Influence of Egg Characteristics on Survival, Growth and Feeding in Larval Walleye (Stizostedion vitreum)

1989 ◽  
Vol 46 (3) ◽  
pp. 516-521 ◽  
Author(s):  
G. E. E. Moodie ◽  
N. L. Loadman ◽  
M. D. Wiegand ◽  
J. A. Mathias
Keyword(s):  
Fatty Acids ◽  
Mortality Rate ◽  
Growth Rates ◽  
Egg Size ◽  
The Other ◽  
Stizostedion Vitreum ◽  
Mean Size ◽  
Survival And Growth ◽  
The Mean ◽  
High Level

A subsample of eggs from 109 walleye (Stizostedion vitreum) from Crean Lake, Saskatchewan, was sieved soon after fertilization to yield four groups of eggs ranging in size from 4.86 to 5.62 mm3. Overall egg size tended to correspond to yolk and oil volumes. At hatching, larvae from the eggs with the least yolk and oil were significantly shorter than larvae from all other egg groups. At the end of the experiment, 13 d after hatching, the larvae from the eggs with the most yolk were significantly larger than larvae from the other egg groups. Differences in the mean amount of food ingested by larvae were related to initial egg size. The yolk of the smallest eggs was deficient in the (n-3) series of polyunsaturated fatty acids. Larvae from these small eggs had a high level of major body deformities and a mortality rate which reached 100% by day 10. Small egg size in itself did not appear disadvantageous; larvae from a different stock (Lake of the Prairies, Manitoba) which produced eggs with a mean size less than that of the smallest sieved eggs, had survival and growth rates comparable with those of the larger Crean Lake eggs.

scholarly journals Observations on the Fat Globules in Milk

1913 ◽  
Vol 5 (3) ◽  
pp. 331-356 ◽  
Author(s):  
W. F Cooper ◽  
W. H Nuttall ◽  
G. A Freak
Keyword(s):  
Annual Report ◽  
The Other ◽  
Optimum Temperature ◽  
Fat Globules ◽  
Chief Factors ◽  
Mean Size ◽  
The Subject ◽  
The Mean ◽  
Definite Result

Results of our previous work were published in the Journ. of Agric. Sri., IV, 1911. There, also, a brief summary of the chief papers published on the subject of the fat globules was given, to which it is unnecessary to refer in detail here.When the work was first commenced in 1909, the problem before us was the consideration of the variation in the size of the fat globules, with relation to churning, as regards the different breeds of cattle. The breed was considered because it was usually supposed that this was one of the chief factors which influenced churning. The most definite result of our work was that it was shown that consideration must be given to the character of the milk, irrespective of the breed. This conclusion is quite contrary to that of other workers, but an examination of their figures shows, undoubtedly, that this is actually the case: the results given by Woll (Digestion Expts., Seventh Annual Report, Agric. Expt. Stat, Wisconsin, 1890, 238; also Agric. Sci., 1892, vi, 445) emphasise this point particularly. It is also shown by this year's work, as may be seen from Tables V–XI.The comparative size of the globules has been worked out very thoroughly by Gutzeit, who measured the mean volume of the globule. Other workers give their results as “relative sizes.” In our work we attempted to ascertain the distribution of the fat in the globules, and to this end the number of globules of each size was determined, and curves were drawn. The result of this, however, was negative. At that time we were considering the breeds of the cows from which the milks were obtained; had we considered them solely as milks of a certain mean size of globule, much more might have been achieved.An apparatus was devised to give an absolute figure for the churnability of any cream, but, until the effect of the other factors has been determined, it is impossible to interpret the results. Some experiments to ascertain the optimum temperature were described also.

