title: Lowering Sperm Dose Rates in Frozen Semen for Bovine Artificial Breeding

authors: Pitt, Colin John

subjects: semen

abstract: The New Zealand Dairy industry relies on artificial breeding to produce high genetic
merit replacement stock. Proven bull semen is extended and preserved as either
ambient temperature product or as frozen doses. High fertility is essential to maintain
synchronicity of lactation with the spring surge of grass growth.
To improve efficiency in the utilization of the very best bulls producers try to lower
sperm dose rates without compromising fertility. Livestock Improvement
Corporation's (LIC) Long Last Liquid ™ (LLL) is most commonly used during the
peak season and is their most important product. However, shortfalls and specifically
targeted matings are met with frozen semen. Lowering sperm dose rates in both liquid
and frozen semen maximises the usage of elite sires increasing genetic gain, lowering
overheads and garnering premium prices for the semen producer.
A product for improving frozen semen technology was developed whereby a discrete
quantity of pretreated semen was placed alongside a beneficial post-thawing
redilution medium in a standard semen straw. This emulated a larger-scale process
developed to freeze semen in times of low demand and redilution into the LLL form
for use as an ambient temperature product. This rediluted product has been proved to
enhance semen survival and to allow fertility to be maintained at sperm dose rates
lower than the widely accepted standard for frozen semen.
The physical packaging of the semen into the industry standard single dose straw in a configuration that separated incompatible components was novel. This configuration
was essential to prevent damage to the sperm during the freezing process from low
solubility components in the post-thaw redilution medium. Separation between the
semen and diluent within the straw was achieved by the introduction of a gas partition
or air bubble between the two liquids.
A large-scale field trial showed that the new product could produce savings of up to
25% of the sperm needed for a semen dose to achieve equivalent fertility.
Furthermore, the production cost per dose was lowered in comparison to the standard
semen processing system used at LIC.

text: Lowering Sperm Dose Rates in Frozen Semen for Bovine Artificial Breeding The New Zealand Dairy industry relies on artificial breeding to produce high genetic
merit replacement stock. Proven bull semen is extended and preserved as either
ambient temperature product or as frozen doses. High fertility is essential to maintain
synchronicity of lactation with the spring surge of grass growth.
To improve efficiency in the utilization of the very best bulls producers try to lower
sperm dose rates without compromising fertility. Livestock Improvement
Corporation's (LIC) Long Last Liquid ™ (LLL) is most commonly used during the
peak season and is their most important product. However, shortfalls and specifically
targeted matings are met with frozen semen. Lowering sperm dose rates in both liquid
and frozen semen maximises the usage of elite sires increasing genetic gain, lowering
overheads and garnering premium prices for the semen producer.
A product for improving frozen semen technology was developed whereby a discrete
quantity of pretreated semen was placed alongside a beneficial post-thawing
redilution medium in a standard semen straw. This emulated a larger-scale process
developed to freeze semen in times of low demand and redilution into the LLL form
for use as an ambient temperature product. This rediluted product has been proved to
enhance semen survival and to allow fertility to be maintained at sperm dose rates
lower than the widely accepted standard for frozen semen.
The physical packaging of the semen into the industry standard single dose straw in a configuration that separated incompatible components was novel. This configuration
was essential to prevent damage to the sperm during the freezing process from low
solubility components in the post-thaw redilution medium. Separation between the
semen and diluent within the straw was achieved by the introduction of a gas partition
or air bubble between the two liquids.
A large-scale field trial showed that the new product could produce savings of up to
25% of the sperm needed for a semen dose to achieve equivalent fertility.
Furthermore, the production cost per dose was lowered in comparison to the standard
semen processing system used at LIC.

