Maintaining a Long‐Term Frozen Semen Storage Tank

2021 ◽  
pp. 591-592
Author(s):  
John J. Dascanio
Keyword(s):  
Storage Tank ◽  
Frozen Semen ◽  
Semen Storage

scholarly journals Artificial selection and maintenance of genetic variance in the global dairy cow population

2005 ◽  
Vol 360 (1459) ◽  
pp. 1479-1488 ◽  
Author(s):  
S Brotherstone ◽  
M Goddard
Keyword(s):  
Genetic Variation ◽  
Genetic Improvement ◽  
Breeding Value ◽  
Payment Systems ◽  
Frozen Semen ◽  
Best Linear Unbiased ◽  
The Uk ◽  
Selection Algorithms ◽  
Global Population

Genetic improvement of dairy cows, which has increased the milk yield of cows in the UK by 1200 kg per lactation in 12 years, is an excellent example of the application of quantitative genetics to agriculture. The most important traits of dairy cattle are expressed only in females, but the main opportunity for selection is in males. Despite this, genetic improvement was achieved by the invention of a new statistical methodology, called ‘best linear unbiased prediction’ to estimate the breeding value of bulls. Intense selection of the best bulls, combined with the worldwide use of these bulls through artificial insemination and frozen semen, has created a global population and caused concern that the genetic variation available in the future will be reduced. Maintenance of genetic variation and long-term genetic gains would be aided by rational payment systems, use of crossbreeding where profitable, inclusion of all economically important traits in the breeding objective, recognition of genotype by environment interactions and the use of selection algorithms that balance estimated breeding value against the average relationship among the selected animals. Fortunately, all of these things are happening to some degree.

scholarly journals A High Incidence of Sperm with Cytoplasmic Droplets Affects the Response to Bicarbonate in Preserved Boar Semen

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2570
Author(s):  
Heiko Henning ◽  
Anne-Marie Luther ◽  
Dagmar Waberski
Keyword(s):  
Calcium Influx ◽  
Specific Response ◽  
Flow Cytometric ◽  
Sperm Abnormality ◽  
High Incidence ◽  
Semen Storage ◽  
Boar Semen ◽  
Calcium Influx Assay

Retained cytoplasmic droplets (CD) are the most frequent sperm abnormality in boar semen. A high incidence of CD is associated with subfertility, but the underlaying reasons are not well understood. The storage of extended semen might augment the adverse effects of CD on essential steps towards fertilization, such as capacitation. The aim of this study was to examine whether the enhanced presence of CD in boar semen influences sperm’s response to the capacitation stimulus bicarbonate during long-term semen storage. Extended semen samples (n = 78) from 13 artificial insemination centers were analyzed using a flow cytometric calcium influx assay. Samples with >15% of CD showed a reduced specific response to bicarbonate and a higher non-specific destabilization after storage for 96 h and subsequent incubation at 38 °C in three variants of Tyrode`s medium (p < 0.05). The size of the bicarbonate-responsive sperm population was inversely correlated with the presence of CD-bearing sperm (r = −0.61, p < 0.01). Samples with ≤15% and samples with >15% of CD did not differ in motility or viability and acrosome integrity during semen storage. In conclusion, incomplete epididymal sperm maturation impairs the in vitro capacitation ability and promotes sperm destabilization in stored boar semen.

scholarly journals One-dimensional Droplet Model for Prediction of Jet-tip Height of Subcooling Mixing Jet for Cryogenic Propellant Storage Tank

2021 ◽  
Author(s):  
Osamu Kawanami ◽  
Kentaro Takeda ◽  
Ryoki Matsushima ◽  
Ryoji Imai ◽  
Yutaka Umemura ◽  
...  
Keyword(s):  
Experimental Data ◽  
Storage Tank ◽  
Thermal Stratification ◽  
Droplet Model ◽  
Spherical Droplet ◽  
One Dimensional ◽  
Long Term Storage ◽  
Proposed Model ◽  
Term Storage

Abstract This study proposes a one-dimensional droplet model to predict the jet-tip height of a subcooling mixing jet issuing from the bottom of a cryogenic propellant storage tank. Cryogenic liquids, such as liquid hydrogen and liquid oxygen, are used as propellants and oxidants in spacecraft propulsion systems that require long-term storage in a closed tank. However, thermal stratification forms near the gas-liquid interface during long-term storage of cryogens due to heat flowing into the tank from the surrounding environment. In addition, boil-off gas (BOG) is generated from the interface, which causes increased pressure in the tank. To reduce the BOG, it is effective to destroy the thermal stratification by mixing in the cold jet issuing from the bottom of the tank. Ground experiments using FC-72 and water as test fluids are conducted to investigate the behavior of the jet using the proposed one-dimensional spherical droplet model as the tip of the jet. The jet behavior is visualized using the Shadowgraph system and the height of the jet-tip is investigated under various experimental conditions. The proposed model is also verified by comparison with experimental data available in the literature. The results show that the proposed model aligns well with the experimental data.

