The dairy calf mortality : the causes of calf death during ten years at a large dairy farm in Korea / 대한수의학회지

The objective of this study was to investigate the calf death and analyse the causes of the mortality by based on medical records and autopsy findings during 10 years in a large dairy farm. Total of 1,361 calf born and 146 calf dead during the invested period. Mortality rate was 10.7% and showed the big difference by year-specific mortality from 2.8% (4 calves) to 19.2% (28 calves). The highest rate of mortality was 1 week age (18.5%, 27 calves) and followed by 2 week age (11.6%, 17 calves) and mortality of more old calf tended to be reduced. The death less than 4 weeks and 8 weeks of age of the entire mortality accounted for 41.1% (60/146 calves) and 70.0% (102/146 calves), respectively. Causes of calf death were digestive diseases (53.4%), respiratory diseases (17.1%), musculoskeletal disease (8.2%), and systemic disease (8.2%) in order. Specific causes of calf death was highest in enteritis (43.2%), followed by pneumonia (14.4%), sepsis (8.2%) and fractures (3.4%). Seasonally, most of calf death happened in winter (48.6%) and then fall (21.2%). This results showed that enteritis and pneumonia are the main reason of calf death but other reasons were involved in calf death on the based on autopsy finding. On going research relating factors of calf mortality is needed.

Risk factors associated with the occurrence of Cryptosporidium parvum infection in calves / Fatores de risco associados à ocorrência de infecção por Cryptosporidium parvum em bezerros

Cryptosporidium parvum oocysts were detected in feces of dairy calves raised in Rio de Janeiro State and the risk factors involved in the infection were determined. A hundred calves aging up to 12-month-old from 13 dairy farms were sampled. Polymerase chain reaction was used to detect the presence of oocysts. The zoonotic C. parvum species was detected in 45 percent animals. Statistical risk factors analyses revealed an association between infection and animals raised in technical systems such as the use of milking equipment, milking cooler, and water trough(P<0.05).

Detectaram-se oocistos de Cryptosporidium parvum em fezes de bezerros leiteiros no estado do Rio de Janeiro e analisaram-se os fatores de risco envolvidos na infecção dos animais. Cem bezerros com idades de 0 a 12 meses, provenientes de 13 propriedades rurais, foram amostrados, e suas fezes examinadas pela reação em cadeia da polimerase para a detecção dos oocistos. A espécie zoonótica C. parvum foi detectada em 45 por cento dos animais. As análises estatísticas dos fatores de risco revelaram haver associação entre infecção e animais criados em propriedades tecnificadas, que usam ordenha mecanizada, resfriamento de leite e fazendas que continham reservatórios de água à disposição dos animais (P<0,05).

Desempenho e saúde de bezerras alimentadas com leite sem resíduo de drogas antimicrobianas ou leite de vacas tratadas contra mastite adicionado ou não de probiótico / Performance and health of calves fed milk without antimicrobials residue or milk from mastitis treated cows with or without probiotic

Quarenta e oito bezerras da raça Holandesa, de um a 60 dias de idade, foram utilizadas para avaliar os efeitos da adição ou não de Lactobacillus acidophillus, Bifidobacterium bifidum e Enterococus faecium ao leite sem resíduo de antimicrobiano (L) e ao leite de vacas em tratamento de mastite (LTM), sobre o consumo de alimentos, ganho de peso e incidência e duração de diarréia. O consumo de concentrado e água foi medido diariamente, e o ganho de peso semanalmente. Utilizou-se um delineamento inteiramente ao acaso, em esquema de parcelas subdivididas, com 12 repetições. Os tratamentos consistiram de um arranjo fatorial 2 x 2 (L ou LTM e ausência ou presença de probiótico). A adição de probiótico reduziu o número de dias com diarréia no grupo de animais que recebeu leite sem resíduo de antimicrobiano (P<0,05), mas não houve efeito sobre os animais que receberam leite de vacas em tratamento de mastite. Também não houve efeito do probiótico sobre os consumos de concentrado e de água, e sobre o ganho de peso e a incidência de diarréia.

Forty-eight Holstein calves from birth until 60-day-old were used to evaluate the effect of commercial probiotic Biobac® (Lactobacillus acidophillus, Bifidobacterium bifidum, and Enterococcus faecium) in addition to milk without antimicrobials residue or milk from mastitis treatead cows on theoccurrence and the length of diarrhea. Consumption of concentrate and water were daily measured and the weight was weekly measured. The experiment was carried out according to a random sample design with 12 repetitions for each treatment, arranged in a split plot. The plots were composed by four treatments combined in a factorial arrangement of 2x2. Subplots were composed by the evaluation times. The addition of probiotic was beneficial to reduce the diarrhea period in the calves fed milk without antimicrobial residue. The consumption of concentrate, water, and the weights of the calves were not different among the groups, irrespectively of probiotic supply.

Differences in the serum immunoglobulin concentrations between dairy and beef calves from birth to 14 days of age

The changes in serum levels of immunoglobulins G, M and A of dairy and beef calves of well-managed herds were monitored from birth to 14 days post partum using single radial immunodiffusion. Serum levels of all three immunoglobulin classes reached its peak at 24 hours in both groups of calves after birth, at which time there were very high levels of each immunoglobulin present. The mean IgM and IgA levels of the two groups became same at 6 days and 8 days of age, respectively but the mean IgG level of beef calves was approximately twice that of dairy calves throughout the experiment.