Mineral concentrations in milk from cows fed seaweed (Saccharina latissima) under different basal protein supplementation
Nanbing Qin, Ásta H. Pétursdóttir, D.J. Humphries, Natasa Desnica, Eric E. Newton, Aila Vanhatalo, Anni Halmemies‐Beauchet‐Filleau, Luke Bell, D.I. Givens, D.T. Juniper, Helga Gunnlaugsdóttir, Sokratis Stergiadis
Abstract
Sixteen multiparous Holstein cows in four blocks of 4 × 4 Latin square over 4-week experimental periods were used to study the effects of seaweed (Saccharina latissima) supplement (with/without) and protein source (rapeseed meal (RSM)/wheat distiller's grain (WDG)) on milk mineral concentrations. Dietary treatments did not affect milk production and basic composition. Feeding seaweed slightly decreased milk Ca and Cu concentrations; whilst increased (by 3.3-fold) milk iodine (I) concentration, due to a higher dietary I supply. Substitution of WDG with RSM increased feed-to-milk transfer of Ca, Na, and Se and decreased that of Mg, P, Fe, and Mn; but only reduced milk Mn and I concentrations (the latter by 27 % as a potential result of increased glucosinolate intake). Seaweed supplement can improve milk I content when cows' I supply/availability is limited, but care should be taken to avoid excess milk I contents that may pose nutritional risks for young children.