Slatted versus Solid Floors in the Dung Area: Comparison of Pig Production System (Moved versus not Moved) and Effects on Hygiene and Pig Performance,Weaning to Four Weeks after Weaning

The effect of weaning pigs in pens with slatted versus solid floor dung alleys, and of moving at weaning, was studied on pigs from 201 litters. Weaning was at 5 weeks and no litters were mixed. Four treatments were performed: slatted + moved, slatted + not moved, solid + moved and solid + not moved. Pen hygiene was significantly better in the slatted floor pens and morbidity significantly lower. There were no significant differences in mortality or in daily weight gain. Escherichia coli-associated diarrhoea was the major cause of disease and death, and joint inflammation was also of importance. It was concluded that slatted flooring improved pen hygiene and reduced morbidity due to gastrointestinal diseases. In addition, moving the pigs at weaning to cleaned, slatted floor pens may further reduce disease problems.     

One or Two Feeders for Groups of 16 Growing–Finishing Pigs: Effects on Health and Production

Over a 3-year period, seven batches of growing-finishing pigs in groups of 16 pigs (total 672 pigs) were fed using one or two singlespace feeders. The pigs with access to two feeders had a significantly lower number of skin lesions (P<0.0001) and higher daily weight gain than did the pigs with access to one feeder (863 vs. 837 g day- 1 , P<0.05). The within-pen variation in daily weight gain was higher in the pens with one feeder than in the pens with two feeders (SD 139 vs. 106g day- 1 , P<0.0001). The pigs with access to two feeders consumed more feed during the period when they were allowed to eat ad libitum , in comparison to the pigs with access to one feeder (2.07 vs. 1.97 kg day- 1 , P<0.05). The feed conversion ratio of the pigs did not differ between the two treatments. No differences in carcass meat percentage, health or number of remarks at slaughter were detected. A comparison was made between using computerized IVOG® feeders, with individual recording of feed intake, and conventional feeders. The feed conversion ratio was poorer for the pigs fed with the IVOG-feeders than for those fed with conventional feeders. The automatic recordings from the IVOG-system showed that there had been a higher daily feed intake during the ad libitum period. During the restricted period the pigs had a lower daily weight gain than with the conventional feeders.     

Evidence of cormorant‐induced mortality,disparate migration strategies and repeatable circadian rhythm in the endangered North Sea houting (Coregonus oxyrinchus): A telemetry study mapping the postspawning migration

Life history theory predicts a trade‐off between migration and residency where migration is favoured when it infers elevated fitness. Although migration to more favourable environments may offer higher growth rates, migrants often experience increased mortality due to predation. Here, we investigated mortality and migration behaviour of the North Sea houting (Coregonus oxyrinchus), an anadromous salmonid endemic to the Wadden Sea. We used acoustic telemetry to map the migration of the only remaining indigenous population by applying stationary hydrophones combined with manual tracking. Data suggested a total mortality of 26%, with 30% of the total mortality attributed to predation by great cormorants (Phalacrocorax carbo sinensis), highlighting that North Sea houting conservation could be jeopardised by increased cormorant predation. Risk of cormorant predation was size‐dependent, with smaller fish suffering higher risk of predation. The study found North Sea houting to exhibit disparate migration strategies and identified a lentic area in the estuary as an important habitat. Two newly established artificial lakes within the river system significantly reduced the migration speeds, possibly indicating constrained navigation through the lakes. The migration into the Wadden Sea correlated with temperature perhaps indicating osmoregulatory constraints of sea entry. Unlike many salmonid species, migration occurred both day and night. Moreover, fish exhibited repeatable individual differences in diel activity patterns, suggesting that individuals differ consistently in their migratory activity throughout the 24‐hr period. Our study provides novel information on salmonid migration, which is crucial for the development of science‐based conservation strategies.     

Oxidants and antioxidants in disease: oxidative stress in farm animals

Important infectious diseases in farm animals, such as pneumonia and enteritis, are thought to be associated with the so-called oxidative stress, i.e. a chemical phenomenon involving an imbalance in the redox status of the individual animal. The specifics of oxidative stress and how it may result in disease or be prevented are complex questions with no simple answers. However, the considerable literature on the subject suggests that many researchers consider oxidative stress-related mechanisms to be important early events in disease development. A particularly intriguing aspect is that, at least theoretically, oxidative stress should be easily prevented with antioxidants yet the use of antioxidants as therapy remains controversial. The present knowledge on oxidative stress in farm animals is the topic of this review.     

Tissue localization of Aeromonas salmonicida in Atlantic salmon, Salmo salar L., following experimental challenge

Three groups of Atlantic salmon, Salmo salar L., were exposed to live, colony-forming, radiolabelled Aeromonas salmonicida bacteria in a bath challenge: (1) fish with artificial wounds; (2) fish with a reduced epidermal mucus layer caused by removal of the mucus layer on two occasions by a swabbing procedure; and (3) a control group of untreated fish. Fish were killed 2, 6 and 24 h after challenge, and radioactivity (cpm g^–1) was measured in the blood, mucus, skin, wound area, gills, anterior kidney, posterior kidney, spleen, midgut and hindgut. The highest levels of radioactivity were measured in the wound areas and in the gills. There was a significant positive correlation between the levels of radioactivity in the gills and blood, and between the mucus and skin at 2 h post-challenge. Two hours after the bath challenge, live A. salmonicida bacteria were found in the blood of fish in the 'swabbed' and 'artificial wound' groups, and not in the control group. Twenty-four hours after the bath challenge, the kidney of fish from all groups contained viable bacteria, whereas the blood was negative.     

