Enterococcal and streptococcal species isolated from faeces of calves, young cattle and dairy cows

Faeces from non-ruminating calves were found to contain several species of enterococci: Enterococcus avium, Ent. cecorum, Ent. durans, Ent. faecalis, Ent. faecium and Ent. hirae. Enterococcus faecalis was the most frequent. Few of these animals carried streptococci.
Streptococcus bovis largely predominated in ruminating calves, young cattle and dairy cows. Other streptococci as well as enterococci were infrequent in dairy cows, but a variety of other streptococci and enterococci were found in the faeces of young ruminating animals.     

Isolation of Yersinia enterocolitica and related species from the faeces of cows

A total of 203 samples of faeces from 124 cows was examined for the presence of Yersinia enterocolitica and related species by a variety of isolation procedures. Cold enrichment at 5°C for three weeks, followed by plating on cefsulodin-irgasannovobiocin agar yielded Yersinia species most frequently. Yersinia enterocolitica or related species were isolated from 50% of the cows.     

The seasonal variation of thermophilic campylobacters in beef cattle, dairy cattle and calves

The epidemiology of clinical cases of campylobacter in temperate climates shows a striking seasonality. In the search for a seasonal environmental reservoir changes in the carriage rate and population size of campylobacters in bovine hosts with time have been measured. Most probable number (MPN) methodology was used to enumerate thermophilic campylobacters in samples taken from the small intestines of beef cattle at slaughter and the fresh faeces of four dairy herds and new-born calves. Statistical analyses revealed significant evidence for seasonal periodicity in the data from dairy herds ( P = 0·044). Not only was there a departure from constancy within a 12-month interval but these data revealed a true seasonality, that is, the same periodicity in numbers from one year to the next. Each herd had two peaks per year, in approximately spring and autumn. Peaks coincided in herds on neighbouring farms but those on farms in the north preceded those on farms in the south by 2 and 1 months, respectively ( P = 0·0057). Intestinal carriage by beef cattle at slaughter was 89·4% ( n = 360) with an average MPN campylobacters per gram fresh weight (MPN gfw⁻¹) of 6·1 × 10². Average MPN gfw⁻¹ in faeces from the dairy herds and calves were 69·9 ( S.D. 3) and 3·3 × 10⁴ ( S.D. 1·7 × 10²). There was no evidence of seasonal periodicity in the size of the campylobacter population in beef cattle at slaughter. Calves were campylobacter free at birth but became colonized within a few days.     

Cryptosporidium species and subtype analysis from dairy calves in Spain

Faecal specimens from 287 diarrhoeic calves younger than 21 days, collected over a 2-year period (2006-2007) from 82 dairy cattle farms in 14 provinces across the north of Spain, were examined for the presence of Cryptosporidium oocysts. Overall, 63 farms (76.8%) and 166 calves (57.8%) tested positive by microscopy. In order to elucidate the genetic diversity, selected positive specimens from 149 calves originating from 61 farms in the 14 provinces were examined by genotyping and subtyping techniques. Cryptosporidium parvum was the only species identified by PCR-RFLP of SSU rDNA from all 149 isolates and sequencing of a subset of 50 isolates, except for 2 specimens that were identified as C. bovis. Sequence analyses of the glycoprotein (GP60) gene revealed that most C. parvum isolates (98%) belonged to the subtype family IIa and 2 isolates were identified as the novel subtype IIdA23G1. Subtype IIaA15G2R1 was the most common and widely distributed (80.3% of the 61 farms), followed by subtype IIaA16G3R1 (14.7%), whereas the remaining IIa subtypes (IIaA16G2R1, IIaA17G2R1, IIaA18G3R1, IIaA19G3R1) were restricted to 1-3 farms. All these C. parvum IIa subtypes have previously been described in human patients, indicating that most isolates from diarrhoeic calves in northern Spain have zoonotic potential.     

