for genetic merit for lactation length would be expected to have lactations 9.2 d longer than cows in the bottom 20%, demonstrating exploitable genetic variability. Given the vast array of genetic and nongenetic factors associated with lactation length, an approach which combines improved management practices and selective breeding may be an efficient and effective strategy to lengthen lactations.


Assuntos
Bovinos/genética , Lactação/genética , Animais , Feminino , Herbivoria , Leite , Paridade , Gravidez , Estações do Ano , Tempo
7.
J Dairy Sci ; 101(2): 1565-1578, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29153515

RESUMO

The objective of this study was to identify the major electricity and water-consuming components of a pasture-based automatic milking (AM) system and to establish the daily and seasonal consumption trends. Electricity and water meters were installed on 7 seasonal calving pasture-based AM farms across Ireland. Electricity-consuming processes and equipment that were metered for consumption included milk cooling components, air compressors, AM unit(s), auxiliary water heaters, water pumps, lights, sockets, automatic manure scrapers, and so on. On-farm direct water-consuming processes and equipment were metered and included AM unit(s), auxiliary water heaters, tubular coolers, wash-down water pumps, livestock drinking water supply, and miscellaneous water taps. Data were collected and analyzed for the 12-mo period of 2015. The average AM farm examined had 114 cows, milking with 1.85 robots, performing a total of 105 milkings/AM unit per day. Total electricity consumption and costs were 62.6 Wh/L of milk produced and 0.91 cents/L, respectively. Milking (vacuum and milk pumping, within-AM unit water heating) had the largest electrical consumption at 33%, followed by air compressing (26%), milk cooling (18%), auxiliary water heating (8%), water pumping (4%), and other electricity-consuming processes (11%). Electricity costs followed a similar trend to that of consumption, with the milking process and water pumping accounting for the highest and lowest cost, respectively. The pattern of daily electricity consumption was similar across the lactation periods, with peak consumption occurring at 0100, 0800, and between 1300 and 1600 h. The trends in seasonal electricity consumption followed the seasonal milk production curve. Total water consumption was 3.7 L of water/L of milk produced. Water consumption associated with the dairy herd at the milking shed represented 42% of total water consumed on the farm. Daily water consumption trends indicated consumption to be lowest in the early morning period (0300-0600 h), followed by spikes in consumption between 1100 and 1400 h. Seasonal water trends followed the seasonal milk production curve, except for the month of May, when water consumption was reduced due to above-average rainfall. This study provides a useful insight into the consumption of electricity and water on a pasture-based AM farms, while also facilitating the development of future strategies and technologies likely to increase the sustainability of AM systems.


Assuntos
Criação de Animais Domésticos/economia , Automação , Bovinos/fisiologia , Eletricidade , Fazendas/economia , Fazendas/estatística & dados numéricos , Estações do Ano , Criação de Animais Domésticos/métodos , Animais , Indústria de Laticínios/economia , Feminino , Irlanda , Lactação , Leite/economia , Fatores de Tempo , Água
8.
J Dairy Sci ; 99(9): 7700-7713, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27423956

RESUMO

The successful integration of automatic milking (AM) systems and grazing has resulted in AM becoming a feasible alternative to conventional milking (CM) in pasture-based systems. The objective of this study was to identify the profitability of AM in a pasture-based system, relative to CM herringbone parlors with 2 different levels of automation, across 2 farm sizes, over a 10-yr period following initial investment. The scenarios which were evaluated were (1) a medium farm milking 70 cows twice daily, with 1 AM unit, a 12-unit CM medium-specification (MS) parlor and a 12-unit CM high-specification (HS) parlor, and (2) a large farm milking 140 cows twice daily with 2 AM units, a 20-unit CM MS parlor and a 20-unit CM HS parlor. A stochastic whole-farm budgetary simulation model combined capital investment costs and annual labor and maintenance costs for each investment scenario, with each scenario evaluated using multiple financial metrics, such as annual net profit, annual net cash flow, total discounted net profitability, total discounted net cash flow, and return on investment. The capital required for each investment was financed from borrowings at an interest rate of 5% and repaid over 10-yr, whereas milking equipment and building infrastructure were depreciated over 10 and 20 yr, respectively. A supporting labor audit (conducted on both AM and CM farms) showed a 36% reduction in labor demand associated with AM. However, despite this reduction in labor, MS CM technologies consistently achieved greater profitability, irrespective of farm size. The AM system achieved intermediate profitability at medium farm size; it was 0.5% less profitable than HS technology at the large farm size. The difference in profitability was greatest in the years after the initial investment. This study indicated that although milking with AM was less profitable than MS technologies, it was competitive when compared with a CM parlor of similar technology.


