RESUMO
O presente estudo tem como objetivo descrever os dados das condenações de pulmões por aspiração de sangue em abate de suínos do estado da Bahia, no período de janeiro de 2018 a outubro de 2020, em abatedouros sob fiscalização do Serviço de Inspeção Estadual (SIE). A coleta retrospectiva foi facilitada pela Agência de Defesa Agropecuária da Bahia (ADAB), através da Guia de Trânsito Animal (GTA), e foram coletados dados de 255.834 suínos abatidos em matadouros frigoríficos, localizados em oito municípios. Nos anos de 2018 e 2019, a aspiração de sangue foi a lesão mais encontrada. Em 2018, foram 15,45% (1131/7322) das alterações macroscópicas e 36,48% (1131/3100) das condenações pulmonares, e em 2019, foram 14,75% (1053/7138) e 36,20% (1053/2909), respectivamente. A congestão foi a lesão mais encontrada em 2020, mas não houve diferença considerável com a aspiração de sangue, que foi destaque das condenações pulmonares, com 38,07% (712/1870). Estes dados revelam a frequência de condenação por aspiração de sangue no estado da Bahia e sugerem implementação de treinamentos de manejo não violento para os funcionários dos abatedouros frigoríficos, visto que esse tipo de lesão indica estresse e uma tecnopatia associada à falha na insensibilização e sangria, em razão do animal agonizar enquanto tenta respirar após a incisão no pescoço.
This study aims to analyze data on lung condemnations for blood aspiration in pig slaughter in the state of Bahia, Brazil from january 2018 to october 2020, in slaughterhouses under supervision of the State Inspection Service (SIE). The retrospective collection was facilitated by the Agricultural Defense Agency of Bahia (ADAB), through the Animal Transit Guide (GTA), and data were collected from 255,834 pigs slaughtered in slaughter houses located in eight municipalities. In 2018 and 2019, blood aspiration was the most common lesion. In 2018, it was 15,45% (1131/7322) of macroscopic changes and 36,48% (1131/3100) of lung condemnations, and in 2019, it was 14,75% (1053/7138) and 36,20% (1053/2909), respectively. Congestion was the most common lesion found in 2020, but there was no considerable difference with blood aspiration, which was highlighted in pulmonary condemnations, with 38,07% (712/1870). These data reveal the frequency of condemnations for blood aspiration in the state of Bahia, Brazil and suggest the implementation of training in non-violent management for employees of slaughterhouses, as this type of injury indicates stress and a technopathy as sociated with failure in stunning and bleeding, because the animal agonizes while trying to breathe after the neck incision
Assuntos
Animais , Suínos/lesões , Ferimentos e Lesões/veterinária , Matadouros/estatística & dados numéricos , Aspiração Respiratória/veterinária , Lesão Pulmonar/veterinária , Abate de Animais/estatística & dados numéricosRESUMO
Industry-led culling of badgers has occurred in England to reduce the incidence of bovine tuberculosis in cattle for a number of years. Badger vaccination is also possible, and a move away from culling was "highly desirable" in a recent report to the UK government. Here we used an established simulation model to examine badger control option in a post-cull environment in England. These options included no control, various intermittent culling, badger vaccination and use of a vaccine combined with fertility control. The initial simulated cull led to a dramatic reduction in the number of infected badgers present, which increased slowly if there was no further badger management. All three approaches led to a further reduction in the number of infected badgers, with little to choose between the strategies. We do note that of the management strategies only vaccination on its own leads to a recovery of the badger population, but also an increase in the number of badgers that need to be vaccinated. We conclude that vaccination post-cull, appears to be particularly effective, compared to vaccination when the host population is at carrying capacity.
