The occurrence of diseases and their relationship with passive immune transfer in Holstein dairy calves submitted to individual management in southern Brazil / Ocorrência de doenças e sua relação com a transferência de imunidade passiva em bezerras Holandês criadas em sistema individual no sul do Brasil

Calves are extremely dependent on colostrum intake for the acquisition of passive immunity. This study aimed to determine the occurrence of diarrhea and respiratory diseases and the impact of Failure of Passive Immune Transfer (FPIT) on the health and zootechnical performance of Holstein dairy calves in individual management. This study has been carried out in five commercial farms in Rio Grande do Sul State, Brazil, from March 2017 to January 2018. In this study, 131 calves were followed from birth to 60 days of age. Total Plasmatic Protein (TPP) has been performed to determine passive immune transfer quality in 53 calves (53/131). A daily clinical follow-up has been accomplished aiming at diagnosing diseases and their incidences, and zootechnical measures such as withers height, width of the croup and weight have been evaluated. FPIT rate was 32.07%, diarrhea occurrence and respiratory diseases were 77.9% and 49.6%, respectively. FPIT increased the chances of calves presenting diarrhea and developing respiratory diseases, but no differences on zootechnical performance were found. The frequency of FPIT is still high and is a factor that corroborated the increased risk for diarrhea and respiratory disease but did not influence the performance of calves in the preweaning phase.(AU)

Bezerras são extremamente dependentes da ingestão de colostro para adquirir imunidade passiva. Este estudo teve o objetivo de determinar os índices de ocorrência de diarreia e de doença respiratória, assim como o impacto da falha na transferência de imunidade passiva (FTIP) no desenvolvimento de doenças e no desempenho zootécnico de bezerras Holandês criadas em sistema individual. O estudo foi desenvolvido em cinco propriedades comerciais no Rio Grande do Sul, Brasil, entre março de 2017 e janeiro de 2018. Assim, 131 bezerras foram acompanhadas, do nascimento aos 60 dias de idade. Em 53 animais, foi realizada avaliação de proteínas plasmáticas totais para determinar a qualidade na transferência de imunidade passiva. Acompanhamento clínico diário foi realizado, a fim de diagnosticar doenças e suas incidências, assim como avaliações zootécnicas, como altura de cernelha, largura de garupa, perímetro torácico e peso. O percentual de FTIP foi 32,07%, a ocorrência de diarreias e de doenças respiratórias foi, respectivamente, 77,9% e 49,6%. A FTIP aumentou as chances de as bezerras apresentarem diarreia e doenças respiratórias, mas não alterou o desempenho zootécnico. Conclui-se que a frequência na FTIP ainda é elevada, fator que corroborou o aumento do risco para as diarreias e doença respiratória. Apesar disso, a FTIP não influenciou no desenvolvimento das bezerras na fase de aleitamento.(AU)

Hematological and biochemical parameters of dairy calves submitted to pegbovigrastim administration.

This study was designed to evaluate the response of hematological and biochemical parameters submitted to pegbovigrastim administration and postchallenge with lipopolysaccharide (LPS). In experiment 1, 20 newborn Holstein calves were divided into 2 groups: the Imrestor (Elanco Saúde Animal, São Paulo, Brazil) group (IMR, n = 10), which received a 25 µg/kg of body weight (BW) subcutaneous administration of pegbovigrastim, and the control group (CTR, n = 10), which received a subcutaneous administration of 0.9% saline solution. Blood samples were collected on d 0, 10, 12, and 14 relative to birth to analyze the biochemical and hematological parameters. Moreover, growth measurements were taken on d 0, 7, 14, 21, and 60 relative to birth. The number of total leukocytes in the IMR group increased on d 12 and 14 in comparison to the CTR group, as well as the counts of segmented neutrophils, band cells, and monocytes. No differences were observed in the other hematological, biochemical, and growth parameters. In experiment 2, 20 Holstein calves from 30 to 60 d old were divided into 4 groups: group 1 (LPS, n = 5) received a 0.25 µg/kg of BW single intravenous dose of Escherichia coli LPS at d 0; group 2 (IMR, n = 5) received a 25 µg/kg of BW subcutaneous dose of pegbovigrastim at d 1; group 3 (IMR + LPS, n = 5) received a 0.25 µg/kg of BW intravenous LPS dose at d 0 and a 25 µg/kg of BW subcutaneous dose of pegbovigrastim at d 1; and group 4 (CTR, n = 5) received an intravenous dose of 0.9% sodium chloride at d 0 and a subcutaneous dose of 0.9% sodium chloride at d 1. For the analysis of biochemical and hematological parameters, blood samples were collected on d -1, 0, 1, 2, 3, 4, 8, 14, and 21 relative to LPS administration. An increase in the number of total leukocytes was observed in the IMR, IMR + LPS, and LPS groups, and the IMR group remained as the highest from d 2 to 21. The levels of paraoxonase 1 were higher in the IMR group compared with all the others. The administration of pegbovigrastim in the dairy calves increased the number of circulating leukocytes, especially neutrophils, with an increase in paraoxonase 1, without altering the metabolites for the hepatic function.