Influence of Parity on the Colostrum Bacterial Community Composition in Holstein Cows

Abstract

The colostrum bacteriome of primiparous (P) and multiparous (M) Holstein cows was analysed by 16S rRNA sequencing. The species richness (Chao 1), diversity (Shannon and Simpson), and beta diversity did not differ between cow groups. The phyla Firmicutes, Tenericutes, Kiritimatiellaeota, and Fibrobacteres were more abundant in M cows, while Proteobacteria, Actinobacteria, Cloacimonetes, and Fusobacteria were more abundant in P cows. At the genus level, no significant differences were observed between groups (P < 0.05), and Prevotella_1 was the most abundant taxon. P and M cows shared 1030 taxonomic operational units (OTUs), with Acinetobacter showing greater abundance. In conclusion, parity did not affect the colostrum bacteriome of P and M cows and a healthy mammary gland could represent a reservoir of Acinetobacter in dairy farms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-022-01016-x.

Dairy calf rearing systems face several challenges during the period from birth to weaning [1]. Specifically, colostrum feeding to neonatal calves plays an important role in the nutrition, growth and health of young ruminants [2]. Colostrum intake promotes the development of the immune system of neonatal calves [3] due to several bioactive compounds with immunological properties [4]. Delaying the first feeding of colostrum affects the establishment of ileum and colon mucosa-associated bacteria potentially affecting the gut health in calves [5].

Nutritional quality of colostrum may vary according to the breed, nutrition, production systems, and cow parities [6–8]. First-calf heifers can produce colostrum of lower nutritional quality and lower abundance of immunoglobulins [9, 10] and fats postpartum [9]. Dairy calves from primiparous (P) cows can also be more susceptible to diseases and have inferior reproductive traits in adult life compared to calves born from multiparous (M) cows [9, 11]. Nevertheless, there is a knowledge gap on parity influence on colostrum bacteriomes of dairy cows. Here, we examine the hypothesis that parity affects the diversity of colostrum bacteriomes in dairy cows. The bacterial composition of colostrum from P and M Holstein cows was characterised through next-generation sequencing to identify opportunities for improving the nutrition and health of calves.

Colostrum samples collected from P and M cows (Explained in Data S1 and S2) generated 1,207,628 raw 16S rRNA sequences with an average size of 240 bp. The Good’s coverage was > 99%, indicating sufficient sampling effort to cover the existing diversity (Table S1). Beta diversity analysis inferred from the Bray–Curtis dissimilarity index (Explained in Data S3) showed no significant differences (ANOSIM, P = 0.66) between the colostrum bacterial communities of both cow groups (Fig. S1). Similarly, within-sample (alpha) diversity metrics of species richness (Chao 1) and diversity (Shannon and Simpson) of the colostrum bacterial communities did not differ between cow groups (Fig. S2). These results partially contrast what was reported by Lima et al. [12], who observed a greater richness of bacterial species (Chao1) in Holstein cows at first calving compared to the M cows [12]. However, in the current study, intramammary antibiotic therapy was not used during the dry period, and composite colostrum samples were collected within 72 h after parturition.

After taxonomic assignment of the OTUs, sequences were classified into 35 phyla, 90 classes, 227 orders, 438 families, and 1044 genera across colostrum samples of P and M cows. The most abundant phyla in the P colostrum samples were Firmicutes (32.97 ± 9.10%), Bacteroidetes (24.33 ± 3.54%), Proteobacteria (23.88 ± 9.99%), and Actinobacteria (7.65 ± 2.84%). The colostrum bacterial community in M cows was represented mainly by Firmicutes (40.0 ± 7.23%), Bacteroidetes (26.23 ± 3.57%), Proteobacteria (15.99 ± 7.00%), and Actinobacteria (5.84 ± 2.56%). The phyla Firmicutes, Tenericutes, Kiritimatiellaeota, and Fibrobacteres were more abundant (White's non-parametric t-test, P < 0.05) in M when compared to P, while Proteobacteria, Actinobacteria, Cloacimonetes, and Fusobacteria were more abundant (White's non-parametric t-test, P < 0.05) in P than M cows (Fig. 1).

Fig. 1.

Bacterial composition at the phylum level of the bacterial communities in the colostrum of primiparous (P) and multiparous (M). Each bar represent the relative abundance of bacterial taxa for individual animals in each group. “Others” corresponds to the phyla with < 0.5% relative abundance

At the family level, the colostrum of P cows showed 34 families with a relative abundance ≥ 0.5%. The most abundant families were Lachnospiraceae (10.22 ± 4.10%), Ruminococcaceae (9.95 ± 3.20%), Prevotellaceae (7.07 ± 4.13%), Moraxellaceae (4.2 ± 5.34%), Weeksellaceae (2.48 ± 2.98%), Chritensenellaceae (2.48 ± 1.04%), Rikenellaceae (2.33 ± 1.33%), Burkholderiaceae (1.98 ± 1.17%), Flavobacteriaceae (1.96 ± 1.27%) and Pseudomonadaceae (1.63 ± 1.70%) (Fig. S3). Our results confirmed Lachnospiraceae and Ruminococcaceae as the most abundant families in the colostrum of P and M cows [12, 13]. Members of the Ruminococcaceae and Lachnospiraceae families have been positively correlated with the diversity metrics within the microbiota of teat canal and mammary secretions (milk and colostrum) [14]. These taxa are potential taxonomic markers of a healthy udder and could serve as candidates to develop diagnostic tools for mammary gland health [13, 15].

