The need to implement the landscape of fear within rodent pest management strategies

Current reactive pest management methods have serious drawbacks such as the heavy reliance on chemicals, emerging genetic rodenticide resistance and high secondary exposure risks. Rodent control needs to be based on pest species ecology and ethology to facilitate the development of ecologically based rodent management (EBRM). An important aspect of EBRM is a strong understanding of rodent pest species ecology, behaviour and spatiotemporal factors. Gaining insight into the behaviour of pest species is a key aspect of EBRM. The landscape of fear (LOF) is a mapping of the spatial variation in the foraging cost arising from the risk of predation, and reflects the levels of fear a prey species perceives at different locations within its home range. In practice, the LOF maps habitat use as a result of perceived fear, which shows where bait or traps are most likely to be encountered and used by rodents. Several studies have linked perceived predation risk of foraging animals with quitting‐harvest rates or giving‐up densities (GUDs). GUDs have been used to reflect foraging behaviour strategies of predator avoidance, but to our knowledge very few papers have directly used GUDs in relation to pest management strategies. An opportunity for rodent control strategies lies in the integration of the LOF of rodents in EBRM methodologies. Rodent management could be more efficient and effective by concentrating on those areas where rodents perceive the least levels of predation risk. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Superovulatory Ovarian Response in Mangalica Gilts is Not Influenced by Feeding Level

The aim of the study was to compare how different feeding levels affect the ovarian potential of follicular development and oocyte maturation in response to superovulatory treatment in native Mangalica (M, n = 17) compared with Landrace (L, n = 20) pigs. Gilts of both breeds were fed high-energy (HI-2.5 kg) or low-energy (LO - 1.25 kg) feed during oestrus synchronization (15 days of Regumate feeding) till the time of oocyte aspiration (Day 6 after Regumate). Follicular growth was stimulated by the administration of 1000 IU equiue choriou gonadotropiu (eCG) 24 h after Regumate treatment, and ovulation was induced by injection of 750 IU human choriou gonadotropiu (hCG) 80 h after eCG administration. Ultrasound (US) investigation was done three times (4-10 h before, and 40-44 and 72-74 h after eCG administration) for the observation of follicular development. Oocyte and follicular fluid (FF) were collected endoscopically 34 h after hCG injection. Cumulus-oocyte complexes were evaluated, their morphology determined, and thereafter fixed and stained for chromatin evaluation. Oocytes were classified as meiosis-resumed (germinal vesicle breakdown, diakinesis, metaphase I to anaphase I) or matured (telophase I and metaphase II). FF concentrations of oestradiol and progesterone were measured by validated radioimmunoassays. In L gilts, differences were observed between HI and LO in the number of preovulatory follicles (32.3 +/- 10.5 vs 17.1 +/- 12.3, p < 0.05), but not in M (25.3 +/- 2.9 vs 28.8 +/- 7.3, p > 0.05). Initial follicular growth was not affected by feeding levels; however, preovulatory follicle size was larger in M (7.1 +/- 0.9 and 6.9 +/- 1.1 mm vs 5.7 +/- 0.7 and 5.5 +/- 0.8 mm; p < 0.05). No differences were obtained with relation to mature chromatin configuration in both breeds (L gilts: HI - 70% and LO-67% vs M gilts: HI - 67% and LO - 63%). A twofold higher oestradiol concentration was detected in FF of HI-M and LO-M (29.6 +/- 6.8 and 30.9 +/- 10.3 ng/ml respectively) compared with that of L (16.9 +/- 9.7 and 17.9 +/- 3.6 ng/ml, respectively; p < 0.05). The mean FF progesterone level was nearly fivefold higher in M (2020.4 +/- 1056 and 1512.2 +/- 1121.8 ng/ml) compared with L (386.2 +/- 113.7 and 298.8 +/- 125.9 ng/ml, p < 0.05). The results indicate an influence of the feeding of altered energy on the number of recruitable preovulatory follicles in modern Landrace but not in native Mangalica breed. Moreover, the follicular steroid hormone milieu differs between Landrace and Mangalica gilts but not depending on feeding levels. Oocyte maturation was not affected by diet.     

