The Impact of Using Alternative Forages on the Nutrient Value within Slurry and Its Implications for Forage Productivity in Agricultural Systems

Alternative forages can be used to provide valuable home-grown feed for ruminant livestock. Utilising these different forages could affect the manure value and the implications of incorporating these forages into farming systems, needs to be better understood. An experiment tested the hypothesis that applying slurries from ruminants, fed ensiled red clover (Trifolium pratense), lucerne (Medicago sativa) or kale (Brassica oleracea) would improve the yield of hybrid ryegrass (Lolium hybridicum), compared with applying slurries from ruminants fed ensiled hybrid ryegrass, or applying inorganic N alone. Slurries from sheep offered one of four silages were applied to ryegrass plots (at 35 t ha⁻¹) with 100 kg N ha⁻¹ inorganic fertiliser; dry matter (DM) yield was compared to plots only receiving ammonium nitrate at rates of 0, 100 and 250 kg N ha⁻¹ year-1. The DM yield of plots treated with 250 kg N, lucerne or red clover slurry was significantly higher than other treatments (Pred clover (81 kg) >kale (44 kg) >ryegrass (26 kg ha⁻¹ yr⁻¹). These FNE values represent relative efficiencies of 22% (ryegrass), 52% (kale), 47% (red clover) and 60% for lucerne slurry, with the ryegrass slurry efficiency being lowest (P = 0.005). Soil magnesium levels in plots treated with legume slurry were higher than other treatments (P<0.001). Overall, slurries from ruminants fed alternative ensiled forages increased soil nutrient status, forage productivity and better N efficiency than slurries from ruminants fed ryegrass silage. The efficiency of fertiliser use is one of the major factors influencing the sustainability of farming systems, these findings highlight the cascade in benefits from feeding ruminants alternative forages, and the need to ensure their value is effectively captured to reduce environmental risks

