Effect of swath treatment on water loss during field-wilting and on feeding value of perennial ryegrass silage

The effect of spreading mown perennial ryegrass (Lolium perenne) herbage over the total ground area on water loss during field-wilting was compared with leaving herbage in swaths (three swaths put together into one, occupying 0·18 of ground area) in three experiments. Spread crops were not tedded during wilting but were rowed up immediately before harvest. In all experiments, conventional silage-making equipment was used on a field scale. Feeding value was assessed with lactating dairy cows and growing heifers (Experiment 1) and sheep (Experiment 3). The periods of field wilting were 48 h (Experiment 1), 24 h (Experiment 2) and both 24 h and 48 h (Experiment 3). Spreading the crop was associated with larger increases in loss of water in all three experiments compared with leaving grass in swaths. Losses of dry matter (DM) during wilting were similar in Experiment 2 but were higher for the swathed crop wilted for 48 h than for 24 h in Experiment 3. Spreading resulted in restricted fermentations associated with higher crop DM contents at ensiling. In Experiment 1 the concentrations of DM, ash and water-soluble carbohydrate in silage were higher (P < 0·001) for spreading the crop and the concentrations of crude protein and neutral-detergent fibre were lower (P < 0·05) than for swathed material. In Experiment 3, spreading was associated with higher concentrations of water-soluble carbohydrates and ethanol and lower concentrations of fermentation acids, ammonia-N and neutralizing value in silage. Voluntary DM intake of silage by dairy cows and heifers was higher for spread than for swathed material (P < 0·05), but in Experiment 3 (sheep) there were no significant differences between treatments in voluntary intake of DM. The increased intake by dairy cows of silage from spread herbage was reflected in increased concentrations of milk fat (P < 0·01) and protein (P < 0·05) but not in milk yield (P > 0·05). It is concluded that spreading herbage during field wilting prior to ensiling accelerates water loss and has the potential to improve the feeding value of the ensiled product.     

Long‐lasting β‐aminobutyric acid‐induced resistance protects tomato fruit against Botrytis cinerea

Minimizing losses to pests and diseases is essential for producing sufficient food to feed the world's rapidly growing population. The necrotrophic fungus Botrytis cinerea triggers devastating pre‐ and post‐harvest yield losses in tomato (Solanum lycopersicum). Current control methods are based on the pre‐harvest use of fungicides, which are limited by strict legislation. This investigation tested whether induction of resistance by β‐aminobutyric acid (BABA) at different developmental stages provides an alternative strategy to protect post‐harvest tomato fruit against B. cinerea. Soil‐drenching plants with BABA once fruit had already formed had no impact on tomato susceptibility to B. cinerea. However, BABA application to seedlings significantly reduced post‐harvest infection of fruit. This resistance response was not associated with a yield reduction; however, there was a delay in fruit ripening. Untargeted metabolomics revealed differences between fruit from water‐ and BABA‐treated plants, demonstrating that BABA triggered a defence‐associated metabolomics profile that was long lasting. Targeted analysis of defence hormones suggested a role of abscisic acid (ABA) in the resistance phenotype. Post‐harvest application of ABA to the fruit of water‐treated plants induced susceptibility to B. cinerea. This phenotype was absent from the ABA‐exposed fruit of BABA‐treated plants, suggesting a complex role of ABA in BABA‐induced resistance. A final targeted metabolomic analysis detected trace residues of BABA accumulated in the red fruit. Overall, it was demonstrated that BABA induces post‐harvest resistance in tomato fruit against B. cinerea with no penalties in yield.     

Highlights of progress in silage conservation and future perspectives

Highlights of progress in the production of silage over the past 50 years include the introduction of improved hybrids of maize (Zea mays L.), the forage harvester, the big baler, polyethylene covering for horizontal silos, stretch‐wrap film for bales and novel additives designed to improve the fermentation and aerobic stability of silage. The key biochemical pathways in the silage fermentation have been described together with the effects of microbial and chemical additives on fermentation and aerobic stability during the feed‐out phase. The significance of oxygen and water in silage fermentation has been quantified and efficacy of covering silos has been established, with recent progress in the development of oxygen barrier film. Future perspectives include improving food safety and animal health by increasing the hygienic quality of silage, reducing the environmental impact of silage by decreasing loss of nitrogen to soil and atmosphere, reducing methanogenesis in the rumen and increasing methane yield from silage as biofuel, and the use of silages as feedstocks for multiple end uses in biorefineries.     

Investigation of farmers' perspectives on the disposal of fallen livestock and animal by-products in Great Britain

Two questionnaires were completed by a selection of farms in Great Britain during 2008 and 2009 to ascertain the role of the National Fallen Stock Company (NFSCo) in fallen livestock disposal, the current disposal methods used for fallen livestock and other animal by-products (ABPs), and factors determining use of a particular method. The results demonstrated a significant difference (P<0.001) in NFSCo membership in relation to geographical location and a significant difference (P<0.001) in disposal choice. Farmers' perceptions as to why they did or did not join NFSCo, and why they used particular disposal methods are discussed. Disposal methods of other ABPs (aborted fetuses/stillborn animals and placentas) demonstrated the illegal disposal of aborted fetuses/stillborn animals (19.5 per cent of respondents) and placentas (57.6 per cent of respondents). Overall, 13.7 per cent of respondents used a variety of illegal disposal methods for fallen livestock carcases and other ABPs.     