Assuntos
Automação/economia , Bovinos , Indústria de Laticínios/economia , Investimentos em Saúde , Lactação , Leite/economia , Animais , Automação/instrumentação , Indústria de Laticínios/instrumentação , Indústria de Laticínios/métodos , Feminino
9.
Br J Biomed Sci ; 71(1): 6-12, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24693569

RESUMO

Recently, Campylobacter ureolyticus has been detected for the first time in the faeces of patients with acute gastroenteritis using polymerase chain reaction (PCR) techniques. Cultural isolation of C. ureolyticusis is not possible using the established selective methods for the isolation of thermophilic Campylobacter spp. from faeces. The aim of the current study is to develop a new selective medium capable of isolating C. ureolyticus from faecal samples. The newly-developed medium consists of Anaerobe Basal Agar with 10 g/L additional agar, 2 g/L sodium formate and 3 g/L sodium fumarate dibasic, to which 10 mg/L nalidixic acid, 10 mg/L amphotericin B and 20 mg/L vancomycin (NAV) are added as selective agents. Validation studies have shown that this experimental selective medium completely inhibits growth of Candida spp. and of Enterococcus spp. and permits reduced growth of selected coliforms and Proteus spp. Growth of Campylobacter ureolyticus on NAV medium is optimal in anaerobic and enriched hydrogen atmospheres. Additionally, an overnight enrichment step using Bolton broth to which 2 g/L sodium formate, 3 g/L sodium fumarate dibasic and the NAV supplement are added, in place of the commercial Bolton broth supplement, allows improved recovery of C. ureolyticus from patients' faeces.


Assuntos
Anfotericina B , Campylobacter/isolamento & purificação , Meios de Cultura , Fezes/microbiologia , Gastroenterite/microbiologia , Ácido Nalidíxico , Vancomicina , Humanos
10.
Br J Biomed Sci ; 80: 11098, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37020476

RESUMO

Environmental contamination is estimated to contribute to up to 20% of all hospital acquired infections. Acinetobacter baumannii is an example of one the most prevalent opportunistic pathogens causing severe and persistent infections in immunocompromised patients. It has proven ability to form biofilms, has significant associated multi-drug resistance and is able to transfer mobile genetic elements to other clinically relevant pathogens. All of these factors point to a definite utility of A. baumannii as an indicator organism for effectiveness of decontamination regimens as well as environmental screening. There is an increased cost, both financial and clinical, associated with multi drug resistant organisms, carbapenem resistant A. baumannii. With a dearth of new antimicrobials in development, now is the time to radically transform and lead the introduction of scientifically based environmental screening and microbiological verified decontamination to control the dissemination of further resistance.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Infecção Hospitalar , Humanos , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/prevenção & controle , Carbapenêmicos/farmacologia , Acinetobacter baumannii/genética , Hospitais , Infecção Hospitalar/microbiologia , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Testes de Sensibilidade Microbiana
11.
Epidemiol Infect ; 140(4): 684-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21676357