Assuntos
Abate de Animais/métodos , Reservatórios de Doenças/veterinária , Mustelidae/microbiologia , Tuberculose Bovina/prevenção & controle , Vacinação/métodos , Abate de Animais/estatística & dados numéricos , Animais , Bovinos , Simulação por Computador , Inglaterra , Incidência , Modelos Estatísticos , Mycobacterium bovis/imunologia , Mycobacterium bovis/isolamento & purificação , Mycobacterium bovis/patogenicidade , Controle da População/métodos , Controle da População/estatística & dados numéricos , Tuberculose Bovina/transmissão , Vacinação/estatística & dados numéricosRESUMO
BACKGROUND: Physical removal of individuals from groups causes reductions in group sizes and changes in group composition, which may affect the predictive ability of estimates of indirect genetic effects of animals on phenotypes of group mates. We hypothesized that including indirect genetic effects of culled animals and of animals without phenotypes in the analysis affects estimates of genetic parameters, improves predictive ability, and reduces bias of predicted breeding values. We tested this by applying different editing procedures, i.e. omission of individuals or groups from the data, and genetic models, i.e. a classical and an indirect genetic model (IGM) without or with weighting of indirect genetic effects based on the relative proportion of time spent in the pen or space allowance. Data consisted of average daily gain for 123,567 pigs in 11,111 groups, from which 3% of individuals in 25% of groups were prematurely removed from the group. RESULTS: The estimate of total heritability was higher (0.29 to 0.34) than that of direct heritability (0.23 to 0.25) regardless of the editing procedures and IGM used. Omission of individuals or groups from the data reduced the predictive ability of estimates of indirect genetic effects by 8 to 46%, and the predictive ability of estimates of the combined direct and indirect genetic effects by up to 4%. Omission of full groups introduced bias in predicted breeding values. Weighting of indirect genetic effects reduced the predictive ability of their estimates by at least 19% and of the estimates of the combined direct and indirect genetic effects by 1%. CONCLUSIONS: We identified significant indirect genetic effects for growth in pigs. Culled animals should neither be removed from the data nor accounted for by weighting their indirect genetic effects in the model based on the relative proportion of time spent in the pen or space allowance, because it will reduce predictive ability and increase bias of predicted breeding values. Information on culled animals is important for prediction of indirect genetic effects and must be accounted for in IGM analyses by including fixed regressions based on relative time spent within the pen or relative space allowance.
Assuntos
Modelos Genéticos , Suínos/genética , Matadouros , Abate de Animais/estatística & dados numéricos , Animais , Viés , Cruzamento , Feminino , Masculino , Suínos/crescimento & desenvolvimento , Suínos/fisiologiaRESUMO
In food webs, fishery can play the role of top predator, competing thus with other top predators for valuable food resources. In this view, it has been claimed in fisheries management that culling of top predators can be a means to improve fishery yield. To investigate this hypothesis, we use theoretical population models to assess in a multispecies context how fishery yield from target species harvest responds to top predator cull. Defying crisp summary, the four analysed food web models show that this response may be either positive or negative or both, indicating that in terms of multispecies fishery management the harvest yield may not accrue as a consequence of predator removal. In addition, this multitude of behaviours points also to the fact that the response of fishery yield to top predator cull may be difficult to assess.
Assuntos
Pesqueiros , Cadeia Alimentar , Abate de Animais/métodos , Abate de Animais/estatística & dados numéricos , Animais , Ecossistema , Pesqueiros/organização & administração , Pesqueiros/estatística & dados numéricos , Conceitos Matemáticos , Modelos Biológicos , Dinâmica não Linear , Comportamento Predatório , Especificidade da EspécieRESUMO
This symposium review examines the association between comfort and cow longevity, with a particular emphasis on optimizing resting behavior in confinement-housed systems. Housed dairy cattle demonstrate a variety of negative behavioral and physiological effects when lying time is restricted, with cows prioritizing the recovery of rest over feeding when both are deprived. There is, however, wide individual-cow variation in daily lying times, influenced by an array of cow-, housing-, and management-related factors. Cow-related factors include individual preference, parity, stage of lactation cycle, milk yield, ill health, and lameness. Lying time tends to increase with age and days in milk and during periods of ill health, whereas milk yield is negatively correlated with lying time. The effect of lameness is complicated by severity and by interactions with bedding type, which modifies the cows' ability to rise and lie down. Generally, lame cows suffer prolonged lying bouts of greater variability in length and take fewer bouts per day. Often this results in an overall increase in lying time. Thus, higher standards of cow comfort and improved cow health are not always reflected by longer lying times. Housing and management factors that influence resting behavior include the design of the resting area, access to the resting space, and the thermal microenvironment of the lying area. Provision of dry, deep loose bedding, stocking cows to allow each animal access to a resting space, allowing sufficient time to access the resting area, and providing heat abatement to reduce heat load optimize resting behavior. Because lameness and poor body condition are commonly found in culled dairy cattle, the link between cow comfort and culling is likely mediated through lameness onset and management. Optimal comfort helps prevent the onset of lameness and facilitates recovery once cows become lame, which limits the effect of lameness on feeding behavior and reduces the risk for other health-related disorders, poor reproductive performance, and early herd removal. Cow comfort cannot be assessed by measuring the duration of lying time alone. Rather, comfort is reflected by the optimization of resting behavior, providing facilities and management to allow cows to lie down when they choose to do so for as long as they need to.
