Nutritive value of triticale fed to cockerels and chicks

1. The chemical composition, and amino acid and starch bioavailabilities of 18 triticale varieties were studied. In addition, the water soluble pentosan (WSP) content of 8 varieties was determined.

2. A wide variation in protein (149 to 203 g/kg DM), starch (563 to 629 g/kg DM) and WSP (27·7 to 50·9 g/kg DM) was found between varieties.

3. The TMEn reproductibility was assessed in two laboratories, using Leghorn cockerels, Isabrown cockerels and 3‐week‐old chicks. There were no sismificant differences in the TMEn values (range 14·0 to 15·2 MJ/kg DM) between the two types of cockerel. The TMEn values of the varieties were similar for chicks (range 13·6 to 14·9 MJ/kg DM) and for cockerels, with the exception of one variety.

4. The bioavailability of starch (range 96·5 to 99·4%) of some varieties was higher for cockerels than for chicks. The mean bioavailability of amino acids for cockerels was 94·5%.

5. TMEn prediction equations were derived from the chemical composition of the varieties. Best‐fit equations were obtained for starch (R ² = 0·62, RSD = 0·24), ash (R ² = 0·58, RSD = 0·25) and WSP (R ² = 0·52, RSD = 0·27).     

Elevated α-esterase levels associated with permethrin tolerance in Aedes aegypti (L.) from Baja California, Mexico

A discriminating dose for permethrin for Aedes aegypti from Baja California, Mexico was determined, and was used to select individuals. Mosquitoes were collected from four different municipalities located in the north and south end of the Baja California Peninsula. Individuals were chosen for further study based on their similar response to the insecticide. We exposed 10 groups of 90 Ae. aegypti females to the discriminating dose (172 μg/ml) and after producing 50% mortality, individuals were divided into two categories: killed and survivors. Each of these groups was dissected to separate the head, thorax, and abdomen. Biochemical tests were performed on the head and thorax to determine resistance-related enzyme activities including: α- and β-esterases, glutathione S-transferase, acetyl cholinesterase, insensitive acetyl cholinesterase, and mixed-function oxidases. The results were compared with those for the susceptible New Orleans strain of Ae. aegypti. All the populations studied showed the consistent presence of α-esterases, with elevated levels in permethrin-selected populations. Although β-esterases and GST levels were present in high proportions, they did not reveal a clear pattern in relation to resistance.     

Effect of Particle Size and Moisture Content on Viscosity of Fish Feed

A model was developed for the influence of particle size on the extrusion of a fish feed and the physical characteristics of the extrudates evaluated. The study was conducted using factorial experiments in a fractional replication design for four variables with three levels, and one‐third of the replicates (3⁴ factorial in 27 units) were examined in a laboratory extruder. The torque‐screw speed measurement was used to develop a viscosity model equation that considered different shear rates, product temperature, initial moisture content, and particle size. When particle size decreased, the apparent viscosity became smaller. The barrel pressure was important in producing extrudate with a uniform volume over the range of processing conditions tested because it had a strong correlation with the volumetric expansion. The material with lower moisture and larger particles caused the specific mechanical energy to increase. The viscosity model developed in this study can be applied to the development of large‐scale extrusion models that determine the effect of particle size on the feed material extrudates.     

Science,capacity building and conservation knowledge: The empowerment of the local community for marine conservation in Rapa Nui

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Muscular and collagenous cerebellar choristoma in a dog

This report aims to describe the first case of muscular and collagenous choristoma in a dog. A 10-yr-old female mixed-breed dog presented with lateral recumbence, vocalization, positional vertical nystagmus, divergent strabismus, anisocoria, and status epilepticus. The clinical condition evolved to stupor and ultimately, death. Necropsy revealed a white mass causing an irregular increase in the volume of the cerebellar vermis. In histological analysis, a well circumscribed, unencapsulated mass was observed in the cerebellum, consisting of fibers of striated skeletal muscle and collagen fibers, mostly mineralized. Based on the histopathological and histochemical findings, a diagnosis of muscular and collagenous cerebellar choristoma was made.     

