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Bovine digital dermatitis (DD) is an infectious claw disease with a negative effect on animal welfare and production. Treponema spp. is the main causative agent, and infected animals produce specific antibodies. Our aim was to estimate sensitivity (Se) and specificity (Sp) of 2 ELISA research tests, Medicago's ELISA test and GD Animal Health's in-house ELISA test, for detection of DD-associated Treponema antibodies in bulk tank milk. We used bulk tank milk samples from 154 Norwegian dairy cattle herds, 96 from an expected high-prevalence region and 58 from a low-prevalence region. Both tests were evaluated separately against herd-level (aggregated) claw-trimming records extracted from the Norwegian Dairy Herd Recording System using latent class models in a Bayesian analysis. Cutoff values were selected using an explorative approach, and both noninformative priors for all parameters and informative β priors for distribution of Se and Sp of claw trimming were explored. The estimated (median) true herd-level prevalence of digital dermatitis varied between 24 and 30% in the high-prevalence region and between 3 and 6% in the low-prevalence region. For Medicago's ELISA test, an Se (95% posterior credible interval) of 0.57 (0.32; 0.94) could be achieved without compromising Sp, and for GD Animal Health's in-house ELISA test, an Se of 0.60 (0.37; 0.92) was achieved. Our study showed that both ELISA tests can detect antibodies against DD-associated Treponema spp. in bulk tank milk. However, neither of the 2 ELISA tests produced satisfactory sensitivity without compromising specificity. Based on these results, inspection at claw trimming in a chute is necessary for surveillance and control of DD at the herd level in Norway, although these ELISA tests of bulk tank milk might be a useful supplement.Maintenance energy is the energy required to conserve the state of an animal when no work is completed. Dietary energy must be supplied to meet maintenance requirements before milk can be produced. The objectives of the current experiment were to quantify the maintenance energy requirement of Jersey cows when lactating or dry. Energetic measures were collected on 8 Jersey cows and evaluated across 3 physiological phases and nutritional planes lactation, dry cows fed at maintenance, and fasted dry cows. Through total collection of feces and urine as well as using headbox-style indirect calorimeters, energy balance and heat production data were measured across all phases. Lactation data were collected across four 28-d periods. Data for cows fed at maintenance were collected after 14 d and fasting heat production was measured during the last 24 h of a 96-h fast. Net energy for maintenance (NEM) requirements, and the efficiency of converting metabolizable energy (ME) into net energy were compared between lactatin for NEM and approximately 0.64 for the slope. Results of this study suggest that NEM and the efficiency of converting ME into NEM of modern lactating Jersey cows are similar to recent measurements on modern Holstein cows and greater than previous measurements.Intensified milk replacer (MR) feeding in calves has nutritional long-term effects and is suggested to increase milk production later in life. However, the underlying mechanisms are not completely understood. The aim of our study was to investigate whether MR feeding intensity has long-term effects on energy metabolism and energy use efficiency of dairy calves. Newborn female Holstein calves (n = 28) were randomly assigned to 2 liquid feeding groups offered daily either 10% of body weight (BW) colostrum followed by 10% of BW MR (10%-MR) or 12% of BW colostrum followed by 20% of BW MR (20%-MR). RZ-2994 ic50 Calves were housed individually. Weaning was completed by the end of wk 12. Hay and calf starter were fed from d 1 until the end of wk 14 and 16, respectively. A total mixed ration was fed from wk 11 onward, and the metabolizable energy intake (MEI) was determined daily. Energy metabolism of calves was measured in respiratory chambers before weaning in wk 6 and 9, and after weaning in wk 14 and 22. The MEI/BW0.75 was hied to BW0.75 and MEI, HP in wk 6 and 9, and COX in wk 9 was lower in 20%-MR calves. In conclusion, 20%-MR calves showed greater efficiency estimates preweaning, but this effect did not occur after weaning, suggesting that energy use efficiency does not persist until later stages in life.A novel galactosidase gene (gal3149) was identified from Bacillus velezensis SW5 and heterologously expressed in Escherichia coli BL21 (DE3). The novel galactosidase, Gal3149, encoded by gal3149 in an open reading frame of 1,299 bp, was 433 amino acids in length. Protein sequence analysis showed that Gal3149 belonged to family 4 of glycoside hydrolases (GH4). Gal3149 displayed higher enzyme activity for the substrate 2-nitrophenyl-β-d-galactopyranoside (oNPG) than for 4-nitrophenyl-α-d-galactopyranoside (pNPαG). This is the first time that an enzyme belonging to GH4 has been shown to exhibit β-galactosidase activity. Gal3149 showed optimal activity at pH 8.0 and 50°C, and exhibited excellent thermal stability, with retention of 50% relative activity after incubation at a temperature range of 0 to 50°C for 48 h. Gal3149 activity was significantly improved by K+ and Na+, and was strongly or completely inhibited by Ag+, Zn2+, Tween-80, Cu2+, carboxymethyl cellulose, and oleic acid. The rate of hydrolyzed lactose in 1 mL of milk by 1 U of Gal3149 reached about 50% after incubation for 4 h. These properties lay a solid foundation for Gal3149 in application of the lactose-reduced dairy industry.Heat treatment is one of the most widely used processing technologies in the dairy industry. Its primary purpose is to destroy microorganisms, both pathogenic and spoilage, to ensure the product is safe and has a reasonable shelf life. In this study microwave volumetric heating (MVH) was compared with a conventional tubular heat exchanger (THE), in terms of the effects of each at a range of temperatures (75°C, 85°C, 95°C, 105°C, 115°C, and 125°C) on indigenous microflora viability and the germination of inoculated Bacillus licheniformis endospores in reconstituted skim milk. To assess the heat treatment-related effects on microbial viability, classical agar-based tests were applied to obtain the counts of 4 various microbiological groups including total bacterial, thermophilic bacterial, mesophilic aerobic bacterial endospore, and thermophilic aerobic bacterial endospore counts, and additional novel insights into cell permeability and spore germination profiles post-heat treatment were obtained using real-time flow cytometry (FC) methods.