RESUMO
The objective of this randomized controlled trial was to evaluate the efficacy of supplementing bovine colostrum replacer during weaning to reduce intestinal permeability and improve gain. For this experiment, 65 calves were enrolled and housed individually until 70 d of age. Calves were fed milk replacer (150 g/L) 3 times daily with 9 L/d, 10.5 L/d, 11.25 L/d, and 12 L/d offered from d 1-7, d 8-14, d 15-21, d 22-56, respectively. Calves were weaned over 8 d from d 57-64, receiving a total of 7.8 L in 2 meals/d from d 57-60 and 3.8 L/d in one feeding from d 61-64. At d 57, calves were blocked by birth weight and randomly assigned to one of 2 treatments, equal in metabolizable energy, which were fed once daily during weaning from d 57-64: control (CON; n = 31 calves): 3.8 L milk replacer (150 g/L) fed by nipple bottle, or colostrum supplementation (COL; n = 34): a mixture of 1 L bovine colostrum replacer (125 g/L) and 3 L milk replacer (150 g/L) with 3.8 L of the mixture fed by nipple bottle. Serum IgG was measured within 48 h of birth and body weight was taken at d 0, 57, 60, 64, 70, 77, and 84. Starter intake and bovine respiratory disease (BRD) score were measured daily from d 50-70 and fecal consistency was examined daily from d 56-70. Serum ß-hydroxybutyrate (BHB) and lung consolidation were evaluated at d 57, 64, and 70 and intestinal permeability was assessed by recovery of chromium-EDTA, lactulose, and d-mannitol from plasma after oral administration at d 56 and 65. There was no difference in body weight between treatment groups at the start of weaning, but COL were 2.79 kg (95% CI: 0.90-4.68) and 2.76 kg (95% CI: 0.86-4.65) heavier than CON at d 77 and 84, respectively. Additionally, COL tended to gain 100.00 g/d more than CON calves (95% CI: -10.41-207.13) from d 57-84. There were no differences in any of the other variables measured. Supplementation of bovine colostrum replacer during weaning may improve weight gain, but the mechanism of action is not clear.
RESUMO
Establishing accurate illness and treatment rates in dairy calves is crucial, yet calf health records are often incomplete. Thus, the objective of this study was to investigate barriers for dairy farmers for recording calf illnesses and treatments on dairy farms in Ontario, Canada. An online survey was completed by a convenience sample of 88 Ontario dairy farms in 2022, with 34 questions regarding farm demographics, current practices surrounding record keeping and analysis, and factors that would improve recording compliance. Multivariable models were built to assess associations between explanatory variables and the following outcomes: likelihood of making management or treatment protocol changes based on records analysis, factors that would increase the use of electronic recording methods, and whether all calf illnesses and treatments are recorded. Pearson's chi-squared tests were also used to investigate associations between explanatory variables and whether the respondent agreed or disagreed with a proposed reason for why a calf illness or treatment would not be recorded on their farm. Producers had 3.45 times greater odds of recording all antimicrobial treatments if they used a computer software system compared with those that did not. With respect to anti-inflammatory treatments, producers had 3.11 times greater odds of recording these treatments if records were located in the calf barn than elsewhere. Nonfamily employees had 6.08 times greater odds of recording all supportive therapy treatments than farm owners. When calf health records were kept in the calf barn, respondents were less likely to report that illnesses were not recorded due to time constraints (5% vs. 36% if records were elsewhere) or because calf health records were not analyzed (10% vs. 34% if records were elsewhere). On farms that recorded calf treatments in a paper booklet, respondents were more likely to report that treatments were not recorded because calf health records were not analyzed (44% for paper records vs. 21% for other systems). The most commonly indicated factors that would increase recording of illness were recording with a mobile app (27% of respondents) and for the recording system to be easy to use (31% of respondents). Overall, these data indicate that recording may be improved by keeping calf health records in close proximity to the calves and using a recording method that allows for data analysis. An easy-to-use mobile app may also improve recording if it could be used in the calf barn, provide data analytics, and allow for time-efficient data entry.
