Altering autumn management affects the herbage mass available in spring. An experiment was established to determine the effect of five autumn closing dates (CDs) on herbage production, herbage quality, leaf, stem and dead proportions and tiller density over winter. In the study 50% of the herbage available in spring was accounted for by autumn CD. Each 1 d extra a sward was closed from 25 September to 9 December increased herbage mass by 16 kg DM/ha in spring. Swards closed earlier (25 September–26 October) had consistently higher herbage masses in spring (1,301 kg DM/ha) compared to swards closed later (11 November–9 December; 703 kg DM/ha). Later closed swards had greater herbage quality compared to earlier closed swards (organic matter digestibility = 852 and 825 g/kg DM, respectively) due to increased stem and dead material in the grazing horizon of earlier closed swards. There was no effect of autumn CD on sward quality in the subsequent defoliation in spring. However, following the initial spring grazing there was an effect of autumn CD on subsequent grass growth rates; swards closed in October had a lower growth rate (33 kg DM/ha per day) compared to swards closed in November and early December (49 kg DM/ha per day). Results indicate that earlier autumn closing is beneficial to meet high-feed demand in spring but can affect sward quality and growth rates in spring.
The patterns of recovery from injury or infection are not well studied in free-ranging animals. Bats that survive the fungal disease white-nose syndrome (WNS) often emerge from hibernation suffering from skin infections and wing damage. The extent of wing damage reflects physiological and immunological responses to WNS and may impact the ability of bats to fly, forage, and reproduce. Here, we built on previous studies of wing damage in both captive and free-ranging bats to better understand the patterns and extent of wing damage healing in little brown bats (Myotis lucifugus) post-hibernation. We quantified two main types of wing damage, black necrotic dots and white spots, and used the extent of damage to assign bats 1 of 6 wing damage scores. We found that the patterns of black dots and white spots on wing membranes of free-ranging bats aligned with the patterns observed in captive bats soon after emergence from hibernation. Black dot extent was highest at the beginning of the active season in May, while white spot extent peaked 3–4 weeks later. Our study also extends our knowledge of wing damage healing throughout the active season. Wing scores of bats recaptured within the summer decreased or stayed the same and >95% had negligible signs of wing damage by August. We found that black dots were more indicative of disease status than other types of wing damage and could be consistently quantified in the field and from photographs by multiple observers. These results suggest that black dots and our wing damage scoring system can be used to better understand the patterns of post-hibernation healing in little brown bats impacted by WNS.
Accumulating herbage mass to facilitate the extension of the grazing season in autumn is commonly practised. The objective of the current study was to investigate the effect of accumulating varying target herbage masses (THM) in autumn and imposing different defoliation dates (DD), on herbage mass, sward quality and water-soluble carbohydrates in autumn and the subsequent spring. A 4 × 3 factorial split plot design was assigned with four THM (Low ≈ 500 kg·DM·ha−1, Medium ≈ 1500 kg·DM·ha−1, High ≈ 2000 kg·DM·ha−1 and Very high ≈ 3000 kg·DM·ha−1) and three DD (DD1—15 October, DD2—7 November and DD3—21 November), across two years. Measurements were carried out at each DD and in spring. Differences in sward quality were found between each THM on different DD. Sward quality reduced from DD2 to DD3 in the high THM (−13 g·kg−1 DM CP, p < 0.001). The very high THM had the lowest sward quality from DD1 (206 g·kg−1 DM CP, p < 0.001 and 787 g·kg−1 DM DMD, p < 0.05). This study has identified the defoliation date of THM in autumn as key to improving autumn management strategies for increased utilisation and sward quality.
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