Separation of feed mixtures and its effect on the production traits of growing-finishing pigs was studied in three experiments. In Experiments I and II the effects of different types of equipment to prevent separation in a silo were studied. Experiment III dealt with separation along a feed transport chain. Experiments I and II clearly demonstrated an increase in feed quality variation by filling a silo without any arrangement to reduce separation. The last feed to be extracted from a silo filled in this manner showed an increasing amount of small particles and contents of crude fibre and ash, a decrease in the bulk density and also in the digestibility of nutrients and in the performance of the pigs. Filling a silo equipped with chutes by an auger or pneumatically through a cyclone did not create separation problems, and consequently there were no differences between these treatments in the production experiments. Separation measured by particle size, bulk density or chemical composition was not noticeable along the feed transport chain (Experiment III). There was no effect on performance of the pigs of their location along the chain. © 1982.

Separation of feed mixtures and its effect on the production traits of growing-finishing pigs was studied in three experiments. In Experiments I and II the effects of different types of equipment to prevent separation in a silo were studied. Experiment III dealt with separation along a feed transport chain. Experiments I and II clearly demonstrated an increase in feed quality variation by filling a silo without any arrangement to reduce separation. The last feed to be extracted from a silo filled in this manner showed an increasing amount of small particles and contents of crude fibre and ash, a decrease in the bulk density and also in the digestibility of nutrients and in the performance of the pigs. Filling a silo equipped with chutes by an auger or pneumatically through a cyclone did not create separation problems, and consequently there were no differences between these treatments in the production experiments. Separation measured by particle size, bulk density or chemical composition was not noticeable along the feed transport chain (Experiment III). There was no effect on performance of the pigs of their location along the chain. © 1982.

Barley of 2 moisture contents, 20-23% and 26-28%, was stored airtight for 2 separate seasons in 2 full-scale silos, and for 3 separate seasons in 12-16 pilot silos (1.25 m3). The microbial dynamics were studied, using colony-forming units (CFU) of microorganisms, the proportion of internally-invaded kernels and ATP content. The ATP content was a good measure of the microbial activity, which decreased after loading and was very low during the winter period. Field-associated moulds and yeasts decreased in numbers of CFU and in the amount of invaded kernels. Fusarium species survived more satisfactorily than most field fungi. The temperature rise in spring caused an increase in ATP content, as a result of extensive growth of yeast of the genera Hansenula and Candida. This activity started earlier in the high-moisture grain (March). In May, a significant increase in CFU of Penicillium was observed and, during May to July, in many silos, all kernels were invaded, mostly by P. roqueforti. In an attempt to increase the time of safe storage, some technical improvements and gaseous and liquid chemical additives were tested. Attachment of "lungs" to the silos, and addition of organic acids or gases (CO2, N2, NH3) to the grain, increased the safe storage time by one to several months. The aerobic storage stability of rolled barley taken in July from the full-scale silos was tested. The rapid deterioration following unloading limited the aerobic storage stability to a few days. © 1988.

This study evaluated losses of N2O, CH4 and NH3 from a rotational grazing system for overwintering beef cattle which spend 1 month on pasture. The cattle density was 71 heifers/ha and they were moved weekly to a new feeding area within the main pasture. The N2O, CH4 and NH3 losses were determined in two feeding areas that were severely trampled (ST) or less trampled (LT) and in a control area from which cattle were excluded. The N input to the pasture was measured. The NH3 losses were measured by micrometeorological mass balance in two periods with heifers present. The N2O and CH4 were measured using a closed chamber method with 9 chambers within each area on 10 occasions after heifers were removed from the pasture. The N input was 510kgN/ha. The NH4-N contents in the clay loam topsoil were 45, 28 and 11kg/ha in the ST, LT and control areas, respectively. Losses of NH3 were low due to rainy and cold conditions, corresponding to maximum 0.3kgN/ha/d. The soil was water logged and this, with the cold conditions, may have lowered N2O emissions. Maximum N2O losses were 7, 30 and 18gN2O-N/ha/d from ST, LT and control areas, respectively. This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture - Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson. © 2011 Elsevier B.V.