Dorsoproximal proximal phalanx osteochondral fragmentation in 117 Warmblood horses

2009 ◽  
Vol 22 (01) ◽  
pp. 1-6 ◽  
Author(s):  
A. Martens ◽  
D. Maes ◽  
B. Boussauw ◽  
R. Forsyth ◽  
K. J. Boening ◽  
...  
Keyword(s):  
Clinical Examination ◽  
Hyaline Cartilage ◽  
Fibrous Tissue ◽  
Proximal Phalanx ◽  
The Other ◽  
Arthroscopic Evaluation ◽  
Hind Limbs ◽  
Mean Size ◽  
The Mean ◽  
Joint Evaluation

SummaryThe objective of the present study was to determine clinical and arthroscopic characteristics associated with dorso-proximal proximal phalanx (P1) fragments in Warmblood horses, as well as to examine their histopathological appearance. One hundred sixty-eight fragments were removed from 150 fetlocks of 117 Warmblood horses. Details of signalment and results of clinical examination were collected prior to surgery. After arthroscopic fragment removal and joint evaluation for synovial and/or cartilage abnormalities, the fragments were measured and evaluated histopathologically. The vast majority of the fragments (95.2%) were found medially, without predilection for front or hind limbs. In 10% of the joints, more than one fragment was present. The mean size of the fragments was 6.8 ± 2.6 mm. Only eight horses presented fetlock-related lameness. Horses of seven years of age and older (OR=13.32; p=0.033) and the presence of more than one fragment (OR=11.12; p=0.016) were significantly associated with lameness. Arthroscopic evaluation revealed one or more abnormalities in 50.7% of the joints. On histopathology, osteochondral fragments presented as a bony center covered with smooth hyaline cartilage on one side and some fibrous tissue on the other side. No clear histopathological signs were indicating precisely their origin. In Warmblood horses with dorsoproximal P1 fragments, the age (seven years and older) and the presence of more than one fragment in a fetlock significantly increased the risk of lameness. The osteochondral dorsoproximal P1 fragments could be defined as a developmental orthopaedic disease.

scholarly journals Specificity and Mode of Action of the Antifungal Fatty Acid cis-9-Heptadecenoic Acid Produced byPseudozyma flocculosa

2001 ◽  
Vol 67 (2) ◽  
pp. 956-960 ◽  
Author(s):  
Tyler J. Avis ◽  
Richard R. Bélanger
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Conformational Changes ◽  
Biocontrol Agent ◽  
The Other ◽  
Sterol Content ◽  
Structural Mechanism ◽  
Inhibition Of Growth ◽  
Molecular Events ◽  
High Level

ABSTRACT cis-9-Heptadecenoic acid (CHDA), an antifungal fatty acid produced by the biocontrol agent Pseudozyma flocculosa, was studied for its effects on growth and/or spore germination in fungi. Inhibition of growth and/or germination varied considerably and revealed CHDA sensitivity groups within tested fungi. Analysis of lipid composition in these fungi demonstrated that sensitivity was related primarily to a low intrinsic sterol content and that a high level of unsaturation of phospholipid fatty acids was not as involved as hypothesized previously. Our data indicate that CHDA does not act directly with membrane sterols, nor is it utilized or otherwise modified in fungi. A structural mechanism of CHDA, consistent with the other related antifungal fatty acids produced by P. flocculosa, is proposed in light of its activity and specificity. The probable molecular events implicated in the sensitivity of fungi to CHDA are (i) partitioning of CHDA into fungal membranes; (ii) a variable elevation in fluidity dependent on the buffering capability (sterol content) in fungi; and (iii) higher membrane disorder causing conformational changes in membrane proteins, increased membrane permeability and, eventually, cytoplasmic disintegration.

Structural Changes in a 304-Type Austenitic Stainless Steel Processed by Multiple Hot Rolling

2011 ◽  
Vol 409 ◽  
pp. 730-735 ◽  
Author(s):  
Zhanna Yanushkevich ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Dynamic Recrystallization ◽  
Grain Boundaries ◽  
Hot Rolling ◽  
Structural Changes ◽  
The Other ◽  
Dynamic Processes ◽  
Mean Size ◽  
The Mean

The microstructure evolution and the dynamic processes of grain refinement in a 304-type austenitic stainless steel during multiple calibre hot rolling at temperatures of 700-1000°C were studied. The structural changes are characterized by the elongation of original grains towards the rolling axis and the development of new fine grains, the mean size of which decreases with decreasing the deformation temperature. During multiple rolling at 1000°C, the new grains resulted from the development of discontinuous dynamic recrystallization involving a bulging of frequently corrugated grain boundaries. On the other hand, the new grain boundaries leading to remarkable refinement of original microstructure were developed at temperatures below 800°C as a result of continuous strain-induced reactions.

