Canine pododermatitis and idiopathic disease

Pododermatitis is a common inflammatory skin disease of dogs. As pedal lesions are reported in many canine dermatoses, a methodical series of diagnostic tests is required to establish the underlying aetiology. However, laboratory/ancillary investigations may prove unrewarding, prompting a diagnosis of idiopathic disease. Various hypotheses have been proposed to explain the pathogenesis of idiopathic pododermatitis including pedal conformation, trauma, immunosuppression, bacterial infection, furunculosis and dermal granuloma formation. Idiopathic pododermatitis accounts for 0.5% of all dermatology referrals to the authors' clinic. A sub-group within this population is characterised histopathologically by epidermal hyperplasia, hyperkeratosis, spongiosis, dermal oedema and perivascular aggregates of lymphocytes and plasma cells. The term lymphocytic-plasmacytic pododermatitis (LPP) has previously been proposed to reflect the histological appearance of such lesions. Affected dogs, although systemically well, characteristically have pruritus, erythema, swelling, pain and alopecia of the feet. Although non-responsive to antimicrobial therapy, antiparasitic agents and elimination diets, these dogs typically respond well to immunomodulatory therapy.     

Salmonella in breeding pigs: Shedding pattern,transmission of infection and the role of environmental contamination in Irish commercial farrow‐to‐finish herds

This study aimed to provide new insights into the epidemiology of Salmonella in pig production, focusing on potential shedding patterns in breeding pigs throughout a full production cycle and the risk of transmission of infection from the sow to her offspring. A longitudinal study was conducted on five farrow‐to‐finish commercial pig farms. In each herd, shedding of Salmonella in faeces was monitored in breeders through service, gestation and lactation. Swabs of the farrowing room floor and pools of faeces from piglets were collected on two occasions during lactation. Environmental pen swabs were also taken in the weaning and finisher houses. Salmonella isolates were serotyped, tested for antimicrobial resistance (AMR) and typed by Multiple‐Locus Variable number tandem repeat Analysis (MLVA). Shedding by breeding pigs was low in all stages of the production cycle; 5% of sows shed at service, the production stage with highest risk of shedding (p < .01), 1.6% shed during gestation and 2.5% after farrowing. Salmonella was detected in 4% of piglet faecal pools in the second week post‐farrowing and 5% in the fourth week. Serotyping and AMR profiles of Salmonella isolates revealed that strains in sows and gilts were mostly different from strains isolated in weaner and finisher facilities. MLVA typing confirmed that the source of infection in piglets was in most instances the contaminated environment rather than their dam. Based on the typing results, it appears that sows do not pose a major risk in the maintenance and transmission of Salmonella to their progeny but instead the contaminated pen environment is more significant in the perpetuation of the organism on farm.     

Effects of acute environmental and handling exposure on physiology and fillet quality of market‐sized Channel Catfish

Catfish Ictalurus spp. are subjected to stressful conditions during harvest, which may be linked to fillet coloration and quality. Poor water quality in ponds, socks or hauling tanks, as well as handling stress, have been suggested to cause red fillets in catfish; however, chronic exposure has not resulted in red fillets. Short‐term occurrences of extreme poor water quality, particularly low dissolved oxygen, high carbon dioxide and high temperature, may occur in ponds or during harvest. Therefore, market‐sized Channel Catfish Ictalurus punctatus were acutely exposed (12 hr) to one of the three water quality treatments while confined during a simulated socking procedure and evaluated for stress responses by means of change in blood parameters and fillet quality. In fish subjected to the extreme treatment, hematocrit, plasma cortisol, glucose and lactate levels increased, with 22% mortality, indicating highly stressful conditions. In fish subjected to moderate and typical (control) treatments, cortisol increased but a lack of change or decrease in glucose and lactate indicated minimal anaerobic metabolism. Only one red fillet was produced by the extreme treatment and two by the typical treatment; therefore, the results suggest red fillets are not a product of poor water quality compounded by handling during harvest.     

Consistent responses of yield and resistance of wheat cultivars to the root-lesion nematode,Pratylenchus thornei,in the Australian northern subtropical region,but not in the temperate southern region

To understand the yield response of cereal cultivars to Pratylenchus thornei, eight experiments were conducted within the subtropical northern, and temperate southern grain-producing regions of Australia. Wheat cultivars (Triticum aestivum) ranging from susceptible to moderately resistant to P. thornei were grown in Year 1 to establish a range of population densities. In Year 2 before sowing, P. thornei was quantified in each plot and six cereal cultivars were each grown on a similar range of population densities (average minimum to maximum of 3.4–60.6 P. thornei/g soil); P. thornei was quantified again at harvest. In the four experiments in the northern region there was a significant, negative logarithmic response of yield of the three most intolerant/susceptible cultivars as P. thornei population densities increased (yield decreased 172–479 kg/ha per unit increase in log_e-transformed P. thornei/g soil). The responsiveness of yield to increasing P. thornei population densities diminished as the tolerance and resistance of the cultivars improved. In the southern region, there was no relationship between yield and P. thornei in three experiments and minor, positive increases in one experiment (1.6 kg/ha per unit increase in P. thornei/g soil). Across both regions, the change in P. thornei population densities from sowing to harvest was logarithmic and positive, and generally greatest in the northern region. The contrast of responses of cereal cultivars between the regions, despite similar population densities of P. thornei, is indicative of the influence of the environment particularly on tolerance, therefore management with a regional focus is essential.     

