What Is Rumination in Cattle? A Full Breakdown of Rumination Time
What is rumination in cattle? Rumination refers to the process in which certain animals, some time after eating, bring semi-digested food back from the stomach into the mouth to chew again. After cattle finish eating forage or while lying down to rest, people will see the cow's mouth constantly chewing the food into a bolus and swallowing it again. Each time takes about 1 to 2 minutes, and about 6 to 8 hours per day are needed for rumination. This can make large amounts of forage finer and softer and allow it to pass more quickly through the rumen to the later parts of the digestive tract, so that cattle can consume more forage.
The Timing of Rumination in Cattle
Rumination in cattle usually begins 30 to 60 minutes after feeding stops, and calves show rumination at about 21 to 30 days. Beef cattle ruminate at night, with 7 to 8 hours used for rumination in a 24-hour period; generally 70% in winter and 54% in summer, with 10 to 15 rumination periods per 24 hours. Each rumination period lasts 24 to 36 minutes for yellow cattle and 40 to 60 minutes for beef cattle. An ordinary cow chews one bolus an average of 48 times in the mouth, while beef cattle chew 30 to 60 times. When eating coarse tough straw or large amounts of withered yellow pasture in winter, the number of chews also increases accordingly.
The Process of Rumination in Cattle
Cattle usually eat rather hastily, especially coarse feed, and most of it is swallowed into the rumen without being fully chewed. After being soaked and softened in the rumen for some time, the food is brought back to the mouth by regurgitation, chewed again, mixed with saliva again, and swallowed back into the rumen. When cattle are sick, overly fatigued, or subjected to strong external stimulation, rumination behavior can be weakened or stop completely. Once rumination stops, food remains in the rumen, and because the gas produced by fermentation cannot be expelled, rumen bloating can result.
The Stomach Structure of Cattle
1. Rumen: The rumen is the largest, accounting for 80% of the total volume of the four stomachs. It contains large numbers of microorganisms growing and reproducing, and a very large portion of the feed is digested here.
2. Reticulum: The reticulum accounts for 5% of the total volume of the four stomachs. Its function is like a sieve, retaining heavy objects swallowed with the feed, such as nails and wire.
3. Omasum: The omasum accounts for 7% of the total volume of the four stomachs. Its main function is to absorb water from the feed and to squeeze and grind the feed.
4. Abomasum: The abomasum, also called the true stomach, accounts for 8% of the total volume of the four stomachs. Its function is the same as the stomach of monogastric animals; it can secrete digestive juices and digestive enzymes and digest feed that was not digested in the rumen as well as the rumen microorganisms that enter the abomasum together with the rumen digesta.
Summary: In fact, rumination is one of the important digestive processes of cattle and other ruminant animals. Through rumination, feed is chewed fine and mixed with saliva (cattle secrete 100 to 200 liters of saliva per day, and the saliva contains large amounts of salt and endogenous urea, etc.), which increases the surface area for breakdown by rumen microorganisms and keeps rumen pH stable between 6 and 7, creating good conditions for rumen fermentation, protein metabolism, and so on.