Improved carp diets based on plant protein sources reduceenvironmental phosphorus loading

ABSTRACT:   As part of on-going efforts to reduce environmental phosphorus(P) and nitrogen (N) loading from culture systems, five experimentaldiets were formulated containing 5–15% of fishmeal (FM) and different levels of soy protein concentrate (10–20%),corn gluten meal (3–5%) and defatted soybean meal(2.0–8.5%). These diets had total P ranging between1.04 and 1.29% and available P between 0.62 and 0.63%.A FM-based (43%) commercial diet was used as the controland this diet had total P of 1.87% and available P of 0.82%.Waste loading was calculated after feeding the diets to 3.4 gcarp for 10 weeks. Feed gain ratios were not significantly differentfor fish fed control and experimental diets having 10–15% FM,but the protein efficiency ratio was lower for the control group.The rates of P absorption and retention in the experimental dietgroups were significantly higher than those of the control group.The lowest N retention was obtained for the control group, althoughabsorption was not markedly different among the treatment groups.Total P and N loading (kg/ton production) produced fromthe experimental diets ranged from 7.1 to 8.9 and from 36.1 to 41.3,respectively, whereas the corresponding values for the control dietwere 15.2 and 48.1.     

Latex agglutination test for canine parvovirus

Canine parvovirus (CPV) was detected in faeces from dogs with diarrhoea by a specific slide agglutination test using latex particles coated with anti-CPV monoclonal antibody (LA-anti-CPV). The agglutination of LA-anti-CPV with CPV on a glass slide was evident macroscopically within 2 min. The sensitivity of the latex agglutination (LA) test was similar to that of the hemagglutination test. The LA test is available for the rapid diagnosis of CPV infection at an animal hospital.     

IMAGING DIAGNOSIS—POLIOENCEPHALOMALACIA IN A CALF

A 2-month-old mix-breed calf developed acute blindness and ataxia. Serum thiamine concentration was deficient. In antemortem magnetic resonance imaging there were laminar T2-hyperintense regions extending along the cerebral cortex that primarily affected the gray matter. The lesions were relatively symmetric between the left and right hemispheres but no abnormalities were present at the frontal lobes. At necropsy, laminar autofluorescence of the cerebral cortex was observed under ultraviolet exposure at 365 nm, consistent with a diagnosis of polioencephalomalacia. Polioencephalomalacia in the bovine species is compared with that in other species, namely humans, dogs, and cats.     

SEQUENTIAL MAGNETIC RESONANCE IMAGING OF AN INTRACRANIAL HEMATOMA IN A DOG

An 8-year-old Yorkshire terrier developed acute onset coma and seizure after cranial trauma. Intracranial hemorrhage was suspected from the clinical signs and history. Low-field magnetic resonance (MR) imaging revealed a round mass within the right cerebral hemisphere, compressing the right lateral ventricle and displacing the longitudinal fissure to the left. The lesion was hypointense on T1-weighted images and hyperintense on T2-weighted images, consistent with an acute hemorrhage. MR imaging was performed every 24 h for 6 days from 1 h after the injury, and then on day 14 of hospitalization. With time, the signal intensity changed to hyperintense on Ti-weighted images. On T2-weighted images the center of the mass changed to hypointense, and then to hyperintense with a hypointense rim. These changes of signal intensity were related to hemoglobin oxidation.     

Comparison of Cryotop and micro volume air cooling methods for cryopreservation of bovine matured oocytes and blastocysts

This study was designed to compare the efficiency of the Cryotop method and that of two methods that employ a micro volume air cooling (MVAC) device by analyzing the survival and development of bovine oocytes and blastocysts vitrified using each method. In experiment I, in vitro-matured (IVM) oocytes were vitrified using an MVAC device without direct contact with liquid nitrogen (LN₂; MVAC group) or directly plunged into LN₂ (MVAC in LN₂ group). A third group of IVM oocytes was vitrified using a Cryotop device (Cryotop group). After warming, vitrified oocytes were fertilized in vitro. There were no significant differences in cleavage and blastocyst formation rates among the three vitrified groups, with the rates ranging from 53.1% to 56.6% and 20.0% to 25.5%, respectively; however, the rates were significantly lower (P < 0.05) than those of the fresh control group (89.3% and 43.3%, respectively) and the solution control group (87.3% and 42.0%, respectively). In experiment II, in vitro-produced (IVP) expanded blastocysts were vitrified using the MVAC, MVAC in LN₂ and Cryotop methods, warmed and cultured for survival analysis and then compared with the solution control group. The rate of development of vitrified-warmed expanded blastocysts to the hatched blastocyst stage after 24 h of culture was lower in the MVAC in LN₂ group than in the solution control group; however, after 48–72 h of culture, the rates did not significantly differ between the groups. These results indicate that the MVAC method without direct LN₂ contact is as effective as the standard Cryotop method for vitrification of bovine IVM oocytes and IVP expanded blastocysts.     

