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Three levels of dry rolled corn (DRC) were reconstituted on sorghum silage to determine fermentations characteristics, losses profile, and the nutritional value of blends post fermentation phase. Laboratory experimental silos, the experimental units, (n = 49; 3/treatment; 18.93 L units with sand in bottom for effluent collection and gas valve on top for gas release) were treated for the three DRC levels (0%, 25%, and 50%, DM basis) on three sorghum hybrid harvesting sites. Experimental silos were assigned in a randomized complete block design and ensiled for 108, 114 and 115 d; silos were opened together and measured for gas and effluent losses. Samples taken post storage period were analyzed for DM, ash, in vitro true dry matter digestibility (24h and 30h), pH, and total starch. An aerobic stability measurement phase (5, 10, and 15d post silo opening) in which, DM losses and pH was evaluated. Data were analyzed using the GLIMMIX procedures of SAS; orthogonal contrasts were used to test for linear and quadratic effects of DRC inclusion of measured variables. Total DM loss of silos for 50% DRC inclusion had the least (P < 0.01) loss (5.96%) compared both DRC at 0 and 25% inclusion. Gas loss linearly decreased (P < 0.01) by 7% as DRC was included. Volume of effluent, L/tonne of DM ensiled linearly decreased (P < 0.01) as DRC 50% was included by 27 L compared to DRC 0%. The 50% DRC inclusion showed linear increase (P < 0.01) in vitro DM digestibility, in both 24 and 30 h; while corn inclusion linearly increased (P < 0.01) digestibility of OM of materials. Silages containing corn were on average 24h more stable (P < 0.01) than control treatment, in which a quadratic effect showing silages containing 25% corn with the greatest (P < 0.01) stability (130 h). Losses post opening tended (P = 0.10) to be decrease in corn treated silages. Current results show the potential for such strategy, since dry-rolled corn reconstitution in sorghum silages not only improved nutritional value of silages, but also minimized losses related to fermentation process, as well as improved stability of material during the silage post-opening aerobic phase. [ABSTRACT FROM AUTHOR]

Corn hybrids designed for silage were evaluated under different irrigation regimens effects on nutritional composition, fermentation losses, and aerobic stability. Corn silage hybrids (n = 6) were randomly assigned into plots (n = 8 per hybrid) divided under two irrigation systems (50 and 100 ET), totaling 48 experimental units (field plots). Forages for all plots were mechanically harvested on the same day, sampled, and ensiled into laboratory experimental silos (18.93 L units with sand in bottom for effluent collection and gas valve on top for gas release) and stored for 98 d. An aerobic stability test was conducted during post silo opening period, with measurements taken at 5, 10, and 15 d. A complete randomized design was used to compare the effects of irrigation level, hybrids, and potential interactions on variables of interest. Data were analyzed using the GLIMMIX procedures of SAS. Upon forage harvesting, DM content of hybrids tended (P = 0.08) to interact with irrigation level, where most of the hybrids under irrigation 50ET had 2 to 6 percent units of DM greater than those under 100 ET. Still at ensiling moment, lower (P = 0.01) pH and greater (P = 0.01) particle size were observed for forages under irrigation 50 ET compared with 100 ET, respectively, regardless of hybrid type. After fermentation period, only subtle differences (P = 0.05) on silage pH were observed, in which all of hybrids and irrigation levels showed desirable pH averages for silage. Hybrids submitted to 50 ET irrigation treatment tended (P = 0.10) to provide drier silages than those at 100 ET. Tendencies (P = 0.08) were also observed for hybrids fermentation losses (DM and gas), regardless of irrigation level (P ≥ 0.81). Silage time to break aerobic stability was not affected (P ≥ 0.14) by treatments; whereas regardless of hybrid type, silages that passed by hydric-stress showed lower pH during post-opening compared to 100 ET treatments. In vitro true digestibility of silages were not affected (P = 0.22) by treatments, averaging 78%. Corn silage hybrids assessed appear to preserve high nutritional value even when submitted to hydric stress. Corn crops assessed under restricted irrigation may require earlier harvesting time due to drier plants; whereas fermentation losses may be more dependent of hybrid type rather than irrigation level. Imminent post-opening of silos (0 to 5 d) appears to be more stable for hybrids that passed by water restriction. [ABSTRACT FROM AUTHOR]

