subject: genetics

How Probiotic Bacteria Protect Against Allergy to Cow’s Milk

How Probiotic Bacteria Protect Against Allergy to Cow’s Milk

Whether it’s to nuts, cow’s milk, eggs, or some other food, food allergies have become increasingly common in recent decades. Allergy to cow’s milk is especially common, affecting up to 3% of children worldwide. There have been many recent efforts to treat cow’s milk allergy, and probiotics have looked particularly promising. Recent studies have shown that feeding infants formula supplemented with the probiotic Lactobacillus rhamnosus GG (LGG) results in higher rates of tolerance to cow’s milk compared to infants fed unsupplemented formula. Read More...

Accounting for Lactase Mutants

Accounting for Lactase Mutants

Back in the 50s and 60s, work on lactose intolerance was often published under cringeworthy and blunt racial titles. A Nature article from 1969 sums it up with ‘Can Asians Digest Milk?’ It was also probably a subliminal non-accident that ‘lactose intolerance’—which is the typical condition for adult humans—became common parlance for a trait for which those with northern European ancestry are the real mutants. Many decades on, the genetic basis of the ability to digest lactose has been largely pinned down. As it turns out, there are different genetic reasons for the mutants’ lactose tolerance in the various populations that drink milk without intestinal incident, and the gene that confers mutant power in Europeans is only part of the story. That research history is discussed below, along with recent work that has extended the field’s reach beyond genetics. Investigations of the transcontinental basis of lactose tolerance are now providing insights into mankind’s cultural, as well as biological evolution. Read More...

Making Sense of Dairy Biosystems

Making Sense of Dairy Biosystems

We live in an information-rich world. Each of us is capable of downloading gigabytes of data on our mobile or desktop devices each day. The upswing in data generation is also true of dairy science, which has moved into the big data realm. My students can create more data in an afternoon than I created in an entire PhD project when I was a student. Needless to say, capturing and analyzing this data is both challenging and rewarding. Since genomic data became more accessible, a number of approaches have been developed to bring the data together in useful ways. Gradually these approaches have become more sophisticated and insightful. A recent study by Widmann et al. provides a great example of how integrating different sources of large-scale genomic data can shed light on how dairy cows convert their feed into milk. Read More...

Predicting Performance in Dairy Cows of the Future

Predicting Performance in Dairy Cows of the Future

Selective breeding of dairy cows is a major part of modern dairy farming. Farmers can select the bulls that they want to use to produce animals for their herd. One bull may sire thousands of daughter cows via highly developed systems for artificial insemination. The availability of lots of stored semen from bulls that have been shown to produce cows with excellent production and health traits has been a backbone of improving efficiency and production in dairy farms for several decades. There has been a continuous effort to build on the methods and procedures that contribute to selective breeding, most recently with the advent of genomic tools. Read More...

Mother’s DNA Alters Baby’s Gut Microbes

Mother's DNA Alters Baby's Gut Microbes

A mother’s genes determine a lot of things about her newborn, and it turns out that their effects extend even to the bacteria that colonize the baby’s gut. The establishment of a baby’s gut microbial community is an important event in a newborn’s life. A new study, conducted by microbial ecologist Zachary Lewis, finds that the gut microbiome of breastfed infants is influenced by the types of sugars present in breast milk [1, 2]. Specifically, a particular gene in mothers that modifies sugars in breast milk influences infants’ gut microbiome. Read More...

The Fat Controllers: Dairy Cattle Genetics and Milk Fat Composition

The Fat Controllers: Dairy Cattle Genetics and Milk Fat Composition

The mixture of fats in milk fat varies a lot between dairy cow breeds, different farms, and even individual cows. Depending on what the cows eat and how long they have been milking, the percentage of fat in the milk will fluctuate. Furthermore, we also know that there is a very strong genetic influence on the quantity of milk fat [2]. The Dutch, and more recently, the Danish dairy scientists, decided to dissect the milk fat into individual components, and measure the impact of the cow’s genetic makeup on each component. Read More...

Milk Protein in Diet Predicts Human Height

Milk Protein in Diet Predicts Human Height

The Dutch and Montenegrins are the tallest men in Europe, measuring in at an average height of just over six feet (1.83 m). Separated by nearly 2000 miles, what might these two countries have in common that explains their above-average stature? The results of a new study [1] suggest their height may have as much to do with what is on their dinner plate as what is in their DNA. Using data from 42 European nations, as well as the U.S., New Zealand, and Australia, Grasgruber et al. [1] found that the strongest predictor of male adult height was the population’s protein index - the amount of protein consumed from animal sources, such as dairy and pork, compared to proteins consumed from vegetable sources, such as wheat. If height is a marker for the health of a population, could the answer to improving health outcomes be as simple as dining like the Dutch? Read More...

Towards Individualized Genomes for Dairy Cows

Towards Individualized Genomes for Dairy Cows

International cooperation between scientists has really taken off in genomic sciences, and now, in a program that has grown out of dairy genetic research, one thousand bulls are set to be immortalized by having their DNA sequenced. The so-called 1000 Bulls Genome Project is an international collaboration between scientists in Europe, USA, and Australia. The project began in 2010, when scientists were looking for a way to share the huge cost of sequencing many entire genomes. The result was the 1000 Bulls Genome Project, which spreads the costs and shares the resources to help geneticists apply their collective knowledge of cattle to improve the productivity of cattle herds. Read More...

Milk and Mortality

Milk and Mortality

A research article published in the British Medical Journal on dairy intake and mortality is causing a lot of fuss [1]. So far, the journal has published 45 rapid responses to this article compared with an average of 3 responses to other articles in the same issue. What’s all the fuss about? Read More...