Differences in the fecal microbiota of dairy calves reared with differing sources of milk and levels of maternal contact

Duration of dam contact had a long effect on calf rumen microbiota without affecting growth

Introduction

Separating calves from their mothers at birth is linked to calf welfare issues and disturbances in the mother-calf relationship. It can also disrupt the maturation of the digestive tract, affecting calf health. It has been demonstrated that separation at weaning allows for the optimal establishment of the ruminal microbiota, whereas separation at birth alters colonization dynamics. We postulated that 4 weeks of cow-calf contact, a potentially more socially acceptable, and economically pragmatic, management practice, would induce a similar development of ruminal microbiota to that observed with separation at weaning, thereby conferring benefits on calf health and growth.

Methods

We studied three groups of 14 cow-calf pairs (Holstein and Montbéliarde breeds) with different cow-calf separation times: 4 weeks of contact with the mother (Mixed group), immediate separation (at birth, Control group) and delayed separation at weaning (11 weeks, Dam group). Rumen microbial colonization was monitored in 9 calves per group at 3, 10, 13, and 20 weeks of age using a metataxonomic approach. Body weight, diarrhea and respiratory disease were recorded to assess the calves' overall health. Serum IgG concentrations were also monitored.

Results

No differences were observed between the groups in diarrhea or IgG concentration. The incidence of respiratory disease was lower in calves that remained in contact with their dams until weaning. After separation, the Mixed group exhibited an increased average daily gain. The metataxonomic analysis demonstrated that as calves aged, there was an increase in richness, accompanied by a corresponding increase in the number of shared microbial species over time between all groups. Nevertheless, three discrete development pathways were identified in the rumen bacterial communities, as evidenced by the differences in beta diversity between the groups over time. Additionally, the presence of the mother had a favorable effect on the transfer of beneficial microbiota during the early stages of life. However, this was offset by the elevated detection of potential pathogens at a later age in the Dam group.

Conclusion

In this study, the rearing method exerted a profound and enduring influence on the gastrointestinal microbiota, with no discernible negative impact on health.

Analysis of the fecal microbiome and metabolome in dairy cows with different body condition scores

Holstein Friesian is the most popular breed of dairy cows worldwide due to its exceptional milk production capabilities. In dairy cow management, the body condition score (BCS) is a useful tool, serving as a reliable indicator of a cow's nutritional status and overall health. It is determined via a subjective visual and tactile assessment of fat cover and muscle mass. A low BCS is associated with decreased milk production and fertility. While genetic and nutritional factors have previously been associated with BCS, their effects are often moderate. In this study, we compared the fecal microbiome and the untargeted fecal metabolome of normal (BCS ≥  3, n =  16) and thin (BCS <  3, n =  16) Holstein Friesian dairy cows. The 16S rRNA gene-based metagenomic analysis revealed that thin cows had significantly higher levels of Clostridiaceae, Erysipelotrichales, Erysipelotrichaceae, and Turicibacter, while normal cows had higher levels of Clostridiales_vadinBB60_group, UCG-010, Bacteroidaceae, Ruminococcaceae, Paludibacteraceae, Alistipes, and Bacteroides. The fecal metabolomic analysis showed that key signaling pathways, including the mechanistic target of rapamycin (mTOR), phosphatidylinositol 3-kinase (PI3K)-Akt, and AMP-activated protein kinase (AMPK) pathways, were enriched in thin cows. In addition, a significant correlation was observed between differential microbial taxa and metabolites. Notably, Clostridiaceae and Erysipelotrichaceae species are linked to inflammation, infectious diseases, and conditions such as ruminal acidosis. Additionally, the mTOR, PI3K-Akt, and AMPK pathways are known to be activated by both nutrient deficiencies and inflammation. We propose that, in addition to genetic and nutritional factors, gut microbiome dysbiosis may contribute to subclinical health conditions, such as chronic inflammation and acidosis, which indirectly affect the cow's BCS. These findings are guiding our ongoing research on the underlying health conditions in thin cows to better understand the role that the gut microbiome plays in the regulation of the body condition.

