The absence of neuromas in beaks of adult hens after conservative trimming at hatch

Objective To determine the effects of the amount of beak removed and cauterisation time on neuroma formation in hens.
Design A pathology study with controls.
Animals Twenty domestic fowl were beak-trimmed. Three non-beak-trimmed domestic fowl were used as controls.
Procedure Beaks of two age groups with two levels of beak removal and either 2 s or 4 s cauterisation, were investigated macroscopically and microscopically for deformities.
Results Scattered trauma-associated neuromas were present in the beaks of pullets 10 weeks after moderate trimming at hatch. Neuromas were not present in beaks of adult hens that had been similarly trimmed. Sensory corpuscles were present 10 and 70 weeks after moderate trimming, though fewer in number than in intact control hens. In contrast, trauma-associated neuromas persisted in beaks of 70-week-old hens that had been severely trimmed at hatch. A range of deformities that were absent in moderately trimmed hens, were observed in hens with severely trimmed beaks. Receptors were not seen in severely trimmed beaks.
Conclusion Beak-trimming at hatch induces the formation of neuromas, regardless of the amount of tissue removed. There is a critical amount of beak tissue that can be removed, beyond which trauma-associated neuromas will not resolve, but will persist in mature hens.     

Nitric Oxide and Superoxide Anion Production During Heparin‐Induced Capacitation in Cryopreserved Bovine Spermatozoa

The aim of this work was to quantify NO, O₂^? and ONOO^? production during heparin‐induced capacitation of cryopreserved bovine spermatozoa. A time dependent hyperbolic increase was observed for heparin‐dependent capacitation, O₂ uptake, and NO production. Conversely, O₂^? production was increased during the first 15 min of incubation, showing a decrease from this time until 45 min. At 15 min of heparin incubation, a threefold increase in O₂ consumption (5.9 ± 0.6 nmol/min × 10⁷ cells), an enhancement in NO release (1.1 ± 0.2 nmol/min × 10⁷ cells), and a five‐fold increase in O₂^? production (1.3 ± 0.07 nmol/min × 10⁷ cells), were observed. Peroxynitrite production rate was estimated taking into account NO and O₂^? generation and the second‐order rate constant of the reaction between these species. To conclude, heparin‐induced capacitation of cryopreserved bovine spermatozoa activates (i) mitochondrial O₂ uptake by high ADP levels due to increased energy requirements, (ii) NO production by a constitutive NOS and (iii) O₂^? production by a membrane‐bound NAD(P)H oxidase. The products of both enzymes are released to the extracellular space and could be involved in the process of sperm capacitation.     

Interactive effects of co-inoculation of Bradyrhizobium japonicum strains and mycorrhiza species on soybean growth and nutrient contents in plant

The main objective of this study was to investigate the effects of co-inoculation with different strains of Bradyrhizobium japonicum (i.e. Helinitro, Rizoking, and Nitragin) and arbuscular mycorrhizal fungi (AMF) species (i.e. Glomus fasciculatum, Glomus versiforme, Glomus intraradices, Glomus mosseae, and Glomus etunicatum) on soybean growth, fungal root colonization, and nutrient uptake of nitrogen (N), phosphorus (P), zinc (Zn), iron (Fe), and copper (Cu). Co-inoculation with various AMF species and rhizobia significantly (p<0.01) increased the soybean biomass production as compared to the non-inoculated controls. Furthermore, AMF colonization of roots of soybean plants increased by 79, 70.1, 67, 63, 57.5, and 50.1% in the presence of G. fasciculatum (GF), G. versiforme (GV), G. intraradices (GI), G. mosseae (GM), and G. etunicatum (GE), and Gmix (a mixed culture of fungi), respectively. Higher nutrient contents were observed in plants co-inoculated with Helinitro and GF. More insight into these results will enable optimization of the effective use of AM fungi in combination with their bacterial partners as a tool for increasing soybean yields in Iran; however, its general analytical framework could be applied to other parts of the world.     

Influences of Follicular Size on Parthenogenetic Activation and in Vitro Heat Shock on the Cytoskeleton in Cattle Oocytes

The availability of cow ovaries from the slaughterhouse has been very limited in Taiwan. To maximize the use of cow ovaries for research purposes, whole ovary dissection was performed and the developmental competence of the oocytes derived from different sizes of follicles was assessed by the rates of in vitro maturation (IVM) and parthenogenetic activation of the oocytes in Experiment 1 (Exp 1). Cumulus-oocyte complexes (COCs) derived from small (1-2 mm) and large (3-8 mm) follicles were subjected to standard IVM culture for 24 h. Mature oocytes were selected and then parthenogenetically activated using A23187 (5 microm, 5 min) or thimerosal (200 microm, 10 min) alone or combined with 6-dimethylaminopurine (2.5 mm and 3.5 h, respectively). Activation rates of the oocytes, neither from the large nor small follicles, were affected by different activation treatments (single or combined stimuli). Whereas maturation rates for the oocytes from large follicles were superior to those from small follicles in both the single (59% vs 45%) and combined treatments (76% vs 40%; p < 0.05). To understand how prolonged heat shock (HS) influences cytoskeletal configurations of mature bovine oocytes, in Experiment 2 (Exp 2), matured oocytes derived from large follicles were randomly allocated to different durations of HS treatments at 41.5 degrees C for 0 (C0h, control, n = 12), 1 (HS1h, n = 28), 2 (HS2h, n = 31), and 4 h (HS4h, n = 30). An additional control group was cultured for 4 h without HS (38.5 degrees C, 4 h, n = 35). Alterations in nuclear structures, microtubules (MTs), and microfilaments (MFs) of the oocytes were examined. Abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with cytoplasmic MTs increased with time of HS treatment. The intensity of the MF distribution in the HS oocytes was also altered. Significant changes in the cytoskeleton after HS may be associated with the reduced development under hyperthermia and, perhaps, with the low pregnancy rates of the animals during hot seasons.     