year: 2007

title: Evolution of Bacillus subtilis: A Novel Phenotype and its Challenges

authors: Murray, Mitchell John

subjects: Evolution

abstract: The enzyme LeuB from the last common ancestor of the firmicutes has been statistically recreated using several different methods. This project deals with two versions, Rec/LG and Rec/EX. To better understand these resurrected enzymes, the proteins were crystallised. Despite extensive efforts to produce crystals of diffraction quality, none of the crystals developed during this project were large enough to be of any use in X-Ray crystallography. Strains of Bacillus subtilis were genetically modified to each have one of either Rec/LG or Rec/Rec/EX in place of the native leuB gene, and then were allowed to evolve alongside an unmodified strain for 500 generations. Attempts were made to extract DNA from the evolved strains at different points throughout the evolution experiment for whole genome sequencing, and to amplify the leuB gene via PCR for direct comparisons of changes that may have occurred to the leuB gene over the course of the evolution experiment. These attempts were ultimately unsuccessful. In lieu of this genetic data, phenotypic changes to the evolved strains were characterised. A new phenotype appeared extremely early on in the experiment (by generation 54), and in less than 300 generations had swept to fixation in 9 independent strains. In all cases, this phenotype included poor growth on LB agar plates, small colonies, and small cells. Similar changes have been observed before in laboratory experiments of B. subtilis, but none occurred so quickly or so uniformly across independent samples.

text: Evolution of Bacillus subtilis: A Novel Phenotype and its Challenges The enzyme LeuB from the last common ancestor of the firmicutes has been statistically recreated using several different methods. This project deals with two versions, Rec/LG and Rec/EX. To better understand these resurrected enzymes, the proteins were crystallised. Despite extensive efforts to produce crystals of diffraction quality, none of the crystals developed during this project were large enough to be of any use in X-Ray crystallography. Strains of Bacillus subtilis were genetically modified to each have one of either Rec/LG or Rec/Rec/EX in place of the native leuB gene, and then were allowed to evolve alongside an unmodified strain for 500 generations. Attempts were made to extract DNA from the evolved strains at different points throughout the evolution experiment for whole genome sequencing, and to amplify the leuB gene via PCR for direct comparisons of changes that may have occurred to the leuB gene over the course of the evolution experiment. These attempts were ultimately unsuccessful. In lieu of this genetic data, phenotypic changes to the evolved strains were characterised. A new phenotype appeared extremely early on in the experiment (by generation 54), and in less than 300 generations had swept to fixation in 9 independent strains. In all cases, this phenotype included poor growth on LB agar plates, small colonies, and small cells. Similar changes have been observed before in laboratory experiments of B. subtilis, but none occurred so quickly or so uniformly across independent samples.

year: 2018

title: Telling “Us” in the “Days Destined to You: Response Life-Telling: Indigenous Oral Autobiography and the Performance of Relation

authors: Mahuika, Nepia

subjects: Arts & Humanities

abstract: This “tau-utuutu” (responsive) protocol feels familiar to me.² My turn to speak, to respond, to share in a conversation with Warren Cariou’s stimulating essay on “Life-Telling,” Indigenous autobiography, and Dovie Thomason. It reminds me of how life-telling, orality, and history, interweave and work in my tribal universe. At home, we take turns speaking. We inherit our words, we respond, carve, and weave new narratives—make them ours. Where I come from, lives are frequently “told,” sung, cried, carved, and performed, through tribal conversations, a chorus of textured tones, sometimes in a grand debate within which our personal and collective pasts, presents, and futures converge and diverge.³ I am glad, then, to be invited, to add my voice to this present discussion. It feels natural . . . normal . . . Native.

text: Telling “Us” in the “Days Destined to You: Response Life-Telling: Indigenous Oral Autobiography and the Performance of Relation This “tau-utuutu” (responsive) protocol feels familiar to me.² My turn to speak, to respond, to share in a conversation with Warren Cariou’s stimulating essay on “Life-Telling,” Indigenous autobiography, and Dovie Thomason. It reminds me of how life-telling, orality, and history, interweave and work in my tribal universe. At home, we take turns speaking. We inherit our words, we respond, carve, and weave new narratives—make them ours. Where I come from, lives are frequently “told,” sung, cried, carved, and performed, through tribal conversations, a chorus of textured tones, sometimes in a grand debate within which our personal and collective pasts, presents, and futures converge and diverge.³ I am glad, then, to be invited, to add my voice to this present discussion. It feels natural . . . normal . . . Native.

year: 2016