Progress report for SW23-946
Project Information
Diarrhea is an early-life health issue in dairy calves and is strongly related to morbidity and mortality in the first weeks of life. Diarrhea is usually treated with antimicrobials; however, governmental organizations have strongly regulated antimicrobial use in cattle production to reduce antimicrobial resistance (AMR) in humans and animals. Weaning is a challenging event in the calf’s life, and depending on how it is conducted, it can lead to short- and long-term consequences such as inflammation and diarrhea. Therefore, it is important to find an alternative means to prevent diarrhea and potentially reduce the need for antimicrobial treatments on dairy farms and raise awareness of AMR for farm employees and producers.
Our objective is new and innovative: to evaluate the benefits to calf health and performance when neonatal calves are fed gut-originated bovine direct-fed microbial (bDFM) during two methods of weaning transition (abrupt and gradual). Bifidobacteria and Lactobacilli species (direct-fed microbes) have the capacity to enhance gut barrier functions, preventing pathogenic colonization, reducing stress during weaning, and improving average daily gain. Direct-fed microbes (DFM) also have the potential to reduce the use of antimicrobials in the livestock industry, which reduces the exposure of antimicrobials in animals and humans. Recent research has shown that host-specific microbes, when used as bDFM, increase beneficial bacteria and reduce pathogenic microbial populations in the host animal. In this proposal, we will evaluate the potential benefits of bDFM on calf health, inflammatory response during weaning, and performance through the first lactation when administered during the weaning transition period. Reducing morbidity combined with greater performance should result in increased profitability for dairy farms. Reducing antimicrobial use and exposure is a step towards reducing AMR in animal and humans as well as increasing the level of awareness of AMR in humans who work in dairy animal health and production settings. The outcomes from this research, along with current knowledge in calf management, nutrition, health, and weaning methods will be disseminated through webinars, social media, websites, Extension workshops, and field days to producers, farm employees, consultants, veterinarians. Additionally, we will educate university-level Animal Science students within the Pacific Northwest region through classroom instruction. Current knowledge and research results will be inserted into three courses taught regularly at the University of Idaho to animal science students including AVFS 471 (Animal Disease Management), AVFS 472 (Dairy Management), and AVFS 411 (Ruminant Nutrition). All courses will be made available for online use by other regional universities.
- Research objectives
Objective I: Evaluate benefits of neonatal calf gut-originated bDFM during the weaning transition to improve heifer calves’ health and performance
Objective II: Evaluate benefits of neonatal calf gut-originated bDFM during the weaning transition to modulate health of male calves, local inflammatory response, and performance
Objective III: Determine the economic impact of the bDFM supplementation during the weaning transition on dairy farm profitability
- Educational objectives
Objective I-E: Disseminate information and educate the public about the benefits of using bDFM and the reductions on antimicrobial demand and resistance using podcasts and webinars
Objective II-E: Disseminate information via Extension Workshops and Field Days
Objective III-E: Disseminate information regarding the use of bDFM associated with weaning strategies on social media and websites
Objective IV-E: Disseminate the results from the present project supported with the current literature for Animal Science students
Objective V-E: Present research results at annual meetings and publish scientific articles
Cooperators
- (Educator and Researcher)
- - Producer
- - Producer
- - Producer
- - Producer
Research
Objective II: Evaluate benefits of neonatal calf gut-originated DFM during the weaning transition period to modulate health of male calves, local inflammatory response, and performance.
Animals and Treatments: Thirty-eight, one-day-old male Holstein dairy calves will be obtained and housed at the University of Idaho Dairy Center. Calves received povidone iodine navel dip and were fed 150mg Igg commercial colostrum within 8 h of birth. Within 48-72 hours of birth, serum samples were collected from each calf and total proteins measured to assess failure of passive transfer (FPT). Calves were blocked by BW at birth and randomly assigned to one of four treatments. Two animals were pulled from the original study due to clinical illness and the need for antibiotic therapy during the study.
This study examined the effects of probiotic supplementation using a calf gut-originated direct fed Lactobacillus agili, L. delbrueckii, L. mucosae, and L. rueteri 1x109 CFU/d (control vs supplemented) and weaning pace (abrupt vs gradual) on feed intake, growth, vitals, perineal area, and hematological values in dairy calves in a 2 x 2 factorial arrangement of treatments. Holstein bull calves (n=38) were blocked by birth weight and randomly assigned to one of four treatments: Abrupt-Control (AC; n=10), Abrupt-Supplemented (AP; n=10), Gradual-Control (GC; n=9), and Gradual-Supplemented (GP; n=9). 3.4L milk replacer (22% CP, 22% fat) was fed twice daily. Water, calf starter (18% CP) and chopped alfalfa were provided ad libitum, with intake of milk replacer, calf starter, and alfalfa recorded daily. The probiotic was supplemented in milk replacer once daily, for 7 days, beginning 4 days prior to weaning. Abrupt weaning occurred over days 54-57 in 3 incremental step-downs of 1.13L. Gradual weaning occurred over days 49-63 in 7 incremental step-downs of 0.49L. Health parameters including fecal scores, hydration status, respiration rate, heart rate and temperature as well as body weights were measured weekly. Blood hematology was measured at days 3 and 7 of age, onset of treatment and the day after completion of weaning. Fresh fecal samples from the abrupt-weaned calves will be collected on d 3, d 7, onset of treatment, and day after completion of weaning. Fresh fecal samples and sterile fecal swabs were collected and placed into sterile vials and immediately stored at -20°C until further processing to determine total bacteria, total coliform, and bacterial shedding (Laegreid et al., 1999; Rosa et al., 2021).
One day after weaning, the animals were humanely euthanized and samples of feces, rumen, duodenum, jejunum, ileum, large intestine, liver, mesenteric lymph nodes, abdominal and perirenal adipose tissues were obtained. All samples were placed in 2cc cyro tubes, immersed in liquid nitrogen and stored in -80 to determine microbiome (feces) and gene expression of inflammatory markers (tissues). Tissues will also be preserved (Mavangira et al., 2015) to determine oxylipids profile.
Data were analyzed using mixed model with pace and supplementation as fixed effects. No differences in red blood cells, white blood cells, and platelets were detected by pace or supplementation. No differences in intakes were detected. During the treatment period (abrupt days 50-58, gradual days 45-64) average daily gain was larger in abrupt weaned calves than gradual weaned calves (1.25 vs 0.83 kg/d, P = 0.009). No differences in vitals were detected. Overall, the abrupt pace influenced average daily gain, while hematological and vital parameters were not significantly affected by pace, supplementation, or their interactions.
Research Outcomes
Overall, the abrupt pace influenced average daily gain, while hematological and vital parameters were not significantly affected by pace, supplementation, or their interactions.
Early in our research for additional outcomes.
Education and Outreach
Participation Summary:
Graduate student's seminar presentation and E-poster.
Education and Outreach Outcomes
NA