Physical load and heart rate behavior in workers in the slaughterhouse and meat packing industries / Carga física e comportamento da frequência cardíaca em trabalhadores de frigorífico

Abstract High physical overload during the workday and some conditions present in the workplace can generate several losses in the worker's health. The use of tools capable of identifying physical load (PL), such as heart rate (HR) analysis, is essential. The aim of the study was to evaluate the physical load and heart rate behavior of workers in the slaughterhouse. The cardiovascular load reached by two individuals was 12% and 24%. In relation to the PL rating, they fit as moderately heavy to heavy work. The HR, was higher at the end of the work when compared to the beginning. Furthermore, it was pointed out that the temperature, noise, and body mass index were above normality values. The physical workload was classified as moderately heavy to heavy. The limit HR was reached in some moments of the work by one of the workers and two of them reached higher HR values at the end of the work.

Resumo A elevada sobrecarga física durante a jornada de trabalho e algumas condições presentes no ambiente de trabalho podem gerar diversos prejuízos na saúde do trabalhador. A utilização de ferramentas capazes de identificar a carga física (CF), como a análise da frequência cardíaca (FC), é fundamental. O objetivo do estudo foi avaliar o comportamento da carga física e da frequência cardíaca dos trabalhadores de frigorífico. A carga cardiovascular alcançada por dois indivíduos foi de 12% e 24%. Em relação à classificação da CF, enquadram-se como trabalhos moderadamente pesados ​​a pesados. A FC, foi maior no final do trabalho quando comparado ao início. Além disso, apontou-se que a temperatura, o ruído e o índice de massa corporal estavam acima dos valores da normalidade. A CF de trabalho foi classificada como moderadamente pesada a pesada. A FC limite foi atingida em alguns momentos do trabalho por um dos trabalhadores e dois deles atingiram valores maiores de FC ao final do trabalho.

Factores ambientales asociados con los días no-productivos de cerdas en el trópico mexicano / Environmental factors associated with lifetime non-productive days of sows in the Mexican tropics

RESUMEN Objetivo. Estimar el número de días no productivos (DNP) de por vida, la proporción de DNP (%DNP) y días no productivos por cerda por año (DNP/Y), y determinar el efecto de factores de hato y cerda sobre las características aquí estudiadas en tres granjas comerciales en el trópico mexicano. Materiales y métodos. Los datos de 6703 cerdas de tres granjas comerciales fueron usados. El modelo que describió las características de interés incluyeron los efectos fijos de granja, año de primer parto, época de primer parto, edad al primer parto, causa de desecho, interacción de año por época y error residual. Resultados. Las medias de DNP de por vida, %DNP y DNP/Y fueron 64 días, 12% y 39.3 días, respectivamente. Todos los factores tuvieron efectos significativos (p<0.01) en todas las características. Las cerdas con primer parto a mayor edad y las eliminadas por razones reproductivas tuvieron más DNP en el hato. Además, las cerdas eliminadas en el primer parto tuvieron menor DNP y mayor %DNP que las cerdas desechadas en partos subsecuentes. Conclusiones. La eliminación temprana de cerdas incrementó la proporción de días no productivos, que a su vez podrían reducir la rentabilidad de las granjas.

ABSTRACT Objectives. To estimate the lifetime non-productive days (NPD), lifetime proportion of NPD (%NPD) and non-productive days per sow per year (NPD/Y), and to determine the effect of herd and sow level factors on the traits here studied in three pig farms in the Mexican tropics. Materials and methods. Data from 6703 sows from three commercial farms were used. The model that described the traits studied comprise the fixed effects of farm, year and season of first farrowing, age at first parity, reasons of removal of sows, year x season interaction and the residual error. Results. The means for lifetime NPD, %NPD and NPD/Y were 64 days, 12.0% and 39.3 days, respectively. All fixed factors had significant effects (p<0.01) on the characteristics evaluated. Sows having their first parity at an old age and sows culled because of reproductive reasons had the highest lifetime NPD. In addition, sows culled at first parity had lower lifetime NPD and higher %NPD than sows culled in subsequent farrowing. Conclusions. The early culling of sows increased the percentage of non-productive days, which in turn is expected to reduce the profit of farms.

