Immunohistochemical determination of the expression of endothelin receptors in bronchial smooth muscle and epithelium of healthy horses and horses affected by summer pasture-associated obstructive pulmonary disease

OBJECTIVE: To immunohistochemically determine the expression of endothelin (ET) receptors in bronchial smooth muscle and epithelium of healthy horses and horses affected by summer pasture-associated obstructive pulmonary disease (SPAOPD). SAMPLE POPULATION: Tissue specimens obtained from 8 healthy and 8 SPAOPD-affected horses. PROCEDURE: Horses were examined and assigned to healthy and SPAOPD groups. Horses were then euthanatized, and tissue specimens containing bronchi of approximately 4 to 8 mm in diameter were immediately collected from all lung lobes, fixed in zinc-formalin solution for 12 hours, and embedded in paraffin. Polyclonal primary antibodies against ET-A or ET-B receptors at a dilution of 1:200 and biotinylated IgG secondary antibodies were applied to tissue sections, followed by the addition of an avidin-biotin immunoperoxidase complex. Photographs of the stained slides were digitally recorded and analyzed by use of image analysis software to determine the intensity of staining. Two-way ANOVA was used for statistical analysis. RESULTS: The left diaphragmatic lung lobe of SPAOPD-affected horses had a significantly greater area of bronchial smooth muscle that immunostained for ET-A, compared with that for healthy horses. All lung lobes of SPAOPD-affected horses, except for the right diaphragmatic lobe, had significantly greater staining for ET-B receptors in bronchial smooth muscle, compared with results for healthy horses. CONCLUSIONS AND CLINICAL RELEVANCE: This study revealed overexpression of ET-A and, in particular, ETB receptors in the bronchial smooth muscle of SPAOPD-affected horses, which suggested upregulation of these receptors. These findings improve our understanding of the role of ET-1 in the pathogenesis of SPAOPD.     

Chitosan associated with whole raw soybean in diets for Murrah buffaloes on ruminal fermentation,apparent digestibility and nutrients metabolism

This study aimed to investigate the effects of chitosan and whole raw soybean on nutrient intake, apparent digestibility, nitrogen utilization, microbial protein synthesis, blood metabolites, feeding behavior, ruminal fermentation, digesta kinetics, and reticular flow of nutrients of buffaloes. Four ruminally‐cannulated Murrah buffaloes (351 ± 15 kg of initial BW) were randomly assigned according to a 4 × 4 Latin square design. Treatments were arranged as 2 × 2 factorial arrangement: the first factor was whole raw soybean (WRS), and the second factor was chitosan (CHI) with or without their inclusion in diets. Intake and apparent digestibility of ether extract (p < .01; p = .04, respectively), non‐fiber carbohydrates intake (p = .03) and apparent ruminal digestibility of dry matter (p = .01) were affected by diets. An interaction effect or tendency was observed for microbial nitrogen (p = .09), concentrations, ruminal ammonia nitrogen (p = .05), total volatile fatty acid (p = .03). Association of chitosan with whole raw soybean has potential effects as a modulator of rumen fermentation; therefore, chitosan can be applied as an alternative non‐ionophore for Murrah buffaloes.     

Sodium hydroxide or urea pretreatment of acerola (Malpighia emarginata) fruit residue increases dry matter degradability and reduces methane production in in vitro rumen fermentation

Tropical Animal Health and Production - The aim of this study was to evaluate the effect of adding different concentrations of either urea or NaOH in dehydrated acerola (Malpighia emarginata) fruit...     

Serum lactoferrin and immunoglobulin G concentrations in healthy or ill neonatal foals and healthy adult horses

BACKGROUND: Lactoferrin is a colostral glycoprotein with antimicrobial properties. HYPOTHESES: (1) Serum lactoferrin and immunoglobulin G (IgG) concentrations are correlated and increase in healthy foals after ingestion of colostrum; (2) compared to healthy foals, ill foals will have lower lactoferrin concentrations that correlate with their IgG concentration, neutrophil count, the diagnosis of sepsis, and survival; and (3) plasma concentrations of lactoferrin will be less than serum concentrations. ANIMALS: Healthy foals (n = 16), mature horses (n = 10), and ill foals 1-4 days old (n = 111) that were examined for suspected sepsis were used for blood collection. Colostrum was obtained from 10 healthy mares unrelated to the foals. METHODS: Blood was obtained from the healthy foals at birth and 1-3 days of age and from the ill foals at admission. Serum IgG was quantified by single radial immunodiffusion (SRID). Lactoferrin concentrations in colostrum and blood were determined by an enzyme-linked immunosorbant assay. The sepsis score, blood culture results, neutrophil counts, and survival were obtained on ill foals. RESULTS: The mean colostral lactoferrin concentration was 21.7 microg/mL. Compared to values at birth, serum IgG (18+/-2 versus 2,921+/-245 mg/dL, SEM) and lactoferrin (249+/-39 versus 445+/-63 ng/mL, SEM) concentrations were significantly greater in healthy foals 1-3 days old. Serum lactoferrin concentration in 1-3-day-old healthy foals was not different from mature horses or ill foals. IgG and lactoferrin concentrations were significantly correlated only in healthy foals. Serum lactoferrin concentrations were significantly lower in ill neutropenic foals. The serum IgG concentration was significantly lower in ill foals as compared to healthy foals. Only serum IgG was significantly less in ill foals with a positive sepsis score and in nonsurvivors, Plasma lactoferrin concentrations were lower than serum concentrations, although values were significantly correlated. CLINICAL IMPORTANCE: Although both serum IgG and lactoferrin concentrations increase in healthy foals after ingestion of colostrum, only serum IgG is significantly correlated with the sepsis score and outcome.     

