Ameliorative Effects of Melatonin against Hydrogen Peroxide‐Induced Oxidative Stress on Boar Sperm Characteristics and Subsequent In Vitro Embryo Development

Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H₂O₂) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ). The sperm were treated with melatonin in the presence or absence of H₂O₂ for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H₂O₂ groups were lower than H₂O₂ only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.     

Effect of dietary nutmeg oil on heat‐stress tolerance‐related parameters in Korean native chicken reared under hot temperature

This study investigated the effect of dietary nutmeg oil (NO) on growth performance, blood parameters, lipid peroxidation and heat shock protein (HSP) 70 expression in Korean native chicken (KNC) reared under hot temperature. We allocated 273 meat‐type KNCs (Hanhyup‐3, 4‐week‐old, body weight [BW] = 539.93 ± 1.75 g) to the following three treatments with seven replicate pens (13 birds/pen) per treatment. Three treatment diets were as follows: (a) Control, basal diet without NO supplementation; (b) NO 250; and (c) NO 500, basal diet supplemented with 250 and 500 ppm NO respectively. Diets and water were provided ad libitum throughout the 6‐week feeding trial. During overall period (0–6 weeks), no differences (p > 0.05) were observed in BW gain (BWG), feed intake (FI) and feed conversion rate (FCR) among treatments. However, the FI at 0–3 weeks decreased (p < 0.05) quadratically with increasing NO levels. Most blood parameters did not differ (p > 0.05) among treatments, although the monocyte level of the NO 500 group was considerably lower (p > 0.05) than that of the other groups. Furthermore, dietary NO did not affect serum triglyceride, cholesterol, total protein, albumin, calcium, phosphorus and alanine aminotransferase (ALT) levels (p > 0.05); however, it linearly decreased serum aspartate aminotransferase (AST) level (p < 0.05). Additionally, serum malondialdehyde (MDA) concentration decreased (p < 0.05) and heart MDA concentration was lower (p = 0.08) with increasing dietary NO supplementation. After a 3‐hr heat (35°C) challenge, the rectal temperature (RT) reduced (p < 0.05) linearly with increasing NO levels. Dietary NO did not affect liver HSP70 (p > 0.05) gene expression. In conclusion, NO potentially enhanced the ability of chickens to alleviate heat stress. Furthermore, our findings suggest that lipid oxidation inhibition by dietary NO likely mediated the enhanced heat‐stress tolerance of the chickens.     

Management of an infected cementless cup with prosthetic retention and antibiotic therapy in a dog

A two‐year‐old Rottweiler presented for acute onset of a right hindlimb lameness 20 weeks after a cementless total hip replacement (THR) and 16 weeks after open reduction to address luxation of the THR. Radiographs revealed periosteal proliferation of the medial acetabulum and a stable implant. Synovial fluid cytology was consistent with inflammatory joint fluid. Treatment consisted of surgical debridement and intravenous and oral antibiotics. THR implants were not removed. Culture of tissue removed from the THR site yielded growth of Pseudomonas and Staphylococcus species. Lameness resolved 2 months after surgery. Twenty months after surgery, the dog was exercising normally with no clinical lameness and pelvic radiographs revealed no evidence of implant loosening and markedly decreased periosteal reaction. To the authors’ knowledge, this is the first report of an infected THR site successfully treated without prosthesis explantation in the dog.     

Effects of xylanase supplementation on growth performance,nutrient digestibility,blood parameters,fecal microbiota,fecal score and fecal noxious gas emission of weaning pigs fed corn‐soybean meal‐based diet

