The use of machine learning methods to predict sperm quality in Holstein bulls.

The aim of this study was to develop prediction models for total sperm motility, morphological abnormalities and sperm output based on 1,551 ejaculate records of 58 Holstein bulls. The data was collected from September 2019 to November 2020 in a single artificial insemination (AI) center located in Eastern Germany. Factors considered for the prediction models include barn climate conditions, semen collector, number of false mounts, libido, semen collection frequency, breed and age (10-74 months). In this study, the prediction models Lasso, Group Lasso and Gradient Boosting were evaluated. The best model for each sperm quality parameter was chosen using cross validation. The models were estimated with five algorithms for sperm motility and sperm morphology and three algorithms for the number of total sperm per ejaculate (sperm output). For sperm motility and morphology a binary classification algorithm was applied, reaching an accuracy of over 80% for all models. For sperm output, no such classification was used and the only variable selected by all three algorithms was age. Furthermore, for sperm morphology, climate variables were frequently selected. Additionally, network diagrams from Group Lasso show the interdependencies between the major variable groups influencing sperm motility and morphology. In conclusion, the implementation of such prediction tools could help AI centers to optimize management factors and stabilize bull semen production in the future.

Development of predictive models for boar semen quality.

In this study a prognosis model is developed that predicts sperm quality characteristics based on external factors such as barn climate conditions, seasonality, semen collection frequency, age and breed of artificial insemination (AI) boars. For this a k-fold cross validation framework is used to test the prediction accuracy of a wide range of regression models that are based on different functional forms (linear, log-linear) and estimation techniques (ordinary least squares, seemingly unrelated regression, two-stage least squares estimation and three-stage least squares estimation). The dataset includes 241 boars from three barns within one boar stud located in Southern Germany, consisting of 7455 ejaculates collected during one year. The winner model predicts sperm motility with little error (Mean Absolute Percentage Error (MAPE): 4.35%), but is of limited use to predict sperm output (MAPE: 23.92%) and especially morphologically abnormal spermatozoa (MAPE: 44.67%). An estimation of marginal effects shows, that once confounding variables are controlled for, the considered barn climate variables do not have a measurable effect on sperm quality. Other factors have a more significant effect on sperm quality, like morphology-motility linkages, sperm concentration, interval between semen collections and to a lesser extent age and breed of the AI boar.

[Perioperative antibiotic prevention in colon and rectum surgery. A randomized study on the value of single dose prevention]. / Perioperative Antibiotikaprophylaxe in der Kolon- und Rektumchirurgie. Eine randomisierte Studie zum Wert der 'single-dose' Prophylaxe.

In a prospective randomized trial clinical results of one-shot-prophylaxis with Tinidazole (Group I, n = 50) versus 9 doses of Metronidazole (Group II, n = 50) as perioperative short-time-prophylaxis were compared. The rate of postoperative wound infections was not significantly different in the groups (p = 0,09). (1/50 in Group I = 2%, 5/50 in Group II = 10%). Postoperative complications clearly occurred less frequently in the first group than in the second one (12% versus 34%, p0,01). Our investigation indicates that prophylactic treatment with Tinidazole as a preoperative high and single dose is important for preventing postoperative infection in patients undergoing bowel surgery.

[Experiences with fibrin adhesives in surgery of the rectum and colon]. / Erfahrungen mit Fibrinkleber im Bereich der Rektum- und Kolonchirurgie.

Fibrin glue was used for sealing a total of 45 anastomoses in colonic and rectal surgery. ILS, SPTU and EEA staplers were used performing anterior resection (low 26, high 15). The incidence of dehiscence of anastomoses after anterior resection of the sigmoid colon and rectum was studied by radiological examination after a Peritrast-enema about 2 weeks after surgery. Suture dehiscence was roentgenologically detected in 2 patients, no clinical insufficiency. Only 1 patient, aged 80, died from haemorrhage. The rate of postoperative complications was very low.

[Value of ileorectal anastomosis in the treatment of ulcerative colitis. Clinical and functional results in 16 patients]. / Zur Wertigkeit der ileorektalen Anastomose bei der Behandlung der Colitis ulcerosa. Klinische und funktionelle Ergebnisse bei 16 Patienten.

Sixteen cases of ulcerative colitis (11 female, 5 male) of the colon, treated by colectomy and ileorectal anastomosis were examined. The average follow-up was 3.6 years. Recto-ileoscopy with histological examination at the follow-up time revealed inflammation of the rectal stump in 6 patients. No cancer or cellular dysplasia could be seen in the present biopsies. The average number of bowel movements during 24 hours was 5.6 (range 3 to 8). Evaluating the anorectal function was made by measuring the resting and squeeze anal canal pressures and by assessing the maximum volume tolerated during distention of a ballon in the rectum. The mean maximum tolerated volume was 178.3 +/- 59.9 ml; the maximum tolerated volumen was less than 150 ml in 5 of 12 patients. There was no significant difference in the maximum of the control group. The maximum resting pressure (100.6 +/- 24.4 cm H2O), (p less than 0.01) squeeze pressure (183.1 +/- 32 cm H2O), (p less than 0.05) and the length of the anal canal 3.07 +/- 1.02 cm (p less than 0.01) were in boths groups significant different. There were no deaths, and no clinical evidence of an anastomotic leak could be found.