Reasons for the culling of dairy cows on low-input mountain farms
Reasons for the culling of dairy cows were scrutinized on thirty-four low-input farms in the Šumava mountains in the Czech Republic. An increase in the frequency of the most common culling category - category 58 (other health reasons) - was identified in both the Holstein and Czech Fleckvieh breeds between 2000 and 2007: from 35% to 59% in the Holstein cows and from 19% to 41% in the Czech Fleckvieh cows (X2 test; P<0.001). This brought the Czech Fleckvieh cows to the same level of frequency as in the Czech Republic population, while the frequency among Holstein cows was on average 11% higher than in the Czech Republic population. The frequency of category 58 was higher in the Holstein than in the Czech Fleckvieh cows, but category 52 (low milk production) was more frequent in the Czech Fleckvieh than in the Holstein cows (P<0.001). There is a link between category 58 ‘other health reasons’ and an increase in the milk productivity of the cows; this results eventually in a higher incidence of metabolic disorders and is discussed in this paper.
Analysis of longterm trends in the performance of dairy cows on low-input mountain farms
The productive and reproductive performance of dairy cows was examined on thirty-four low-input farms in the Šumava Mts. between 2000 and 2007. Milk production increased by an average of 986 kg and 948 kg per lactation by Holstein and by Czech Fleckvieh cows, respectively (P<0.001), while the mean number of lactations decreased from 2.7 to 2.5 in Holstein and from 3.4. to 3.0 in Czech Fleckvieh cows (P<0.001) in the same period. The mean number of lactations decreased also in the culled cows - from 3.2 to 2.9 by Holstein and from 4.3 to 3.5 by Czech Fleckvieh cows (P<0.001). A higher cow milk yield was accompanied by a deterioration in reproductive performance. Between the periods 2000-2003 and 2004-2007 the number of days open lengthened by an average of 6 and 4 days (P<0.01) and the calving period by an average of 11 and 6 days (P<0.001) in Holstein and Czech Fleckvieh cows respectively. The results indicated an increased replacement of cows in the herds examined as a coincidental feature of the steadily rising milk performance. This may have a negative impact on the rentability of low-input mountain dairy farming in the region.
The effects of biological additives on the fermentation process and fibre composition of farm-scale grass silages
The effects of bacterial and enzymatic additives on the course of fermentation process and on changes in the fibre composition of grass silages were investigated under farm-scale conditions over three years. Fourteen silages were prepared from die back grass stands in each of three variants, with no additive (control), with inoculants of lactic acid bacteria (LAB), and with LAB combined with cellulase and hemicellulase. The content of lactic acid was significantly (P<0.05) elevated, while the degree of proteolysis decreased (P<0.01) in both variants with the additives. The changes in the fermentation processes resulted in pH values about 4.8 and 4.3 in the control and the variants with additives, respectively. The qualitative parameters of fermentation were very similar for both the groups of additives.
The occurrence of Erysiphe trifolii on Lathyrus pratensis in a foothill area of South Bohemia
The aim of small-site experiments carried out in the foothills of the Šumava Mts. was to determine the effect of the etiological agent powdery mildew (Erysiphe trifolii) on meadow peavine (Lathyrus pratensis). Over three consecutive years, we observed a whitish to grey-white soft cover of mycelium on the meadow peavine during the vegetation period. This characteristic symptom of the disease was observed on the plants during summer and autumn. In a plot trial with permanent grassland we evaluated the following management systems: i) mulched, ii) fallow, iii) mown stands, and iv) pasture stands grazed by cattle. We evaluated the total number of Lathyrus pratensis plants as well as the number of the plants attacked by Erysiphe trifolii. The three-year investigation of Lathyrus pratensis yielded statistical evidence that the most significant growth of the fungal disease was recorded in fallow stands (68.9%), while the lowest occurrence of the disease (4.4%) was found in the pasture stands grazed by cattle.
A pasture-based system for dairy cattle is not common due to the need for milking, despite the fact that this system provides the possibility of natural animal behaviour. Six behavioural observations were carried out during the grazing season in dairy herds bred in a mountainous area (700 m a. s. l.) The basic herd was comprised of 53 cows, mainly of the Holstein breed. From April to November the herd was located on pastures near the stables and milked twice a day in a tandem milking parlour. Feed ration was composed of pasture and concentrated feed in the stable. During the grazing season, there was a slight variation with a tendency to extend the grazing period to the autumn months. The cattle grazed the shortest time in May - 35.0% of the day or 8.4 hours. In the autumn months the grazing time increased by 2.2 and 2.6 hours respectively. Cows were resting the longest time period in May and June (8.9 and 9.1 h respectively). On the other hand, cows were resting for the shortest time in October (6.8 hours). During the grazing period the milk yield decreased from 20.4 kg in April to 14.4 kg in November.