Organic milk production based entirely on home-grown feed

The aim of the Ph.D. project was to examine the consequences for the farm of an organic milk production based entirely on home-grown feed. The project included interviews that identified what in farmers’ opinion is crucial for obtaining organic milk production based entirely on home-grown feed, production experiments that examined the effects of different types of home-grown concentrated feed on milk production and scenario calculations that described the consequences for productivity, economy, and nutrient balances of organic milk production based entirely on home-grown feed

A Comparison of Well-Quasi Orders on Trees

Well-quasi orders such as homeomorphic embedding are commonly used to ensure termination of program analysis and program transformation, in particular supercompilation. We compare eight well-quasi orders on how discriminative they are and their computational complexity. The studied well-quasi orders comprise two very simple examples, two examples from literature on supercompilation and four new proposed by the author. We also discuss combining several well-quasi orders to get well-quasi orders of higher discriminative power. This adds 19 more well-quasi orders to the list.Comment: In Proceedings Festschrift for Dave Schmidt, arXiv:1309.455

Concentrate Mixture, Grass Pellets, Fodder Beets, or Barley as Supplements to Silage ad libitum for High-yielding Dairy Cows on Organic Farms

A total of 246 Danish Holstein cows were included in three experiments. In each experiment, Barley (B) was compared with another type of supplementary feeds: a Concentrate mixture (C), Grass pellets (G), or Fodder beets (F). The concentrate mixture resulted in a higher (P = 0.002) milk yield (25.9 vs 23.7 kg), a tendency of a lower (P = 0.07) fat content (4.08 vs 4.25%), and a higher (P = 0.006) ECM yield (25.7 vs 24.1 kg) compared to feeding barley as supplement at the same energy level. Grass pellets resulted in a lower (P = 0.01) milk fat content (3.74 vs 4.07%), a tendency of a lower (P = 0.12) protein content (3.14 vs 3.23%), but no different milk or ECM yield compared to feeding barley as supplement at the same dry matter level. The total mixed ration with fodder beet tended to decrease (P = 0.12) milk yield (20.7 vs 22.0 kg) and the ECM yield (P = 0.05) was lower (21.5 vs 22.9 kg) whereas the composition of the milk was unaffected compared to the total mixed ration with barley

Effect of barley or rape seed cake as supplement to silage for high-yielding organic dairy cows

An experiment was carried out to investigate the effects of barley or rape seed cake as supplement to silage given ad libitum on milk production and health of dairy cows. A total of 103 cows were divided into two groups on two farms. Before the experiment, the cows had an average milk yield of 26.9 kg ECM and they were in milk for an average of 99 days. Their average parity was 2.3 and their weight 596 kg. The cows in each group received either solely barley or an isoenergetic mixture of rape cake seed and barley as supplement. The supplement feed was fed frequently by automatic feeding. A mixture of clover grass silage and whole crop silage was fed ad libitum. The daily milk yields were not significantly different in the barley and rape seed cake treatment (22.8 v. 24.1 kg). The milk fat content was not significant different either (4.51% v. 4.35%). However, the protein content tended to be higher in the barley treatment (3.51% v. 3.45%). But the energy corrected milk yield (ECM) was not significantly different in the barley and rape seed cake treatments either (24.2 v. 24.9 kg ECM). No differences in health as indicated by clinical illness treated by the vet and somatic cell count (SCC) was seen. It was concluded that barley and a mixture of isoenergic rape seed cake and barley had similar feeding value when used as supplement with a high proportion of easily digestible clover grass silage allocated ad libitum and frequently allocation of supplementary feed

Graphical modeling of stochastic processes driven by correlated errors

We study a class of graphs that represent local independence structures in stochastic processes allowing for correlated error processes. Several graphs may encode the same local independencies and we characterize such equivalence classes of graphs. In the worst case, the number of conditions in our characterizations grows superpolynomially as a function of the size of the node set in the graph. We show that deciding Markov equivalence is coNP-complete which suggests that our characterizations cannot be improved upon substantially. We prove a global Markov property in the case of a multivariate Ornstein-Uhlenbeck process which is driven by correlated Brownian motions.Comment: 43 page

The competitiveness of different herbs in grass/clover pastures.

On Danish dairy farms, herbs are often sown together with grass/clover, but the amount of herbs in the sward is often limited. The competitiveness of different herbs is therefore examined over three years (2007-2009) in grazed grass/clover pastures on five organic dairy farms and further on a research station. The seed mixture was composed of perennial ryegrass (Lolium perenne), white clover (Trifolium repens), red clover (Trifolium pratense), chicory (Cichorium intybus), long-leaved plantain (Plantago lanceolata), caraway (Carum carvi), birds foot trefoil (Lotus coniculatus), salad burnet (Poterium sanguisorba), sainfoin (Onobrychis viciifolia) and chervil (Anthriscus cerefolium). The botanical composition varied between the experimental sites, but in general, the proportion of the single herb decreased over time. Chicory and plantain had the highest competitiveness and therefore the highest proportion of dry matter. Caraway, lotus and burnet had a considerable lower competitiveness. Sainfoin and chervil disappeared rapidly after establishment

A decision support model simulating the vitamin supply over the year on a farm

The aim of this new project is to develop a prototype of a decision support model simulating the feed and vitamin supply during a year to different groups of animals (calves, heifers, dry cows, cows in early and late lactation) on a farm self-sufficient with feed. The model takes into account that the content of vitamin depends on choice of crops, utilization method, cutting date, conservation method and duration of storage together with traditional optimizing the feed-ing scheme