Farm Atlantic salmon escape and invade rivers throughout the North Atlantic annually, which has generated growing concern about their impacts on native salmon populations. A large-scale experiment was therefore undertaken in order to quantify the lifetime success and interactions of farm salmon invading a Norwegian river. Sexually mature farm and native salmon were genetically screened, radio t...

The wind farm layout program FLaP (Farm Layout Program) estimates the wind speed at any point in a wind farm and the power output of the turbines. The ambient flow conditions and the properties of the turbines and the farm are used as input. The core of the program is an axis-symmetric wake model, describing the wake behind one rotor. Here an approach based on the simplified Reynolds equation w...

Mixing of unfamiliar pigs is a standard management procedure in commercial pig production and is often associated with a period of intense and physically damaging aggression. Aggression is considered a problem for animal welfare and production. The objective of the present paper was to investigate the genetic background of aggressive behavior traits at mixing of unfamiliar gilts under 2 differe...

The maintenance of low-intensity farming is important for the conservation of habitats and species and is a particular issue in Europe as areas under extensive farming regimes continue to diminish. Current proposals for agricultural reform in Europe are seeking to retain and encourage extensive farming partly by seeking to redirect farm workers into non-farm activities such as leisure activitie...

BACKGROUND Tractors and other slow-moving self-propelled farm equipment are often used on public roadway to transfer goods from the farm to a market or distributer. Increased roadway exposure has led to a growing concern on the occurrence of farm equipment crashes. This study aims to compare characteristics of road segments with farm equipment crashes to road segments without farm equipment cra...

More efficient and economical production systems are needed to improve the sustainability of dairy farms. One concept to consider is using perennial cows. Perennial cows are those that maintain a relatively high milk production for >or=2 yr without going through the typical dry period followed by calving. Farm records show that some cows have produced over 20 kg/d after 4 yr of continuous lacta...

The cost of milk production by farm size was decomposed into frontier and efficiency components with a stochastic cost curve using data on 755 USA dairy farms from the year 2000. The estimated frontier function is much flatter than the composite cost curve, and although the frontier cost of production decreases with farm size, that cost reduction is not as pronounced as a cost curve that includ...

Agricultural policy faces conflicting social goals. On one hand, efficient large-scale agriculture provides an adequate, low cost food supply, but many Americans continue to idealize the smaller family farm, believing that it promotes a democratic society with strong values. The changing structure of agriculture from many small farms to fewer but larger farms is a concern often expressed. Many ...

BACKGROUND In early 2009, a dairy-goat annex care farm in South Limburg, the Netherlands, reported 220 Coxiella burnetii-related abortions in 450 pregnant goats. These preceded human cases and occurred in a region that was Q-fever free before 2009, providing a unique quasi-experimental setting for investigating regional transmission patterns associated with a Q-fever point source. METHODS Ind...

Ammonia (NH) emissions vary considerably among farms as influenced by climate and management. Because emission measurement is difficult and expensive, process-based models provide an alternative for estimating whole farm emissions. A model that simulates the processes of NH formation, speciation, aqueous-gas partitioning, and mass transfer was developed and incorporated in a whole farm simulati...