This study was conducted to evaluate the effects of xylanase supplementation on nutrient digestibility, growth performance, blood parameters, fecal microflora shedding, fecal score and fecal noxious gas emission of weaning pigs fed corn‐soybean meal based diet. A total of 150 weaning pigs with an average initial body weight (BW) of 7.85 ± 0.93 kg were randomly allocated to three treatments based on BW and sex (10 replicate pens with five pigs, two gilts and three barrows) were used in this 42‐day trial. Dietary treatments were: (1) CON, basal diet; (2) X1, basal diet +0.005% xylanase; (2) X2, basal diet +0.01% xylanase. The xylanase supplementation linearly increased (P < 0.05) average daily gain (ADG), and gain : feed ratio (G:F) from days 29 to 42 and the in overall period, dry matter, nitrogen and energy digestibility, and fecal Lactobacilli counts, and linearly decreased (P < 0.05) blood urea nitrogen (BUN) concentration, fecal NH₃ and H₂S emission. Additionally, at weeks 5 and 6, there was a linear decrease in fecal score with xylanase supplementation. In conclusion, dietary supplementation of xylanase improved growth performance, nutrient digestibility, shifted microbiota by increasing fecal Lactobacillus counts, decreased BUN concentration, fecal score, and fecal NH₃ and H₂S emission in weaning pigs.     

The nutritional value of degermed,dehulled corn for pigs and its impact on the gastrointestinal tract and nutrient excretion

Three experiments were designed to assess the feeding value and potential environmental benefits of feeding degermed, dehulled corn, a low fiber by-product originating from the corn dry milling process, to pigs. Twelve 27-kg (SE = 0.8) barrows were used in Exp. 1 to measure the apparent fecal digestibility of DM, GE and N of degermed, dehulled corn compared with corn grain. Two diets were formulated to contain either 96.4% of degermed, dehulled corn or corn grain plus supplemental vitamins and minerals. Digestibilities of DM, GE, and N were greater in degermed, dehulled corn (96.2, 96.0, and 93.6%, respectively) compared with corn grain (89.0, 89.0, and 78.4%, respectively) (P < 0.01). Overall, a 67 and 29% reduction in DM and N excretion, respectively, was observed. In Exp. 2, eight 70-kg (SE =1.8) barrows were surgically fitted with ileal cannulae and fed the same diets as in Exp. 1, to measure the ileal digestibility of nutrients in degermed, dehulled corn. Ileal digestibility of DM, energy, and N was 13, 15, and 7% greater in degermed, dehulled corn (P < 0.05). Apparent ileal digestibility coefficients of leucine, methionine, and phenylalanine were greater in degermed, dehulled corn compared with corn grain (P < 0.05) while a trend for a lower tryptophan digestibility in degermed, dehulled corn was observed (P = 0.067). In Experiment 3, 96 nursery pigs with an initial average BW of 8.8 kg (SE = 0.08), fed a starter diet formulated with degermed, dehulled corn or corn grain as the major grain source, were used in a 28-d growth performance study. At the end of the study, 24 pigs (1 pig per pen) were sacrificed and gastrointestinal tract measurements were taken. Daily growth rates of pigs were the same between diets (0.64 kg/d). A trend for reduced feed intake (P = 0.073) in pigs fed degermed, dehulled corn led to a 4% improvement in gain to feed (P < 0.05). Feeding degermed, dehulled corn had no effect on gut fill, gastrointestinal tract weight, or liver weight (P > 0.05). Ileal villus lengths and crypt depths were not affected by feeding degermed, dehulled corn although ileal villus widths were greater in pigs fed corn grain. Results from these trials suggest that corn processed to remove poorly digestible fiber fractions provides more digestible nutrients than corn grain. As a result, degermed, dehulled corn reduces fecal and N excretion, thus providing a means to reduce nutrient excretion.     

Double in situ hybridization for simultaneous detection and differentiation of porcine circovirus 1 and 2 in pigs with postweaning multisystemic wasting syndrome

Double in situ hybridization using a digoxigenin-labelled porcine circovirus 1 (PCV1) and biotinylated PCV2 probe, was developed for the simultaneous detection and differentiation of PCV1 and PCV2 in formalin-fixed, paraffin-embedded tissues from pigs with postweaning multisystemic wasting syndrome. The combination of an alkaline phosphatase conjugated antidigoxigenin system with alkaline phosphatase conjugated streptavidin-biotin system allowed identification of PCV1 and/or PCV2. No evidence of cross-reaction was observed. Positive cells exhibited a red or dark brown reaction product for PCV1 and PCV2, respectively. Both PCV DNAs were observed mainly in the cytoplasm but occasionally in the nucleus. Co-localization of hybridization signal for both PCV1 and PCV2 was present in macrophages and multinucleated giant cells of the lymph node and spleen. This double-labelling technique for the differentiation between PCV1 and PCV2 is suitable for pathogenesis studies and diagnostic applications.     