scholarly journals Comparative geomorphological observations in two groups of alluvial fans of Sperchios and Eurotas regions, Greece

2007 ◽  
Vol 40 (4) ◽  
pp. 1552
Author(s):  
A. Kontou ◽  
K. Gaki-Papanastasiou ◽  
H. Maroukian
Keyword(s):  
The Other ◽  
Alluvial Fans ◽  
Morphometric Characteristics ◽  
Drainage Basins ◽  
Mean Size ◽  
Formation And Evolution ◽  
The Mean

In the present study two groups of alluvial fans from two different regions in Greece were comparetively studied, the first in the region of Sperchios river and the second in the region ofEurotas river. Distinct morphometric characteristics of the drainage basins of the tributaries Ts er lias, Xerias, Gorgopotamos, Kerasias, Retsas and Kakaris, as well as their fans were measured and compared. Furthermore ,the longitudinal stream profiles were mapped, pebble measurements were made and contour crenulations of the fans were studied. In gravelometry, it was found that the mean size M of the pebbles decreases from the apex to the apron of the fan. The crenulation analysis showed that the fans of the streams ofEurotas region have undergone greater erosion than those of Sperchios region. Remarkable differences exist between the fans of the two regions. These results lead to the conclusion that recent tectonism, the prevailing lithology and climate are responsible for the formation and evolution of the fans and also influence their shape, area and all the other morphometric characteristics

Further Observations on Breeding of Dermochelys coriacea in Australia

1984 ◽  
Vol 11 (3) ◽  
pp. 567 ◽  
Author(s):  
CJ Limpus ◽  
NC McCachlan ◽  
JD Miller
Keyword(s):  
Gas Exchange ◽  
Hatching Success ◽  
Fine Sand ◽  
Dermochelys Coriacea ◽  
Leatherback Turtle ◽  
Mean Size ◽  
The Mean ◽  
High Level ◽  
Embryonic Death

In Australia, breeding of the cosmopolitan leatherback turtle, Dermochelys coriacea, is concentrated on 22.3 km of beach near Wreck Rock (24�19'S., 151�58'E.) in south-east Queensland. Up to three females nest there in most years. The mean size of 14 clutches was 82.79; the mean hatching success was 15.3% for clutches on the beach and 51.8% for these moved to dunes near the laboratory. The high level of failure is attributed to early embryonic death, probably caused by the fine sand, when damp, restricting gas exchange round the eggs.

Physiological attributes as possible selection criteria for milk production 3. Plasma hormone concentrations and metabolite and hormonal responses to changes in energy equilibrium

1983 ◽  
Vol 37 (2) ◽  
pp. 165-178 ◽  
Author(s):  
R. B. Land ◽  
W. R. Carr ◽  
I. C. Hart ◽  
T. J. Osmond ◽  
R. Thompson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Plasma Concentration ◽  
Milk Production ◽  
Selection Criteria ◽  
The Other ◽  
Hormonal Responses ◽  
Energy Equilibrium ◽  
Plasma Hormone ◽  
High Level

ABSTRACTPlasma hormone concentrations and metabolite responses to changes in energy equilibrium were measured in experiments designed to compare a) Hereford × Friesian with Friesian calves and b) Friesian calves sired by bulls with a high level of Improved Contemporary Comparison with those sired by bulls of a low level. The concentration of thyroxine and triiodothyronine tended to be greater in calves of higher dairy merit. The concentration of growth hormone was largely unrelated to dairy merit in the circumstances studied. The concentration of insulin was greater in Hereford × Friesian than in Friesian calves following feeding and following the injection of propionate. Responses to the injection of insulin and of growth hormone (as measured by changes in the plasma concentration of urea nitrogen, free fatty acids, glucose or the other hormone) were little affected by the level of Improved Contemporary Comparison of a calfs sire.It was concluded that the thyroid system and the response of insulin to perturbation of energy balance may provide criteria of genetic merit for milk production which are neither age- nor sex-limited.