Fallas humanas y accidentes de trabajo: una contribución de las investigaciones en prevención, control de los riesgos y accidentes / Human errors and accidents at work: contribution of accident investigations in the prevention and control of risks

RESUMEN Con el objetivo de contribuir en el control de accidentes de trabajo, esta investigación busca analizar si el estudio de los errores humanos en investigaciones de accidentes contribuye en las acciones para el control y reducción de accidentes de trabajo en una planta de sacrificios. El método de análisis utilizado fue la evaluación de los tipos de erro res humanos a través de una secuencia de preguntas donde hay siempre dos opciones de respuestas -sí o no- y conforme el trazado de las respuestas se crea un algoritmo que permite la detección del error. Los mayores porcentajes de errores fueron evidenciados en dos gru pos, órdenes de los supervisores y procedimientos inadecuados. Al contrario al resultado encontrado en el estudio, las acciones de segu ridad del trabajo están enfocadas en condiciones que no contribuyen en la prevención y control de los riesgos. Se puede concluir que la herramienta de análisis de riesgos utilizada por la empresa, además de despreciar el análisis de los errores huma nos, no soluciona de forma adecuada las causas ni las acciones levantadas en la investigación del accidente.

ABSTRACT In order to contribute to the control of industrial accidents this research seeks to analyze the study of human error in accident inves tigations contributes in actions for the control and reduction of accidents in a poultry slaughterhouse. The method of analysis was used to assess the types of human errors through a series of questions in which there are always two choices of answers, with a yes or no and as the way of answers creates an algorithm for error detection. The largest percentages of errors were found in two groups, the supervisor order and inadequate procedures. Contrary to the results found in the study, the work safety actions are focused on conditions that do not contribute to the prevention and control of risks. It can be concluded that the risk analysis tool used by the company in addition to neglecting the analysis of human error, does not address properly the causes and actions raised in the investigation of the accident.

Efecto del sacrificio de perros vagabundos en el control de la rabia canina / Effect of free-roaming dogs culling on the control of canine rabies

RESUMEN En la ciudad de Arequipa, Perú, se han detectado perros con rabia desde marzo de 2015, señal de la reintroducción del virus de la rabia (VR) en esta zona previamente declarada libre de esta enfermedad. La alta densidad de perros vagabundos ha sido considerada una de las causas de la continua transmisión del VR en el brote de la ciudad de Arequipa, alentando el sacrificio de perros como medida de salud pública. Sin embargo, la efectividad de esta medida de control no ha sido evaluada. El objetivo de esta revisión fue determinar la efectividad del sacrificio de perros vagabundos como medida de control de la rabia urbana. Se realizó la búsqueda de artículos sobre control de rabia canina o urbana en las bases de datos de Medline, Scopus y LILACS. Se incluyeron estudios originales y revisiones que hayan evaluado algún efecto del sacrificio de perros en la transmisión del VR. Veinte de 21 artículos concluyen que el sacrificio de perros vagabundos es inefectivo en reducir la trasmisión del VR e, incluso, puede tener consecuencias imprevistas que empeoren el problema. En conclusión, la evidencia disponible indica que sacrificar perros vagabundos no es efectivo para controlar la rabia urbana. Además, las diversas consecuencias negativas del sacrificio de los perros vagabundos reportadas en otras partes del mundo sugieren que el sistema de rabia urbana es altamente complejo y todos sus componentes deben ser tomados en cuenta durante la implementación de actividades de control.