Genotype by environment interaction for livability of dairy calves from first parity cows

Death of calves around parturition is a matter of concern for dairy farmers. Relatively high stillbirth rates and unfavourable trends have been reported for Holstein heifers in the Netherlands and several other countries. In our study, we investigated herd differences, genetic parameters and genotype by environment interaction for heifer calf livability. A large dataset with data from calvings between 1993 and 2012 of Dutch dairy farms was used. There were considerable differences between herds in livability of calves from heifers, with averages ranging from 74% to 95%. Both herds with relatively high and low averages showed the same negative trend between 1993 and 2012, with largest declines in herds with the lowest averages. We found that heritability and genetic variation of first parity livability were substantially larger in herd environments where the likelihood of stillbirth was high v. environments where stillbirth was at a low level. The genetic correlations between herd environment levels were all very close to unity, indicating that ranking of sires was similar for all environments. However, for herds with a relatively high stillbirth incidence selecting sires with favourable breeding values is expected to be twice as profitable as in herds with a relatively low stillbirth incidence.     

Isolation, screening and characterization of thermophilic Bacillus species isolated from dairy products

Proteolytic thermophilic bacterial cultures (171 strains) were isolated from different milk and milk products. After screening these isolates for protease production in a liquid medium, fifty that exhibited enzyme activity in excess of 100 units/ml were selected and identified. Twenty-nine were Bacillus stearothermophilus (constituting 58% of the total), twelve were B. coagulans , five were B. circulans and four were B. licheniformis . Skim milk powder contributed the maximum number of B. stearothermophilus (64.7%) followed by raw milk (63.2%) and pasteurized milk (44.4%). When the culture supernatant liquids from the selected isolates were given heat treatment, five cultures retained 100% protease activity at 65°C for 30 min. Protease of B. stearothermophilus RM-67 had the maximum heat resistance because it retained 87.5% of its activity at 70°C for 30 min.     

Isolation, screening and characterization of thermophilic Bacillus species isolated from dairy products

Proteolytic thermophilic bacterial cultures (171 strains) were isolated from different milk and milk products. After screening these isolates for protease production in a liquid medium, fifty that exhibited enzyme activity in excess of 100 units/ml were selected and identified. Twenty-nine were Bacillus stearothermophilus (constituting 58% of the total), twelve were B. coagulans, five were B. circulans and four were B. licheniformis. Skim milk powder contributed the maximum number of B. stearothermophilus (64.7%) followed by raw milk (63.2%) and pasteurized milk (44.4%). When the culture supernatant liquids from the selected isolates were given heat treatment, five cultures retained 100% protease activity at 65 degrees C for 30 min. Protease of B. stearothermophilus RM-67 had the maximum heat resistance because it retained 87.5% of its activity at 70 degrees C for 30 min.     

Comparative studies of microbial populations in the rumen,duodenum, ileum and faeces of lactating dairy cows

Aims: Understanding factors that influence the composition of microbial populations of the digestive system of dairy cattle will be key in regulating these populations to improve animal performance. Although rumen microbes are well studied, little is known of the dynamics and role of microbial populations in the small intestine of cows. Comparisons of fingerprints of microbial populations were used to investigate the effects of gastrointestinal (GI) segment and animal on community structure. Methods and Results: Samples from four lactating dairy cows with ruminal, duodenal and ileal cannulae were collected. Terminal‐restriction fragment length polymorphism (T‐RFLP) comparisons of small subunit rRNA genes revealed differences in microbial populations between GI segments (P < 0·05). No significant differences in either methanogen populations or microbial community profiles between animals were observed. Quantitative PCR was used to assay relative changes in methanogen numbers compared to procaryote rRNA gene numbers, and direct microscopic counts were used to enumerate total procaryote numbers of the duodenal and ileal samples. Conclusions: T‐RFLP comparisons illustrate significant changes in microbial diversity as digesta passes from one segment to another. Direct counts indicate that microbial numbers are reduced by eight orders of magnitude from the rumen, through the abomasum, and into the duodenum (from c. 10¹² to c. 3·6 × 10⁴ cells per ml). Quantitative PCR analyses of rRNA genes indicate that methanogens are present in the duodenum and ileum. Significance and Impact of the Study: The contribution of microbial populations of the small intestine to the nutrition and health of cattle is seldom addressed but warrants further investigation.     