Assuntos
Abate de Animais/estatística & dados numéricos , Doenças dos Bovinos/fisiopatologia , Bovinos/fisiologia , Indústria de Laticínios/métodos , Abrigo para Animais/classificação , Coxeadura Animal/fisiopatologia , Animais , Comportamento Animal/fisiologia , Indústria de Laticínios/normas , Comportamento Alimentar/fisiologia , Feminino , Marcha/fisiologia , Abrigo para Animais/normas , Lactação/fisiologia , Leite/metabolismo , Paridade , Gravidez , Descanso/fisiologia , Sono/fisiologiaRESUMO
Adaptive hunting management is commonly used for controlling the populations of overabundant large herbivores; however, induced behavioural changes can make the effective control of target populations difficult. However, few studies have compared the impact of different levels of hunting intensities on the activity patterns of ungulates before, during, and after a culling program. We investigated how different culling intensities affect the activity patterns of sika deer on Nakanoshima Island in Lake Toya, Hokkaido, Japan using camera-trap surveys comparing the period of treatment before, during, and after a culling program. We used the number of deer photographed per hour per camera as an index of activity. Sika deer showed consistent crepuscular activity patterns (i.e., dawn and dusk) during spring-summer and trimodal activity patterns (i.e., dawn, dusk, and midnight) in autumn throughout the study period. In response to increased culling intensity, the activity peaks shifted slightly towards the night. The shift towards nocturnal activity persisted during post-culling period. Understanding the changes in activity patterns in response to culling intensity could be used to facilitate population control and assist in establishing a night shooting program. Thus, wildlife managers should consider night shooting once hunting during day time has shifted the normal diurnal activity of deer to nocturnal activity.
Assuntos
Abate de Animais/estatística & dados numéricos , Comportamento Animal , Cervos/fisiologia , Ecossistema , Estações do Ano , AnimaisRESUMO
Peripartum disorders in dairy cows negatively influence their productivity and reproductive performance. However, only a few reports have clearly indicated the influence of such disorders on the productivity and reproductive performance at a local-area or cow-level in Japan. This study aimed to elucidate the influence of diseases occurring within 60 days after calving on subsequent productivity and reproductive performance. Accordingly, a wide-area database on dairy production was used for epidemiological analysis; subsequently, multivariable analysis was performed to investigate the association of such diseases with productivity or reproductive performance in 6,545 cows from 178 farms in Fukuoka. We used 305-day energy-corrected milk (305 ECM) as an index of productivity and conception and culling as indices of reproductive performance. With regard to causality, mixed-effects model was used for analyzing the association between disease and productivity, and Cox proportional hazard model was used for analyzing the association between disease and reproductive performance. Compared to the disease absence group, the disease presence group demonstrated significantly lower 305 ECM [-154 kg; 95% confidence interval (CI), -229 to -79] and risk of pregnancy [hazard ratio (HR), 0.85; 95% CI, 0.80-0.91] and higher risk of culling (HR, 1.36; 95% CI, 1.17-1.59). These results indicate that, in Fukuoka, dairy cows affected by diseases within 60 days after calving exhibit lower productivity and reproductive performance. Therefore, proper dairy cow management during the peripartum period to prevent diseases during early lactation may maintain or improve productivity.