ABSTRACT In the Peruvian city of Arequipa, rabid dogs have been detected since March 2015, signaling the reintroduction of the rabies virus (RV) in this previously officially-declared rabies free zone. High dog density is considered one of the causes for the continuous transmission of the RV in the outbreak in the city of Arequipa, which seemingly lends support to the culling of dogs as a public health measure. However, the effectiveness of culling free-roaming dogs to control urban rabies has not been evaluated. Objective to determine the effectiveness of free-roaming dog culling as a control measure of urban rabies. Source of data: We searched for articles on dog rabies control or urban rabies control in the databases of PubMed, Scopus and LILACS. The characteristics and results of the documents obtained were recorded. Eligibility criteria: We included original studies and reviews that have evaluated an effect of culling dogs in the transmission of RV. Data collection and evaluation: One of the authors (RCN) screened the articles found in the search based on their titles and abstracts. The data and results of the articles selected for full reading were evaluated by at least two authors. Results: 21 articles were eligible for full reading. 20 of 21 articles conclude that free-roaming dog culling is ineffective in reducing the transmission of RV and may even have unintended consequences that worsen the problem. We believe that the available evidence indicates that the sacrifice of free-roaming dogs is not effective to control urban rabies. In addition, the various negative consequences of free-roaming dog culling reported in other parts of the world suggest that the system of urban rabies is highly complex and all its components must be taken into account during the implementation of control activities.

Occupational accidents related to cattle slaughter in Mato Grosso, Brazil / Acidentes de trabalho relacionados ao abate de bovinos em Mato Grosso, Brasil

Resumo Introdução A criação de gado no sul da Amazônia tem crescido rapidamente, sendo que o Mato Grosso é um dos primeiros estados na produção de carne. Esse crescimento permitiu a contratação de mais trabalhadores para a atividade de refrigeração, trazendo um aumento de acidentes de trabalho nesse setor. Objetivo Analisar a influência de abate de gado nos acidentes de trabalho e sua distribuição espacial no estado de Mato Grosso, Brasil. Métodos Estudo ecológico que investigou a autocorrelação espacial global das taxas de acidentes de trabalho e o número de bovinos abatidos em municípios de Mato Grosso, usando a estatística Moran “global” pelo método LISA e, posteriormente, uma regressão múltipla espacial, tendo como variáveis de exposição o abate de cabeças de gado e, como variável resposta, a taxa de acidentes de trabalho. Resultados Foram encontrados padrões espaciais globais na distribuição do número de cabeças de gado abatidas. Na regressão múltipla, foram observadas correlações estatisticamente significantes entre o número de bovinos abatidos e a taxa de acidentes de trabalho. Conclusão O abate de gado está relacionado ao aumento do número de acidentes de trabalho no Estado de Mato Grosso, Brasil.

Abstract Introduction Cattle rising in the southern Amazon have grown rapidly, being Mato Grosso one of the top states in meat production. This growth led to the hiring of more workers to the chilling activity, increasing the number of workplace accidents in this sector. Objective To analyze the influence of slaughter cattle on occupational accidents and their spatial distribution in the state of Mato Grosso, Brazil. Methods This is the first ecological study investigating the global spatial autocorrelation of the occupational accident rate and the number of slaughtered cattle in Mato Grosso municipalities; this study used the statistic Moran “global” by LISA method and subsequently held a spatial linear regression, with cattle slaughter exposure variables and as an outcome it showed the rate of workplace accidents. Results The study showed a global spatial pattern of number of cattle slaughtered. Statistically significant correlations were observed, in multiple regression analysis, between the number of cattle slaughtered and rate of occupational accidents. Conclusion The cattle slaughter is related to the increase of industrial accidents in the State of Mato Grosso, Brazil.

Comparação entre a análise macroscópica realizada durante a inspeção em abatedouro bovino e o exame microscópico na detecção de processos patológicos / Comparison between the macroscopic analysis during the inspection in bovine slaughterhouse and the microscopic examination to detect pathological processes

