Ovarian activity in F1 prepubertal ewe lambs under tropical conditions

Seventy crossbred ewe lambs, born from Pelibuey (PB) dams mated with five sire breeds: White Dorper × PB (WD × PB), Black Head Dorper × PB (BHD × PB), Ile de France × PB (Ile × PB) Katahdin × PB (KT × PB) and Pelibuey (PB × PB), were used to determine age and weight to puberty, follicular populations during prepubertal development, ovulation rate at first ovulation and function of the first corpus luteum (FCL). Ewe lambs were maintained under grazing conditions and were supplemented with 300 g head^− 1 day^− 1 of a concentrate with 14% CP and 3.0 Mcal ME kg^− 1 of DM. From 145 days of age, monthly observations were performed by endoscopy to monitor follicular populations and luteal structures. Ovarian follicles were classified according to size into small (≥ 1 and < 3 mm), medium (≥ 3 and ≤ 4 mm) and large (> 4 mm). Additionally, weekly observations by ultrasonography were performed in four ewes per genotype to assess follicular populations. Luteal function from first ovulation was determined by circulating concentrations of progesterone. Ovulation rate was not affected by genotype (P > 0.05). All breed groups had the same pattern of follicular populations, where most of follicles were small, followed by medium and a small proportion of large follicles. Maximum diameter of follicles was similar for all genotypes during prepubertal development (P > 0.05), with an average range of 3.9 ± 0.20 to 4.4 ± 0.20 mm. The BHD × PB reached puberty at the youngest age of 240.9 ± 13.0 days, compared to all other genotypes (P < 0.05), 259.1 ± 11.7 for WD × PB, 279.3 ± 9.6 for KT × PB and 289.0 ± 15.3 days for PB × PB and 308.6 ± 11.9 days for Ile × PB ewe lambs. Ile × PB had greater weight to first ovulation (31.5 ± 1.19 kg) as compared to other breed groups (P < 0.01). The largest percentage of FCL was for KT × PB ewes (100%) (P < 0.05), followed by BHD × PB (88.9%), PB × PB (83.3), WD × PB (78.6%) and Ile × PB (77.8%). There were no differences in ovulation rate attributable to type of lambing from which ewe lambs came from (P > 0.05). BHD × PB ewe lambs reached puberty at an earlier age than other in this study. KT × PB ewe lambs had the highest percentage of FCL in their first ovulation. Breed of sire Ile de France increased weight to puberty and decreased FCL at first ovulation. In conclusion, the BHD × PB ewe showed puberty at an earlier age than other genotypes, while the KT × PB had the highest percentage of functional corpus luteum in their first ovulation. Ewe lambs coming from single lambings reach puberty at a heavier weight than those coming from multiple lambings. The ovulation rate in the first ovulation of ewe lambs is not affected by genotype and type of lambing.     

The expression of histamine H4 receptor mRNA in the skin and other tissues of normal dogs

The histamine 4 (H₄) receptor was first cloned and characterized in 2000 using the human H₃ receptor DNA sequence. The H₄ receptor has been shown to participate in various aspects of inflammation, such as chemotaxis, upregulation of adhesion molecule expression and modulation of cytokine secretion. The primary goal of this study was to determine whether H₄ receptor mRNA is expressed in normal canine skin by performing an RT‐PCR. An additional goal was to determine the expression of this receptor in the colon, liver, spleen and kidney. Tissues were collected from five healthy, young‐adult pit bull dogs. Samples were immediately placed in RNAlater^® solution and stored at ?20°C until processed. The amplified products in all skin samples in addition to the colon, liver, spleen and kidney (variable expression) had the expected size of 400–500 bp. The sequenced amplicons matched the National Center for Biotechnology Information published sequence for the canine H₄ receptor. The study results showed that canine normal skin expresses the H₄ receptor mRNA. Further studies using immunohistochemistry should be conducted to demonstrate the expression of the H₄ receptor at the protein level and to localize the expression of this receptor in the skin.     

