Texas A&M AgriLife Extension Service

About: Texas A&M AgriLife Extension Service is a based out in . It is known for research contribution in the topics: Population & Shrimp. The organization has 346 authors who have published 343 publications receiving 5524 citations.

Fish offal recycling by the black soldier fly produces a foodstuff high in omega-3 fatty acids

Abstract: .— The black soldier fly, Hermetia illucens, has the potential to reduce animal waste on livestock facilities and produce an animal-grade feedstuff high in protein and fat. The lipid content of insects is largely dependent on their diet. Data from this study suggest that black soldier fly prepupae incorporate α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) when fish offal is included in their diet. Fly larvae were fed three different proportions of fish offal and cow manure diets over a 21-d trial. An additional group of larvae were fed 22% fish offal diet within 24 h of their pupation. Larvae fed fish offal were, on average, 30% lipid, which was 43% more than the controls fed cow manure only, and approximately 3% of this lipid was omega-3 fatty acids (EPA, DHA, and ALA). Furthermore, this concentration of omega-3 fatty acids was achieved within 24 h of feeding fish offal. These omega-3 fatty-acid-enhanced prepupae may be a suitable fish meal and fish oil replacement for carnivorous fish and other animal diets. In addition, they may provide a method of reducing and recycling fish offal from processing plants.

Technical note: Exit velocity as a measure of cattle temperament is repeatable and associated with serum concentration of cortisol in Brahman bulls

Abstract: The objectives of this study were 1) to compare temperament assessments, using multiple techniques and over repeated observations, to gauge temperament over the long-term and 2) to evaluate the relationship of the temperament appraisals with serum concentrations of cortisol (CS). Measures of temperament were gathered over 3 repeated observations (60-d interval) of yearling, fall-born Brahman bulls (initial BW = 320 +/- 4 kg; n = 66). Temperament assessments included exit velocity (EV), which was the rate at which the bulls exited the squeeze chute and traversed a fixed distance (1.83 m); pen scores (PEN; 1 = quiet to 5 = excited), ascertained from animal behavior while penned in small groups (n = 5); and chute scores (CHUTE; 1 = quiet to 5 = excited), determined from behavioral responses to restraint on the weigh scale. Temperament measures obtained during the initial data collection (d 0) were all positively correlated (r > or = 0.35, P 0.31, P 0.31, P 0.3). Exit velocity was positively correlated with CS within d 0 (r = 0.26, P = 0.04) and 120 (r = 0.44, P 1 SD above the mean. Mean EV (P < 0.01) decreased from d 0 (2.82 +/- 0.07 m/sec) to 120 (2.11 +/- 0.10 m/sec). Time also influenced (P < 0.01) CS; mean CS decreased between d 0 (14.6 +/- 0.7 ng/mL) and 120 (11.1 +/- 0.8 ng/mL). Measures of EV can be a valuable tool for the assessment of cattle temperament and a possible predictor of temperament and stress responsiveness to future animal handling events.

Rainfall partitioning within semiarid juniper communities: effects of event size and canopy cover

Abstract: Partitioning bulk rainfall into canopy interception, litter interception, stemflow and throughfall allows an estimate of the physical impact of trees on the local hydrologic budget. Despite recognition of the potentially large effect of interception and associated processes on the hydrologic budget, few, if any, studies have quantitatively evaluated the multiple components simultaneously in semiarid savannas, nor have the effects of rainfall intensity within storms been rigorously evaluated. We monitored interception and rainfall partitioning in individual Ashe juniper (Juniperus ashei Buchholz) canopies at ten sites over a 3-year period. Averaged over all ten sites for 2700 total rain events, about 35% of the bulk rainfall falling on juniper trees was intercepted by the tree canopy, 5% was intercepted by the coarse litter and duff beneath the tree, 55% reached the ground surface as direct and released throughfall, and 5% was redirected to the base of the tree as stemflow. Small amounts of rainfall ( 60% interception). High intensity rainfall was less influenced by juniper canopies. At high intensities (e.g. > 70 mm over a 15-h period) only 20% of the bulk precipitation was intercepted by the canopy and litter. The hourly pattern of rainfall within extended storms demonstrated periods with low intensity and periods with high intensity. The interception rates during these periods closely mimic the rates seen in similar intensity short duration storms. Canopy and litter interception effectively reduced the beneath-canopy precipitation from 600 to 360 mm in the western region and from 900 to 540 mm in the eastern region. Copyright © 2006 John Wiley & Sons, Ltd.