Endre Brydl

Risk assessment of postpartum uterine disease and consequences of puerperal metritis for subsequent metabolic status, reproduction and milk yield in dairy cows

The objective of this study was to determine some metabolic and other factors predicting the risk of postpartum uterine disease (PUD), and the effects of puerperal metritis (PM) on metabolic status, reproduction and milk yield were analysed. A total of 105 Holstein-Friesian cows were included, and sampled on day < -14 prepartum and days 4, 10-14, 28-35 and 56-63 postpartum for metabolic tests. From day 4 the development of PUD, and from days 28-35 the ovarian activity was monitored. When grade > or = 1 + ketonuria was present on day 4 postpartum, this indicated a higher probability of PUD [odds ratio (OR) 2.64; P < 0.05] including PM occurring on days 10-14 (OR: 2.65; P < 0.05). Plasma nonesterified fatty acid (NEFA) concentrations > 0.200 mmol/l on days < -14 prepartum indicated a higher risk of uterine diseases (OR: 3.44; P < 0.05). The odds of PUD increased, depending on whether a body condition score (BCS) loss of > or = 1.0 occurred between days < -14 and 28-35 (OR: 2.82; P < 0.05), between days < -14 and 10-14 (OR: 4.79; P < 0.01) or between days 10-14 and 28-35 (OR: 10.81; P < 0.01). PM was more probable (OR: 27.3; P < 0.001) in cows with retained placenta. The risk of uterine diseases was lower in multiparous than in primiparous cows (OR: 0.29; P < 0.01). PM increased the risk of ovarian inactivity between days 28 and 35 (OR: 2.83; P < 0.05). Cows affected with PM (PM+ cows) showed lower milk production on day 4 (kg; P < 0.05) and lower milk production (P < 0.05), milk fat and milk protein production (kg; P < 0.01; P < 0.01) in the first 100 days of lactation than did PM-cows.

Characterisation and effects of a xylanase enzyme preparation extracted from Thermomyces lanuginosus cultures

This paper describes the production of an enzyme preparation from the fungus Thermomyces lanuginosus. Thermal resistance, pH stability and lignocellulolytic activity of the enzyme preparation high in xylanase were studied on a variety of grains and forages. The enzyme preparation preserved more than 70% of its original xylanase activity for 4 and 1 h at 60 and 70 degrees C, respectively. The xylanase activity remained over 80% when the preparation was incubated for 30 min at pH 4.5. In vitro digestibility studies indicated that the enzyme digested 7.5, 8.5 and 8.0% of the dry matter (DM) of barley meal, wheat bran and oat meal samples, respectively. When applying 60-min incubation, 7.5, 7.3 and 8.4% of DM of the oat straw, alfalfa hay and triticale straw was digested, respectively. When the time of digestion was increased to 360 min, the sunflower hull showed 15.8% DM digestibility.

The effects of Saccharomyces cerevisiae strains on the rumen fermentation in sheep fed with diets of different forage to concentrate ratios

The objective of this study was to compare the effects of two different Saccharomyces cerevisiae yeast strains on the rumen fermentation of sheep fed with two different total mixed rations. Three rumen-cannulated Merino wethers were used in a pilot study in which a phase of feeding a higher proportion of concentrate in the diet (HC; forage to concentrate ratio 40:60, as fed) was followed by a phase of lower proportion of concentrate in the diet (LC; forage to concentrate ratio 49:51, as fed). Both phases consisted of three 3-week periods as follows: no yeast supplementation, trehalose non-producing and trehalose-producing S. cerevisiae supplementations, respectively. Rumen fluid samples taken in the last days of each period were measured for pH, short chain fatty acid (SCFA) concentrations and ammonia content. The degradability of neutral detergent fibre (NDF) and starch was estimated by the in sacco method. Supplementation with the trehalose non-producing strain did not alter any variables tested in the HC phase. In the LC phase, though degradability was not altered, total SCFA concentration increased, resulting in a decrease of rumen fluid pH. The trehalose-producing strain increased total SCFA content and effectively prevented the consequent decrease in pH in both phases. These effects were more pronounced in the high-concentrate phase, as shown by higher molar proportion of propionate, increased level of ammonia content, and higher ruminal degradability of NDF and starch compared to control and the trehalose non-producing yeast strain.