Agriculture : Animal biotech


Predicting Male Fertility in Cattle

A UW–Madison researcher has developed a method for predicting whether a sperm sample will have high or low fertility based on average sperm head brightness. Generally, samples that exhibit brighter DNA staining have lower fertility.

In the process, a fresh or frozen sample is stained with DNA-binding fluorescent dye and imaged with a microscope. The brightness of the sperm head is averaged and compared with samples of known fertility.

Kit Predicts Twinning in Cattle

A UW–Madison researcher has developed a genetic test to determine the likelihood a cow or a bull’s female progeny will produce twin offspring. The test is based on the presence or absence of the ‘trio’ haplotype, which is a set of three genetic markers on bovine chromosome 10 (BTA10). In combination, these markers suggest a cow or bull has a higher propensity for twinning.

Genes Predict Developmental Fate of Bovine Embryos

A UW–Madison researcher has identified 10 imprinted genes that impact embryo development. Some of the genes act positively to promote normal development while others act negatively to cause degeneration. The genes are: CDKN1C, IGF2R, MAGEL2, MKRN3, NAP1L5, NDN, PEG3I, PHLDA2, TSSC4 and UBE3A.

The expression levels of these genes can be measured in IVF embryos. Embryos showing the most promising expression patterns may be selected for IVF implantation. Furthermore, the genes that have a negative impact can be inhibited in fertilized eggs to improve the odds of successful development.

Genetic Markers for Bull Fertility

The UW–Madison researcher now has identified several SNPs associated with improved bull fertility, as measured by sire conception rate. These SNPs are found in three spermatogenesis genes, MAP1B, PPP1R11 and DDX4. These genes are highly conserved from flies to humans but were not known to affect reproduction in cattle.

Heat Shock Proteins Are Associated with Reproductive Performance in Cattle

Using an in vitro fertilization system, the UW–Madison researcher now has identified a set of two SNPs of heat shock proteins that are positively associated with fertilization rate and embryonic survival. These SNPs can be used to identify cattle with superior reproductive traits for breeding. 

Progesterone Receptor Gene Is Associated with Increase in Conception Rate and Embyronic Survival

Using an in vitro fertilization system, the UW–Madison researcher now has identified a novel SNP in the PGR gene that is associated with increased conception rate and embryonic survival in cattle. This SNP can be used to identify cattle with superior reproductive traits for breeding. 

Gene Interactions Positively Affect Embryonic Survival in Dairy Cattle

Using an in vitro fertilization system, the UW–Madison researcher now has identified two SNPs in the STAT3 gene that are associated with reproduction.  He discovered that the combination of the two STAT3 SNPs, as well as the combination of a previously known STAT1 SNP and one of the STAT3 SNPs, are correlated with embryonic survival.  The presence of both STAT3 SNPs or one of the STAT3 SNPs and the STAT1 SNP showed a greater association with desirable reproduction traits than either STAT3 SNP alone.

New Genetic Marker Enables Testing for Improved Embryonic Survival Rate & Milk Production in Cattle

The UW-Madison researcher now has identified another SNP that is highly correlated with embryo survival in cattle.  This SNP, which is in the fibroblast growth factor 2 (FGF2) gene, is a predictive marker for improved fertility in dairy cattle.  Alleles of the SNP also are associated with improved milk production and health traits. This SNP can be used to identify cattle with superior traits for breeding.

Genetic Marker for Improved Longevity and Milk Production in Cattle

UW-Madison researchers studied the effects of POU1F1 on health and milk production traits in two independent North American Holstein populations. They identified a single nucleotide polymorphism (SNP) in exon 3 of POU1F1 that changes the amino acid proline to histidine.

This SNP is significantly associated with milk yield and productive life (a measure of longevity), making POU1F1 a strong candidate for marker-assisted selection in dairy cattle breeding programs. Dairy cattle could be screened for the presence of this SNP, and animals with the beneficial allele could be selectively bred.

Genetic Marker for Improved Milk Production and Longevity in Dairy Cattle

A UW-Madison researcher has developed a genetic marker for improved milk production, longevity and other health traits in dairy cattle. The researcher used a positional candidate gene approach to study the association of the proteinase inhibitor (PI) gene with milk production traits in Holstein dairy cattle. Several single nucleotide polymorphisms (SNPs) were identified. One haplotype of PI is strongly associated with increased milk protein percentage, increased milk fat percentage, decreased somatic cell count and increased productive life in dairy cattle.

Dairy Cattle Breeding for Improved Milk Production Traits in Cattle

A UW-Madison researcher has identified genetic markers for improved production traits, including fat content, fat percentage, protein percentage, somatic cell count and productive life. The markers include single nucleotide polymorphisms (SNPs) in four genes: bovine uterine milk protein (UTMP), signal transducer and activator of transcription (STAT1), osteopontin (OPN) and lectin-like oxidized LDL receptor (OLR1). Alleles of these SNPs are associated with increased milk-fat yield and percentage, increased milk-protein percentage, decreased somatic cell score and/or increased productive life.