Formation of Chiral Interdigitated Multilayers at the Air-Liquid Interface Through Acid-Base Interactions

Thin interdigitated films composed of a long-chain, water-insoluble chiral acid (p-pentadecylmandelic acid of absolute configuration R) and a water-soluble chiral base (phenylethylamine, R') were constructed at the air-solution interface. The (R, R') structure was characterized to near-atomic resolution by grazing-incidence x-ray diffraction (GIXD). The two diastereomeric systems, (R, R') and (R, S'), demonstrate similar surface pressure-molecular area isotherms, but their structures are completely different on the molecular level, as monitored by GIXD. Complementary data on these two architectures were provided by atomic force microscopy.     

Progestagen supplementation during early pregnancy does not improve embryo survival in pigs

Progesterone supplementation during early pregnancy may increase embryo survival in pigs. The current study evaluated whether oral supplementation with an analogue of progesterone, altrenogest (ALT), affects embryo survival. A first experiment evaluated the effect of a daily 20-mg dosage of ALT during days 1-4 or 2-4 after onset of oestrus on embryo survival at day 42 of pregnancy. A control group (CTR1) was not treated. The time of ovulation was estimated by transrectal ultrasound at 12-h intervals. Altrenogest treatment significantly reduced pregnancy rate when start of treatment was before or at ovulation: 25% (5/20) compared to later start of treatment [85% (28/33)] and non-treated CTR1 [100% (23/23)]. Altrenogest treatment also reduced (p < 0.05) number of foetuses, from 14.6 ± 2.6 in CTR1 to 12.5 ± 2.5 when ALT started 1-1.5 days from ovulation and 10.7 ± 2.9 when ALT started 0-0.5 days from ovulation. In a second experiment, sows with a weaning-to-oestrous interval (WOI) of 6, 7 or 8-14 days were given ALT [either 20 mg (ALT20; n = 49) or 10 mg (ALT10; n = 48)] at day 4 and day 6 after onset of oestrus or were not treated (CTR2; n = 49), and farrowing rate and litter size were evaluated. Weaning-to-oestrous interval did not affect farrowing rate or litter size. ALT did not affect farrowing rate (86% vs 90% in CTR2), but ALT20 tended to have a lower litter size compared with CTR2 (11.7 ± 4.1 vs 13.3 ± 3.1; p = 0.07) and ALT10 was intermediate (12.3 ± 2.9). In conclusion, altrenogest supplementation too soon after ovulation reduces fertilization rate and embryo survival rate and altrenogest supplementation at 4-6 days of pregnancy reduces litter size. As a consequence, altrenogest supplementation during early pregnancy may reduce both farrowing rate and litter size and cannot be applied at this stage in practice as a remedy against low litter size.     

Effects of Pre‐Weaning Energy Substitutions on Post‐Weaning Follicle Development,Steroid Hormones and Subsequent Litter Size in Primiparous Sows

The present study investigated the effects of pre‐weaning energy substitutions on follicular development, endocrine characteristics and subsequent litter size in primiparous sows. Sows were fed a standard lactation diet (14.1 DE MJ/kg) and then allocated to a Control (C, n = 24), Fat (F, n = 23), Sugar (S, n = 23) or post‐weaning Regumate (positive control; R, n = 22) treatment at 9 days before weaning of the C, F and S treatments. During the treatment period (8 days), 1 kg of the lactation diet was substituted with 1 kg of a fat‐rich (F, 23.85 DE MJ/kg) or sugar‐rich (S, 15.75 DE MJ/kg) substitution for F and S sows, respectively. For the R treatment, sows were weaned 8 days earlier than other treatments and fed a lactation diet at 3.5 kg with two doses of altrenogest as topdressing from 1 day before weaning until the day on which the other sows were weaned. The F treatment aimed to increase energy intake, and the S treatment aimed to elevate post‐prandial glucose and insulin concentrations. Weaning‐to‐ovulation interval tended to be reduced in the S treatment compared with C (p = 0.06) and F (p = 0.08) treatments. Body weight (BW) loss during the treatment period, post‐weaning follicle development, plasma oestradiol and pre‐weaning leptin did not differ among C, F and S sows, although BW loss was lower and leptin was higher in the R treatment. Post‐ovulatory progesterone concentration in the S treatment was higher (p < 0.05). Sows in the S and R treatments had a greater proportion of litters with larger litter sizes (p < 0.05). The outcome suggests that increasing circulating insulin and glucose concentrations during late lactation or a week of metabolic recovery positively improves subsequent litter size in primiparous sows.     