RESUMO

From January 2009 to May 2010, 436 faecal samples from patients with diarrhoeal illness in Southern Ireland were identified as Campylobacter genus-positive by an automated multiplex PCR; however, 204 (46·8%) of these samples were culture-negative for campylobacters. A combination of Campylobacter-specific uniplex PCR and 16S rRNA sequencing confirmed the presence of Campylobacter DNA in 191 (93·6%) of the culture-negative samples. Species-specific PCR identified C. jejuni (50·7%) C. ureolyticus (41%) and C. coli (5·7%) as the most prevalent species while C. fetus, C. upsaliensis, C. hyointestinalis and C. lari accounted for 10% of culture-negative samples; mixed Campylobacter spp. were detected in 11% of samples. We conclude that non-culturable Campylobacter spp. are responsible for a considerable proportion of human enteritis and the true incidence of infection is likely to be significantly underestimated where conventional Campylobacter culture methods are used in isolation.


Assuntos
Infecções por Campylobacter/microbiologia , Campylobacter/genética , Gastroenterite/microbiologia , Infecções por Campylobacter/diagnóstico , Campylobacter coli/genética , Campylobacter jejuni/genética , Fezes/microbiologia , Gastroenterite/diagnóstico , Humanos , Reação em Cadeia da Polimerase
12.
J Appl Microbiol ; 110(5): 1187-94, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21338448

RESUMO

AIMS: To assess the contribution of proline biosynthesis to listerial barotolerance. METHODS AND RESULTS: Using a Listeria monocytogenes proBA deletion mutant, incapable of synthesizing proline, together with a proline-overproducing strain, the contribution of proline synthesis to listerial barotolerance was determined. The ΔproBA strain does not survive as well as the wild type when subjected to treatment of 500 MPa in rich media and 400 MPa in minimal media (c. 1 log lower survival in both conditions). Betaine and carnitine decrease the ability of the wild type to survive at low pressures (300 MPa), but confer normal or slightly increased levels of protection at higher pressures (350 and 400 MPa). CONCLUSIONS: A functional proline synthesis system is required for optimal survival of Listeria following treatment at high-pressure (HP) levels (500 MPa in brain heart infusion and 400 MPa in defined medium), particularly where other compatible solutes are absent or limiting. SIGNIFICANCE AND IMPACT OF THE STUDY: Given the potential of HP processing as an effective food processing/safety strategy, understanding how pathogens such as Listeria have evolved to cope with such stresses is an important food safety consideration. In this context, the work presented here may help to develop safer and more effective processing regimens.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes/metabolismo , Pressão , Prolina/biossíntese , Betaína/farmacologia , Carnitina/farmacologia , Meios de Cultura , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/genética , Viabilidade Microbiana , Deleção de Sequência
13.
J Appl Microbiol ; 110(3): 618-30, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21223465

RESUMO

AIMS: To identify Listeria monocytogenes genes with a role in high-pressure (HP) resistance. METHODS AND RESULTS: A L. monocytogenes genomic library constructed in an Escherichia coli background was screened for loci conferring increased HP resistance. Pressure treatments at 400 megapascals for 5 min in Luria-Bertani (LB) agar were used to screen for increased resistance to pressure. Colonies arising on the treated agar plates were isolated, the plasmid extracted and the inserts sequenced to identify the genetic loci conferring HP resistance. Seven different genetic regions were identified, which encoded proteins similar to an inorganic polyphosphate/ATP-NAD kinase, the septation ring formation regulator EzrA, flagellar motor proteins MotA and MotB, proteins similar to the quorum sensing Agr system from Staphylococcus (AgrA, AgrC and AgrD), proteins similar to a transcription regulator (RpiR family) and a fructose phosphotransferase system, proteins of unknown function, and a Fur regulator. Of the seven loci confirmed, three (EzrA, MotA/B and the Agr system) maintained significantly reproducible HP tolerance when expressed in a different E. coli background. CONCLUSIONS: Novel genetic loci from the L. monocytogenes genome confer increased HP resistance when heterologously expressed in an E. coli background. SIGNIFICANCE AND IMPACT OF THE STUDY: Molecular and functional approaches to the screening of genetic elements linked to HP resistance provide greater insights into microbial inactivation and/or survival mechanisms when using HP as a means of controlling/eliminating bacterial growth. This information will ultimately have significant implications for the use of HP processing in the food industry, in terms of both food quality and safety.