Characterization and Localization of Membrane Vesicles in Ejaculate Fractions from the Ram, Boar and Stallion

Membrane vesicles, separated by differential centrifugation from the seminal plasma, were detected in the sperm-rich ejaculate fractions of four boars and three stallions, and in the whole ejaculates of seven rams. The volume and percentage of vesicles, determined by a stereological technique, were higher in the sperm-rich than in the post-sperm-rich fractions of the boar and stallion ejaculates, and no vesicles were detected in the pre sperm-rich fractions. Vesicles were examined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). For boar, stallion and ram semen, the mean (+/- s.e.m.) vesicle diameters were 130.9 +/- 3.22 (range 18-577), 164.1 +/- 4.42 (range 15-671) and 159.7 +/- 2.92 nm (range 22-986), respectively, although they were not significantly different (p = 0.709). The vesicles had approximately round (TEM) or spherical shape (SEM), were surrounded by single, double or multi-laminar membranes, and were trapped within ample amorphous material, sometimes containing short, flattened membranous elements. The majority of the vesicles had a clear interior but some contained granule-dense material. Ram membrane vesicles, purified from ultracentrifuged plasma by size exclusion chromatography, kept their round shape and the amorphous material was less evident compared with the sections taken before purification. This is the first report to identify seminal plasma membrane vesicles in the different fractions of ejaculated semen in the boar and stallion, and confirms their presence in ram seminal plasma. The origin and function of these vesicles are yet to be elucidated.     

Synchrony of Ovulation and Follicular Dynamics in Merino Ewes Treated with GnRH in the Breeding and Non-breeding Seasons

The effect of gonadotropin releasing hormone (GnRH) treatment on the time of ovulation and the occurrence of follicular dominance during the non-breeding and breeding seasons (experiment 1), and on fertility after artificial insemination (AI) in the non-breeding season (experiment 2), was examined in Merino ewes. Oestrus was synchronized in 40 nulliparous ewes (experiment 1; n = 20, in the non-breeding and breeding seasons) and in 79 multiparous ewes (experiment 2) using intravaginal sponges and pregnant mare serum gonadotropin. Thirty six hours after sponge removal (SR), half the ewes were injected (i.m.) with 40 microg of synthetic GnRH and the remainder used as controls. GnRH improved the synchrony of ovulation compared with the controls in the breeding (SD = 2.8 vs 5.7 days, p = 0.04) but not the non-breeding season (SD = 3.8 vs 4.4 days, p = 0.69), with ewes ovulating from 42 to 54 h (mean 50.4 +/- 4.08 h) and 42-60 h (mean 54.4 +/- 5.47 h) after SR for GnRH and control, respectively. For both treated and control ewes, ovulation occurred earlier in the non-breeding than the breeding season (50.1 vs 54.6 h; p = 0.002). GnRH had no effect on follicular dominance, as assessed by divergence (D: the time the ovulatory follicle exceeded the average size of the other non-ovulating follicles) or on the interval from D to ovulation (IDO). However, follicular dynamics differed between seasons. The mean follicle diameter increased at a faster rate up to 36 h after SR in the non-breeding compared with the breeding season and then rapidly declined, compared with a later peak (42 h after SR) in mean follicular size during the breeding season. IDO was shorter in the non-breeding than in the breeding season (26.7 +/- 4.30 h vs 39.6 +/- 4.53 h; p = 0.05). In experiment 2, ewes (n = 38 GnRH-treated, n = 40 controls) were inseminated in the uterus by laparoscopy 42 h or 48 h after SR with frozen-thawed sperm. The fertility of ewes treated with GnRH (nine of 39, 23%) was not different to the controls (eight of 38, 21%; p = 0.01). In conclusion the application of GnRH improved synchronization of ovulation but did not improve fertility rates after AI.     

Brain damage in sheep from penetrating captive bolt stunning

Objective To determine the severity and distribution of structural changes in the brains of adult sheep stunned by penetrating captive bolt.
Procedure The unconstrained heads of ten, anaesthetised, unhorned, 2-year-old Merino sheep were impacted at the summit of the head with a penetrating captive bolt pistol. Six sheep were ventilated and four received no respiratory support. Two hours after impact, brains from the six ventilated sheep were perfusion-fixed with 4% paraformaldehyde. Sixteen whole, serial coronal sections from each brain were stained with haematoxylin and eosin and immunohistochemi-cally for amyloid precursor protein, a sensitive marker of axonal and neuronal reaction in the brain after trauma. Pathological changes in these brains were then quantified by morphometric analysis.
Results Structural change in all impacted brains was a mixture of focal injury around the wound track and more widely distributed damage in the cerebral hemispheres, cerebellum and brainstem, but varied considerably in severity between individual sheep. All nonventilated sheep died rapidly following respiratory arrest.
Conclusions After penetrating captive bolt stunning, damage to the central reticular formation, axonal connections, and the cortical mantle is the likely reason for failure of respiratory control and traumatic loss of consciousness.