O presente trabalho teve por objetivo comparar o resultado da análise macroscópica realizada pelo Serviço de Inspeção Federal durante o exame post-mortem com a avaliação das características microscópicas de lesões indicativas de doenças em órgãos e vísceras condenados, em um matadouro-frigorífico do município de Castanhal, Pará. Amostras de diferentes órgãos e vísceras condenados pelo Serviço de Inspeção durante a análise post mortem foram coletadas em um matadouro-frigorífico e encaminhadas ao Laboratório de Anatomia Patológica da Faculdade de Medicina Veterinária da Universidade Federal do Pará – Campus Castanhal, para realizar a análise histopatológica. Durante o período de quatro meses foram acompanhados 30.223 abates bovinos, que resultaram em 12.467 órgãos e vísceras condenados, dos quais foram coletadas 26 amostras para o presente trabalho. Este estudo demonstrou que o diagnóstico macroscópico realizado pelos agentes de inspeção foi compatível com a análise microscópica em 20 (76,9 %) das 26 amostras analisadas. Neste contexto, os critérios de condenação sanitária adotados pelos agentes de inspeção foram muito semelhantes aos resultados de diagnósticos histopatológicos encontrados neste trabalho.

This study aimed at comparing the result of macroscopic analysis performed by the Federal Inspection Service during the post-mortem examination and the evalation of the microscopic characteristicsof lesions indicative of diseases in the condemned organs and viscera in an industrial slaughterhouse in the city of Castanhal, Pará-Brazil. Samples of diverse organs and viscera condemned by Federal Inspection Service during the post-mortem investigation were collected in a slaughterhouse locatedin the city of Castanhal-Pará. These samples were sent to the Pathology Laboratory of the Faculty of Veterinary Medicine of the Federal University of Pará – Campus Castanhal, where the histopathological analysis was performed. During the four-month period, 30,223 cattle slaughter were followed,and of these 12.467 organs and viscera were condemned. Among the condemned samples, 26 werecollected for conducting the study. This investigation showed that the macroscopic diagnosis performedby the inspection agents were consistent with the microscopy analysis findings in 20 (76.9 %)of 26 evaluated samples. In this context, the sanitary condemnation criteria adopted by the inspection agents were very similar to the histopathological diagnosis results found in this study.

Avaliação histopatológica de órgãos reprodutivos e bexiga de fêmeas suínas descartadas / Histopathology of reproductive organs and bladder of culled sows

Em um sistema intensivo de produção de suínos, as falhas reprodutivas são uma das principais razões de descarte de matrizes e queda nos índices produtivos. A infecção urinária (cistite) e as endometrites são consideradas importantes causas de descarte em fêmeas suínas, por terem consequências reprodutivas relevantes e elevarem a taxa de reposição do plantel. O presente estudo teve o objetivo de avaliar o aparelho reprodutivo e a bexiga de fêmeas suínas de descarte normal de granjas, bem como investigar a existência de relação entre as patologias encontradas. Foram examinadas 79 matrizes suínas oriundas de 20 rebanhos localizados no Estado de Santa Catarina. De cada fêmea foram coletados os ovários, fragmentos de útero e bexiga. Dentre as fêmeas avaliadas, 32 (40,5%) tinham diferentes graduações de cistite, 24 (30,4%) tinham algum tipo de inflamação uterina, e 9 (11,4%) estavam em anestro, com ovários inativos. Contudo, não foi observada dependência significativa entre cistite e endometrite nas amostras analisadas.

Reproductive failures are the major reasons for removal of sows and decrease of production rates in an intensive swine production system. Urinary infection and endometritis are considered important causes for culling of sows, due to relevant reproductive consequences and increase of the replacement rates. The present study aimed to evaluate the reproductive and urinary system of culled sows, as well as investigate the occurrence of cystitis and endometritis in analyzed sows. Samples, such as ovaries, uterus fragments and bladder were collected from 79 sows originated from 20 farms of Santa Catarina State. Results showed that, 32 (40,5%) analyzed sows presented cystitis in different levels, 24 (30,4%) had some class of uterine inflammation, and 9 (11,4%) were in anestrous, with inactive ovaries. However, unsignificative dependence between cystitis and endometritis in analyzed samples was observed.

