László Könyves

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.

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.

Detection of 70 kDa heat shock protein in the saliva of dairy cows.

This Research Communication describes, for the first time, the detection of HSP70 in saliva of dairy cows. Thermal stress is a major environmental stress that limits animal growth, metabolism, and productivity. The cellular response to heat stress involves the synthesis of heat shock proteins (HSPs), presumably to protect the functional stability of cells at increasing temperatures. HSP70 has been found to be present in cattle blood serum and may also be present in other secretory fluids, such as saliva, as already observed in humans. The aim of this study was to detect heat shock protein HSP70 in bovine saliva. Saliva samples were taken from higher- (n = 5) and lower milk producing (n = 5) Holstein-Friesian cows in summer and in winter for the detection of HSP70. HSP70 concentrations were assayed using the ELISA technique. Salivary HSP70 concentrations ranged from 0·524 to 12·174 ng/ml in cows. Higher salivary HSP70 concentrations were significantly associated with higher milk production and higher environmental temperature, but not with rectal temperature.

Effects of subclinical Mycobacterium avium ssp. paratuberculosis infection on some physiological parameters, health status and production in dairy cows

Milk yield, milk ingredients, health and other, production-related parameters of subclinically infected, Mycobacterium avium ssp. paratuberculosis (MAP-) shedding (positive faecal PCR, n = 20) and non-shedding (negative faecal PCR, n = 10) dairy cows were compared in the period from 10 days prepartum to 120 days postpartum. Body condition, rumen fill and faeces scores were lower in the MAP-shedding cows. There was no significant difference in plasma or urine metabolic parameters between the groups. Milk yield and lactose content tended to be lower (P = 0.074 and 0.077, respectively), somatic cell count tended to be higher (P = 0.097), while milk fat content was significantly higher (P = 0.006) in MAP-shedding cows than in the controls. Milk protein content did not differ between the groups. All other health and production parameters [number of reproductive tract treatments, number of udder treatments, number of artificial inseminations (AIs), calving interval, and service period] were significantly better in the control group. It is concluded that MAP infection, even in a subclinical form, has a significant impact on some production and health parameters of dairy cows.