Effect of commercial long-term extenders on metabolic activity and membrane integrity of boar spermatozoa stored at 17°C

2013 ◽  
Vol 16 (3) ◽  
pp. 517-525 ◽  
Author(s):  
A. Dziekońska ◽  
L. Fraser ◽  
A. Majewska ◽  
M. Lecewicz ◽  
Ł. Zasiadczyk ◽  
...  
Keyword(s):  
Metabolic Activity ◽  
Storage Time ◽  
Membrane Integrity ◽  
Prolonged Storage ◽  
Atp Content ◽  
Liquid Storage ◽  
Semen Storage ◽  
Boar Semen ◽  
Boar Spermatozoa

Abstract This study was aimed to analyze the metabolic activity and membrane integrity of boar spermatozoa following storage in long-term semen extenders. Boar semen was diluted with AndrohepR EnduraGuardTM (AeG), DILU-Cell (DC), SafeCell PlusTM (SCP) and Vitasem LD (VLD) extenders and stored for 10 days at 17oC. Parameters of the analyzed sperm metabolic activity included total motility (TMOT), progressive motility (PMOT), high mitochondrial membrane potential (MMP) and ATP content, whereas those of the membrane integrity included plasma membrane integrity (PMI) and normal apical ridge (NAR) acrosome. Extender type was a significant (P < 0.05) source of variation in all the analyzed sperm parameters, except for ATP content. Furthermore, the storage time had a significant effect (P < 0.05) on the sperm metabolic activity and membrane integrity during semen storage. In all extenders the metabolic activity and membrane integrity of the stored spermatozoa decreased continuously over time. Among the four analyzed extenders, AeG and SCP showed the best performance in terms of TMOT and PMI on Days 5, 7 and 10 of storage. Marked differences in the proportions of spermatozoa with high MMP were observed between the extenders, particularly on Day 10 of storage. There were not any marked differences in sperm ATP content between the extenders, regardless of the storage time. Furthermore, the percentage of spermatozoa with NAR acrosomes decreased during prolonged storage, being markedly lower in DC-diluted semen compared with semen diluted with either AeG or SCP extender. The results of this study indicated that components of the long-term extenders have different effects on the sperm functionality and prolonged semen longevity by delaying the processes associated with sperm ageing during liquid storage.

Hormonal control of reproduction in cattle

1975 ◽  
Vol 4 ◽  
pp. 71-78 ◽  
Author(s):  
G. E. Lamming ◽  
H. D. Hafs ◽  
J. G. Manns
Keyword(s):  
Dairy Cattle ◽  
Second World War ◽  
Hormonal Control ◽  
Dairy Herds ◽  
High Fertility ◽  
Frozen Semen ◽  
Beef Herds ◽  
Average Size ◽  
Second World

In countries with developed agricultural systems the proportion of dairy cattle inseminated artificially increased substantially following the Second World War, but a similar expansion in the use of artificial insemination (AI) has not been experienced for beef herds. The availability of deep frozen semen provided a further incentive to increase the percentage of dairy cattle artificially inseminated, for the more progressive herd owners soon realized that the technique offered the advantage of a long-term breeding programme with semen from progeny-tested sires available at a relatively modest cost. More recently, however, various developments in herd management have tended to militate against the use of AI in dairy herds, and during the past year there has been a substantial decrease in the total number of dairy cows inseminated which can only be partially explained by the smaller decrease in the size of the national herd. Amongst reasons advanced is the increase in average size of individual herds, resulting in more cows per man and therefore less time available for the observations of oestrus. Since accurate detection of the onset of oestrus is so important in obtaining high fertility following AI, some herd owners have returned to using natural mating. Evidence supporting this view can be derived from the fact that during 1973/74 there was an increase of over one thousand in the number of bull licences issued in England and Wales above the seventeen thousand issued in 1972/73. Of the 18.2 thousand bulls licensed, there were 3.2 thousand crossbred bulls, some obviously for use in dairy herds. The availability of synchronized and controlled ovulation would largely remove the difficulties which have been encountered, and would permit planned management techniques to be more widely applied within such herds.

Long-term thermal storage: a parametric analysis of the thermal discharge of an embedded large-size storage tank

1984 ◽  
Vol 7 (3) ◽  
pp. 273-282 ◽  
Author(s):  
C. Bellecci ◽  
A. Bonanno ◽  
M. Camarca ◽  
M. Conti ◽  
L. La Rotonda ◽  
...  
Keyword(s):  
Parametric Analysis ◽  
Storage Tank ◽  
Thermal Storage ◽  
Thermal Discharge ◽  
Large Size

scholarly journals Minimising inbreeding in small populations by rotational mating with frozen semen

2004 ◽  
Vol 84 (2) ◽  
pp. 87-93 ◽  
Author(s):  
ROSS K. SHEPHERD ◽  
JOHN A. WOOLLIAMS
Keyword(s):  
Gene Pool ◽  
Small Populations ◽  
Asymptotic Level ◽  
Frozen Semen ◽  
Inbreeding Level

Mating plans are investigated in order to minimize inbreeding in small populations when frozen semen is available. For a single dam line it was found that specific sire rotations minimized the asymptotic level of inbreeding when semen is used repeatedly from certain generations. When semen of N foundation (G0) sires is used rotationally over generations it is shown that the inbreeding level asymptotes to 1/(2N+1−2). However, if only G0 sires are used then all genes will eventually descend from the founder sires. Inbreeding can be reduced further by using sires from generation one (G1) and later as this retains genes from the founder dams in the long-term gene pool. If semen from NG0 sires and N unrelated G1 sons is used rotationally then inbreeding asymptotes to (2N−1+1)/(22N+1−2). When there are more founder dams than sires, the asymptotic inbreeding can be reduced even further by using the semen of half-sib G1 sires in rotation. Optimal rotations using full-sib G1 sires or generation 2 (or later) sires will lower the asymptotic inbreeding also, but generally not by much. It was found that when unlimited frozen semen from a specified group of sires was available, the optimal mating plan was achieved by selecting each generation the sire with the least co-ancestry with the current female of the dam line.

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