Protective immunity induced through two calving seasons following administration of live epizootic bovine abortion agent (EBAA) vaccine.

A live, infectious vaccine candidate for epizootic bovine abortion, designated EBAA Vaccine, USDA-APHIS Product code #1544.00, has been reported to be both safe and effective. Previous studies established that a single dose of EBAA vaccine administered to cows at potencies of either 2000 or 500 live P.

Germline ablation achieved via CRISPR/Cas9 targeting of in bovine zygotes.

is expressed in migrating primordial germ cells (PGCs) to protect them from apoptosis, and it is known to be a critical factor for germline development of both sexes in several organisms. However, to date, live knockout (KO) cattle have not been reported, and the specific role of in male cattle, or bulls, remains unexplored. This study generated KO cattle cytoplasmic microinjection of the CRISPR/Cas9 system produced bovine zygotes and evaluated the effect of elimination on bovine germline development, from fetal development through reproductive age.

Gender disparity in survival of early porcine fetuses due to altered androgen receptor or associated U2 spliceosome component.

A single locus on the X chromosome codes for androgen receptor (AR) although this gene is subject to alternative splicing. AR is expressed in multiple tissues in males and females and is essential for reproductive success in the male. Since male and female mice are viable following naturally occurring and engineered loss of function with male mice infertile as anticipated, functional deletion of AR in pigs was hypothesized to provide a genetic containment strategy for males with edited genomes.

LincRNA#1 knockout alone does not affect polled phenotype in cattle heterozygous for the celtic POLLED allele.

A long intergenic non-coding RNA (lincRNA#1) is overexpressed in the horn bud region of polled (hornless) bovine fetuses, suggesting a potential role in horn bud suppression. Genome editing was used to test whether the absence of this sequence was associated with the horned phenotype. Two gRNAs with high mutation efficiencies targeting the 5' and the 3' regions flanking the lincRNA#1 sequence were co-injected with Cas9 as ribonucleoprotein complexes into bovine zygotes (n = 121) 6 h post insemination.

Protection of Cattle against Epizootic Bovine Abortion (EBA) Using a Live Vaccine.

Epizootic bovine abortion (EBA) is an arthropod-borne bacterial disease that causes significant economic loss for cattle producers in the western United States. The etiologic agent, , is an intracellular pathogen that has yet to be cultivated in vitro, thereby requiring novel methodologies for vaccine development. A vaccine candidate, using live -infected cells (-LIC) harvested from mouse spleens, was tested in beef cattle.

A deletion at the polled P locus alone is not sufficient to cause a polled phenotype in cattle.

Dehorning is a common practice in the dairy industry, but raises animal welfare concerns. A naturally occurring genetic mutation (P allele) comprised of a 212 bp duplicated DNA sequence replacing a 10-bp sequence at the polled locus is associated with the hornless phenotype (polled) in cattle. To test the hypothesis that the 10 bp deletion alone is sufficient to result in polled, a CRISPR-Cas9 dual guide RNA approach was optimized to delete a 133 bp region including the 10 bp sequence.

Effects from disruption of mitochondrial electron transport chain function on bull sperm motility.

Sperm mitochondrial function is essential for normal physiology and fertility, but the importance of mitochondrial activity to support specific sperm functions, such as motility, varies between species. It was previously believed that mitochondrial function was not necessary for bull sperm motility [1]; however, this theory is contradicted by recently reported findings that the upper fraction of bull sperm swim-up preparations had both high motility and elevated mitochondrial oxygen consumption rates [2]. The objective of this study was to investigate the relationship between mitochondrial function and motility in bull sperm.

One-step generation of a targeted knock-in calf using the CRISPR-Cas9 system in bovine zygotes.

Background: The homologous recombination (HR) pathway is largely inactive in early embryos prior to the first cell division, making it difficult to achieve targeted gene knock-ins. The homology-mediated end joining (HMEJ)-based strategy has been shown to increase knock-in efficiency relative to HR, non-homologous end joining (NHEJ), and microhomology-mediated end joining (MMEJ) strategies in non-dividing cells.

Results: By introducing gRNA/Cas9 ribonucleoprotein complex and a HMEJ-based donor template with 1 kb homology arms flanked by the H11 safe harbor locus gRNA target site, knock-in rates of 40% of a 5.