Thermal Properties of Corn Starch Extraction Intermediates by Differential Scanning Calorimetry

Thermal properties of corn starch extraction intermediates from four types of corn were studied using differential scanning calorimetry. Starch at four different stages of extraction, including a standard single-kernel starch isolation procedure and three starch extraction intermediates, was isolated from mature corn kernels of B73 and Oh43 inbreds and the mutants of waxy (wx) and amylose extender (ae) in an Oh43 background. Differences in thermal properties and moisture and protein contents of starch from the extraction stages were statistically analyzed. Most thermal properties (gelatinization and retrogradation onset temperatures, gelatinization and retrogradation ranges, gelatinization and retrogradation peak temperatures, gelatinization and retrogradation enthalpies, peak height index, and percentage of retrogradation) of starches extracted at stage 3 intermediate (a procedure that did not include a final washing step) were similar to those of starch extracted by the standard single-kernel isolation procedure. Values for gelatinization peak temperature, gelatinization enthalpy, and peak height index were different between the standard and the stage 3 intermediate. The values obtained from starches extracted at stage 3, however, were consistent and predictable, suggesting that this extraction intermediate might be used in screening programs in which many starch samples are evaluated. By using the stage 3 extraction, samples could be evaluated in three rather than four days and the procedure saved ≈0.5 hr of labor time. The other two starch extraction intermediates, which excluded filtering and washing or filtering, washing, and steeping, produced starch with thermal properties generally significantly different from starch extracted by the standard single-kernel isolation procedure.     

Using acoustic telemetry and snorkel surveys to study diel activity and seasonal migration of round goby (Neogobius melanostomus) in an estuary of the Western Baltic Sea

In just two decades, round goby Neogobius melanostomus (Pallas) has dispersed throughout most of the Baltic and the North American Great Lakes. It thrives in shallow sheltered areas, where it is impacting native fauna. In Denmark, researchers, governmental institutions and fishers have joined in an effort to establish a sustainable round goby fishery. To do so, basic information about the movement of round goby is essential, so the movements of 50 round gobies were tracked using acoustic telemetry. The results revealed that activity took place mainly at night and seasonal migrations were common. The most frequent migration behaviour observed was a seaward return migration during winter, which was further confirmed by a snorkel survey. Tracking data also revealed riverine upstream dispersal. The results demonstrate that the round goby can be mapped using telemetry, and it is suggested that fishing for round goby may improve efficiency by targeting seasonal migration corridors.     

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.     

Antioxidative Effects of Astaxanthin against Nitric Oxide‐Induced Oxidative Stress on Cell Viability and Gene Expression in Bovine Oviduct Epithelial Cell and the Developmental Competence of Bovine IVM/IVF Embryos

The aim of the present study was to elucidate the fundamental mechanism of bovine oviduct epithelial cell (BOEC) co‐culture on developmental capacity of bovine in vitro oocyte maturation/in vitro fertilization (IVM/IVF) embryos. We examined the effects of astaxanthin against nitric oxide‐induced oxidative stress on cell viability by MTT assay, lipid peroxidation (LPO) by using thiobarbituric acid (TBA) reaction for malondialdehyde (MDA) and the expression of antioxidant genes (CuZnSOD, MnSOD and Catalase) or apoptosis genes (Bcl‐2, Caspase‐3 and Bax) by RT‐PCR in BOEC. We also evaluated the developmental rates of bovine IVM/IVF embryos co‐cultured with BOEC pre‐treated with astaxanthin (500 μm ) in the presence or absence of sodium nitroprusside (SNP, 1000 μm ) for 24 h. Cell viability in BOEC treated with SNP (50–2000 μm ) lowered, while astaxanthin addition (50–500 μm ) increased it in a dose‐dependent manner. Cell viability in astaxanthin plus SNP (1000 μm ) gradually recovered according to the increase in astaxanthin additions (100–500 mm ). The LPO in astaxanthin group (50–500 μM) gradually decreased in a dose dependent manner and among SNP or astaxanthin plus SNP group, SNP alone and astaxanthin (50 μM) plus SNP shown a significant increase than other groups (p < 0.05). Expression of apoptosis or antioxidant genes was detected by RT‐PCR. Bcl‐2 and antioxidant genes were detected in astaxanthin or astaxanthin plus SNP group, and Caspase‐3 and Bax genes were only found in SNP group. When bovine IVM/IVF embryos were cultured for 6–7 days under co‐culture system such as BOEC treated with astaxanthin in the presence or absence of SNP, the developmental ability to blastocysts in 500 μm astaxanthin group was the highest of all groups. These results suggest that astaxanthin has a antioxidative effect on cell viability and LPO of BOEC, and development of bovine IVM/IVF embryos due to the induction of antioxidant genes and suppression of apoptosis genes.