Pasture feeding has a beneficial effect on the nutritional composition of milk and dairy products, according to a study conducted by Teagasc.
The study – known as ‘Profiling Milk from Grass’ – examined the impact of pasture and indoor total mixed ration (TMR) feeding systems on the composition and quality of milk and dairy products.
The results of which were discussed by Teagasc’s Tom O’Callaghan, last week, during the National Dairy Council’s (NDCs) annual farm walk and seminar.
It is estimated that just “10% of global bovine milk supply is derived from pasture-feeding systems”. This puts Irish dairy manufacturers in a unique position when marketing Irish dairy products.
The ‘Profiling Milk from Grass’ study compared three spring-calving herd’s – each containing 54 cows – over the course of a full lactation.
Three diets were studied, which included: a perennial ryegrass pasture; a perennial ryegrass with 20% clover pasture and a total mixed ration (TMR) (7.15kg grass silage, 7.15kg of maize and 8.3kg of concentrates/day) indoor system.
Looking at all systems in terms of production, he said: “As expected, the TMR cows produced a lot more milk throughout the entire lactation because they were on a specially formulated diet.
“But, on a litre-by-litre basis the pasture-feeding systems produced milk with significantly higher total milk solids and this followed through throughout the entire lactation.
“This was driven by significantly higher levels of fat and crude protein in the grass,” he added.
The grass clover diet also increased milk solid yield by 39kg MS/cow compared to the grass only diet. In addition, the grass clover diet increased milk production compared to the grass-only diet from June until the end of lactation – due to increased herbage quality.
Competitive advantage
Going further, he said: “The diet of cows is primarily going to affect the fat composition and we see that pasture-feeding produces milk with significantly higher Ω-3 fatty acids – which are healthy fatty acids.
“Also, pasture-based feeding systems showed a two-fold increase in conjugated linoleic acid (CLA) which is a beneficial nutrient with a variety of benefits.”
In comparison, the TMR diet “increased the level of Ω-6 fatty acids – which are essential fatty acids – that we can’t make these ourselves; but, because of different food trends we are trying to increase the level of Ω-3 fatty acids and decrease the level of Ω-6 fatty acids in our diets”.
Finally, Tom made reference to the distinct yellow colour and flavour which Irish dairy products are so well-known for.
“Pasture-feeding systems give off a distinctive sensory profile, that is why Irish dairy has a characteristic taste and colour.
“We are known for our soft yellow golden butter with other products such as yogurt and cheddar cheeses also having a distinct golden colour, texture and aroma proprieties.
“This yellow colour is due to increased levels of ß-carotene that come through the fresh grass and this follows throughout processing – which gives us our characteristic golden yellow colour,” concluded Tom.
This is why the Irish Kerrygold butter is the number two butter brand in the US and the fastest selling food or drink item on supermarket shelves in Germany last year.