Although there are numerous reports on the influence of dietary fats on milk yield and milk composition in the dairy cow (see review by Palmquist, 1984) little is known about the value of fat supplements in the diet of lactating ewes, a species which produces milk of a much higher fat content than the dairy cow. We now report the results of three experiments in which lactating ewes received diets supplemented with a lipid source that was protected from hydrolysis in the rumen.

Individually-penned Finnish Landrace x Dorset Horn ewes, each suckling two lambs by Suffolk rams were used in all three experiments. They were given a diet containing (per kg): 500 g hay (milled through a 4 cm screen), 300 g barley, 90 g white fish meal, 5 g dicalcium phosphate, 3 g salt and 2 g of a trace mineral/vitamin supplement. The crude protein and metabolizable energy contents per kg dry matter were 145 g and 10 MJ respectively. The source of the protected lipid was calcium palmitate (Megalac, Volac Ltd) with lipid and calcium contents (g/kg) of 850 and 90 g respectively.