Autor(es): Silva, Flávio ; Conceição, Cristina ; Silva, Severiano ; Caetano, Pedro ; Ramalho, Joana ; Pedro, Sofia ; Azevedo, Inês ; Martins, Luís ; Pereira, Alfredo ; Cerqueira, Joaquim
Data: 2023
Identificador Persistente: http://hdl.handle.net/10174/33599
Origem: Repositório Científico da Universidade de Évora
Assunto(s): calves; bed hygiene; colostrum; health
Calves are born agammaglobulinemic and naturally vulnerable to pathogenic agents before developing their immune system. Therefore, soiled environments and bad hygiene practices can greatly increase the risk of infectious diseases. Passive immune transfer (PIT), with colostrum consumption, can help the calf cope with the microbiological load in the environment; however, PIT is greatly affected by management colostrum practices. So, calves housed in soiled conditions and with PIT failure are prone to a high occurrence of diarrhoea, pneumonia, and omphalitis. This study aimed to relate calves’ bedding hygiene and colostrum practices to calves’ health. Data from 24 calves were collected in two dairy farms until calves were sold (15 to 30 days) or weaned (60 days). At every calving, birthplace (maternity pen), cow, calves’ pens and calf hygiene were assessed using visual scoring systems. Nesting score was evaluated to access bed comfort related to physical injuries and respiratory diseases. Colostrum intake, time and method of administration was recorded, and IgG level was estimated with a Brix % refractometer. PIT was evaluated by total serum proteins (TSP) 24h after birth. On days 2, 7, 30 and 60, health status was evaluated with a health scoring system to detect diarrhoea, pneumonia, omphalitis, and physical injuries. In this study, birthplace hygiene was poor, but calves’ pens had good scores on hygiene and nesting score. Colostrum practices seemed adequate, and mean Brix % values (23.71 ± 2.31% Brix) were just above the breaking point for high-quality colostrum (21%); however, there was a high failure of PIT (50% of the calves), with subsequent elevated diseases’ prevalence (diarrhoea [75%] and pneumonia [25%]). Failure in PIT could have been more related to the quantity of colostrum (3.30 ± 0.73 litres) or microbiological quality. Diseases occurred manly after one week of life, suggesting no influence of the birthplace’s poor conditions. Calf’s cleanliness score, no cases of omphalitis and physical injuries can be related to the calves’ clean and comfortable beds. Also, a multi regression model (R2=0.7; P=0.001) showed a positive relation between TSP and total litres of colostrum and Brix, but not with time and method. It highlights the importance of quantity and quality of colostrum, with no significant changes on PIT if colostrum is consumed within 2:05 ± 1:08 hours.