Developing Sustainable Livestock Systems through Participatory Farmer Research

Application Understanding muscular adaptations could inform objective lameness-detection for early diagnosis/treatment, ultimately serving to detect sub-clinical issues in supposed healthy horses and to reduce pain/ incapacity in lame horses. Introduction The prevalence and impact of lameness on equine welfare has led to extensive research, which has biomechanically analysed lameness-related alterations in movement. Despite this, limited information is available about adaptive muscle activity that facilitates movement during lameness. Surface electromyography (sEMG) is a non-invasive method for quantifying muscle activity. However, no equine studies have employed sEMG to compare inherent and adaptive activity during non-lame and standardised lameness conditions, respectively. The aim of this preliminary study was to compare Triceps Brachii (TB) muscle activity in horses before and after induced forelimb (FL) lameness, using sEMG data. Material and methods Six clinically non-lame horses (5 mares, 1 stallion, age: 7.0±3.7 years, height: 162.3±4.0 cm, body mass: 572.7±45.8 kg) were used. sEMG sensors (Delsys Trigno, Delsys Inc.) were attached bilaterally to locations above TB (long head), that were prepared by removing all hair and cleaning with isopropyl alcohol. Retro-reflective markers were attached to anatomical landmarks for quantitative lameness evaluation (QHorse, Qualisys AB) and gait event detection. sEMG (2000 Hz) and 3D kinematic (200 Hz) data were synchronously collected from horses during in-hand trot trials, conducted on a straight, hard surfaced runway before (baseline) and after FL lameness induction. Baseline data were initially collected, then temporary, mild FL lameness (2-3/5 AAEP Lameness Scale) was induced using mechanical bolt pressure, applied to the tip of the frog and monitored by qualified veterinarians (T.S., F.S.B.) using a modified horseshoe (Merkens and Schamhardt, 1988). Left and right FL lameness induction were randomised. Following data collection, the bolt/ sole pressure was removed and no horses showed adverse reactions to lameness inductions, or residual lameness. For stride segmentation, gait events were detected using kinematic data that were low-pass filtered (Butterworth 4th order, 10 Hz cut-off) and analysed in accordance with the methods described by Holt et al. (2017). To quantify lameness, MinDiff was calculated using poll vertical displacement data, where healthy horses exhibit MinDiff between -6 – 6mm and left and right FL lameness are exhibited as more positive and negative values, respectively (Rhodin et al., 2016). Raw sEMG signals were DC-offset removed, high-pass filtered (Butterworth 4th order, 40 Hz cut-off) (St. George et al., 2018), and fullwave rectified. Integrated EMG (iEMG) and average rectified value (ARV) were calculated using stride duration as temporal domain. To reduce inter-subject variability, iEMG and ARV from each horse were normalised to the maximum value observed for each limb (left/ right FL) across all strides from the baseline condition. Data from the “lame” and “nonlame” limb were grouped, according to the limb where lameness was induced. A 2x2 repeated measures ANOVA was used to compare muscle activity between limb (lame, non-lame) and condition (baseline, induced FL lameness). Post-hoc analyses using Bonferroni correction were performed where significant main effects were found. Results Mean ± sd MinDiff were baseline:-1.8 ± 8.7 mm, left FL lameness induction:-55.3 ± 34.1 mm, right FL lameness: 56.8 ± 17.9 mm. Significant interactions between limb and condition were found for iEMG (p < 0.05, n2=0.74) and ARV (p < 0.05, n2=0.75). Post hoc analyses of iEMG and ARV data revealed muscle activity was significantly higher in the lame limb (p < 0.05) and significantly lower in the non-lame limb (p < 0.01) during the induced FL lameness condition. Conclusion Preliminary findings reveal neuromuscular adaptations in TB during induced FL lameness. Significant increases in stance duration have been reported during FL lameness (Weishaupt et al., 2006). Therefore, significant increases in lame limb muscle activity may be due to prolonged stabilisation of the shoulder and elbow joints, as a compensatory mechanism of gait adaptation to lameness. Further investigations of additional muscles and chronic lameness cases are required to determine whether sEMG can provide a complimentary tool for objective lameness detection

The legacy of cover crops on the soil habitat and ecosystem services in a heavy clay, minimum tillage rotation

Abstract Cover crops are grown as potential ways to improve soil fertility, soil structure, and biodiversity, while reducing weed/pest burdens. Yet, increased costs (in both time and fuel), farmer knowledge requirements, and yield uncertainty (green bridge effect and variable crop establishment) have led to hesitation among farmers. This study was conducted at the field scale (covering an area of nearly 20 hectares) to determine whether different cover crop mixtures affected soil properties and ecosystem services on a heavy clay soil. Measurements of soil chemistry, physics, biology, weed abundance, and subsequent crop performance were taken within a minimum tillage management system, across three cover crop mixtures (commonly sold to UK farmers). The cover crop mixtures included oats (Avena sativa), radish (Raphanus sativus), phacelia (Phacelia tanacetifolia), vetch (Vicia sativa), legumes, buckwheat (Fagopyrum esculentum) and a bare stubble control followed by a spring oat crop. Soil physics (penetrometer and bulk density) and chemistry (N, P, K, Mg, Ca, and organic matter) varied little across treatments, although there was significantly lower Mg in the cover crop including legumes and an increase in NO3 within this treatment. Soil biology and botanical composition were also assessed, monitoring earthworm and mesofauna abundance; and sown and unsown (weed) biomass. Epigeic earthworms were found to have significantly larger abundance in cover crop mixtures with radish present, although other meso- and macrofauna did not differ. Significant weed suppression was found during both the cover crop growing period and as a legacy in the subsequent crop, leading to significant yield increases and economic benefits in some treatments. Our study confirms that cover crops are providing benefits, even on heavy clay soils, including improvements in nutrient leaching risk reduction, weed suppression, and crop yield, coupled with wider ecosystem benefits. We therefore consider cover crops to have a role in sustainable management of arable rotations