Registros de desempenho e de status sanitário de um rebanho bovino leiteiro no sul do Brasil / Records of performance and sanitary status from a dairy cattle herd in southern Brazil

Over the last decades, the emphasis on the health of dairy cows has changed from an individual to a herd level. In this scenario, the role played by the recording system and its interpretation by veterinarians has gained primordial importance. The records of productive and reproductive performance and of sanitary status from a southern Brazilian dairy cattle herd have been presented and discussed. The period of study was 2000-2009. Mean values per lactation period were 349D 8436M 290F 275P 201SCS (D: days in lactation, M: kg of milk yield, F: kg of fat, P: kg of protein and SCS: somatic cell score in 1000 cells/ml of milk). Major indexes of reproductive efficiency included age at first calving (31 months), services per conception (2.1), intercalving interval (428 days), calving to conception interval (146 days), mean annual rates of parturitions (76.2%), fetal losses (9.8-19.0%), and stillbirths (3.6%), apart of voluntary waiting period (94 days). Main information on sanitary status of the herd was associated with the mean prevalence of common disorders of dairy cattle such as anaplasmosis (29.8%), mastitis (27.8%), digital diseases (26.3%), ovarian cysts (21.3%), placental retention (19.7%), postpartum uterine infections (10.6%), and calf diarrhea (23.7%) and pneumonia (16.8%), among others. In addition, culling reasons (low reproductive performance [56.3%] and udder/mastitis problems [33.6%]), causes of cattle deaths (anaplasmosis [16.4%] and leukosis [11.4]), and the impact of cattle diseases such as tuberculosis, leukosis, and neosporosis on the herd have also been presented and succinctly discussed. Numbers between brackets represent rates accumulated in the 10-year period.

Nas últimas décadas, os cuidados sanitários de vacas leiteiras passaram por um processo de adaptação, no qual o enfoque individual foi substituído pelo coletivo, cujo sistema de manutenção e interpretação de registros por veterinários assumiu papel fundamental. Os registros de eficiência produtiva e reprodutiva, bem como os de ordem sanitária observados em um rebanho bovino leiteiro no Sul do Brasil foram apresentados e discutidos. O período estudado foi 2000-2009. Os dados de produção leiteira média incluíram, por período de lactação de 349 dias, 8436 kg de leite, 290 kg de gordura e 275 kg de proteína, com média de contagem de células somáticas de 201000 células/ml de leite. Idade ao primeiro parto (31 meses), serviços por concepção (2,1), intervalo entre partos (428 dias), intervalo parto-concepção (146 dias), taxas médias anuais de parição (76,2%), perdas fetais (9,8-19%) e natimortos (3,6%), além de período de espera voluntária (94 dias) foram alguns dos índices de desempenho reprodutivo registrados. Informações sanitárias do rebanho incluíram prevalência média de doenças comuns em bovinos leiteiros tais como anaplasmose (29,8%), mastites (27,8%), doenças digitais (26,3%), cistos ovarianos (21,3%), retenção de placenta (19,7%), infecções uterinas (10,6%), diarreia (23,7%) e pneumonia (16,8%) em terneiras, entre outras. Além disso, razões de descartes (baixo desempenho reprodutivo [56,3%], alterações de úbere [33,6%], etc.), causas de morte (anaplasmose [16,4%], leucose [11.4], etc.) e o impacto de doenças de bovinos como tuberculose, leucose e neosporose sobre o rebanho foram também apresentados e sucintamente discutidos...

The impact of the duration of retained placenta on postpartum diseases and culling rates in dairy cows / 대한수의학회지

The objective of this study was to evaluate the duration of retained placenta (RP) on postpartum diseases and culling in dairy cows. Data were collected from 456 Holstein cows between 2008 and 2010. RP (> or = 24 h after parturition) and postpartum diseases were diagnosed by farm managers and a veterinarian according to standardized definitions. The overall incidence rate of RP was 14.0%, and the incidence rate of RP with fourth and higher parity was two times that of cows having offspring for the first time. The duration of RP was 2 to 15 days with a mean of 6.8 days, except for cases of fourth and higher parity which had a mean of 10.5 days. A total of 63% of cows with RP had postpartum diseases. Among the cows diagnosed with RP, 23.4% developed metritis, and of those, 35.3% developed endometritis or pyometra. A total of 25% (n = 16) cows with RP were culled within 60 days in milk (DIM) and of those culled, 75% (n = 12) had postpartum diseases. These results suggest that RP increases the risk of postpartum diseases such as metritis and mastitis and is a culling hazard up to 60 DIM.