The BIOEXPLOIT Project

The EU Framework 6 Integrated Project BIOEXPLOIT concerns the exploitation of natural plant biodiversity for the pesticide-free production of food. It focuses on the pathogens Phytophthora infestans, Septoria tritici, Blumeria graminis, Puccinia spp. and Fusarium spp. and on the crops wheat, barley, tomato and potato. The project commenced in October 2005, comprises 45 laboratories in 12 countries, and is carried out by partners from research institutes, universities, private companies and small-medium enterprises. The project has four strategic objectives covered in eight sub-projects. These objectives relate to (i) understanding the molecular components involved in durable disease resistance, (ii) exploring and exploiting the natural biodiversity in disease resistance, (iii) accelerating the introduction of marker-assisted breeding and genetic engineering in the EU plant breeding industry, and (iv) coordinating and integrating resistance breeding research, providing training in new technologies, disseminating the results, and transferring knowledge and technologies to the industry.     

Control of structure and growth of polymorphic crystalline thin films of amphiphilic molecules on liquid surfaces

The spontaneous formation and coexistence of crystalline polymorphic trilayer domains in amphiphilic films at air-liquid interfaces is demonstrated by grazing incidence synchrotron x-ray diffraction. These polymorphic crystallites may serve as models for the early stages of crystal nucleation and growth, helping to elucidate the manner in which additives influence the progress of crystal nucleation, growth, and polymorphism and suggesting ways of selectively generating and controlling multilayers on liquid surfaces. Auxiliary molecules have been designed to selectively inhibit development of the polymorphs, leading primarily to a single phase monolayer.     

Evaluation of a technique to obtain development-stage-synchronised earthworms (Eisenia fetida )

 The aim of this experiment was to investigate whether Eisenia fetida hatchlings of different ages, kept initially without food, could be used to obtain worms of a comparable development stage (measured as growth) with similar maturation properties (measured as clitellum development). Seven groups of hatchlings, each differing in age by 7 days (range: 0–42 days) were collected as follows. Cocoons were kept in water in multicell containers and individuals that hatched during a 24-h period were placed on moist vermiculite with no food, at weekly intervals. The longest period that hatchlings were fasted was 42 days, after which food was added and growth monitored for 50 days. No differences in weight gain between the different batches were observed. Analysis of the growth curves and attainment of sexual maturity (clitellum development) indicated no effect of age or stage of development at the onset of feeding. It was concluded that this technique allows the production of cohorts of E. fetida, synchronised with respect to development stage, for use in toxicological and biological investigations that require control of factors such as development stage, age and size, and in particular for use in toxicological experiments complying with OECD regulatory procedures. Received: 16 June 1997     

Effect of body condition score and reuse of progesterone‐releasing intravaginal devices on conception rate following timed artificial insemination in Nelore cows

This study had the aim of investigating the efficiency of timed artificial insemination (TAI) through the progesterone‐releasing intravaginal device (PRID), used in new condition and for the second and third times in Nelore cows. The effects of device reuse and body condition score (BCS) on the conception rate (CR) were evaluated in 1,122 multiparous Nelore cows (mean BCS of 2.7 ± 0.4), which were randomly distributed into three groups that received new (n = 330), once (n = 439) and twice used (n = 353) PRID. Among the 1,122 females that underwent TAI, 573 became pregnant, thus representing an overall CR of 51.06%. Cows with BCS between 2.75 and 4.0 had greater (p < .0001) CR (69.75%) than cows with BSC of 2.0–2.5 (32.98%). It was observed that the CR through using PRID was 60.00%, 51.71% and 41.93% for new, once and twice used PRID, respectively, with difference between all groups (p < .0001). Under tropical conditions, animals with BCS greater than 2.5 had a higher CR, and the CR decreased proportionally with the number of times that the PRID had been used.