What Can Influence Lactation in Sheep?

Much of the world's sheep milk that is used for human consumption is made into cheese of various types. Among these are Romano, Roquefort and Feta, though there are numerous other varieties that are made of sheep milk. Understanding the factors that influence lactation in sheep is an important part of animal husbandry, as it can increase milk production and milk quality. Increased production of better quality milk benefits the herd, as the lambs are healthier and stronger, and can increase the production and profitability of products relying on sheep milk.

  1. Nutrition

    • The amount of feed and the quality of nutrition during pregnancy and during milk production are important factors in sheep lactation, according to the Department of Animal Sciences at the University of Wisconsin-Madison. If poorly nourished during pregnancy, the ewe will lack the physical reserves to produce an adequate amount of high quality milk. Without nutritional support while lactating, milk quality will also suffer. Data from the University of Sassari in Sardinia, Italy, indicates that the season in which lambs are born can affect lactation in sheep that obtain a significant portion of their nourishment from grazing. That is because better grazing opportunities are available in the spring than in the autumn, demonstrating the relationship between nutrition and lactation.

    Milking Frequency

    • As demonstrated by experiments conducted by multiple researchers, according to the University of Sassari, as cited by a University of Wisconsin-Madison Extension publication, milking frequency can impact lactation in sheep. If the milk is not used, either via lambs suckling or by milking, the sheep will produce less milk. Increasing milking frequency can increase milk production, however there is an upper limit to that. Non-dairy sheep seem to demonstrate a higher increase than do dairy sheep because their udders are typically smaller than those of dairy sheep, which are bred for enhanced milk production, and thus empty faster. The emptying of the udder signals the body to produce more milk.

    Genetics

    • Genetics has a strong influence on lactation in sheep. Some breeds of sheep are known for the high volume of milk they produce, as well as for the superior quality of that milk. Among these breeds are the East Friesian and the Lacaune, according to information from the website Sheep 201: A Beginner's Guide to Raising Sheep. David L. Thomas of the University of Wisconsin-Madison Department of Meat and Animal Science specifically addressed the relationship between genetics and lactation when discussing ways of improving the milk production rates of American sheep. Thomas wrote that by introducing the genes of high-producing European sheep breeds into American breeds, a significant gain in annual production could be achieved.

    Hormones

    • According to a 1975 article in the "Australian Journal of Biological Sciences" detailing the clinical work of numerous researchers, hormones have a strong impact on lactation in sheep. Estrogen, progesterone and oxytocin each have roles in the lactation process. Estrogen and progesterone help develop the mammary glands and oxytocin serves to stimulate lactation. With this combination of hormones, in clinically performed experiments, even sheep that were not pregnant could produce significant amounts of milk.