Endometrial Expression of IFNAR‐1 and Oxytocin Receptor (OTR) is not Improved by Prostaglandin Analogues when Compared to Progestagens in Ewes

The objective of this study was to investigate differences on the endometrial immunoexpression of type I IFN receptor subunit 1 (IFNAR1) and oxytocin receptor (OTR) during the time of maternal recognition of pregnancy in sheep, when oestrus is synchronized with either prostaglandin analogues (group PG) or conventional progestagens (group P). Plasma progesterone was measured from day 0 to 21 post‐coitus (pc) (day 0 = day of oestrus). Immunohistochemistry was performed in samples of uterine horns from pregnant sheep on days 9pc, 13pc, 15pc, 17pc and 21pc to locate IFNAR1 and OTR expression in different endometrial compartments. Mean levels of plasma progesterone were different between treatments, obtaining higher levels in the PG group than in the P group (p < 0.05). Comparing days of pregnancy, IFNAR1 protein expression was different in the luminal epithelium (LE) (p < 0.05), while OTR was different in the LE and in the superficial glandular epithelium (SG) (p < 0.05). Temporal variation on the expression of both proteins from day 9pc to 21pc has been evidenced. IFNAR1 and OTR expression did not show significant differences between treatments. However, the response observed in the endometrium was highly inconsistent when prostaglandin analogues were used. Therefore, the protocol based on prostaglandin analogues still needs to be optimized before being considered as a better alternative to progestagens for oestrous synchronization in sheep.     

Spores of Ascosphaera apis contained in wax foundation can infect honeybee brood

Chalkbrood disease in honeybees (Apis mellifera L.) is caused by an infection with Ascosphaera apis. Disease expression requires the consumption of fungal spores and a predisposing condition in the susceptible brood. A. apis spores within sheets of wax foundation could be a source of inoculum leading to chalkbrood, but it is also possible that these spores remain confined in the wax and do not contribute to disease. We have resolved this topic by chilling susceptible brood within wax combs built on contaminated foundation (using treatments of spores from 1 mummy and spores from 10 mummies) versus uncontaminated foundation. We found significantly higher levels of chalkbrood in brood exposed to the higher dosage. Our results demonstrate that foundation wax contaminated with spores of A. apis spores may be a source of chalkbrood in honeybee colonies.     

Frequency and intensity of pyrethroid resistance through the CDC bottle bioassay and their association with the frequency of kdr mutations in Aedes aegypti (Diptera: Culicidae) from Mexico

BACKGROUND

The control of Aedes aegypti (L.), the main urban vector that causes arboviral diseases such as dengue, Chikungunya and Zika, has proved to be a challenge because of a rapid increase in insecticide resistance. Therefore, adequate monitoring of insecticide resistance is an essential element in the control of Ae. aegypti and the diseases it transmits. We estimated the frequency and intensity (Resistance Frequency Rapid Diagnostic Test [F‐RDT] and Resistance Intensity Rapid Diagnostic Test [I‐RDT]) of pyrethroid resistance in populations of Ae. aegypti from Mexico using the bottle bioassay and results were related to the frequencies of knockdown resistance (kdr) mutations V1016I and F1534C.

RESULTS

All populations under study were resistant to the pyrethroids: bifenthrin (99%), d‐(cis–trans)‐phenothrin (6.3% cis, 91.7% trans) and permethrin (99.5%) according to F‐RDT, and showed moderate to high‐intensity resistance at 10× the diagnostic dose (DD) in I‐RDT. Frequencies of the kdr mutation V1016I in Ae. aegypti populations were correlated with moderate permethrin resistance at 10× DD, whereas F1534C mutation frequencies were correlated with high bifenthrin resistance at 5× DD. Both I1016 and C1535 were highly correlated with high‐intensity phenothrin resistance at 1× to 10× DD.

CONCLUSIONS

This study showed that high frequencies of kdr mutations V1016I and F1534C are reflected in the results of F‐RDT and I‐RDT tests. Bioassays in conjunction with the characterization of genetic resistance mechanisms are indispensable in the strategic and rational management of resistance in mosquitoes. © 2018 Society of Chemical Industry