The association between selective dry cow therapy, milking routine and dry cow management practices with somatic cell count in early lactation cows from 21 commercial grazing dairy herds.

This observational study aimed to explore the association of farmer-driven selective dry cow therapy (DCT), milking routine and dry cow management practices with somatic cell count (SCC) in early lactation cows from 21 commercial dairy herds. Milking routine practices evaluated referred to cow preparation for milking, in-lactation mastitis management and recording. Dry cow management practices related to dry cow environment and cleaning, dry-off procedure, milk cessation strategy and calving environment. Data from 2,016 multiparous cows in 21 commercial spring-calving grazing dairy herds were available for the study. Herd owners self-reported DCT (the assignment and administration of DCT was at the discretion of the herd owners with no involvement from the research team), management practices during milking and the dry period. Cow-level last test-day SCC records in 2020 [range = 105 to 285 d in milk (DIM)] and first test-day records in 2021 (range = 5 to 60 DIM) were obtained from milk recording databases. Quarter-level milk sampling was carried out on all cows in late lactation of 2020 (range = 240 to 261 DIM) for bacterial culturing. Bacteriological results were used to define cows with intramammary infection (IMI) when ≥ 1 quarter sample resulted in bacterial growth and there were no contaminated samples from that cow. Mixed model analyses were used to evaluate the association of selective DCT, milking routine and dry cow management practices with cows' first test-day log 10 SCC (logSCC) in 2021. At dry-off in 2020, 47.6% of the cows were administered an internal teat sealant alone (ITS) while 52.4% were administered an antibiotic plus an internal teat sealant (AB+ITS). The mean herd-level percentage of cows with IMI was 19.7% (range = 9.8% to 39.5%); Staphylococcus aureus accounted for the majority of cow-level IMI (89.9%, 357/397). Between herds, the proportion of cows administered ITS ranged from 17.7% (14/79; in a herd with an IMI prevalence of 10.1%) to 86.8% (66/76; in a herd with an IMI prevalence of 27.6%). In total, 11.8% (105/889) and 29.8% (292/980) of cows that were administered ITS or AB+ITS had an IMI in late lactation 2020, respectively. The mean untransformed SCC at the last test-day in 2020 of cows administered ITS and AB+ITS was 55,000 and 197,200 cells/mL, respectively. The statistical analysis showed a significant interaction between selective DCT and milk yield at last test-day in 2020; cows with a milk yield of 15 kg and administered ITS had a 0.1 higher (untransformed SCC of 19,000 cells/mL higher) first test-day logSCC compared with cows administered AB+ITS. Additionally, greater parity, IMI in late lactation, higher log SCC at the last test-day in 2020 and longer dry periods were associated with higher logSCC at the first test-day in 2021. The current study identified cow- and herd-level management practices that could aid dairy farmers in improving the outcome of selective DCT and decrease early lactation SCC.

Evaluation of test-day milk somatic cell count to predict intramammary infection in late lactation grazing dairy cows.

Use of selective dry cow antimicrobial therapy requires to precisely differentiate cows with an intramammary infection (IMI) from uninfected cows close to drying-off to enable treatment allocation. Milk somatic cell count (SCC) is an indicator of an inflammatory response in the mammary gland and is usually associated with IMI. However, SCC can also be influenced by cow-level variables such as milk yield, lactation number and stage of lactation. In recent years, predictive algorithms have been developed to differentiate cows with IMI from cows without IMI based on SCC data. The objective of this observational study was to explore the association between SCC and subclinical IMI, taking cognizance of cow-level predictors on Irish seasonal spring calving, pasture-based systems. Additionally, the optimal test-day SCC cut-point (maximized sensitivity and specificity) for IMI diagnosis was determined. A total of 2,074 cows, across 21 spring calving dairy herds with an average monthly milk weighted bulk tank SCC of ≤200,000 cells/mL were enrolled in the study. Quarter-level milk sampling was carried out on all cows in late lactation (interquartile range = 240-261 d in milk) for bacteriological culturing. Bacteriological results were used to define cows with IMI, when ≥1 quarter sample resulted in bacterial growth. Cow-level test-day SCC records were provided by the herd owners. The ability of the average, maximum and last test-day SCC to predict infection were compared using receiver operator curves. Predictive logistic regression models tested included parity (primiparous or multiparous), yield at last test-day and a standardized count of high SCC test-days. In total, 18.7% of cows were classified as having an IMI, with first parity cows having a higher proportion of IMI (29.3%) compared with multiparous cows (16.1%). Staphylococcus aureus accounted for the majority of these infections. The last test-day SCC was the best predictor of infection with the highest area under the curve. The inclusions of parity, yield at last test-day, and a standardized count of high SCC test-days as predictors did not significantly improve the ability of last test-day SCC to predict IMI. The cut-point for last test-day SCC which maximized sensitivity and specificity was 64,975 cells/mL. This study indicates that in Irish seasonal pasture-based dairy herds, with low bulk tank SCC control programs, the last test-day SCC (interquartile range days in milk = 221-240) is the best predictor of IMI in late lactation.

Internal teat sealants alone or in combination with antibiotics at dry-off - the effect on udder health in dairy cows in five commercial herds.