A study on knowledge and practice related to bird flu in a rural community of Hooghly District of West Bengal.

For last few years in the early spring bird flu poses a threat to India. The causative agent H5N1 virus is also getting robust day by day acquiring an ability to cross the species barrier. It is now known as (H5N1) which is emerging as killer virus to man. Although human casualty is yet to be recorded from India, but the threat is not over. The present study had been undertaken in the village of Hakimpur of Singur Block of District Hooghly, West Bengal, with a population 862 of 215 families. The objective of the study was to assess the knowledge of the study population regarding bird flu and to study their practice regarding poultry maintenance. The head of the family from each family was interviewed. A house to house survey in the census method on a pre-designed, pre-tested, semi-structured schedule was done. Information regarding socio-demographic profile, poultry keeping, correct knowledge about bird flu, mode of transmission, culling, etc was recorded. The data were collected and analyzed by relevant statistical methods. The results showed that 46% respondents knew what bird flu is, 62.8% knew the mode of transmission, and 35.3% knew the procedure of culling. Out of literates about 53% and out of the illiterates only 0.93% were aware of the transmission of the virus through body fluids. The predominant source of information was mass media. 57.14% of the families rearing poultry, kept the birds in shed, 40.48% in cage, and 2.38% in living room.

How not to fight a rabies epidemic: a history in Bali.

Bali, an island, should never have been afflicted with canine rabies, but in 2008 a lack of surveillance allowed the import of an unvaccinated rabid dog from Flores, a distant island where canine rabies was similarly introduced in 1997 and has since become endemic. The initial rabies outbreak on Bali occurred in a remote village at the end of an isolated peninsula, but five months elapsed before the outbreak was officially recognized. Even then, rabies had yet to escape the peninsula. However, Bali officials relied on exterminating dogs as their primary control strategy. They did not vaccinate enough dogs on the neck of the peninsula to keep the outbreak confined, they prevented nongovernmental organizations and private citizens from vaccinating dogs until approximately a year after the outbreak started, they used unreliable indigenous vaccines of only short-term potency; killed vaccinated dogs, and they repeatedly disregarded the advice of visiting rabies control experts. Two years after the outbreak started, 44,000 people had received post-exposure vaccination after suffering bites from suspected rabid dogs. The number of human rabies deaths had doubled each six months since the first death occurred.

Propriedades físico-químicas e sensoriais de embutidos fermentados formulados com diferentes proporções de carne suína e de ovelhas de descarte / Physico-chemical and sensorial properties of fermented sausages formulated with different proportions of meat from swine and culling ewes

Avaliou-se a inclusão de diferentes níveis de carne de ovelhas de descarte (animais Texel × Ile de France com idade superior a seis anos) em relação à carne suína sobre a qualidade de embutidos fermentados do tipo salame. Os embutidos foram elaborados com 0, 15, 35, 55 ou 75 por cento de carne da perna, paleta e pescoço das ovelhas, acrescidos de pernil suíno e 10 por cento de toucinho suíno. A evolução do pH e da atividade de água (a w) foi avaliada nos dias zero, três, sete e 14 após o embutimento. Após a maturação dos salames, foram determinadas, ainda, a perda de peso, a qualidade microbiológica e as características sensoriais dos embutidos prontos. A inclusão de carne ovina na formulação não alterou a evolução do pH e a w. Entretanto, influenciou (P<0,05) os valores finais de pH, a w e a perda de peso. Os embutidos com carne ovina na formulação apresentaram valores de pH final inferiores àquele observado para o embutido elaborado somente com carne suína. Este último apresentou a w inferior e maior perda de peso, em comparação ao produto contendo 15 por cento de carne ovina na formulação. Todas as formulações atenderam a legislação quanto à qualidade microbiológica. Na análise sensorial, o embutido elaborado com 15 por cento de carne ovina foi considerado superior ao embutido elaborado somente com carne suína para os aspectos cor, sabor e textura; contudo, não diferiu dos demais embutidos elaborados com carne ovina. Assim, é possível elaborar embutido fermentado com até 75 por cento de carne de ovelhas de descarte na formulação.

