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.

This study aimed to evaluate lytic bacteriophage supplementation in pre-weaned dairy calves on disease occurrence, performance, and biochemical parameters. Two hundred Holstein × Gyr crossbred female calves were divided into two groups: CON, no supplementation; and PHAGE, bacteriophage supplementation (1 g·d−1) from day 3 until day 70 of life. Calves were monitored daily for age of first diarrheal episode and its duration. Fecal samples were cultured for bacterial isolation and PCR was performed to identify Escherichia coli virulence genes and to confirm Salmonella spp. Performance outcomes were evaluated up to 80 d of age. Blood samples were collected to determine serum levels of total proteins, albumin, cholesterol, γ-glutamyl transferase, and urea. PHAGE group had fewer days with diarrhea (PHAGE: 4.68 d, CON: 6.61 d; P = 0.03). Fecal samples of three animals in PHAGE and nine in CON were positive for E. coli after PCR tests. Average daily gain of PHAGE was higher up to 80 d of life (P < 0.05). PHAGE mean was lower for albumin and higher for urea (P = 0.004 and P < 0.001, respectively). Phage therapy during the pre-weaned period reduced the duration of neonatal diarrhea, providing greater weight gain for calves.

No abstract

Bezerros são uma categoria animal de extrema importância dentro do sistema pecuário, necessitando atenção em relação a parasitoses gastrointestinais. O objetivo deste trabalho foi demonstrar os efeitos de um antihelmíntico no ganho de peso e controle de helmintos em bezerros de corte. Foram utilizados 40 bezerros, da raça Angus, com 45 a 100 dias de idade, peso médio 112,9 ± 19 Kg divididos em dois grupos: Grupo Tratamento (n = 20), composto por animais que receberam 1 mL / 50 Kg de peso vivo do produto doramectina 1 % e Grupo Controle (n = 20), composto por animais que não receberam algum tratamento. Foram realizadas 2 pesagens para avaliação do ganho médio diário (GMD) durante o período experimental e, 4 coletas de fezes para realização de exame parasitológico contagem de ovos por grama de fezes (O.P.G.). O resultado do O.P.G. não apresentou diferença estatística entre os grupos (p > 0,05), contudo, o GMD em Kg do Grupo Tratamento foi superior ao do Grupo Controle (p <0,0001), apresentando GMD de 0,884 Kg e 0,446 Kg, respectivamente. Em suma, o tratamento com doramectina 1% (dual oil) foi eficaz em bezerros de corte no aumento do ganho de peso durante o período estudado.

The aim of this study was to determine zootechnical and health performance of Girolando calves born with high or low birth weight, and compare metabolic parameters between groups. The study was carried out on a commercial dairy farm located in Passos, Minas Gerais, Brazil. In this sense, a hundred Girolando calves were divided into 2 groups: Control, which consisted of calves that were born weighing ≤ 35 kg; and HBW, calves that were born weighing > 35 kg. Calves were monitored for zootechnical parameters; epidemiological indexes such as morbidity, mortality, recurrence of diarrhea, pneumonia; as well as serum concentrations of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, cholesterol, triglycerides, paraoxonase1, albumin, urea and globulin). Calves from the HBW group had a higher mortality rate as well as a tendency to more cases of pneumonia, but no effect on zootechnical performance was seen. The reasons for the differences in mortality need to be clarified since our study found no changes in biochemical parameters between the groups. The results allow us to conclude that Girolando calves from in vitro fertilization that are born heavier have a greater chance of clinical complications and a higher mortality rate, but the birth weight does not influence the zootechnical performance.

This study aimed to evaluate lytic bacteriophage supplementation in pre-weaned dairy calves over neonatal calf diarrhea and respiratory diseases occurrence, performance and biochemical parameters. Also, to determine bacterial agents causing NCD. Two hundred Holstein×Gyr crossbred female calves were divided into two groups: Control (CON, n = 100), no supplementation; and Bacteriophage (PHAGE, n = 100) bacteriophage supplementation (1 g/day) from d 3 until d 70 of life. Calves were monitored daily for respiratory disease and diarrhea, as for age at the first diarrheic episode and its duration. Fecal samples were cultured for isolation of Escherichia coli and Salmonella spp. colonies and PCR was performed to identify E. coli virulence genes and to confirm Salmonella spp. Performance outcomes were evaluated up to 80 d of age. Blood samples were collected to determine serum levels of total proteins, albumin, cholesterol, γ-glutamyl transferase and urea. PHAGE group had fewer days in diarrhea and duration of the first episode was lower, compared to CON group. Fecal samples of three animals in PHAGE and nine in CON were positive for E. coli in PCR. Thoracic perimeter tended to be higher in supplemented animals. Average daily gain mean of PHAGE was higher in the first 30 d of life, at the beginning of step-down weaning (up to 42 d) and after weaning (up to 80 d). PHAGE mean was lower for albumin and higher for urea. Therefore, phage therapy during the pre-weaned period reduced the duration of neonatal diarrhea, providing greater weight gain for calves.