Assuntos
Doenças dos Bovinos/epidemiologia , Indústria de Laticínios/estatística & dados numéricos , Período Pós-Parto , Abate de Animais/estatística & dados numéricos , Animais , Bovinos , Doenças dos Bovinos/etiologia , Estudos de Coortes , Feminino , Japão , Lactação , Leite/estatística & dados numéricos , Gravidez , Estudos RetrospectivosRESUMO
O Brasil no primeiro semestre de 2016 exportou 571,5 mil toneladas de produtos cárneos. O Centro-Oeste tem papel importante nessa expansão, sendo a criação pecuária na região favorecida pela proximidade de centros produtores de grãos e à pouca distância de abatedouros-frigoríficos. As questões sanitárias são de grande importância no âmbito comercial para produtos de origem animal, e é crescente a preocupação de que estas devam se tornar barreiras para alguns criadores que não conseguem atingir qualidade nos seus produtos. Dessa forma, analisou-se 788.885 bovinos abatidos e contabilizou-se as condenações por abscessos e contaminações. Os resultados apontam 0,717% no ano de 2015, 1,051% em 2016 e 2,016% em 2017 de condenações por contaminações e 0,089% no ano de 2015, 0,081% em 2016 e 0,068% em 2017, por abscessos. Através dos achados pode-se concluir que contaminações e abscessos são causas frequentes de condenações, acarretam em prejuízo financeiro e alteram a qualidade da carne.
Assuntos
Animais , Bovinos , Abate de Animais/estatística & dados numéricos , Abscesso/veterinária , Carne , Contaminação de Alimentos/estatística & dados numéricos , Perda e Desperdício de Alimentos , MatadourosRESUMO
A cisticercose é um agravo de origem parasitária. A zoonose é relevante no contexto da higiene da carne, do ponto de vista social, econômico - sanitário e de saúde coletiva. A escolha da pesquisa fundamentou-se na carência de estudos acerca do tema na região e na importância da utilização das informações no planejamento e implementação de políticas públicas de saúde, identificar a cidade de origem do animal infectado, calcular o percentual da perda econômica na microrregião em decorrência do número de carcaças com cisticercose. Nos quatro anos, foram abatidos e inspecionados 355.208 bovinos, na microrregião do extremo sul da Bahia (Alcobaça, Caravelas, Itamaraju, Itanhém, Jucuruçu, Lajedão, Medeiros Neto, Mucuri, Nova Viçosa, Prado, Teixeira de Freitas, Ibirapuã e Vereda). O presente trabalho teve como objetivos descrever a prevalência de cisticercose em bovinos abatidos em frigorífico sob inspeção federal no extremo sul da Bahia no período de janeiro de 2014 a maio de 2017.
Assuntos
Animais , Bovinos , Abate de Animais/economia , Abate de Animais/estatística & dados numéricos , Cisticercose/economia , Cisticercose/epidemiologia , Cisticercose/veterinária , PrevalênciaRESUMO
Objetivou-se identificar as principais causas de condenação de aves em um abatedouro frigorífico localizado no sul do estado de Mato Grosso do Sul. Os dados foram coletados a partir dos registros do Serviço de Inspeção Federal, com a quantificação das lesões encontradas e o destinado dado às carcaças, divididas em condenação parcial e total. Das aves abatidas entre janeiro de 2011 a dezembro de 2016, 9,08% apresentaram alguma lesão que levou à condenação post-mortem, sendo 8,05% condenações parciais e 1,03% condenações totais. Dentre o total de condenações a que prevaleceu foi a parcial (88,69%) e 11,31%, condenação total. As causas mais frequentes para a condenação parcial foram contusão/fratura (39,14%), aerossaculite (13,34%) e dermatose (11,92%). Já as causas de condenação total mais frequentes foram colibacilose (28,31%), aspecto repugnante (24,79%) e síndrome ascítica (11,39%).
