Unlocking dairy potential: Insights into drinking water minerals composition effects on lactating cow performance.

Genetic selection, optimizing feed, inseminations, and housing conditions are among the major strategies aimed at improving production and profit in the dairy industry, with a great number of studies focusing on those topics. Absent from the list is a strategy that explores the ability to control the mineral composition of drinking water. The common practice is to ensure unlimited access to fresh water, and as long as the water is not too loaded with dissolved solids (below 1000 ppm), it is considered safe to drink. However, very little is known of what happens if the water mineral composition within these parameters is altered. The aim of the study cited was thus to see what happens if the water composition is changed; in this instance by measuring the effect of drinking water salinity and hardness (calcium and magnesium) on lactating cow performance.

After constructing experimental systems capable of controlling and measuring the drinking of individual cows and executing two independent trials (4 x 4 Latin square), it was found that lactating Israeli Holstein cows drank approximately 142L in an average of eight drinking events per day, ranging from a few litres up to 83L in a single event. The cows consumed from 120 to 160L per day, with consumption positively related to feed intake (R² = 0.66). The results of the first trial, conducted in the summer of 2022, examined the effect of drinking water salinity by adding sodium chloride to create a water with electrical conductivities of 400, 600, 800, and 1000 μS per cm respectively. Analysis of the milk production data revealed an increased milk yield of up to 2kg per day with the higher water salinity. In the second trial, conducted in the summer of 2023, it was found that by increasing the drinking water hardness to respectively 80, 160, 240, or 360 ppm (calcium carbonate equivalent), by adding 46, 92, or 138 mg per litre of calcium chloride and magnesium sulphate (with a calcium-to-magnesium ratio of 2:1), the milk yield was increased by up to 2.2 kg per day.

The results are surprising, but nevertheless show a potential of manipulating drinking water to enhance dairy production. The subject clearly warrants further research.