Functional habitat connectivity for beach mice depends on perceived predation risk

Landscape features that promote animal movement contribute to functional habitat connectivity. Factors that affect the use of landscape features, such as predation risk, may alter functional connectivity. We identify factors important to functional habitat connectivity by quantifying movement patterns of the Santa Rosa beach mouse (Peromyscus polionotus leucocephalus) in relation to landscape features and by examining how ambient perceived predation risk, which is altered by moon phase, interacts with landscape features. We use track paths across the sand to relate the probability that beach mice cross gaps between vegetation patches to gap width, patch quality, landscape context and moon phase. Overall activity levels were lower during full versus new moon nights, demonstrating that beach mice respond negatively to moonlight. Gap crossing was more likely during new moon nights (25 % of gaps crossed vs. 7 % during full moon nights), and across narrower gaps (<8.38 m) that led to larger vegetation patches (>11.75 m²). This study suggests that vegetation recovery is necessary for functional connectivity in post-hurricane landscapes commonly inhabited by beach mice and provides initial guidelines for restoring landscape connectivity. More broadly, this study highlights the importance of considering predation risk when quantifying landscape connectivity, as landscape features that facilitate connectivity when predation risk is low may be ineffective if predation risk increases over time or across space.     

Effect of whole-crop pea (Pisum sativum L.) silages differing in condensed tannin content as a substitute for grass silage and soybean meal on the performance, metabolism, and carcass characteristics of lambs

Two experiments were conducted to investigate the effect of inclusion of whole-crop pea (WCP) silages, differing in condensed tannin content, as a substitute for grass silage (GS) and soybean meal on lamb metabolism, performance, plasma metabolites, digestibility, and carcass characteristics. In both experiments lambs were offered either solely GS or a 50:50 mix on a DM basis of GS with either low-tannin (LTPS) or high-tannin (HTPS) pea silage ad libitum. Each forage mix was fed with either 400 g/d of low-protein (LP) concentrate or 400 g/d of LP with an additional 200 g/d of pelletized soybean meal (HP), resulting in 6 dietary treatments. Experiment 1 examined the effects of the diets on metabolism, digestibility, and N balance using 6 lambs in 4 periods of 21 d in an incomplete crossover design. Experiment 2 used 48 lambs and examined the effects of the diets on ADG, plasma metabolites, and carcass characteristics over 56 d. Both experiments were analyzed using a 3 × 2 factorial arrangement of treatments. In Exp. 1, lambs offered the LTPS diets had a greater (P < 0.05) digestibility of DM and OM than those offered the GS diets. Lambs offered the WCP silages had an increased (P < 0.05) N intake, N output, and digestibility of GE compared with those offered GS. Mean N digestibility was greatest (P < 0.05) in lambs offered LTPS. Lambs offered HP diets had increased (P < 0.001) digestibility of DM, OM, GE and N, and N- intake, output, retention, and digestibility compared with those offered the LP diets. In Exp. 2, there was no effect (P > 0.05) of forage type on intake, slaughter BW, or feed conversion efficiency (FCE). However, lambs offered the LTPS had a greater (P < 0.05) ADG than those offered the GS diets. Feeding diets containing HP increased (P < 0.001) total DMI, slaughter BW, ADG, and FCE. Lambs offered the WCP had a greater (P < 0.05) plasma β-hydroxybutyrate and urea concentration compared with those offered the GS diets. Feeding lambs HP diets increased (P < 0.05) plasma urea and total protein. Forage mix had no effect (P > 0.05) on carcass composition except for fat depth, which was greater (P < 0.05) in lambs offered WCP silage. Diets containing the HP increased (P < 0.05) carcass weight, hind leg circumference, chop dimensions, and kidney weight. It was concluded that lambs offered LTPS performed better than those offered GS and that LTPS has a concentrate sparing effect. Additionally, the increased tannin concentration in HTPS did not increase performance over lambs offered either GS or LTPS.     

Influence of nitrate‐nitrogen and ammonium‐nitrogen on calcium (45Ca2+) absorption in sorghum root tips

Abstract

Root‐tip, 1‐cm of Sorghum bicolor (L.) Moench cv SC283, SC574, GP‐10, and Funk G522DR were exposed to calcium (⁴⁵Ca²⁺) at pH 5.5 for 2‐hr in the presence of nitrate‐nitrogen (NO3^?‐N) or ammonium‐nitrogen (NH4+‐N). Nitrate (0.1 mM) induced significantly increased ⁴⁵Ca uptake in Funk G522DR, SC283, and GP‐10 while 0.01 mM NO₃ ^?‐N induced significantly increased ⁴⁵Ca'uptake in SC574, but ⁴⁵Ca absorption was significantly decreased at 1 mM NO₃—N. In the presence of the NH4⁺ ion, ⁴⁵Ca uptake was increased up to 8X that of the NH₄ ⁺‐N untreated roots. When ammonium chloride (NH₄CI) was used, the Cl^? tended to induce an increased ⁴⁵Ca uptake. Cultivar variation was present.