Reduction in the mRNA expression of sVEGFR1 and sVEGFR2 is associated with the selection of dominant follicle in cows

The vascular endothelial growth factor (VEGF) is essential for follicular development by promoting follicular angiogenesis, as well as for the proliferation and survival of granulosa cells. The biological effects of VEGF are regulated by two membrane receptors, VEGFR1 and VEGFR2, and two soluble receptors, sVEGFR1 and sVEGFR2, which play an antagonistic role. Thus, the objective of this study was to identify the mRNA expression pattern of total VEGF, VEGFR1, VEGFR2, sVEGFR1 and sVEGFR2 in bovine preselected follicles (PRF) and post‐selected follicles (POF). The mRNA expression of these five genes in both granulosa cells (GC) and theca cells (TC) was compared between follicles classified as PRF and POF based on their diameter and on their ratio of estradiol/progesterone (E2/P4). Results showed a lower expression of mRNA of sVEGFR1 and sVEGFR2 in POF than in PRF (p < .05). Regarding the mRNA expression of total VEGF, VEGFR1 and VEGFR2, there was no difference between POF and PRF follicles (p > .05). Our results showed that the mRNA expression of VEGFR2 and sVEGFR1 was more abundant than the expression of VEGFR1 and sVEGFR2, while GC was the main source of mRNA for total VEGF. On the other hand, TC was the follicular compartment where the receptors were most expressed. Our results suggest that non‐dominant follicles maintain a greater concentration of the mRNA expression of both membrane and soluble VEGF receptors. On the other hand, follicular dominance is related to a reduction in the mRNA expression of sVEGFR1 and sVEGFR2, which may favour VEGF binding with VEGFR2 and, hence, improve the follicular health and development.     

Effect of sodium bisulfate on skin and hooves of horses

OBJECTIVE: To evaluate the safety of sodium bisulfate for use in horse barn environments by determining its irritant effect on skin and hooves. ANIMALS: 6 female mixed-breed ponies. PROCEDURE: Sodium bisulfate was applied to clipped intact skin of 6 ponies to evaluate its irritant effect after single (48 hours) and repetitive (6 h/d for 10 days) applications; similar areas of skin were used as untreated control sites. In addition, sodium bisulfate was applied to the sole of both front hooves of each pony and covered with wet gauze, and the entire hoof was covered with adhesive tape for 48 hours. RESULTS: Contact with moistened sodium bisulfate for 48 hours had no effect on pony skin. Contact with sodium bisulfate for 6 hours on 10 consecutive days did not cause gross changes but did cause mild to moderate microscopic changes including epidermal necrosis, hyperkeratosis, capillary congestion, edema, and diffuse mixed inflammatory cell infiltrate. All changes were limited to the epidermis and superficial dermis. Gross changes in hoof sole, signs of lameness, and increase in digital pulse pressure or pulse intensity were not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Duration of contact with sodium bisulfate in this study was in excess of that expected under typical husbandry conditions. Despite this fact, gross changes in skin and hooves were not detected. Microscopic lesions were confined to the epidermis and superficial dermis. Results suggest that contact with sodium bisulfate under these conditions is safe.     

Detection of genes encoding virulence factors and bacteriocins in fecal enterococci of poultry in Portugal

Seventy-six Enterococcus isolates (43 E. faecalis, 30 E. faecium, two E. durans, and one E. hirae) recovered from fecal samples of poultry in a slaughterhouse (one isolate per fecal sample and one fecal sample per lot of animals) were studied for bacteriocin production and for the presence of genes encoding bacteriocins and virulence factors. The presence of genes encoding virulence factors (cpd, geE, fsr, ace, agg, and esp) and bacteriocins (entA, entB, entP, entQ, entAS-48, entL50A/B, cyl, and bac31) were studied by polymerase chain reaction in all enterococci. At least two virulence genes were detected in all 43 E. faecalis isolates, cpd and gelE being the most frequently detected genes (97.7%) followed by ace (62.8%), agg (39.5%), fsr (27.9%), and esp (2.3%). No virulence genes were detected in the other enterococcal species with the exception of one E. faecium and one E. durans isolates that harbored the gelE gene. Antimicrobial activity against eight indicator bacteria (including Listeria monocytogenes) was assayed in the enterococci, and 23 (30.3%) showed inhibitory activity against L. monocytogenes, the other 22 enterococci showing activity against indicator bacteria other than L. monocytogenes. Only the entA, entB, and cyl genes were detected in our study (entA + entB in nine E. faecium isolates and the cyl gene in seven E. faecalis isolates). A wide variety of virulence genes have been detected in fecal E. faecalis isolates from poultry, but not in the other enterococcal species. However, the presence of known bacteriocin structural genes is associated more with the E. faecium species.     