The effects of Eucalyptus citriodra essential oil on OM digestion, microbial efficiency, pH, and ammonia levels using the continuous culture system technique were evaluated. Three Eucalyptus inclusions (0; 500 and 1,000 mg/kg of DM) were randomly assigned to continuous culture flasks (experimental unit; n = 9; 3 per treatment) following a completely randomized design. Culture flasks (1 L) were equipped with drainage system for effluent (which was collected and kept under refrigeration) and CO2 plug on the lid. Inoculum (rumen fluid) for culture system was collected from 3 donors (steers; BW = 520 ± 30kg) for all batches (n = 2). Steers were fed diets containing 37% steam-flaked corn, 35% wet corn gluten feed, 25% roughage, and 3% supplement (DM basis). A 7-d incubation period was used for each batch, in which the first 3 d were used for the system adaptation followed by 4 d of collections. Continuous culture substrate was added twice daily, and contents collected at 0, 0.5, 1, 2, and 12 h post-feeding. Data were analyzed using the GLIMMIX procedures of SAS; day was used as repeated measure; and orthogonal contrasts were used to evaluate linear and quadric effects of Eucalyptus citriodra inclusion. No interaction treatment x time was observed for in vitro ruminal ammonia and pH (P = 0.98 and 0.99, respectively). Eucalyptus inclusion did not affect (P ≥ 0.83) in vitro ruminal ammonia, while in vitro ruminal pH decreased linearly (P < 0.01); in which 1,000 ppm dose showed a more acidic environment compared to other oil inclusions. Regardless of Eucalyptus inclusion, ruminal ammonia concentration peaked (P < 0.01) at 0.5 and 1h post in vitro system feeding time, while in vitro pH values reached the least (P < 0.01) levels at same collection times. No changes in true digestion of OM (P = 0.88), microbial efficiency (P = 0.31), NH3 flow (P = 0.76), total N digestibility (P = 0.95), and microbial N flow (P = 0.38) were observed. Eucalyptus oil does not appear to negatively affect ruminal in vitro deamination or OM digestion. Increased acidity may confer potential positive effects on ruminal energetic load released within the first hour of fermentation post feeding. [ABSTRACT FROM AUTHOR]

The decline in managed honey bee (Hymenoptera: Apidae) colony health worldwide has had a significant impact on the beekeeping industry. To mitigate colony losses, beekeepers in Canada and around the world introduce queens into replacement colonies; however, Canada's short queen rearing season has historically limited the production of early season queens. As a result, Canadian beekeepers rely on the importation of foreign bees, particularly queens from warmer climates. Importing a large proportion of (often mal-adapted) queens each year creates a dependency on foreign bee sources, putting beekeeping, and pollination sectors at risk in the event of border closures, transportation issues, and other restrictions as is currently happening due to the 2020 Covid-19 pandemic. Although traditional Canadian queen production is unable to fully meet early season demand, increasing domestic queen production to meet mid- and later season demand would reduce Canada's dependency. As well, on-going studies exploring the potential for overwintering queens in Canada may offer a strategy to have early season domestic queens available. Increasing the local supply of queens could provide Canadian beekeepers, farmers, and consumers with a greater level of agricultural stability and food security. Our study is the first rigorous analysis of the economic feasibility of queen production. We present the costs of queen production for three Canadian operations over two years. Our results show that it can be profitable for a beekeeping operation in Canada to produce queen cells and mated queens and could be one viable strategy to increase the sustainability of the beekeeping industry., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America.)

We examined whether alfalfa leafcutting bees (ALCB, Megachille rotundata) experienced a higher incidence of seven viruses commonly found honey bees (Apis mellifera) when placed alongside honey bees for hybrid canola seed pollination. Although two viruses - sacbrood virus (SBV) and deformed wing virus (DWV) - were detected in ALCB adults, their presence appeared independent of whether honey bees were present in the same field or not. A further survey of viruses among ALCB adults in three different alfalfa seed growing regions in Western Canada confirmed the ubiquity of sacbrood virus (SBV) as well as the infrequent presence of acute bee paralysis virus (ABPV), both of which had not been previously reported on ALCB. Moreover, SBV and ABPV were detected in the cocoon stage and only in one region. Co-infection among pools of ALCB adults with both of these viruses was more closely correlated with decreasing levels of cocoon viability than infection levels in cocoons themselves. This research suggests ongoing viral transmission between honey bees and ALCB in the same fields is likely low but that co-infection with these viruses may lower ALCB productivity., (Copyright © 2017. Published by Elsevier Inc.)