Assuntos
Escherichia coli/genética , Loci Gênicos/genética , Listeria monocytogenes/genética , Pressão , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/ultraestrutura , Biblioteca Genômica , Viabilidade Microbiana/genética , Técnicas Microbiológicas , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Plasmídeos/genética , Estresse Fisiológico/genética
14.
Transl Anim Sci ; 5(3): txab101, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34278237

RESUMO

Validation of beef total merit breeding indexes for improving performance and profitability has previously been undertaken at the individual animal level; however, no herd-level validation of beef genetic merit and profit has been previously investigated. The objective of the present study was to quantify the relationship between herd profitability and both herd-average terminal and maternal genetic merit across 1,311 commercial Irish beef herds. Herd-level physical and financial performance data were available from a financial benchmarking tool used by Irish farmers and their extension advisors. Animal genetic merit data originated from the Irish Cattle Breeding Federation who undertake the national beef and dairy genetic evaluations. Herd-average genetic merit variables included the terminal index of young animals, the maternal index of dams, and the terminal index of service sires. The herds represented three production systems: 1) cow-calf to beef, 2) cow-calf to weanling/yearling, and 3) weanling/yearling to beef. Associations between herd financial performance metrics and herd average genetic merit variables were quantified using a series of linear mixed models with year, production system, herd size, stocking rate, concentrate input, and the two-way interactions between production system and herd size, stocking rate, and concentrate input included as nuisance factors. Herd nested within the county of Ireland (n = 26) was included as a repeated effect. Herds with young cattle excelling in terminal index enjoyed greater gross and net profit per hectare (ha), per livestock unit (LU), and per kg net live-weight output. The change in gross profit per LU per unit change in the terminal index of young animals was €1.41 (SE = 0.23), while the respective regression coefficient for net profit per LU was €1.37 (SE = 0.30); the standard deviation of the terminal index is €37. Herd-average dam maternal index and sire terminal index were both independently positively associated with gross profit per ha and gross profit per LU. Each one unit increase in dam maternal index (standard deviation of €38) was associated with a €1.40 (SE = 0.48) and €0.76 (SE = 0.29) greater gross profit per ha and per LU, respectively. Results from the present study at the herd-level concur with previous validation studies at the individual animal level thus instilling further confidence among stakeholders as to the expected improvement in herd profitability with improving genetic merit.

15.
Arch Virol ; 155(8): 1247-59, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20526785

RESUMO

Porcine group A rotaviruses (GARV) are causative agents of enteritis in piglets and are a large reservoir of genetic material for the diversification of human GARVs. Accumulation of information on the genetic heterogeneity of porcine viruses is pivotal for readily characterising unusual human strains. Screening of 292 fecal samples, collected from 4-5- to 8-9-week-old asymptomatic pigs from four herds in Ireland between 2005 and 2007 resulted in 19 (6.5%) samples testing positive by reverse-transcription PCR (RT-PCR) for GARV. The strains were molecularly characterized to collate data on the VP7 and partial VP4 outer capsid genes. By sequence analysis of the VP7 gene, the Irish strains were identified as G2, G4, G5, G9 and G11 viruses. The G11 strains were closely related to other human and porcine G11 strains, while the G2 strains resembled porcine G2 viruses detected recently in Europe and southern Asia. The G4 strains were distantly related to other G4 human and animal strains, constituting a separate G4 VP7 lineage. Analysis of the G5 strains revealed that they were similar to a selection of G5 human and porcine strains, while the G9 strains resembled other porcine G9 viruses. By sequence analysis of the VP8* fragment of the VP4, the Irish viruses were characterised as P[6], P[7], P[13], P[13]/[22], P[26] and P[32].