Assuntos
Animais , Abate de Animais/estatística & dados numéricos , Contaminação de Alimentos , Galinhas/lesões , Inspeção de Alimentos , Perda e Desperdício de AlimentosRESUMO
A cadeia produtiva de carne bovina ocupa um lugar de destaque no cenário da economia brasileira gerando empregos e renda à população. A inspeção post mortem, é realizada através do exame macroscópico de vísceras e carcaças, a partir do exame visual, obtém assim o destino final de carcaças e vísceras. O objetivo do trabalho foi levantar as principais causas de condenação total de carcaças bovinas em um abatedouro frigorífico de acordo com os critérios de inspeção, e avaliar os possíveis fatores que podem levar a ocorrência das mesmas. O estudo foi realizado em um abatedouro frigorífico de bovinos e suínos, localizado na cidade de Boa Esperança - MG. Para o levantamento dos dados de condenação foi consultado o mapa nosográfico mensal, no período de agosto de 2017 a agosto de 2018. Observou-se nas amostragens que o maior índice de condenações no abatedouro frigorífico foi tuberculose (25,2%), cisticercose (6,5%), caquexia (19,6%), contusão generalizada (32,2%) e neoplasias (4%). Com os resultados encontrados observamos que houve uma maior taxa de condenações de carcaças por contusão generalizada, dessa forma ressaltamos que é de extrema importância a implantação do programa de bem estar animal para que haja uma redução nos números de condenações. Uma vez que conhecido os fatores que levam a determinadas patologias, medidas profiláticas devem ser adotadas para a redução de perdas geradas pelas condenações, desde a fazenda até o abate.
Assuntos
Animais , Bovinos , Abate de Animais/estatística & dados numéricos , Contaminação de Alimentos , Contusões/veterinária , Inspeção de Alimentos , Perda e Desperdício de AlimentosRESUMO
A vigilância em matadouros frigoríficos através da inspeção post mortem fornece um mecanismo importante para a detecção de infecções por tuberculose bovina (Mckinley et al 2018). As taxas de detecção de tuberculose bovina em matadouros frigoríficos dependem de fatores como eficácia da inspeção de produtos de origem animal bem como perfil de risco e susceptibilidade da população bovina abatida. Este trabalho teve por objetivo demonstrar a taxa de condenações por lesões sugestivas de Tuberculose bovina em estabelecimentos frigoríficos sob fiscalização Estadual no estado do Rio Grande do Sul entre janeiro de 2015 a dezembro de 2017. Nestes estabelecimentos foram abatidos em 2015 um total de 1.020.554 (100%) animais dos quais 3.622 (0,35%) condenados. Em 2016, 1.002.496 (100%) bovinos foram abatidos, e 5.587 (0,55%) foram condenados. Já em 2017 estes dados totalizaram 1.055.585 (100%) animais abatidos e 6.466 (0,61%) condenados. Os resultados demonstram um aumento gradativo da identificação de lesões sugestivas de tuberculose em matadouros frigoríficos no estado do RS nos anos estudados.
Assuntos
Animais , Bovinos , Abate de Animais/estatística & dados numéricos , Matadouros , Tuberculose Bovina , Perda e Desperdício de Alimentos , RefrigeraçãoRESUMO
Nos últimos anos as autoridades veterinárias nacionais e internacionais têm se preocupado com as condições em que os bovinos são transportados e o manejo que recebem até o abate, bem como com os prejuízos acarretados à toda a cadeia produtiva da carne e a necessidade de obtenção de produtos e com características sensoriais desejáveis. Objetivou-se com este trabalho avaliar fatores pré-abate que podem influenciar em parâmetros de qualidade da carne. Em um abatedouro-frigorífico de bovinos em Mato Grosso foram feitas avaliações do manejo pré-abate de animais sãos, com idade média de 25 a 36 meses, todos criados sob sistema extensivo e submetidos por 12 a 24 horas de descanso, jejum e dieta hídrica. Os resultados obtidos nos possibilitaram detectar índices de 7% de escorregões, 3% de quedas, 11% de vocalizações e 12% de falha no atordoamento, ou seja, todos fora dos padrões aceitáveis e estabelecidos pela literatura, demonstrando que o manejo pré-abate neste estabelecimento foi ineficiente. Foram também contabilizadas contusões em geral das carcaças e seus respectivos pH's, onde dos 204 animais avaliados ante-mortem quanto à distância de transporte,119 (58,33%) apresentaram algum tipo de lesão, sendo as regiões mais acometidas o traseiro, seguido do dianteiro e da ponta de agulha. Já com relação ao pH, os animais provenientes das maiores distâncias de transporte apresentaram o maior índice de alteração (42,64%). Podemos concluir que as práticas de Bem-Estar animal poderiam reduzir os prejuízos ocasionados pelo manejo inadequado no estabelecimento, reduzindo os prejuízos decorrentes das condenações das carcaças e/ou suas partes alteradas, com maior oferta de produtos ao consumidor.