Search for <Emphasis Type="Italic">Salmonella</Emphasis> spp. in ostrich productive chain of Brazilian southeast region

We analyzed ostriches from an equipped farm located in the Brazilian southeast region for the presence of Salmonella spp. This bacterium was investigated in 80 samples of ostrich droppings, 90 eggs, 30 samples of feed and 30 samples of droppings from rodents. Additionally, at slaughter-house this bacterium was investigated in droppings, caecal content, spleen, liver and carcasses from 90 slaughtered ostriches from the studied farm. Also, blood serum of those animals were harvested and submitted to serum plate agglutination using commercial Salmonella Pullorum antigen. No Salmonella spp. was detected in any eggs, caecal content, liver, spleen, carcass and droppings from ostriches and rodents. However, Salmonella Javiana and Salmonella enterica subsp. enterica 4, 12: i:- were isolated from some samples of feed. The serologic test was negative for all samples. Good sanitary farming management and the application of HACCP principles and GMP during the slaughtering process could explain the absence of Salmonella spp. in the tested samples.     

Grassland responses to grazing disturbance: plant diversity changes with grazing intensity in a desert steppe

This study quantifies the impact of four different grazing regimes (heavy, moderate, light and ungrazed) on the vegetation dynamics of rangeland ecosystems along the southern boundary area of the Mu Us Desert, China. As the grazing intensities decreased, the soil quality, canopy cover, height, density, above‐ and below‐ground biomass, litter, root/shoot ratio and native plant (Aneurolepidium dasystachys) and grass abundances significantly increased; the above‐ground biomass of grasses increased, but the above‐ground biomass of forbs decreased. Ungrazed grassland has significantly improved from grasslands experiencing three other levels of grazing pressure, especially in the grassland biomass. Species richness increased as the grazing intensity decreased in the grazing grasslands, but peak species richness appeared under moderate and light grazing against lower productivity. Grazing exclusion causes desirable transitions in plant communities of desert steppe rangelands. Therefore, appropriate and efficient grazing exclusion is an available way to counteract local grassland degradation and promote rangeland sustainability.     

Pleuroscopic diagnosis of gastroesophageal squamous cell carcinoma in a horse

A 15-year-old Quarter Horse gelding was examined because of chronic intermittent colic of 40 days' duration. The clinical signs included acute onset of depression, ptyalism, abdominal splinting, and rolling within an hour of eating. An intramural mass of the esophagus was identified during esophagoscopy. A large soft-tissue density surrounding the distal portion of the esophagus, creating a stricture, was identified on an esophagogram. With the horse slightly sedated, pleuroscopy was performed, allowing direct visualization and biopsy of the mass. The histopathologic diagnosis was squamous cell carcinoma.     

Bighorn sheep habitat use and selection near an urban environment

To further understand the impact of urban development on wildlife populations, we examined habitat use and selection by female bighorn sheep Ovis canadensis in two endangered subpopulations near a metropolitan area in southern California. One subpopulation, which had previously been found to have low reproductive success, selected urban environments while the other did not use urban areas. In the subpopulation that used urban areas, females had smaller core activity areas and selected lower elevations and gentler slopes. These females used urban sources of water but a clear relationship between levels of urban use and periods of increased water need was not evident. Diet quality was higher among females that selected urban areas, and this increase was correlated with the level of urban use. Thus, optimal foraging behavior may have contributed to the selection of urban areas. Urban use was lowest during peak months of parturition, suggesting that reproductive strategies may also have influenced temporal patterns of urban use. Although urban areas provided bighorn sheep with forage and water resources, the use of these areas may have substantial costs. For example, females using urban areas had internal parasites that were not found elsewhere in the Peninsular Ranges.