Assuntos
Infecções por Rotavirus/veterinária , Rotavirus/genética , Doenças dos Suínos/virologia , Animais , Antígenos Virais/genética , Proteínas do Capsídeo/genética , Fezes/virologia , Genótipo , Irlanda , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/fisiopatologia , Infecções por Rotavirus/virologia , Análise de Sequência de DNA , Suínos/virologia , Doenças dos Suínos/fisiopatologia
16.
Infect Prev Pract ; 2(4): 100100, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34368728

RESUMO

BACKGROUND: Carbapenems are a family of end line antibiotics with increasing levels of resistance that are a cause for concern. AIM: To ascertain whether the CPE screening programme employed in an acute tertiary hospital is fit for purpose. METHOD: We outlined the current working algorithm employed using a universal screening programme over a 26-month screening period. Rectal swabs are cultured on arrival. Those with suspicious growth are further investigated using NG-Carba 5 lateral flow tests and Vitek 2.0 sensitivity cards. These practices were compared with NHS guidelines. FINDINGS & CONCLUSIONS: In all, 53 true positives were detected from 45 patients since the screening was implemented in early 2018 (46 OXA-48, 6 KPC, 1 NDM). As the rate of screening increased, the number of positive screens decreased over time. There were a lot of similarities between the HSE guidelines and the published NHS CPE toolkit. It was evident that there is no standard practice being employed across all hospitals. Comparing the MUH to national guidelines it appears to be quicker and more effective with universal screening in place at reducing the potential contacts and identifying carriers. Cost analysis indicates that the need to confirm all positive strains in a reference lab is costly, unnecessary and time consuming. There are adequate confirmatory tests available in-house for routine positive screens. It was concluded that infection prevention and control are key to identifying and controlling possible outbreaks in a hospital setting.

17.
J Appl Microbiol ; 104(4): 1221-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17976173

RESUMO

AIMS: To investigate the effect of glycine betaine (GB) on the survival of Listeria monocytogenes on leaf surfaces under low relative humidity (RH). METHODS AND RESULTS: The addition of GB (> or = 25 mmol l(-1)) improved the survival of L. monocytogenes under low RH on parsley leaves, thus suggesting that GB can improve the tolerance of L. monocytogenes to desiccation. Ten times less GB was needed to improve L. monocytogenes survival under low RH on nonbiological surfaces compared with parsley leaves, suggesting that, on the leaf surface, L. monocytogenes may have to compete for the available GB with autochthonous bacteria and/or the plant itself. Wild type and mutants carrying deletions in the three GB uptake systems, BetL, Gbu and OpuC, behaved similarly with and without added GB on parsley leaves (P > 0.05). In addition, preaccumulation of GB, triggered by osmotic stress prior to inoculation, failed to improve survival under low RH compared with osmotic stress without GB accumulation. CONCLUSIONS: Exogenous GB had a protective effect on L. monocytogenes cells from desiccation during survival on parsley leaves. This effect was independent of intracellular GB accumulation by the known uptake systems. SIGNIFICANCE AND IMPACT OF THE STUDY: Presence of GB could improve the survival of L. monocytogenes to desiccation on leaf surfaces and nonbiological surfaces.


Assuntos
Betaína/farmacologia , Microbiologia de Alimentos , Listeria monocytogenes/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Técnicas Bacteriológicas , Betaína/metabolismo , Transporte Biológico , Transporte Biológico Ativo , Contagem de Colônia Microbiana , Meios de Cultura , Dessecação , Listeria monocytogenes/efeitos dos fármacos , Listeriose/transmissão , Viabilidade Microbiana , Pressão Osmótica , Petroselinum/microbiologia , Folhas de Planta/microbiologia , Virulência
18.
Lett Appl Microbiol ; 47(5): 361-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19146522

RESUMO

The total number of prokaryotic cells on earth has been estimated to be approximately 4-6 x 10(30), with the majority of these being uncharacterized. This diversity represents a vast genetic bounty that may be exploited for the discovery of novel genes, entire metabolic pathways and potentially valuable end-products thereof. Metagenomics constitutes the functional and sequence-based analysis of the collective microbial genomes (microbiome) in a particular environment or environmental niche. Herein, we review the most recent sequence-based metagenomic analyses of some of the most microbiologically diverse locations on earth; including soil, marine water and the insect and human gut. Such studies have helped to uncover several previously unknown facts; from the true microbial diversity of extreme environments to the actual extent of symbiosis that exists in the insect and human gut. In this respect, metagenomics has and will continue to play an essential part in the new and evolving area of microbial systems biology.