In the dairy industry, the dry period has been identified as an area for potential reduction in antibiotic use, as part of a one health approach to preserve antibiotic medicines for human health. The objective of this study was to assess the impact of dry cow treatment on somatic cell count (SCC), intramammary infection (IMI) and milk yield on five commercial Irish dairy herds. A total of 842 cows across five spring calving dairy herds with a monthly bulk tank SCC of < 200 000 cells/mL were recruited for this study. At dry-off, cows which had not exceeded 200 000 cells/mL in the previous lactation were assigned one of two dry-off treatments: internal teat seal (ITS) alone (Lo_TS) or antibiotic plus ITS (Lo_AB + TS). Cows which exceeded 200 000 cells/mL in the previous lactation were treated with antibiotic plus ITS and included in the analysis as a separate group (Hi_AB + TS). Test-day SCC and lactation milk yield records were provided by the herd owners. Quarter milk samples were collected at dry-off, after calving and at mid-lactation for bacteriological culture and quarter SCC analysis. Cow level SCC was available for 789 cows and was log-transformed for the purpose of analysis. Overall, the log SCC of the cows in the Lo_TS group was significantly higher than the cows in Lo_AB + TS group and not statistically different to the cows in the Hi_AB + TS group in the subsequent lactation. However, the response to treatment differed according to the herd studied; the log SCC of the cows in the Lo_TS group in Herds 3, 4 and 5 was not statistically different to the cows in Lo_AB + TS group, whereas in the other two herds, the log SCC was significantly higher in the Lo_TS when compared to the Lo_AB + TS group. There was a significant interaction between dry-off group and herds on SCC and odds of infection in the subsequent lactation. The results of this study suggest that the herd prevalence of IMI may be useful in decision-making regarding the treatment of cows with ITS alone at dry-off to mitigate its impact on udder health.

MUTYH-Associated Polyposis: The Irish Experience>.

MUTYH is involved in DNA damage repair. Bi-allelic MUTYH mutations predispose to polyposis and gastrointestinal malignancies, distinct genetically from autosomal dominant familial adenomatous polyposis coli. Two common European MUTYH mutations account for 90% of MUTYH-associated polyposis (MAP). We aimed to examine the incidence of MAP in Ireland. A retrospective cohort study was undertaken. Patients undergoing MUTYH testing from 2003-2016 were identified by searching electronic databases using terms "MUTYH" and "MYH". Phenotypic and genotypic details were obtained by chart review. Bi-allelic mutations were confirmed in 26 individuals (17 families), of whom 16 (62%) developed colorectal malignancies, and 22(85%) polyposis. Eleven families had bi-allelic status for one/both common European mutations. Regional variation was noted, with over-representation of bi-allelic mutation carriers in the South-west of Ireland. MAP is under-diagnosed in Ireland. Increased awareness is required to facilitate appropriate identification and surveillance of bi-allelic mutation carriers for colorectal pathology.

Protein and microsatellite single locus variability in Salmo salar L. (Atlantic salmon).

We describe genetic variation at three microsatellite single loci and six allozyme loci of seven natural Atlantic salmon populations from Ireland and Spain. A comparison of genetic variability detected at both types of loci is performed. Also, the relative value of microsatellite single locus variability with regard to the identification of individual salmon populations is assessed. Microsatellite loci are shown to display higher levels of variation than allozyme loci. Mean number of alleles (6 +/- 1.53) and heterozygosity (0.46 +/- 0.04) at microsatellite loci are greater than those found for allozymes (1.85 +/- 0.05 and 0.21 +/- 0.03, respectively), and some microsatellite alleles appear to be specific for a location or geographical area. Allozyme and microsatellite variation show the same pattern of differentiation between populations with Irish and Spanish populations grouped into different clusters. However, greater values of genetic distance were found among microsatellite (D = 0.0747 +/- 0.011) rather than among allozyme loci (D = 0.0449 +/- 0.008). These results provide evidence that microsatellite-based analysis of genetic variation will be useful in the identification of individual populations of Atlantic salmon.

A NOR-associated repetitive element present in the genome of two Salmo species (Salmo salar and Salmo trutta).

A repetitive element was isolated from the genome of Atlantic salmon. Nucleotide sequence analysis revealed the existence of variant monomers that range in length from approximately 200 to 230 bp. Repeat monomers contain regions of cryptic simplicity, internal repetition, and long direct repeats with deletions and insertions between individual units. The repetitive element was shown to have a tandem unit arrangement and was estimated to occupy between two and three percent of the Atlantic salmon genome. Southern blot analysis revealed the repetitive element to be unique to Atlantic salmon and brown trout species. In situ hybridization analysis showed this element to be localized at the main nucleolar organizer region bearing chromosomes of Atlantic salmon (Salmo salar), AS cell line (derived from S. salar), and brown trout (Salmo trutta).

Cloning, characterization and chromosomal location of a satellite DNA from the Pacific oyster, Crassostrea gigas.

We report the cloning and characterization of a high-copy-number, tandem-repeat satellite DNA sequence from the genome of the Pacific oyster, Crassostrea gigas (Cg). The monomeric unit was found to be 166 (+/- 2) bp in length with 79-94% homology between monomers of the array. The sequence is A+T-rich (60%) and lacks internal repetition and substructural features. The repeat was estimated to account for 1-4% of the Cg genome. Fluorescence in situ hybridization (FISH) studies mapped the repeat to two distinct heterochromatic regions of two pairs of homologous chromosomes on Cg embryonic metaphases. Also, the number of metaphase chromosomes containing this repeat varied with the ploidy of the cell.

Ultrasound as part of a 1-day gastroenterology clinic: advantages and problems.

Ultrasound was introduced into a 1-day gastroenterology clinic so that clinical assessment, endoscopy and ultrasound could be performed as appropriate in a single hospital visit. The findings in 602 patients are reported. A total of 256 (43%) patients underwent ultrasound, 35% of which showed positive findings including cholelithiasis in 12% and tumours in 7%. This system of referral for ultrasound is very convenient for patients and their general practitioner and is less costly than traditional referral methods. It is, however, time-consuming for the radiologist.