Presence of carbohydrate-digesting enzymes throughout the digestive tract of sheep

Abstract

IntroductionSheep breeding is one of the oldest professions closely associated with human civilization. The group of livestock called ruminants has a great utility. Sheep breeding yields meat and lambs, and, to a lesser degree, milk, wool, and hide. The physiology and morphology of sheep reflect adaptations to particular ecological niches. Based on food preference, sheep are herbivorous animals that prefer food rich in cellulose, i.e. 'grass/roughage eaters' (1). The most important feature of ruminants is the four-chambered stomach in the front of the gastrointestinal tract. Digestion of plant material occurs in the largest chamber, in the rumen, thanks to symbiotic microorganisms belonging to three taxonomic groups: bacteria, fungi, and protozoa (2). Among the protozoa, the most abundant and most important are the ciliates belonging to the family Ophryoscolecidae, followed by the family Isotrichidae. Protozoa differ in food preferences. Representatives of Ophryoscolecidae prefer insoluble carbohydrates, e.g., starch and cellulose, whereas Isotrichidae ciliates prefer soluble polysaccharides and do not utilize cellulose (3).Numerous studies have assessed digestive processes in the rumen, but relatively few provided information about digestion later in the digestive tract of ruminants. The goal of this work was to characterize degradation of carbohydrates in the full gastrointestinal tract of adult sheep. Materials and methods Animals, feeds, and feedingSix adult Polish Merino sheep with an average body mass of 55.3 kg were kept in separate pens. Their diet consisted of high-quality ingredients: 1560 g of meadow hay (which was collected on approximately 20 May, before heading), 250 g of ground barley, and 20 g of vitamin-mineral premix (Polfamix OK, Trouw Nutrition Polska, Grodzisk Mazowiecki, Poland), as shown in Table 1. The daily ration was divided into two equal parts and fed at 0700 and 1900 hours. Water was available ad libitum. Feed analyses were conducted in the Laboratory of Chemistry, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, using AOAC methods (4). Cellulose was calculated as ADF -ADL according to Rinne et al. (5). Measurements of the length and weight of the digestive organsAnimals were weighed and then slaughtered 3 h after the morning feeding according to standard procedures. Immediately after slaughtering, the entire digestive tract of sheep was removed and the connective tissues and lipids were removed carefully. Particular organs in the digestive tract (the stomach including the rumen, reticulum, omasum, and abomasum, as well as the small intestine, cecum, and large intestine) were isolated by ligating these

The Effect of Protozoa on the Bacterial Composition and Hydrolytic Activity of the Roe Deer Rumen

“…With the exception of a single article focused on cellulolytic activity [29], the existing literature lacks information on the degradation parameters of food carbohydrates for roe deer. The methods applied here for measuring hydrolytic activities were those previously employed in our studies on sheep [25]. A comparison between these animals indicated that sheep digested all carbohydrates to a higher extent, with the exception of pectin, which was digested at a comparable level.…”

“…In order to determine the hydrolytic activity of rumen samples, an enzymatic fraction was extracted using the carbon tetrachloride and lysozyme method as described by Miltko et al [25]. The resulting enzymatic fraction was used to determine the digestion rate of storage compounds (starch and inulin) and structural carbohydrates (xylan, cellulose and pectin), according to Miltko et al [25]. The reaction mixture contained substrate (solutions or suspensions of one of the following carbohydrates: starch, inulin, xylan, carboxymethyl cellulose or pectin); enzymatic fraction; and 0.01 M phosphate buffer (pH 6.0).…”

Effect of seasonal diet composition changes on the characteristics of the gastrointestinal tract contents of the Eurasian beaver (<i>Castor fiber</i>)

“…The mean values of the Eh detected in cecum of beaver varied from −237 to −259 mV, and were lower in comparison to the value of Eh found in cecum of rabbits. The low Eh value is necessary to obtain optimal conditions for development of anaerobic population of microorganisms (Michelland et al, 2010) and intensive digestive as well as fermentation processes (Miltko et al, 2016a).…”

Influence of humic acid supplemented to sheep diets on rumen enzymatic activity

“…Po tym czasie, w celu zatrzymania reakcji, dodano kwas 3,5-dwunitrosalicylowy i próby inkubowano w temperaturze 100°C przez 5 minut. Szybkość trawienia węglowodanów -skrobi, pektyny, celulozy i ksylanu przez frakcję enzymatyczną treści żwacza oznaczono jako ilość uwolnionych cukrów redukujących podczas inkubacji (8). Ilość tych cukrów oznaczono spektrofotometrycznie przy długości fali 560 nm.…”