WINTER BONUS MAGAZINE 2025

ally, a strong rumen epithelium acts as a barrier against pathogens, mately, better rumen development leads to improved performance in estinal tract bered terial. cows, ents: rumen ng up g to as the down s. The s as a rients. astric place. xtract nique 1. Rumen The rumen’s inner surface is covered with papillae (finger-like projections), which increase the surface area for the absorption of volatile fatty acids (VFAs) produced during fermentation. The papillae are densely arranged and help in the absorption of nutrients, providing a large surface area for microbial action and nutrient uptake. 2. Reticulum The reticulum has a honeycomb-like pattern, with hexagonal cells that help trap and process food. This structure aids in the separation of smaller particles from larger ones and helps move ingesta back into the rumen for further fermentation (regurgitation) or toward the omasum. 3. Omasum The omasum has many layers of folds, or laminae, that resemble pages of a book. These folds increase the surface area for absorption of water, nutrients, and VFAs. The surface is smooth, but the structure itself allows efficient passage and absorption of digested material. 4. Abomasum The inner surface of the abomasum is lined with gastric pits and rugae (folds), which help in the secretion of digestive enzymes and acids. Unlike the other compartments, the abomasum functions similarly to a monogastric stomach with a smooth surface designed for enzymatic digestion. The inner surface of the abomasum is lined with gastric pits and rugae (folds), which help in the secretion of enzymes and acids. Unlike the other compartments, the abomasum functions similarly to a monogastric sto smooth surface designed for enzymatic digestion. Together, these specialized surface structures enable ruminants to process and absorb nutrients from plant them uniquely adapted to an herbivorous diet. Why is a ruminant born with an underdeveloped rumen? There are mainly 4 reasons why ruminants are born with underdeveloped rumens: 1. During the calving process the calve must squeeze through the narrow pelvic opening. This will eithe or the rumen fluid will be regurgitated and contaminate the birth canal. 2. When the animal is born the rumen is sterile, it would not be possible to populate the rumen with rume the newborn is in utero. 3. With a fully developed rumen, there will be no esophageal groove. The colostrum will have to enter rumen the colostrum will be either diluted by the rumen fluid or destroyed by the rumen microbes. With rumen at birth there will be no colostral immunity. 4. It takes 12 to 24 hours for the rumen to produce and absorb nutrients. Even if the rumen is develop with microbes at birth, the neonate will not be able to get enough dry matter intake fast enough to sust 1 2 3 4 Together, these specialised surface structures enable ruminants to process and absorb nutrients from plant material, making them uniquely adapted to a herbivorous diet. Why is a ruminant born with an underdeveloped rumen? There are mainly four reasons why ruminants are born with underdeveloped rumens: 1. During the calving process the calv must squeeze through the narrow pelvic opening. This will either burst the rumen or the rumen fluid will be regurgitated and contaminate the birth canal. 2. When the animal is born the rumen is sterile; it would not be possible to populate the rumen with rumen microbes while the newborn is in utero. 3. With a fully developed rumen, there will be no esophageal groove. The colostrum will have to enter the rumen and in the rumen the colostrum will be either diluted by the rumen fluid or destroyed by the rumen microbes. With a fully developed rumen at birth there will be no colostrum immunity. 4. It takes 12 to 24 hours for the rumen to produce and absorb nutrients. Even if the rumen is developed and populated with microbes at birth, the neonate will not be able to get enough dry matter intake fast enough to sustain life. Rum When conce chang stoma undev the tot to no r The ru called and a from e The si rest of densit shorta The gr Rumen development When a ruminant is born, it is born with an underdeveloped rumen and reticulum. The neonate is essentially a monogastric concerning its gastrointestinal system. The relative size and development of the Winter 2025 BONUS www.agribonus.co.za 42