Gastric juice and enzymes in animals Gastric juice Gastric juice is a colorless fluid, containing HCl, enzymes and mucus. Concentration of HCI in the stomach content varies with the nature of food, stage of digestion, amount of saliva to be neutralized etc. Hydrochloric acid HCl is actively secreted by the parietal/oxyntic cells of the fundic […]
Gastric glands in animals The glandular mucosa of the stomach has many pores known as gastric pits. The surface area of the stomach lining the pits is covered with mucous cells which secrete mucus to protect the surface epithelium. Secretions of gastric glands Cardiac glands secrete only mucus Parietal/fundic glands secrete HCl and pepsinogen Pyloric glands secrete mucus and
Intestinal motility in animals The functions of the intestinal movements are To mix the ingesta with digestive secretions To bring the digested products in contact with intestinal mucous membrane for absorption To move the food masses from place to place in the intestine To expel the residue from the rectum through anus To assist in
Abomasal motility in ruminants Abomasum does not show cyclical rhythmic activity as that of the three compartments. Emptying of duodenum increases Abomasal contractions. Enteric hormones (secretin, CCK, pancreozymin) produced by duodenal mucosa decreases abomasal activity and secretion. Distension of abomasum has negative effect on other three compartments i.e. distension of abomasum decreases the contractions of
Gastric motility in animals Mechanism of gastric motility Gastric motility in animals is the function of the stomach is to regulate the flow of food to the small intestine at a controlled rate. The proximal region (fundus) near the oesophageal end serves storage function and the distal region serves grinding and sieving function. Muscular activity of
Fat Digestion in ruminants Fate of rumen lipids Dietary lipids occur as structural lipids in forages and storage lipids in oilseeds. In forages, less than 50% of total lipids are free fatty acids and the majority of them are phospholipids. In oilseeds, 65-80% of lipids are free fatty acids. Rumen microbes hydrolyze the dietary lipids
Protein digestion in ruminants Rumen microbial population have proteolytic activity. The diet of ruminants contains proteins and non-protein nitrogenous (NPN) substances (ammonia, nitrates, urea). Of the total proteins entering the rumen, 20 to 100% will be degraded to ammonia which are referred as rumen degradable protein (RDP). The fraction which is not degraded by the microbes
Significance of methane production in ruminants The carbohydrate fermenting bacteria produce formate, hydrogen and CO2. The methanogens transform the H2 and CO2 into CH4. The formate is converted into H2 and CO2. Methanogens preferentially use formate as substrate for methanogenesis. The methanogens act as an electron sink and favors acetate production. This is known as interspecies H2 transfer that
Degradation of different carbohydrates Four steps are involved in the degradation of carbohydrates. these are Adherence, Disaggregation, Extra-cellular and Intra-cellular degradation. 1. Adherence Adherence is the most important factor in fiber digestion. Coccoid show preference to get attached to plant cell wall. Adherence helps the bacteria to be retained for a longer time and facilitates sustained
Rumen Microorganisms and functions Rumen Bacteria 1. Cellulolytic Species Fibrobacter succinogenesRuminococcus albus & R. flavifaciensButyrivibrio fibrisolvens 2 Hemicellulolytic Species Butyrivibrio fibrisolvensRuminococcus sp. &Bacteroides ruminicola 3. Pectinolytic Species Butyrivibrio fibrisolvensBacteroides ruminicolaSuccinivibrio dextrinosolvens 4. Amylolytic Species Bacteroides amylophilusStreptococcus bovisSuccinomonas amylolytica 5. Ureolytic Species Succinivibrio dextrisolvensSelenomonas sp.Butyrivibrio spBacteroides ruminicola 6. Methane producingSpecies Methanobrevibacter ruminantiumMethanobacterium formicicumMethanomicrobium mobile 7. Sugar-Utilising Species Treponema