Effect of continued metabolic acidification into the first 3 days of lactation on blood calcium status in postpartum dairy cattle: A randomized controlled trial.

Although incidence of clinical hypocalcemia in postpartum dairy cows is low in US dairies, subclinical hypocalcemia after calving is common and has been associated with metabolic and infectious disease. It is widespread farm practice to feed a diet rich in anions to prepartum dairy cattle to support calcium homeostasis. However, this diet is typically discontinued at parturition, when calcium needs are still high.

Harnessing endogenous repair mechanisms for targeted gene knock-in of bovine embryos.

Introducing useful traits into livestock breeding programs through gene knock-ins has proven challenging. Typically, targeted insertions have been performed in cell lines, followed by somatic cell nuclear transfer cloning, which can be inefficient. An alternative is to introduce genome editing reagents and a homologous recombination (HR) donor template into embryos to trigger homology directed repair (HDR).

Author Correction: CRISPR/Cas9 microinjection in oocytes disables pancreas development in sheep.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Author Correction: Genomic and phenotypic analyses of six offspring of a genome-edited hornless bull.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Genomic and phenotypic analyses of six offspring of a genome-edited hornless bull.

Genome editing followed by reproductive cloning was previously used to produce two hornless dairy bulls. We crossed one genome-edited dairy bull, homozygous for the dominant P Celtic POLLED allele, with horned cows (pp) and obtained six heterozygous (Pp) polled calves. The calves had no horns and were otherwise healthy and phenotypically unremarkable.

The use of progesterone intravaginal devices is superior to use of the ram effect at hastening the reproductive performance in transitional Targhee ewes.

To compare the use of controlled intravaginal drug release (CIDR, EAZI-BREED™ CIDR Sheep, USA, Zoetis) with the ram effect, a combination of CIDR and ram effect and the addition of P.G.600 to each of these scenarios on their contribution to inducing the onset of cyclicity and their ability to improve reproductive efficiency in a commercial sheep flock, a randomized clinical trial was conducted.

Mineral status of California beef cattle.

Optimal mineral nutrition is required for cattle reproduction, immune function, and structural development. Formal evaluation of the current mineral status of California beef cattle is currently lacking. In 2017, a survey was initiated that evaluated a panel of 10 different minerals in 14 counties across California.

Mosaicism diminishes the value of pre-implantation embryo biopsies for detecting CRISPR/Cas9 induced mutations in sheep.

The production of knock-out (KO) livestock models is both expensive and time consuming due to their long gestational interval and low number of offspring. One alternative to increase efficiency is performing a genetic screening to select pre-implantation embryos that have incorporated the desired mutation. Here we report the use of sheep embryo biopsies for detecting CRISPR/Cas9-induced mutations targeting the gene PDX1 prior to embryo transfer.

CRISPR/Cas9 microinjection in oocytes disables pancreas development in sheep.

One of the ultimate goals of regenerative medicine is the generation of patient-specific organs from pluripotent stem cells (PSCs). Sheep are potential hosts for growing human organs through the technique of blastocyst complementation. We report here the creation of pancreatogenesis-disabled sheep by oocyte microinjection of CRISPR/Cas9 targeting PDX1, a critical gene for pancreas development.

CRISPR-Cas9 mediated one-step disabling of pancreatogenesis in pigs.

Genome editing using programmable nucleases has revolutionized biomedical research. CRISPR-Cas9 mediated zygote genome editing enables high efficient production of knockout animals suitable for studying development and relevant human diseases. Here we report efficient disabling pancreatogenesis in pig embryos via zygotic co-delivery of Cas9 mRNA and dual sgRNAs targeting the PDX1 gene, which when combined with chimeric-competent human pluriopotent stem cells may serve as a suitable platform for the xeno-generation of human tissues and organs in pigs.

Hydrops associated with chondrodysplasia of the fetus in a miniature Scottish Highland cow.

CASE DESCRIPTION A 2-year-old primiparous miniature Scottish Highland cow with an unknown breeding date was evaluated for suspected hydrops. CLINICAL FINDINGS Transabdominal and transrectal ultrasonographic examination identified a large amount of hypoechoic fluid within an enlarged uterus; the fetus could not be identified. Presence of a severely distended uterus and concerns regarding associated health risks to the cow led to the decision to induce labor.