Environmental and genetic factors influence the vitamin D content of cows’ milk

Abstract

Vitamin D is obtained by cattle from the diet and from skin production via UVB exposure from sunlight. The vitamin D status of the cow impacts the vitamin D content of the milk produced, much like human breast milk, with seasonal variation in the vitamin D content of milk well documented. Factors such as changes in husbandry practices therefore have the potential to impact the vitamin D content of milk. For example, a shift to year-round housing from traditional practices of cattle being out to graze during the summer months and housed during the winter only, minimises exposure to the sun and has been shown to negatively influence the vitamin D content of the milk produced. Other practices such as changing dietary sources of vitamin D may also influence the vitamin D content of milk, and evidence exists to suggest genetic factors such as breed can cause variation in the concentrations of vitamin D in the milk produced. The present review aims to provide an overview of the current understanding of how genetic and environmental factors influence the vitamin D content of the milk produced by dairy cattle. A number of environmental and genetic factors have previously been identified as having influence on the nutritional content of the milk produced. The present review highlights a need for further research to fully elucidate how farmers could manipulate the factors identified to their advantage with respect to increasing the vitamin D content of milk and standardising it across the year.

Short communication: Technological and seasonal variations of vitamin D and other nutritional components in donkey milk

“…This is probably due to the dif-ferent sun exposure of the animals facilitated by the outdoor farming system. Seasonal variations in vitamin D content of milk have been well documented in cows, with higher concentrations in the summer months than in the winter (Jakobsen and Saxholt, 2009;Weir et al, 2017) In conclusion, raw and pasteurized donkey milk showed a high content of vitamin D. Although donkey milk is a niche product, the interest of our results derives from its use in consumers at risk of nutritional deficiencies. In fact, for these categories of people, donkey milk could be helpful (together with appropriate integrations) in meeting deficiencies of vitamin D.…”

“…Research has highlighted the variability factors of vitamin D in milk by analyzing endogenous, exogenous, and technological factors, such as season, age of the animal, treatment, and conservation (Jakobsen and Saxholt, 2009;Weir et al, 2017). However, most of the studies focus on bovine milk, whereas little information regarding donkey milk is available (Gentili et al, 2013;Bulgari et al, 2015).…”

Environmental selection during the last ice age on the mother-to-infant transmission of vitamin D and fatty acids through breast milk

“…Milk vitamin D content varies by cattle breed, with some producing notably higher concentrations irrespective of UV exposure (reviewed in ref. 106 ). Functional associations of 31 genes expressed in cows producing different milk protein and fat concentrations include transcriptomes of genes involved in mammary gland bud elongation ( 107 ), suggesting that mammary duct branching contributes to the genetic underpinnings of variation in milk composition.…”

Chemical composition, adulteration, total microbial load, and heavy metal in raw milk samples collected from dairy farms and urban areas in Lahore District, Pakistan

“…There was a certain change in composition of milk available in all the areas during all the collecting intervals falling in different seasons of the year. Regional nutrition patterns and seasonal climatic conditions are the important factors that control the milk composition (Ozrenk & Selcuk Inci, ; Weir et al, ). But here also the water and other adulterants play a vital role as the adulteration of milk is more during summer season and less in winter months.…”