Reduction in elemental waste loading from commercial carp feeds by manipulating the dietary phosphorus levels

ABSTRACT:   The effect of dietary phosphorus (P) manipulation on environmental loading of P and nitrogen (N) from carp was investigated. Two commercial diets (A and B) were re-prepared as four experimental diets A, B, AP, and BP, the latter two being topped up to the required available P level for carp. The total P ranged between 1.52 and 1.99% and water-extractable (or available) P was 0.50, 0.36, 0.62, and 0.63% for A, B, AP, and BP, respectively. A 20% fishmeal diet was chosen as the control and it contained 1.41% total P and 0.67% water-extractable P. Duplicate groups of carp (size, 8.6 g) were fed the test diets for 12 weeks. The best growth performance was that of fish fed the control diet, followed by the test diets supplemented with P. The highest rates of P absorption and retention of P and N were obtained for the control group followed by the AP, A, BP, and B experimental groups. In the case of waste discharge, the reduction in P loading was marginal, but N loading was markedly lower for P supplemented test diets. The control diet was the least-loading diet. Thus commercial carp feed formulations could be improved by incorporating sufficient available P in order to reduce discharges of P and N into the water.     

Phosphorus and nitrogen excretion during growth span of carp kept under two rearing systems

ABSTRACT:   Two feeding trials were performed on carp to investigate phosphorus (P) and nitrogen (N) excretion during their growth span. Trial I was conducted under laboratory conditions by feeding 3.9 g carp an experimental diet (crude protein 34.8%, total P 1.41% and available P 0.67%) for 280 days under controlled conditions. Trial II was performed with 72.8 g carp, feeding them a commercial diet (CP 35.8%, total P 1.62% and available P 0.75%) for 180 days on a practical scale. Fish grew throughout the experiment in trial I, whereas they stopped growing in trial II when the water temperature fell below 15°C. In both trials, P and N content in fish body increased with increasing weight until it plateaued when fish were between 500 and 600 g. The retention rates of the two elements also followed a similar pattern, but decreased beyond the size range mentioned above. In both trials, P and N loading increased with an increase in fish size, but such a pattern was less evident until a bodyweight of 600 g, the trend being more pronounced in trial II. The results of the present study indicate that excretion is higher during the slow-growing stage of carp and is, hence, influenced by fish size.     

Nucleotide sequence of myostatin gene and its developmental expression in skeletal muscles of Japanese Black cattle

Myostatin, a member of the transforming growth factor‐β superfamily, is a well known negative regulator of skeletal muscle growth. In the present study, the 6660 bp nucleotide sequence of the myostatin gene in Japanese Black cattle (JBC), including the entire coding region of 1128 bp, was determined. The amino acid sequence deduced from the nucleotide sequence of JBC was well conserved with its sequence of other cattle, although it was found that an Α→G transition at nucleotide position 641 results in the substitution of asparagine by serine at amino acid position 214. In order to examine the expression pattern of the myostatin gene in the skeletal muscles of JBC, its expression in three skeletal muscles, Semitendinosus (ST) muscle, Biceps femoris muscle and Longissimus lumborum muscle, of fetal and calf stages was analyzed by real time polymerase chain reaction. The highest level of the myostatin expression was observed in the fetal stage. In calf stages the highest expression was observed in ST muscle compared with the other two muscles. These results suggest that a higher expression of myostatin gene, especially in the fetal stage and in ST muscle during calf stages, is involved in the arrest in skeletal muscle growth and that its functional domains and genomic structure in JBC are well conserved with those in other mammals.