Effectiveness of GnRH plus prostaglandin F2alpha for estrus synchronization in cattle of Bos indicus breeding

Postpartum and lactating crossbred cows containing a percentage of Bos indicus breeding at three locations were studied to determine the efficacy of GnRH + PGF2alpha combinations for synchronization of estrus and(or) ovulation. Cows were equally distributed to each of three treatments by body condition score at the start of the experiment (d 0). All cows received 100 microg of GnRH on d 0 and 25 mg of PGF2alpha 7 d later. The three insemination protocols included 1) AI 12 h after exhibiting estrus during d 7 to 12 of the experiment (Select-Synch; n = 197); 2) timed-AI + 100 microg of GnRH on d 9 of the experiment (CO-Synch; n = 193); 3) AI 12 h after exhibiting estrus during d 7 to 10 of the experiment. Cows not exhibiting estrus by d 10 were timed-AI and injected with 100 microg of GnRH on d 10 of the experiment (Hybrid-Synch; n = 200). The percentage of cows exhibiting estrus during d 7 to 12 of the experiment was lower (P < 0.05) for CO-Synch (17.6%) cows than for Select-Synch or Hybrid-Synch (45.2 and 33.0%, respectively) cows, which did not differ (P > 0.05). For the Select-Synch and Hybrid-Synch cows that exhibited estrus during d 7 to 10 of the experiment and were artificially inseminated, conception rates were similar across treatments (50.5%). Pregnancy rates were greater (P < 0.01) for CO-Synch and Hybrid-Synch (31.0 and 35.5%, respectively) cows than for Select-Synch (20.8%) cows. A greater (P < 0.01) percentage of cycling cows became pregnant (34.5%) than noncycling cows (25.9%) across all treatments. The CO-Synch and Hybrid-Synch synchronization protocols resulted in greater pregnancy rates compared with the Select-Synch protocol in postpartum and lactating crossbred cows containing a percentage of Bos indicus breeding.     

饲料磷含量对黄颡鱼生长和磷代谢的影响

【目的】探讨饲料磷含量对黄颡鱼生长和磷代谢的影响。【方法】以磷酸二氢钙为磷源,制备磷含量分别为0.28%,0.46%,0.67%,0.89%,1.13%,1.38%和1.57%的7种精制试验饲料,用其饲养黄颡鱼(体质量(8.75±0.72)g/尾)8周,试验结束后取样,测定生长、饲料利用、钙磷代谢、肌肉营养成分和脊椎骨钙磷沉积等指标。【结果】饲料磷含量为0.67%组的平均增重率和特定生长率与0.46%组差异不显著,但显著高于其他各组(P0.05);当饲料磷含量为0.67%和0.89%时,饲料效率和蛋白效率显著高于其他各组(P0.05);当饲料磷含量为0.67%时,饲料蛋白质生产率显著高于除0.89%组以外的其他各组(P0.05)。血清降钙素随着饲料磷含量的升高先升高后降低(P0.05),在1.13%组时达到最高,显著高于除0.89%和1.38%组外的其他各组(P0.05);血清甲状旁腺素含量随饲料磷含量的升高呈先下降后上升的趋势,在1.13%组时降到最低。肌肉粗脂肪含量随饲料磷含量的升高而显著降低,而肌肉粗灰分含量则随饲料磷含量的升高而显著升高,在磷含量为1.13%时,肌肉粗脂肪含量显著低于0.28%,0.46%和0.67%各组(P0.05)。在磷含量为0.89%时,肌肉粗灰分含量与除0.28%组外的其他各组差异不显著。脊椎骨磷含量随饲料磷含量的升高呈先升高后降低的趋势,当饲料磷含量为1.13%时,脊椎骨磷含量最大,与除0.28%,0.46%和0.89%各组外的其他各组差异不显著。脊椎骨钙含量随饲料磷含量的升高亦呈现先升高后降低的趋势,在饲料磷含量为0.89%时达到最大值,显著高于0.28%组(P0.05)。脊椎骨钙磷比在0.89%组达到最高,显著高于1.38%和1.57%组(P0.05)。【结论】在本试验条件下,黄颡鱼最适生长、饲料利用和磷代谢的适宜饲料有效磷含量为0.46%~1.13%。     

Evaluation of Commercial‐scale Approaches for Cryopreservation of White Crappie,Pomoxis annularis,Sperm

