There is an increasing trend to label milk and dairy products according to production system, absence of certain feed additives and non-use of specific technologies. These claims include the practice of organic farming, the absence of ionophore antibiotics and recombinant bovine somatotropin (r-bST) free milk. Absence-claim labels may imply to some consumers that certain milk is safer and more nutritious than other milk. Milk from r-bST supplemented cows is completely safe for human consumption, since bST is a protein, which is digested like other animal and plant proteins, it is species specific, and most bST in milk is denaturated by pasteurization. Fears of higher insulin growth factor 1 (IGF-1) levels in r-bST milk are unfounded, since these are insignificant compared with the daily secretion of IGF-1 in human saliva and gastro-intestinal secretions. r-bST does not affect milk composition. All milk (i.e. conventional, r-bST free and organic) is compositionally similar, and all milk is wholesome. Various studies have also confirmed that r-bST does not affect milk flavour or manufacturing characteristics that are important during the production of processed dairy foods such as cheese or yoghurt. There is no pathway for ionophore antibiotics from feed to milk and there is no scientific basis for concerns that these additives can give rise to transmissible resistance factors that may compromise the therapeutic use of antibiotics in humans. Organic farming is recognized as a possible way forward to improve sustainability in agriculture. However, it typically requires more resources and produces less food, which currently makes it less profitable and a questionable solution to meeting the world’s growing food supply needs. Improving productive efficiency by using technologies is currently the most logical approach to mitigating the environmental impact of the dairy herd. The potential of r-bST and feed additives such as ionophore antibiotics to reduce greenhouse gas emissions should be recognized and implemented where applicable.
Keywords: Dairy production systems, r-bST, ionophores, organic milk