Comparative breed studies of beef cattle. I. Changes in body weight

1963 ◽  
Vol 14 (6) ◽  
pp. 882 ◽  
Author(s):  
NM Tulloh
Keyword(s):  
Body Weight ◽  
Growth Rates ◽  
The Other ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Breed Differences ◽  
Weaning Age ◽  
Absolute Growth ◽  
The Mean ◽  
One Year

A comparative growth study was made of Hereford, Aberdeen Angus, and beef Shorthorn cattle reared and kept together throughout their lives on irrigated perennial pastures at the Metropolitan Farm, Werribee, Vic. Records of body weight as a function of age were obtained on 404 Hereford, 172 Aberdeen Angus, and 127 Shorthorn cattle, representing cattle born in 1955, 1957, 1958, 1959, and 1960. At birth, male calves were significantly heavier than females, and Hereford calves were significantly heavier than Shorthorn and Aberdeen Angus calves, the birth weights of Shorthorn and Aberdeen Angus calves being similar. Up to the age of 5 years, the younger and lighter 2-year-old cows produced lighter calves than cows which were both older and heavier. At weaning age (9.5 months) steers were significantly heavier than heifers. Herefords were significantly heavier than Aberdeen Angus in two years out of three; and in one year out of three, Herefords were significantly heavier than Shorthorns. Shorthorns were significantly heavier than Aberdeen Angus in one year out of three. When the steers were finally weighed off grass at the mean age of either 20 months (1958, 1959, and 1960 cattle) or 25 months (1957 cattle), Herefords were significantly heavier than Aberdeen Angus in four successive years, and in one year out of four the Herefords were significantly heavier than Shorthorns. In three years out of four, Shorthorns were significantly heavier than Aberdeen Angus. Breed differences between the mean weights of breeding cows were not significant and, up to the age of 5 years, as breeding cows grew older they became heavier. Body weight growth curves indicated that the cattle experienced a severe check in growth during the winter months (June, July, August). At other times of the year, growth rates were satisfactory. Cattle born in some years grew better than cattle born in others. This was thought to be due partly to differences between years in the quality and quantity of pasture available, even though the pastures were irrigated. Average absolute and average relative growth rates were calculated for the 1957 and 1958 steers before and after weaning. Breed differences in absolute growth rates before weaning were not statistically significant, but after weaning, rates were significantly the highest for Herefords in both years. The breed differences in average relative growth rates were in the same direction as those for absolute growth rates. However, the pre-weaning relative growth rate of Shorthorns was significantly higher than those of the other breeds among the 1957 steers. When due allowance was made for the smaller size of Aberdeen Angus steers at birth and at weaning, the relative growth rates of this breed were less than those of the other breeds. Absolute and relative growth rates were higher for all breeds before weaning than afterwards. This was mainly a reflexion of low post-weaning growth rates during the winter months. Rank correlation coefficients between birth weight and weight at subsequent ages were low and variable in different breeds and in different seasons. However, coefficients calculated between subsequent ages, beginning at weaning age, were generally highly significant. The breed and sex differences presented in this paper have been compared with the limited data from the literature and, in general, the results are similar.

scholarly journals The Growth Rate Of Verruca Stroemia (O. Müller)

1958 ◽  
Vol 37 (2) ◽  
pp. 427-433 ◽  
Author(s):  
H. Barnes
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
Maximum Size ◽  
Rhythmic Pattern ◽  
The Mean ◽  
Rhythmic Growth ◽  
Specific Growth Rates ◽  
High Level ◽  
Balanus Balanoides

Data are presented on the growth rate of Verruca stroemia under natural conditions and when exposed continuously and cleaned repeatedly. Several series exposed at different times of the year were followed.Rapid growth takes place (under raft conditions) following settlement; the maximum size is virtually reached in one season's growth between spring and early winter. There is little growth in midwinter.Differences between the mean specific growth rates of the various series can be ascribed to differences in the availability of food.The question is discussed as to whether there is any seasonal rhythm; the evidence indicates that no marked rhythmic pattern of growth exists.Observations on deep-water populations would be of value for comparison and to unmask any relatively weak rhythmic growth.The mean specific growth rates at half their maximum size are compared for several species—Balanus balanoides, B. crenatus, B. balanus, Chthamalus stellatus and Verruca stroemia; it is similar for all species except Chthamalus stellatus. The high level barnacle may require stimulation such as is provided by wave action to elicit full metabolic activity.

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