Assuntos
Animais , Bovinos , Abate de Animais/estatística & dados numéricos , Abate de Animais/normas , Bem-Estar do Animal , Carne/normas , Meios de Transporte , Matadouros/normas , Qualidade dos AlimentosAssuntos
Abate de Animais/legislação & jurisprudência , Mustelidae , Política Pública , Tuberculose Bovina/prevenção & controle , Abate de Animais/métodos , Abate de Animais/estatística & dados numéricos , Bem-Estar do Animal/normas , Animais , Bovinos , Humanos , Licenciamento , Reino Unido , Medicina Veterinária/organização & administraçãoRESUMO
Currently, little objective data is available describing the movements of cull sows and cull pigs through market channels or the association these movements with disease transmission risk. In this pilot study, we collected data to describe the scope and complexity of movements within the sow market channel. Premise ID tags where collected from all animals moving through a single slaughter plant over a one-week period in 2017. The premise ID's were each cross referenced with a public database to obtain origin location, and each tag was matched with its final collection point (FCP). This allowed terminal market, FCP, and point of origin of each sow to be determined. Approximately 90.4% of all sows moving to the plant during the one-week period were identified, indicating the utility of this data collection approach. Sows originated from premises in 21 states and Canada, and shipped from collection points in 7 states and Canada. Sows traveled a median straight-line distance of 1057 km, identifying the national scope of the sow market. Of the sows identified, 86% entered the plant from a final shipping point that was within 240 km to the source farm. The remaining 14% traveled more than 240 km from the premise of origin to the final point of shipment with 2.5% traveling distances 5 times greater between premise and FCP, then from FCP to the plant. From this it was hypothesized that not only is the sow market national in scope, but a significant number of sows are moved between multiple collection points prior to arriving at the terminal market. The combination of these two factors makes the sow network a likely candidate of pathogen transmission throughout the swine industry.
Assuntos
Matadouros/estatística & dados numéricos , Suínos , Abate de Animais/estatística & dados numéricos , Sistemas de Identificação Animal , Animais , Feminino , Projetos Piloto , Fatores de Tempo , Meios de Transporte , Estados UnidosRESUMO
We consider the harvesting of a population in a stochastic environment whose dynamics in the absence of harvesting is described by a one dimensional diffusion. Using ergodic optimal control, we find the optimal harvesting strategy which maximizes the asymptotic yield of harvested individuals. To our knowledge, ergodic optimal control has not been used before to study harvesting strategies. However, it is a natural framework because the optimal harvesting strategy will never be such that the population is harvested to extinction-instead the harvested population converges to a unique invariant probability measure. When the yield function is the identity, we show that the optimal strategy has a bang-bang property: there exists a threshold [Formula: see text] such that whenever the population is under the threshold the harvesting rate must be zero, whereas when the population is above the threshold the harvesting rate must be at the upper limit. We provide upper and lower bounds on the maximal asymptotic yield, and explore via numerical simulations how the harvesting threshold and the maximal asymptotic yield change with the growth rate, maximal harvesting rate, or the competition rate. We also show that, if the yield function is [Formula: see text] and strictly concave, then the optimal harvesting strategy is continuous, whereas when the yield function is convex the optimal strategy is of bang-bang type. This shows that one cannot always expect bang-bang type optimal controls.
