Tensile properties for netting materials used in aquaculture net cages

In order to perform a strength analysis of a net cage, it is crucial to know the tensile stiffness properties of the netting material. A new method for testing was established in order to determine the tensile properties of knotless netting materials. We applied it to a variety of netting materials and developed stress–strain relations. The stiffness was expressed as a constant value for relatively small strains, while for large strains the stress–strain relation was defined by a third degree polynomial. The average value of the constant stiffness for the tested wet netting materials was 81 N mm⁻² with a standard deviation of 9 N mm⁻² for strains less than 10%. For netting materials treated with anti-fouling paint, the average constant stiffness value was 131 N mm⁻² with a standard deviation of 13 N mm⁻² for strains less than 30%. The results are valid for uniaxial static loading of netting.     

Xylazine-induced sedation in axis deer (Axis axis) and its reversal by atipamezole

Eight free-ranging axis deer (Axis axis) were captured in drive nets and injected with xylazine (3.4±0.1 mg/kg; mean ±SEM) intramuscularly using a hand-held syringe. Xylazine induced complete immobilization and sedation in three animals, heavy sedation in three, and moderate sedation in two. The mean induction time was 10.4±1.0 min. The mean rectal temperature, heart and respiratory rates of immobilized animals were 39.2±0.4°C, 75.5±6.5 beats/min and 62.1±4.2 breaths/min, respectively.All the animals were given atipamezole intravenously for reversal. The mean time from injection of xylazine to administration of atipamezole was 37.8±4.6 min. A dose ratio (w/w) for xylazine:atipamezole-HCl of 10:1 was used. The mean time from injection of atipamezole to mobility was 2.41±0.58 min.Atipamezole given intravenously effectively antagonized xylazine-induced sedation in axis deer. Only one animal showed signs of overalertness after reversal and no cases of resedation were observed.Abbreviations i.m. intramuscular(ly) - i.v. intravenous(ly) - SEM standard error of the mean     

COMPUTED TOMOGRAPHY OF HEREDITARY MULTIFOCAL RENAL CYSTADENOCARCINOMAS IN GERMAN SHEPHERD DOGS

the purpose of the study was to characterize the renal lesions of hereditary renal cystadenocarcinomas in the German shepherd dog using computed tomography (CT), Fourteen dogs with renal cystadenocarcinomas and nodular dermatofibrosis, and two unaffected dogs were studied. There were nine dogs with spontaneous disease and seven dogs from a test mating. The characteristic renal CT findings of renal cystadenocarcinomas were bilateral multiple cysts and tumor masses of various sizes. The earliest change were detected between 4 and 5 years of age and the smallest cysts measured 2-3 mm in diameter. Abdominal CT examination gives a wide field view and excellent anatomic images of the kidneys. It is easy to differentiate between cysts and solid tumors. CT examination is useful for the early detection of renal cystadenocarcinomas and for screening suspected carrier dogs before breeding.     

Effect of Feed Structure on Performance and Welfare in Laying Hens Housed in Conventional and Furnished Cages

A small-scale experiment was conducted to examine layers' selection pattern of whole wheat (WW), protein concentrate (PC) and coarse shell meal (SM) throughout the light day. Consumption of all feed components increased prior to darkness. However, an interaction between SM and the other feed components was found (P<0.05), caused by a greater increase in SM consumption prior to darkness than WW and PC. This interaction is probably related to the requirement for calcium for eggshell formation. Energy (WW)/ Protein (PC) consumption ratio did not vary throughout the light day. In a large-scale experiment, a diet with 40% whole wheat incorporated into 3 mm pellets was compared with a complete diet, also as 3 mm pellets, but containing no whole wheat. Coarse shell meal was added in the feed trough for the experimental diet. These diets were examined in conventional 3-hens cages and two furnished cage systems. The hybrids LSL and Shaver 2000 were used. A tendency towards a lower (P=0.07) feed conversion ratio (FCR) was found in the experimental diet relative to the control diet. This may be a result of a better plumage condition for birds fed the experimental diet. Weight of gizzard and gizzard contents was higher among birds on the experimental diet. Self-selection of shell meal did not affect eggshell strength and legbone strength. Birds housed in furnished cages with 16 birds per cage unit showed higher (P<0.05) feed consumption than birds housed in furnished cages with 8 hens per cage and birds housed in conventional 3-hens cages. Egg production was similar in all cage systems, except for a tendency for lower (P=0.06) egg production in the 8-hens cages in the second half of the experiment period. Plumage condition was generally poorer (P<0.05) in the furnished cages than in the conventional 3-hens cages. Fewer comb lesions were found among birds in furnished cages, which may indicate less aggression in layers housed in furnished cages compared with conventional barren 3-hens hen cages.     

Effect of including whole oats into pellets on performance and plumage condition in laying hens housed in conventional and furnished cages

In an experiment including 2400 layers, a diet with 40% whole oats incorporated into 3 mm pellets (experimental diet) was compared with a complete diet, also as 3 mm pellets, but containing no whole oats (control diet). These diets were examined in conventional 3-hens cages and two furnished cage systems with 8 or 16 birds per group including nest, perches and litter. The effects of diet, rearing condition and cage system on performance, plumage condition, comb lesions and rear body wounds were studied. Furthermore, the effect of feed structure on gizzard characteristics and interactions with access to litter during rearing and laying periods were examined. The hybrids LSL and Shaver 2000 were included in the experiment. Egg production was lower (P<0.05) in furnished cages than in conventional cages. No difference in plumage condition was found between diets, but a significantly poorer plumage condition (P<0.05) was observed with increasing group size. Also, the frequencies of rear body (P<0.05) wounds increased as the group sizes increased, while no such effect was observed for comb lesions. Higher (P<0.05) feed consumption was observed in furnished cages than in the conventional, causing a corresponding increase (P<0.05) in feed conversion rate (FCR). Higher (P<0.05) FCR was observed for birds fed pellets with whole oats than the control. Whole oats also increased (P<0.05) the weight of gizzard and gizzard contents. For LSL, better (P<0.05) plumage condition was found for birds reared on a deep litter floor compared to cage rearing. It was concluded that no beneficial effect of replacing high amounts of ground oats with whole oats was observed. Genotype and rearing method may interact with housing system.     

Genotype distribution and allele frequencies of the genes associated with body composition and locomotion traits in Myanmar native horses

Myanmar native horses are small horses used mainly for drafting carts or carriages in rural areas and packing loads in mountainy areas. In the present study, we investigated genotype distributions and allele frequencies of the LCORL/NCAPG, MSTN and DMRT3 genes, which are associated with body composition and locomotion traits of horses, in seven local populations of Myanmar native horses. The genotyping result of LCORL/NCAPG showed that allele frequencies of C allele associated with higher withers height ranged from 0.08 to 0.27, and 0.13 in average. For MSTN, allele frequencies of C allele associated with higher proportion of Type 2B muscular fiber ranged from 0.05 to 0.23, and 0.09 in average. For DMRT3, allele frequencies of A allele associated with ambling gait ranged from 0 to 0.04, and 0.01 in average. The presences of the minor alleles of these genes at low frequencies suggest a possibility that these horse populations have not been under strong selection pressure for particular locomotion traits and body composition. Our findings of the presence of these minor alleles in Southeast Asian native horses are also informative for considering the origins of these minor alleles associated with body composition and locomotion traits in horse populations.