Distribution of Cryptosporidium species isolated from diarrhoeic calves in Japan

Cryptosporidium spp. are enteric protozoan parasites that infect a wide range of hosts including humans, and domestic and wild animals. The aim of this study was to molecularly characterize the Cryptosporidium spp. found in calf faeces in Japan. A total of 80 pre-weaned beef and dairy calves' diarrhoeic faecal specimens were collected from nine different prefectures in Japan. A nested polymerase chain reaction targeting the small subunit 18S rRNA and GP60 genes were used to detect the Cryptosporidium genotypes and subtypes. 83.8% (67 out of 80) of the specimens were positive for Cryptosporidium spp.; Cryptosporidium was found in both beef and dairy calves. Cryptosporidium parvum was the predominant species, detected in 77.5% (31/40) of beef calves and 80% (32/40) of dairy calves. Cryptosporidium bovis was also detected, 5.0% (2/40) of dairy calves, and C. ryanae was also found 2.5% (1/40) of dairy calves. One mixed-species infection, 2.5% (1/40) was detected in a beef calf having C. parvum, and C. ryanae. We detected the most common subtype of C. parvum (i.e., IIaA15G2R1), as well as other subtypes (i.e., IIaA14G3R1, IIaA14G2R1, and IIaA13G1R1) that have not previously been detected in calves in Japan. Our results demonstrate the widespread diversity of Cryptosporidium infection in calves in Japan.     

Multiresistant strains ofEscherichia coli isolated from the rumen of young calves

Five multiresistant strains ofEscherichia coli were isolated from the rumen fluid of young calves. Resistance to tetracycline and ampicillin was found to be associated with the transfer of a 6.4 kbp plasmid present in two investigated strains.     

Shiga-toxin-producing Escherichia coli in faeces of healthy dairy cows, sheep and goats: prevalence and virulence properties

The prevalence of Shiga-toxin-producing Escherichia coli (STEC) in healthy dairy ruminants was investigated between 1996 and 1998 by a multiplex polymerase chain reaction (mPCR) technique. A total of 13 552 E. coli colonies from 726 cows, 28 sheep and 93 goats out of 112 randomly selected dairy farms in Hessia, Germany were analysed. STEC strains were recovered from 131 (18.0%) cows, nine (32.1%) sheep and 70 (75.3%) goats. Further characterization of the STEC isolates showed that 89 (0.66% of the investigated colonies) of animal field strains carried stx1 gene, 64 (0.47%) stx2 gene and 57 (0.42%) stx1 and stx2 gene. Sixty (93.8%) out of 64 stx2 field strains were harboured by cows. In contrast, 74 (83.1%) out of 89 stx1 dairy animal field strains were from ovine or caprine origin. Only 17 (8. 1%) stx-positive isolates (13 from cattle, three from sheep and only one from goat) were positive for eaeA gene. Eight (9.0%) of the stx1, five (7.8%) of the stx2 and four (7.0%) of the stx1/stx2 gene-positive field strains carried the eaeA gene. The prevalence of EHEC-haemolysin (EHEC-hlyA) gene sequence was 88.8% (79 isolates) of the stx1 and 68.8% (44 isolates) of the stx2 isolates. Out of 57 stx1- and stx2-positive field-strains, 34 (59.6%) carried the EHEC-hlyA gene. E. coli O serovars O:157 and O:111 were not found. Only one isolate was positive with O26 antiserum.     

Metabolism and some characteristics of lactobacilli isolated from the rumen of young calves

Fourteen strains of lactobacilli isolated from the rumen of young calves were studied to determine their biochemical characteristics, growth parameters, metabolism on lactose and sensitivity to 28 antimicrobial agents. Thirteen homofermentative strains belonged to Lactobacillus acidophilus and one heterofermentative strain resembled Lact. fermentum. The relevance of rumen lactobacilli to the nutrition of calves is discussed.     

Metabolism and some characteristics of lactobacilli isolated from the rumen of young calves

Fourteen strains of lactobacilli isolated from the rumen of young calves were studied to determine their biochemical characteristics, growth parameters, metabolism on lactose and sensitivity to 28 antimicrobial agents. Thirteen homofermentative strains belonged to Lactobacillus acidophilus and one heterofermentative strain resembled Lact. fermentum. The relevance of rumen lactobacilli to the nutrition of calves is discussed.     