At the genus level, the taxonomic classification resulted in a high proportion of unclassified sequences (22.5 ± 3.15% in P cows and 21.37 ± 3.23% in M cows). The most abundant genera (> 1.0%) in P and M were, respectively, Prevotella_1 (4.21 and 5.87%), Christensenellaceae_R-7_group (2.62 and 3.46%), Rikenellaceae_RC9_gut_group (2.06 and 3.17%), Mollicutes_RF39_ge (1.67 and 2.29%), F082_ge (1.41 and 2.07%), Acinetobacter (3.49 and 1.62%) and Ruminococcaceae_UCG-014 (1.09 and 1.36%) (Table S2). Prevotella is metabolically versatile and considered one of the most abundant genus in the rumen environment [16, 17]. The genus is found during the early colonisation of the calves' gastrointestinal tract (2 weeks of age) and plays a role in the transition to a fibre-rich diet during pre-weaning [6, 18]. However, the origins of the colostrum and bovine milk microbiota are not well understood. An endogenous or entero-mammary pathway for translocation of bacteria from the intestine to the mammary gland has been suggested [19]. If confirmed, this hypothesis may explain the presence of anaerobic bacteria such as Prevotella and Ruminococccus in the colostrum of dairy cows, thus emphasising the importance of maintaining a healthy rumen microbiome in pregnant heifers and cows.

Our findings also indicate a high abundance of Acinetobacter (approximately 2.6%) in the colostrum of P and M cows. Thus, the mammary gland could be an important reservoir of this bacterial taxon in dairy farms. Some Acinetobacter, particularly Acinetobacter baumannii, carry resistance genes to multiple antibiotics [20] and are often associated with clinical samples of patients that develop nosocomial infections caused by multidrug-resistant (MDR) bacteria [21]. The genus Acinetobacter is widely distributed in the environment [22] and can be isolated from animal faeces, soil [22], and the colostrum of dairy cows [12, 23].

After data normalisation, 2777 OTUs were identified in the colostrum samples from both P and M cows. Among these, 1030 OTUs were shared between cow groups, while 797 OTUs were unique to first-calf heifers and 950 were only observed in M cows (Fig. S4). The ten most abundant OTUs in the colostrum of P cows ranged from 1.06% to 5.13%, while in M cows the most abundant OTUs varied from 0.98% to 3.94%. Among the 10 most abundant OTUs shared between P and M cows, four belong to the genus Acinetobacter, with relative abundances ranging from 0.98% (M) to 5.13% (P) (Table 1).

Table 1.

Taxonomic classifications and mean relative abundance (%) of the 10 most abundant shared OTUs between primiparous and multiparous cows

OTUs	Taxonomy	Primiparous (%)	SD	Multiparous (%)	SD	P value	P value (corrected)
Otu00001	Escherichia-Shigella	1.06	0.651	1.46	1.447	0.526	1
Otu00002	Acinetobacter	5.13	8.084	3.94	6.311	0.771	1
Otu00006	Chryseobacterium	4.53	6.046	3.26	5.513	0.680	1
Otu00007	Enterobacteriaceae (unclassified)	1.13	1.321	1.22	1.596	0.908	1
Otu00008	Acinetobacter	4.61	4.348	1.28	1.953	0.098	0.98
Otu00010	Saprospiraceae (uncultured)	3.49	4.088	3.30	5.163	0.921	0.921
Otu00011	Acinetobacter	2.82	2.417	1.48	2.073	0.271	1
Otu00019	Membranicola	2.03	1.764	1.35	1.276	0.377	1
Otu00022	Acinetobacter	1.89	2.832	0.98	1.251	0.489	1
Otu00031	Actinomarinales (uncultured)	1.09	0.759	1.14	0.638	0.883	1

Values represent mean and standard deviation

The association between Acinetobacter and dysbiosis of the udder microbiota or calf health has been poorly explored. Considering that parity number also increases the likelihood of dairy cows receiving antibiotic therapy [12, 24], the effects of parity on the abundance of antibiotic resistance genes in the microbiota of mammary secretions (milk and colostrum) should also be addressed in future studies. Additionally, monitoring the species of Acinetobacter, as well as MDR bacteria potentially circulating in dairy farms could be useful to guide antimicrobial stewardship programs in dairy production and the development of prophylactic/control strategies within the One Health concept [25].

Supplementary Information

Below is the link to the electronic supplementary material.

Funding

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq; Brasília, Brasil) (Grant 142496/2014-6), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES; Brasília, Brasil, Grant number 0001), Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG; Belo Horizonte, Brasil) e INCT Ciência Animal.

Data Availability

All data generated or analysed during this study are included in this published article.

Code Availability

Not applicable.

Declarations

Conflict of interest

The authors declare that there are no conflicts of interest in this manuscript.

Consent for publication

Not applicable.

Ethical approval

All procedures for handling the animals were conducted in accordance with current legislation and the recommendations of the Ethics Committee on the use of food animals (CEUAP-UFV) at the Universidade Federal de Viçosa, where the project was approved under the protocol number 062/2016.

Consent to participate

Not applicable.