Le millet perlé sucré et le sorgho sucré comme cultures énergétiques en conditions québécoises : potentiel de production, utilisation de l'azote, morphologie des racines et apport de carbone au sol

Le millet perlé sucré [Pennisetum glaucum (L.) R.BR.] et le sorgho sucré [Sorghum bicolor (L.) Moench] sont des cultures annuelles dont la sève sucrée peut être transformée en éthanol. Ces cultures semblent avoir des besoins limités en azote, mais leur efficacité d’utilisation de l’azote n’a pas été démontrée dans les conditions de l’est du Canada. De plus, la morphologie des systèmes racinaires de ces espèces a peu été étudiée, alors qu’elle pourrait fournir des explications concernant l’efficacité d’utilisation de l’azote. Les objectifs de cette étude étaient de (i) comparer le millet perlé sucré et le sorgho sucré quant à leur rendement et leur utilisation de l’azote (N), (ii) déterminer la réponse des deux espèces à des doses croissantes d’azote minéral, (iii) comparer leur réponse à l’azote minéral et l’azote de source organique (lisiers de porc et de bovin), (iv) comparer leurs traits racinaires et ceux du maïs-grain (Zea Mays L.), l’espèce actuellement utilisée pour produire de l’éthanol dans l’est du Canada, et (v) comparer l’apport en carbone au sol de ces trois espèces. Les espèces ont été cultivées à deux sites expérimentaux situés au Québec. Les doses d’azote favorisant les plus hauts rendements en sucres chez le millet et le sorgho ont été de 86 et 91 kg N ha-1, selon le site. La fertilisation minérale a généré des rendements plus élevés que l’utilisation de lisiers, lesquels ont montré une efficacité fertilisante variant de 15 à 52 % de celle de l’engrais minéral. Le sorgho a donné des rendements en sucres 68 % plus élevés que ceux du millet. Le millet et le sorgho ont récupéré dans leurs parties aériennes 54 à 82 % de l’azote minéral appliqué. Alors que la biomasse racinaire et l’apport annuel en carbone ont été supérieurs pour le maïs, la longueur des racines et la proportion de racines très fines étaient plus élevées pour le millet perlé sucré et le sorgho sucré. Les résultats démontrent la haute efficacité avec laquelle le millet et le sorgho utilisent l’azote ainsi que les faibles risques environnementaux associés, et suggèrent que la morphologie racinaire contribue à cette efficacité.Sweet pearl millet [Pennisetum glaucum (L.) R.BR.] and sweet sorghum [Sorghum bicolor (L.) Moench] are annual crops from which the sweet sap can be fermented to ethanol. They appear to have a high nitrogen (N) use efficiency, but this remains to be demonstrated in eastern Canada. Studying the morphological traits of their rooting system could help understanding their N use efficiency. The main objectives of this study were to (i) compare both species for yield and N use efficiency, (ii) determine their response to increasing mineral N rate, (iii) compare their response to mineral vs. organic N sources (liquid swine and liquid dairy manures), (iv) compare their root morphological traits with those of grain corn (Zea Mays L.), the sole feedstock used for ethanol production in eastern Canada, and (v) compare annual carbon input to soil from these three species. Species were grown at two experimental sites in Quebec. The N rates that led to maximum sugar yield for sweet pearl millet and sweet sorghum were 86 and 91 kg N ha-1, depending on site. Mineral N fertilization resulted in greater yields than the liquid manures, which showed fertilizer N equivalences varying from 15 to 52%. Fifty-four to 82% of applied mineral N fertilizer was recovered in the aboveground biomass of sweet pearl millet and sweet sorghum. While root biomass and annual carbon input were greater with corn, the length of the rooting system and the proportion of very fine roots were greater with sweet pearl millet and sweet sorghum. Our results show a high N use efficiency of sweet pearl millet and sweet sorghum, and therefore indicate low environmental risk associated with their fertilization. Moreover, our results suggest that the peculiar root morphology of these crops contribute to their high N use efficiency