A survey on management and housing of peri-parturient dairy cows and their calves

Housing and management around the time of calving impact dairy cow behaviour, health and welfare, but little is known about current practice. The aim was to provide an overview of current calving practice and the study describes the main calving housing and management based on replies to an online questionnaire by 42 dairy cattle experts in 28 countries, or regions, in Europe, Canada and USA. The survey suggests that in the majority of countries and regions included in this study, dairy cows typically calve in indoor calving facilities; either individual pens, group pens or a system where the cow is moved from a group pen into an adjacent individual pen before calving. Regarding individual calving pens, the survey suggests that in the majority of countries and regions included in this study, most pens have open sides and offer cows no opportunity to isolate, although research shows that a secluded corner of an individual pen creates a preferred calving site. Further, the survey suggests that when cows calve in individual calving pens or tie-stalls, they are often moved there with signs of imminent calving, although research shows that this practice increases the duration of calving and it is recommended to move cows before their expected calving time. Regarding group pens, none of the 42 respondents replied that group pens typically offer cows the opportunity to isolate at calving. Recent research suggests that when cows calve in a secluded area of a group calving pen, this reduces the risk of failure of passive transfer of immunity. Regarding calving facilities where group pens are combined with adjacent individual pens, this was reported to be the most typical in 10 of the 24 countries and regions with indoor calving sections covered by the survey. The same concerns regarding when the cow is moved from the group pen to an individual pen apply, as outlined above. Irrespective of pen type, the most frequently reported surface was deep bedded straw and the most frequent type of separation between pens was open sides. Cow-calf separation within 12 hours of birth, and thereafter individual housing of calves combined with milk feeding via a teat bucket or bar was indicated the most frequent management. The survey presents experts’ evaluations of current practice of housing and management of peri-parturient dairy cows and their calves, and suggests that there is a discrepancy between current calving management and housing and recommendations based on recent research.     

Excretion rate of progesterone in milk and faeces in lactating dairy cows with two levels of milk yield.

This study was conducted to measure the effect of the level of daily milk yield on the excretion rate of progesterone (P4) in milk and faeces in high-producing (HP) and low-producing (LP) lactating dairy cows. A GnRH-agonist was implanted to block endogenous production of P4. A CIDR device was inserted into the vagina and left in place for 11 days. The average and peak milk yields were greater in HP cows (P < 0.0001). Mean plasma concentrations of P4 were also similar in both groups (P = 0.44), even though the average mass of P4 delivered from a CIDR device was higher with HP cows (P = 0.02). Average milk P4 concentration was similar in both groups (P = 0.81), so that average daily excretion of P4 in the milk was greater with HP cows (P = 0.05). The concentrations (P = 0.83) and daily yields (P = 0.4) of total faecal progesterone metabolites were not affected by level of milk yield. These data show that the concentrations of plasma and milk P4, and the concentration and yield of P4 metabolites are not affected by the levels of daily milk yield.     

Isolation and characterization of a novel catalase-negative, urease-positive Campylobacter from cattle faeces

Forty-four strains of a phenotypically unique Campylobacter were isolated from the faeces of 26 of 45 cows in a single herd. Isolation involved enrichment and membrane filtration onto blood agar or plating onto cefoperazone amphotericin teicoplanin agar. The strains exhibited phenotypic characteristics typical for Campylobacter species. However, they were unusual in that they produced urease and copious H₂S in triple sugar iron (TSI) medium, but did not produce catalase. They did not grow aerobically. None of the strains grew on modified cefoperazone charcoal deoxycholate agar (mCCDA). Macrorestriction profiles of chromosomal DNA were prepared for 15 strains using pulsed-field gel electrophoresis (PFGE). Twelve of 15 profiles were identical and all appeared to be closely related. These catalase-negative, urease-positive campylobacters (CNUPC) represent a group not previously reported. Their sensitivity to antibiotics normally used in selective media for campylobacters might explain why they have not previously been encountered. Their ecological significance and importance with respect to human and animal disease remain to be assessed.