Comparative study on calretinin immunoreactivity in gerbil and rat retina

Expression of calretinin in retina has been ascribed to multiple biological and functional aspects in the visual system. In this study, we examined the distribution patterns of calretinin immunoreactivity in gerbil and rat retina. In the gerbil, calretinin immunoreactivity was present in bipolar and amacrine cells of the inner nuclear layer and in neurones of the ganglion cell layer. In the rat, amacrine and ganglion cells showed calretinin immunoreactivity, but bipolar cells did not contain calretinin immunoreactivity. In both species, calretinin immunoreactivity was absent in cones, cone bipolars, and horizontal cells. In conclusion, gerbil as well as rat has a rod-dominant retina. The differences in calretinin expression between rat and gerbil require further investigations under various functional and developmental conditions.     

Contact and fumigant toxicity of oriental medicinal plant extracts against Dermanyssus gallinae (Acari: Dermanyssidae)

The acaricidal activity of methanolic extracts from 40 oriental medicinal plant species and a steam distillate of Cinnamomum camphora towards poultry house-collected adult Dermanyssus gallinae De Geer was examined using direct contact and vapour phase toxicity bioassays. Results were compared with those of 15 acaricides currently used. In filter paper contact toxicity bioassays using adult D. gallinae, C. camphora steam distillate (0.0051 mgcm(-2)) was the most toxic material, followed by extracts from Asarum sieboldii var. seoulens whole plant, Eugenia caryophyllata flower bud and Mentha arvensis var. piperascens whole plant (0.0063-0.0072 mgcm(-2)), based upon 24h LD(50) values. The acaricidal activity of these four plant preparations was almost comparable to that of profenofos (LD(50), 0.003 mgcm(-2)) but less effective than dichlorvos (LD(50), 0.0004 mgcm(-2)). The toxicity of Illicium verum fruit and Lysimachia davurica leaf extracts (0.09 mgcm(-2)) was almost comparable to that of benfuracarb, prothiofos, propoxur and fenthion (0.053-0.070mgcm(-2)). In vapour phase toxicity tests, these plant preparations were more effective in closed containers than in open ones, indicating that the mode of delivery of these plant extracts was largely a result of action in the vapour phase. Plants described herein merit further study as potential D. gallinae control agents.     

Glutathione content of in vivo and in vitro matured canine oocytes collected from different reproductive stages

Glutathione (GSH) concentrations of oocytes are considered as an important marker of the cytoplasmic maturation. The present study was designed to compare GSH concentrations of in vivo and in vitro matured canine oocytes. In vivo matured oocytes were collected 72 hr after ovulation by flushing fallopian tubes after laparotomy. Ovaries were collected from bitches with different reproductive stages, and collected oocytes were divided into 2 groups according to the size viz. < 120 microm and > 120 microm in diameter and cultured for 72 hr in Tissue Culture Medium-199 supplemented with 10% FBS, 2.2 mg/ml sodium bicarbonate, 2.0 microg/ml estrogen, 0.5 microg/ml FSH, 0.03 IU/ml hCG, and 1% penicillin-streptomycin solution in the presence or absence of 50 microM beta-mercaptoethanol. GSH concentrations were determined by the dithionitrobenzoic acid-glutathione disulfide (DTNB-GSSG) reductase recycling assay. GSH concentrations of immature canine oocytes were 2.9 and 3.8, 3.5 and 6.8, and 3.1 and 6.5 pM/oocyte for < 120 microm and > 120 microm in diameter oocyte groups at anestrous, follicular and luteal stage, respectively (P<0.05). In vivo matured oocytes had significantly higher GSH concentrations compared with in vitro matured oocytes. The GSH content was 19.2 pM/oocyte for in vivo matured oocytes, while 4.1 to 8.1 and 5.7 to 13.2 pM/oocyte for in vitro matured oocytes cultured in the absence or presence of beta-mercaptoethanol, respectively (P<0.05). Presence of beta-mercaptoethanol increased GSH synthesis in canine oocytes cultured in vitro, and oocytes collected from follicular and luteal stage was superior to anestrus oocytes.