Crappie, Pomoxis spp., are popular game fish throughout North America and are produced by public and private hatcheries. However, production is limited by a lack of information on tank culture and induced spawning methods. Development of techniques for storage of sperm and in vitro fertilization would increase flexibility in spawning. Therefore, techniques for sperm cryopreservation were examined in white crappie, Pomoxis annularis. Sperm from adult wild white crappie were used to evaluate sperm extender, cryoprotectant agent and concentration, and cooling technique based on post‐thaw sperm motility. Percent egg fertilization was also compared between sperm stored in the two best cryopreservation protocols and two different osmotic activator solutions. Sperm were cryopreserved using treatment combinations of two extenders (350 mOsmol/kg Hanks' balanced salt solution [HBSS] and 350 mOsmol/kg Ca²⁺free HBSS) and two cryoprotectants (dimethyl sulfoxide [DMSO] and methanol) at concentrations of 5, 10, and 15% that were cooled at four different rates: 5, 10, 20, and 40 C/min. Post‐thaw sperm motility and fertilization rates indicated white crappie sperm can be cryopreserved using either extender, cryoprotectants of either 5% DMSO or 10% methanol, and cooling at 40 C/min. A follow‐up experiment demonstrated sperm in suspensions on ice retained viability after overnight transport.     

Effect of ammonium sulfate fertilization on bahiagrass quality and copper metabolism in grazing beef cattle

To assess the impact of S fertilization on bahiagrass (Paspalum notatum) quality and Cu metabolism in cattle, two studies were conducted during the summer grazing season (1999 and 2000). Pasture replicates (16.2 ha; n = 2/treatment) received the same fertilizer treatment in each growing season, consisting of 1) 67 kg N/ha from ammonium sulfate (AS), 2) 67 kg N/ha from ammonium nitrate (AN), and 3) control (no fertilizer; C). Forage sampling was conducted at 28-d intervals following fertilization by the collection of whole plants (four samples/pasture) in randomly distributed 1-m2 grazing exclusion cages and analyzed for CP, in vitro organic matter digestibility, S, P, Ca, K, Mg, Na, Fe, Al, Mn, Cu, and Zn. To determine the effect of fertilizer treatment on liver trace mineral concentrations in grazing cattle, random liver tissue samples were collected (n = 12; four/treatment) at the start and end of the study period in 2000. Ammonium sulfate fertilization increased (P < 0.001) forage S concentration in both years. Plant tissue N concentrations were increased by N fertilization, regardless of source, in 2000, but not in 1999. Cows grazing AS pastures had lower (P < 0.05) liver Cu concentrations at the end of the study period in 2000 compared to AN and C. In Exp. 2, 37 Cu-deficient heifers grazing AS fertilized pastures were obtained from the same location and allocated to one of two treatments, consisting of supplements providing 123 mg/d of either inorganic (Cu sulfate; n = 12) or organic (Availa-Cu; n = 15) Cu. Treatments were delivered for 83 d. Liver Cu increased over time in all heifers regardless of treatment; however, heifers supplemented with Availa-Cu tended (P = 0.09) to have higher mean liver Cu concentrations than those receiving Cu sulfate. The results of these studies indicate that AS fertilization of bahiagrass increases forage S concentrations. When provided free-choice access to a complete salt-based trace mineral supplement, cows grazing AS-fertilized pastures had lower liver Cu concentrations than cows grazing pastures fertilized with AN; upon removal from high-S pastures, cattle were able to respond to Cu supplementation.     

Luteal function and reproductive response in suckled beef cows after metestrus administration of a norgestomet implant and injection of estradiol valerate with various dosages of injectable norgestomet.

In an experiment replicated over 2 yr, 149 suckled beef cows were administered Syncro-Mate-B (SMB), a 6-mg Norgestomet (NOR) ear implant (in situ 9 d) in conjunction with an i.m. injection of 5 mg of estradiol valerate (EV), and either 3.0, 4.5, or 6.0 mg of NOR, 2 d after estrus. All cows were artificially inseminated at 48 h (timed insemination; TI) after implant removal (IR) and cows were reinseminated at any estrus subsequent to 24 h of TI through 30 d. Blood samples collected before treatment, every 3 d through IR, and at TI were assayed for progesterone (P4). At TI, 44, 39, and 12% of cows treated with 3.0, 4.5, or 6.0 mg of NOR, respectively, had serum concentrations of P4 greater than 1 ng/mL (3.0 and 4.5 mg vs 6.0 mg, P less than .01). Fifty-eight, 63, and 84% of cows treated with 3.0, 4.5, or 6.0 mg of NOR, respectively, exhibited a synchronized (within 5 d of IR) estrus (3.0 and 4.5 mg vs 6.0 mg, P less than .05). Pregnancy rates for the 5-d synchronized period were 38, 45, and 66% for cows treated with 3.0, 4.5, or 6.0 mg of NOR, respectively (3.0 and 4.5 mg vs 6.0 mg, P less than .05). First-service pregnancy rates were 66, 71, and 79% for cows treated with 3.0, 4.5, or 6.0 mg of NOR, respectively (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)