Physiologic responses and plasma endothelin-1 concentrations associated with abrupt cessation of nitric oxide inhalation in isoflurane-anesthetized horses

OBJECTIVE: To assess physiologic responses and plasma endothelin (ET)-1 concentrations associated with abrupt cessation of nitric oxide (NO) inhalation in isoflurane-anesthetized horses. ANIMALS: 6 healthy adult Standardbreds. PROCEDURES: Horses were anesthetized with isoflurane in oxygen and placed in dorsal recumbency. Nitric oxide was pulsed into the respiratory tract for 2.5 hours, and then administration was abruptly discontinued. Just prior to commencement and at cessation of NO administration, and at intervals during a 30-minute period following cessation of NO inhalation, several variables including PaO(2), mean pulmonary artery pressure, venous admixture or pulmonary shunt fraction (Qs/Qt), and plasma ET-1 concentration were recorded or calculated. RESULTS: After cessation of NO inhalation, PaO(2) decreased slowly but significantly (172.7 +/- 29.8 mm Hg to 84.6 +/- 10.9 mm Hg) and Qs/Qt increased slowly but significantly (25 +/- 2% to 40 +/- 3%) over a 30-minute period. Mean pulmonary artery pressure increased slightly (14.0 +/- 1.3 mm Hg to 16.8 +/- 1 mm Hg) over the same time period. No change in serum ET-1 concentration was detected, and other variables did not change or underwent minor changes. CONCLUSIONS AND CLINICAL RELEVANCE: The improvement in arterial oxygenation during pulsed inhalation of NO to healthy isoflurane-anesthetized horses decreased only gradually during a 30-minute period following cessation of NO inhalation, and serum ET-1 concentration was not affected. Because a rapid rebound response did not develop, inhalation of NO might be clinically useful in the treatment of hypoxemia in healthy isoflurane-anesthetized horses.     

Antipredator responses to overhead fright stimuli in hatchery-reared and wild European sea bass (Dicentrarchus labrax L.) juveniles

In this study, shoals of hatchery‐reared and wild sea bass juveniles (Dicentrarchus labrax L.) were tested for differences in their antipredator responses towards a visual (shadow) and a mechanical (dummy bill) overhead stimulus. Two behavioural variables – distance from the bottom and freezing duration – were measured during post‐stimulus phases of each test and compared between wild and hatchery‐reared shoals, composed of 10 juveniles each. The results showed that in both hatchery‐reared and wild juveniles, stimulus exposure elicited a significant decrease in the mean shoal distance from the bottom. Similarly, individuals from both groups engaged a freezing reaction, but the mean freezing duration was significantly higher in wild‐ than in hatchery‐reared juveniles. Results are discussed in the light of their relevance for the enhancement of restocking programmes.     

Anti-Mullerian hormone and its relationship to ovulation response and fertility in timed AI Bos indicus heifers

This study evaluated the association between plasma anti-Mullerian hormone (AMH) concentration and fertility in Nelore (Bos indicus) heifers submitted to timed artificial insemination (TAI). At the onset of the synchronization protocol, heifers (n = 289) received a subcutaneous P4 ear implant (3 mg) and 2 mg of oestradiol benzoate. Eight days later, the P4 implant was removed and 0.5 mg of oestradiol cypionate, prostaglandin (0.265 mg, i.m.) and equine chorionic gonadotropin (300 UI, i.m.) was administered, and TAI was performed 48 hr after ear implant removal. Ovarian ultrasound evaluations were performed to measure number of ovarian follicles, dominant follicle size and ovulation response. Pregnancy diagnosis was performed by ultrasound 30 days after AI. Heifers with greater circulating AMH had more antral follicles, a smaller dominant follicle near timed ovulation and lower ovulation response to the timed AI protocol compared to heifers with lower circulating AMH. Although AMH and pregnancy outcome had a quadratic-shaped pattern, AMH was not significantly associated with fertility. In conclusion, heifers with lower AMH had larger follicles towards the end of the synchronization protocol and greater ovulation responses, whereas greater circulating AMH was unrelated to conception success.     

Sound features and vocal rhythms as a proxy for locating the spawning ground of Sciaena umbra in the wild

• 1. The brown meagre (Sciaena umbra) is a demersal sciaenid fish recognized as indicative of good environmental quality and is defined as an umbrella species for the ecological community of rocky coastal habitats. Sciaena umbra is classified as a Vulnerable fish species by the International Union for Conservation of Nature (IUCN) and knowledge on the distribution of its spawning habitats is essential for its conservation.
• 2. Passive acoustic monitoring (PAM) is a suitable tool to monitor S. umbra distribution because of the high consistency, over space and time, of the communication sounds that this species emits during the reproductive period, with irregular or regular rhythms, or with calls merging into a chorus.
• 3. During the summer of 2019, the presence of this species was investigated acoustically at 40 listening points distributed along the tidal inlets that connect the Venice lagoon with the open sea.
• 4. Longer sounds, comprising a higher number of faster repeated pulses, were found during the chorus and were used as a proxy of spawning activity; similar sound features have been recorded in different captive Sciaenids during spawning.
• 5. The three inlets were classified as more or less suitable for spawning on the basis of the vocal rhythms identified, demonstrating a clear preference along a north–south gradient and indicating higher spawning activity in the internal‐facing areas of the inlets, compared with the seaward‐facing areas. The chorus occurred in localized areas consistently throughout the breeding season, suggesting that spawning is concentrated in preferred areas.
• 6. For the first time a relationship between the sound features and vocal rhythms of fish has been highlighted by an in situ study. This validates the use of the chorus as a reliable natural indicator of S. umbra breeding sites, and in turn suggests a potential non‐invasive approach based on PAM for mapping the key reproductive areas of this vulnerable species in the Mediterranean Sea.