Assuntos
Archaea/genética , Bactérias/genética , Trato Gastrointestinal/microbiologia , Genômica/métodos , Células Procarióticas , Microbiologia do Solo , Microbiologia da Água , Animais , Humanos , Insetos
19.
Lett Appl Microbiol ; 46(2): 143-7, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18028323

RESUMO

The increasing incidence of antibiotic resistance, coupled with a growing prevalence of cancer and allergic conditions in an aging population, has forced clinical research to explore alternative therapeutic and prophylactic avenues. One such approach involves the use of probiotics: beneficial bacterial cultures, which, when administered as a part of the daily dietary intake, reduce the incidence and severity of acute and chronic infection, facilitate prevention and reduced recurrence of certain cancers and lower the incidence of several atopic conditions. Herein, we review the most recent advances in the emerging area of patho-biotechnology in the context of improving probiotic production, delivery and clinical efficacy, in addition to the emerging area of 'designer probiotics'- strains specifically tailored to target certain pathogens and/or toxins in vivo.


Assuntos
Gastroenteropatias/terapia , Intestinos/microbiologia , Probióticos/uso terapêutico , Humanos , Pesquisa/tendências , Projetos de Pesquisa
20.
Animal ; 12(4): 853-863, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28931455

RESUMO

The objective of this experiment was to establish the effect of low-concentrate (LC) and high-concentrate (HC) supplementation in the early and late periods of lactation on milk production and cow traffic in a pasture-based automatic milking (AM) system. In total, 40 cows (10 primiparous and 30 multiparous) were randomly assigned to one of the two treatments. The experimental periods for the early and late lactation trials extended from 23 February to 12 April 2015 and 31 August to 18 October 2015, respectively (49 days in each trial period). The early lactation supplement levels were 2.3 and 4.4 kg/cow per day for LC and HC, respectively, whereas the late lactation supplement levels were 0.5 and 2.7 kg/cow per day for LC and HC, respectively. Variables measured included milking frequency, milking interval, milking outcome and milking characteristics, milk yield/visit and per day, wait time/visit and per day, return time/visit and the distribution of gate passes. As the herd was seasonal (spring) calving, the experimental periods could not run concurrently and as a result no statistical comparison between the periods was conducted. There was no significant effect of treatment in the early lactation period on any of the milk production, milking characteristics or cow traffic variables. However, treatment did significantly affect the distribution of gate passes, with the HC cows recording significantly more gate passes in the hours preceding the gate time change such as hours 7 (P<0.01), 15 (P<0.05), 20, 21 (P<0.001), and 22 (P<0.05), whereas the LC treatment recorded significantly more gate passes in the hours succeeding the gate time change, such as time points 2 (P<0.01) and 10 (P<0.05). There was a significant effect of treatment in late lactation, with HC having a greater milk yield (P<0.01), milking duration and activity/day (P<0.05), while also having a significantly shorter milking interval (P<0.05) and return time/visit (P<0.01). The distribution of gate passes were similar to the early lactation period, with HC also recording a significantly greater number of gate passes during the early morning period (P<0.01) when visitations were at their lowest. Any decision regarding the supplementing of dairy cows with concentrates needs to be examined from an economic perspective, to establish if the milk production and cow traffic benefits displayed in late lactation outweigh the cost of the concentrate; thereby ensuring that the decision to supplement is financially prudent.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Bovinos/fisiologia , Indústria de Laticínios/instrumentação , Lactação/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Indústria de Laticínios/métodos , Dieta/veterinária , Suplementos Nutricionais , Feminino , Leite , Paridade , Gravidez , Estações do Ano
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