Impact of dairy calf management practices on the intestinal tract microbiome pre-weaning

Introduction. Microbiota in the gastrointestinal tract (GIT) consisting of the rumen and hindgut (the small intestine, cecum and colon) in dairy calves play a vital role in their growth and development. This review discusses the development of dairy calf intestinal microbiomes with an emphasis on the impact that husbandry and rearing management have on microbiome development, health and growth of pre-weaned dairy calves.Discussion. The diversity and composition of the microbes that colonize the lower GIT (small and large intestine) can have a significant impact on the growth and development of the calf, through influence on nutrient metabolism, immune modulation, resistance or susceptibility to infection, production outputs and behaviour modification in adult life. The colonization of the calf intestinal microbiome dynamically changes from birth, increasing microbial richness and diversity until weaning, where further dynamic and drastic microbiome change occurs. In dairy calves, neonatal microbiome development prior to weaning is influenced by direct and indirect factors, some of which could be considered stressors, such as maternal interaction, environment, diet, husbandry and weaning practices. The specific impact of these can dictate intestinal microbial colonization, with potential lifelong consequences.Conclusion. Evidence suggests the potential detrimental effect that sudden changes and stress may have on calf health and growth due to management and husbandry practices, and the importance of establishing a stable yet diverse intestinal microbiome population at an early age is essential for calf success. The possibility of improving the health of calves through intestinal microbiome modulation and using alternative strategies including probiotic use, faecal microbiota transplantation and novel approaches of microbiome tracking should be considered to support animal health and sustainability of dairy production systems.

Maternal Transmission of Rotavirus to Calves and Comparison of Colostrum and Fecal Microbiota in Holstein and Hanwoo Cattle

This study aimed to evaluate rotavirus transmission to calves and analyze microbial communities in cow milk and neonatal calf feces within dairy and beef cattle. A total of 20 cattle, Hanwoo (n = 10), and Holstein (n = 10) were allotted for the study, with each breed comprising five cows and five calves. Colostrum samples were obtained from the dam, while feces were obtained from both the dam and calf. Group A rotavirus was identified in the fecal samples through real-time reverse transcription PCR (RT-qPCR). Bacterial communities present in the colostrum and bovine feces were explored using 16S rRNA metagenomic sequencing. The RT-qPCR results showed that the Cq value of one calf and one cow in the Holstein group was < 35, confirming the presence of rotavirus, whereas the Cq value in the Hanwoo group was > 35, indicating a negative result. For the bacterial communities, significant differences (p < 0.05) were found between the colostrum and fecal samples from the dams and calves, but there were no significant differences between Hanwoo and Holstein cattle. Alpha diversity analysis showed that the Chao1 and Shannon indices revealed significant differences (p < 0.05) among the sample types (cow colostrum, cow feces, and calf feces). The bacterial communities in various sample types from both Hanwoo and Holstein cattle were dominated by the phyla Firmicutes, Proteobacteria, and Bacteroidetes. In addition, the genera shared between the cow colostrum and calf fecal microbiota were higher than those shared between cow and calf feces. Overall, the current study detected rotavirus in Holstein but not in Hanwoo cattle; however, no clear evidence showed the transmission of rotavirus from dam to calf. Moreover, significant variations in bacterial compositions were observed among calf feces, cow feces, and colostrum samples, suggesting the presence of unique microbial profiles.

INVITED REVIEW: Impact of Maternal Health and Nutrition on the Microbiome and Immune Development of Neonatal Calves

This comprehensive review highlights the intricate interplay between maternal factors and the co-development of the microbiome and immune system in neonatal calves. Based on human and mouse studies, multiple prenatal and postnatal factors influence this process by altering the host-associated microbiomes (gut, respiratory tract, skin), microbial colonization trajectories, and priming of the immune systems (mucosal and systemic). This review emphasizes the importance of early life exposure, highlighting postnatal factors that work in synergy with maternal factors in further finetuning the co-development of the neonatal microbiome and immunity. In cattle, there is a general lack of research to identify the maternal effect on the early colonization process of neonatal calves (gut, respiratory tract) and its impact on the priming of the immune system. Past studies have primarily investigated the maternal effects on the passive transfer of immunity at birth. The co-development process of the microbiome and immune system is vital for lifelong health and production in cattle. Therefore, comprehensive research beyond the traditional focus on passive immunity is an essential step in this endeavor. Calf microbiome research reports the colonization of diverse bacterial communities in newborns, which is affected by the colostrum feeding method immediately after birth. In contrast to human studies reporting a strong link between maternal and infant bacterial communities, there is a lack of evidence to clearly define cow-to-calf transmission in cattle. Maternal exposure has been shown to promote the colonization of beneficial bacteria in neonatal calves. Nonetheless, calf microbiome research lacks links to early development of the immune system. An in-depth understanding of the impact of maternal factors on microbiomes and immunity will improve the management of pregnant cows to raise immune-fit neonatal calves. It is essential to investigate the diverse effects of maternal health conditions and nutrition during pregnancy on the gut microbiome and immunity of neonatal calves through collaboration among researchers from diverse fields such as microbiology, immunology, nutrition, veterinary science, and epidemiology.