The influence of including different proportions of meat from swine and culling ewes on the quality of fermented sausage type salami was evaluated. Five different formulations were prepared containing 0, 15, 35, 55, or 75 percent of meat from leg, shoulder, and neck of the ewes, added of swine meat and 10 percent of swine fat. Evolution of pH and water activity (a w) was evaluated on days 0, 3, 7, and 14 of the maturation period. After that, it was still determined the weight loss, microbiological quality, and the sensorial features of the sausages. The inclusion of sheep meat in the formulation did not changed pH and a w evolution. However, differences in final values of pH, a w, and weight loss were found (P<0.05). Sausages with sheep meat in the formulation had lower pH than that without sheep meat. The control sausage (0 percent sheep meat) also showed lower a w and a greater weight loss than sausage with 15 percent of sheep meat. All formulations attended the actual legislation about microbiological quality. In the sensorial analysis, the sausage prepared with 15 percent of sheep meat in the formulation was considered better than that formulated just with swine meat in relation to color, flavor, and texture features. However, there were no differences in sensorial characteristics among sausages with sheep meat. Thus, it is possible to produce fermented sausages with until 75 percent of meat from culling ewes in the formulation.

Modelagem da dinâmica de rebanho de bovino de corte por meio de cadeia de Markov / Modeling dynamics of the beef cattle herd through Markov chain

A estrutura etária do rebanho e a estratégia de descarte de matrizes são pontos importantes na avaliação da eficiência do sistema de produção de gado de corte. Neste trabalho foi monitorado o rebanho de cria, cujas matrizes eram mantidas ou descartadas com base em critério técnico, conforme a avaliação do desempenho reprodutivo. Para tanto, foi utilizada a cadeia de Markov com o objetivo de simular a probabilidade de descarte por idade, ao longo da vida, e de calcular a expectativa de vida da matriz no rebanho. Após a introdução da estação de monta, a pressão de descarte foi maior, com aumento da probabilidade de descarte e da diminuição da probabilidade de permanência da matriz no rebanho nas idades mais avançadas. Com a introdução de tecnologias e especialmente da monta controlada, o processo torna-se mais dinâmico com a identificação e descarte de novilhas e matrizes improdutivas, diminuindo a idade média das vacas no rebanho e de descarte das mesmas.

The determination of age structure in a herd and the culling strategy in dams are important points to evaluate efficiency of a beef cattle production system. A breeding herd was monitored, where cows were maintained or discard according to technical criterion. Using the Markov chain the culling probability due to age throughout the life time of the cow was simulated. Life expectancy of the dam in the herd was also calculated. After the breeding season, culling pressure was higher and culling probability increased while permanency probability in the herd for older cows decreased, this made the herd more dynamic.

Advancing parity is associated with high milk production at the cost of body condition and increased periparturient disorders in dairy herds

The objectives of this study were to determine the effects of parity on milk production, body condition change, periparturient health, and culling in Korean dairy herds. The data utilized included; milk yield, body condition score, cow parity, calving condition, periparturient disorders, culling, and reproductive status, which were recorded from 1290 calvings in eight dairy herds. The mean milk yield in cows over 305 days increased with increasing parity (p < 0.01). Cows with parities of 3, 4, and 5 or higher lost more body condition than those with a parity of 1 during month 1 of lactation (p < 0.01), and body condition recovery by cows with parities of 4 and 5 or higher was slower (p < 0.01) than recovery by cows with parities of 1, 2, or 3 until month 3 of lactation. The risk of retained placenta, metabolic disorder, and endometritis also increased with advancing parity (p < 0.05). Moreover, the incidence of ovarian cysts was lower in cows with a parity of one than in cows with greater parities (p < 0.01). Culling rate due to reproductive failure also increased with advancing parity (p < 0.01). These results suggest that parity increases milk yield, body condition loss during early lactation, the risk of periparturient disorders, and culling due to reproductive failure in dairy herds.