Assuntos
Modelos Biológicos , Dinâmica Populacional , Abate de Animais/estatística & dados numéricos , Animais , Biologia Computacional , Conservação dos Recursos Naturais , Extinção Biológica , Modelos Logísticos , Conceitos Matemáticos , Dinâmica Populacional/estatística & dados numéricos , Processos EstocásticosRESUMO
In order to describe the proportion and pattern of culling in commercial goatherds, this survey was carried out in an industrialized goatherd in Torbat-e-Jam, Iran, over a period of 18 years from 1996 to 2013. In total, the data of 3945 goats were used in this study. Finally, out of all samples, 499 (12%) goats were culled. The involuntary culling was performed mainly due to shortage disorders (3.8%), viral disorders (3.3%), microbial diseases (2.8%), and other disorders (2.1%). Sheep pox was the most important reason (64%) for culling due to viral disorders. Tick paralysis was the most common parasitic disease that contributed to culling and responsible for 88% of parasitic disorders. On the other hand, enterotoxemia accounted for 55% of microbial disorders is considered the most common cause of culling. The high proportion of culling due to shortage disorders, especially nutritional deficiencies should be considered the most important cause of culling. It requires precautionary measures and planning in order to reduce the aforementioned rate.
Assuntos
Abate de Animais/estatística & dados numéricos , Doenças das Cabras/prevenção & controle , Animais , Feminino , Cabras , Irã (Geográfico) , MasculinoRESUMO
The objectives of this study were to estimate the direct effects of clinical mastitis (CM) occurring in early productive life (defined as the first 100 d of the first lactation) of Holstein dairy cows on the future rate of CM occurrence and on the length of total productive lifetime. Information on CM cases and other data occurring in 55,144 lactations in 24,831 cows in 5 New York State Holstein herds was collected from January 2004 until February 2014. For the first objective, a generalized linear mixed model with a Poisson distribution was used to study the effects of CM cases occurring in the first 100 d of a cow's first lactation, as well as farm indicator and number of days in the cow's lifetime, on the future lifetime rate of CM. Only cows that had completed their productive life [i.e., all had been culled (or sold) or had died; n = 14,440 cows] were included in this analysis. For the second objective, a Cox proportional hazards model was used to study the effects of CM cases occurring in the first 100 d of a cow's first lactation on the length of total productive lifetime. The model was stratified by farm. All 24,831 cows were included in this analysis with right censoring. Cows experienced between 0 and 4 CM cases in the first 100 d of lactation 1. Over their lifetime, cows experienced between 0 and 25 CM cases. During the study period, 10% of all cows died and nearly half of all cows were culled. The average length of productive life, including censored observations, was 2.0 yr after first calving. Compared with cows having no CM cases in the first 100 d of lactation 1, cows with 1 CM case in that time period had a 1.5 times higher rate of total number of CM cases over their lifetime. Cows with 2 (or 3 or more) CM cases in the first 100 d of lactation 1 had a 1.7 times (or 2.6 times) higher rate of total number of CM cases over their lifetime. For each additional CM case occurring in the first 100 d of lactation 1, the hazard rate of culling increased by 34%. Given economic conditions for preferentially culling mastitic cows, the study findings may help farmers make optimal decisions with regard to culling of such cows.
Assuntos
Abate de Animais/estatística & dados numéricos , Mastite Bovina/epidemiologia , Animais , Bovinos , Indústria de Laticínios , Feminino , Incidência , Lactação , New York/epidemiologia , Modelos de Riscos ProporcionaisRESUMO
In this paper, a very general model of impulsive delay differential equations in n-patches is rigorously derived to describe the impulsive control of population of a single species over n-patches. The model allows an age structure consisting of immatures and matures, and also considers mobility and culling of both matures and immatures. Conditions are obtained for extinction and persistence of the model system under three special scenarios: (1) without impulsive control; (2) with impulsive culling of the immatures only; and (3) with impulsive culling of the matures only, respectively. In the case of persistence, the persistence level is also estimated for the systems in the case of identical n patches, by relating the issue to the dynamics of multi-dimensional maps. Two illustrative examples and their numerical simulations are given to show the effectiveness of the results. Based on the theoretical results, some strategies of impulsive culling are provided to eradicate the population of a pest species.