Periodontitis Disease in Farmed Ruminants-Current State of Research

Periodontal disease in ruminants is common and occurs in farmed and wild animals. Periodontal lesions can result from the secretion of endotoxins by pathogenic bacteria and as consequences of immune system activity. Three main types of periodontitis have been described. The first is chronic inflammation involving mainly premolars and molars-periodontitis (PD). The second type is an acute inflammatory reaction occurring with calcification of the periosteum of the jawbone and swelling of the surrounding soft tissues (Cara inchada, CI-"swollen face"). Finally, a third type, similar to the first but located in the incisor area, is called "broken mouth" (BM). Etiological variation between the different types of periodontitis is indicated. This particularly manifests in the composition of the microbiome, which is characteristic of the different forms of periodontitis. The widespread detection of lesions has drawn attention to the current nature of the problem.

The Influence of Feeding with Colostrum and Colostrum Replacer on Major Blood Biomarkers and Growth Performance in Dairy Calves

Bovine colostrum (BC) is the first milk produced by lactating cows after parturition. BC is rich in various amino acids, proteins, and fats essential for the nutrition of the neonate calves. Despite the evident beneficial effect of BC on calves, the effect of BC on blood biomarkers is poorly understood. Calves that received BC showed significantly higher body mass at days 7 and 30 (38.54 kg and 43.42 kg, respectively) compared to the colostrum replacer group (p = 0.0064). BC induced greater quantities of blood neutrophils (0.27 × 10⁹/L) and monocytes (4.76 × 10⁹/L) in comparison to the colostrum replacer (0.08 and 0.06 × 10⁹/L, respectively) (p = 0.0001). Animals that received BC showed higher levels of total serum protein (59.16 g/L) and albumin (29.96 g/L) in comparison to the colostrum replacer group (44.34 g/L and 31.58 g/L, respectively). In addition, BC induced greater intestinal mucus production in the Wistar rat model. Collectively, these results demonstrate that BC is important for the growth of calves and that it provides a significant beneficial effect on morphological and biochemical blood parameters.

Effect of Type of Cow-Calf Contact on Health, Blood Parameters, and Performance of Dairy Cows and Calves

Prolonged cow-calf contact (CCC) could potentially improve dairy calf welfare. However, it is currently unknown how different types of CCC affect animals' biological functions. We evaluated health and performance parameters of dairy calves and their dams, where calves: (i) had no contact with their dam (NC), in which the calf was removed from the dam directly after birth (n = 10); (ii) were allowed to have partial contact (PC) with their dam, in which the calf was housed in a calf pen adjacent to the cow area allowing physical contact on the initiative of the dam but no suckling (n = 18); (iii) were allowed to have full contact (FC) with their dam, including suckling, in which calves were housed together with their dams in a free-stall barn (n = 20). Throughout the first 7 weeks postpartum, data were collected on the health status, fecal microbiota, hematological profile, immune and hormonal parameters, and growth rates of calves, and on the health status, metabolic responses, and performance of dams. Overall, FC calves had more health issues (P = 0.02) and a tendency for higher antibiotic usage (P = 0.07) than NC calves. Additionally, FC calves showed elevated levels of erythrocytes, hematocrit, hemoglobin, and leukocytes on day 49 compared to NC calves (P < 0.001). Calf fecal microbiota changed over time, and we found preliminary evidence that fecal microbiota is affected by the type of CCC, as reflected by differences in relative abundances of taxa including Lactobacillus in FC calves compared to NC and PC calves except on days 7 and 66. The FC calves had a greater average daily gain in body weight than NC and PC calves (P = 0.002). Cow health was not affected by the type of CCC, although in the first 7 weeks of lactation FC cows had a lower machine-gained milk yield accompanied by a lower fat percentage than NC and PC cows (P < 0.001). These results indicate that full contact posed a challenge for calf health, presumably because the housing conditions of FC calves in this experimental context were suboptimal. Secondly, ad libitum suckling leads to higher weight gains and negatively affected milk fat content besides machine-gained yields. More research into strategies to improve cow-calf housing and management in CCC systems is warranted.