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S Boisen

Publications and source records attributed to S Boisen.

5 recordsLinked to original sources

Apparent ileal dry matter and crude protein digestibility of rations fed to pigs and determined with the use of chromic oxide (Cr2O3) and acid-insoluble ash as digestive markers.

Two experiments were conducted to determine apparent ileal DM and crude-protein (CP) digestibilities in rations fed to pigs. An evaluation was made of Cr2O3 and HCl-insoluble ash as digestive markers. In addition, the effects of body weight (BW) on apparent ileal DM and CP (N x 6.25) digestibilities were studied. In Expt 1, thirteen barrows averaging 35 kg BW were fitted with post-valve T-caecum (PVTC) cannulas to determine the apparent ileal DM and CP digestibilities of a wheat gluten-bran ration (B2) and a soyabean-meal ration (E1). Immediately after morning feeding ileal digesta samples were collected on an hourly basis for a total of 12 h. Subsequently. N and marker contents were determined in the samples. The postprandial patterns of N and Cr passage were more similar than those of N and HCl-insoluble ash. Therefore Cr2O3 is more suitable as a marker than HCl-insoluble ash. The apparent ileal CP digestibility coefficient of ration B2 derived using Cr2O3 as a marker was significantly (P < 0.05) higher by 0.018 compared with the value obtained using HCl-insoluble ash. The corresponding values for ration E2 obtained using Cr2O3 and HCl-insoluble ash were both 0.825. In Expt 2, apparent ileal DM and CP digestibilities were determined in eighteen rations using twelve barrows also fitted with PVTC cannulas (BW from 40 to 100 kg). The protein sources for these rations were from different groups of feedstuffs. In four and three of the rations apparent ileal DM and CP digestibilities respectively were significantly different (P < 0.05) when assessed using the two markers. The digestibility coefficients were not systematically higher or lower for either marker. Absolute differences were < 0.049 on average. Significant effects of live weight on apparent ileal CP digestibilities were found.

Animal Feed↗

Comparative physico-chemical studies on purified trypsin inhibitors from the endosperm of barley, rye, and wheat.

The dominant trypsin inhibitors of the endosperm of barley, rye and wheat were investigated in a series of comparative studies. The barley and rye inhibitors showed a reaction of partial immunochemical identity, whereas no immunological cross-reactions between the wheat inhibitor and the inhibitors from barley and rye were detected. The molecular weight of the barley inhibitor is about 14,500, and of the rye and wheat inhibitors about 12,000. The three inhibitors had very similar amino acid compositions, but the wheat inhibitor seemed to contain nine disulfide bridges whereas the barley and rye inhibitor contain five and four, respectively. This may explain the higher stability of the wheat inhibitor towards proteolytic inactivation by pepsin and chymotrypsin. All three inhibitors were very stable to temperatures at 100 degrees C. The barley inhibitor was much less active against porcine trypsin, and especially human trypsin, than against bovine trypsin, whereas the inhibition by the rye and wheat inhibitor was less dependent on the origin of the enzyme.

Amino Acids↗

In vitro assay for protein digestibility: interlaboratory study.

True protein digestibilities of 17 protein sources were estimated by 6 laboratories using an in vitro, 3-enzyme digestion system in a pH stat. Samples from animal, vegetable, and mixed food sources were freeze-dried (if not already dried), ground, mixed, and shipped to each collaborator along with a sodium caseinate standard and trypsin, chymotrypsin, and peptidase. The uptake of titrant during enzymatic digestion was used to calculate estimates of digestibility. Digestibilities ranged from 100% for casein to 89.9% for whole wheat cereal. Mean relative standard deviations for repeatability were 1.4% for rolled oats and less than 1% for the remaining 16 samples. Mean relative standard deviations for reproducibility ranged from 5.0 to 0.8%; values were less than 2.5% for 13 of the 17 samples.

Animals↗

[Iron deficiency in domestic animals].

Iron is essential for the organism. In ionized forms (Fe++, Fe ), it constitutes an integrated part of a lot of different functional proteins (Figure 1). The most important functions are participation in oxygen transport in blood, oxygen storage in muscle tissues and oxidation of nutrients in the mitochondria. Iron is an essential part of cytochrome C and alpha-glycerolphosphate dehydrogenase, and early stages of iron deficiency may, therefore, cause disturbances in tissue metabolism before development of anaemia. Thus, haemoglobin determinations is not very suitable for diagnosing early iron deficiency. The content of iron in roughages, apart from root crops (Table II), is usually sufficient to cover the requirement of domestic animals (Table III), which is met by about 50 mg per kg feed dry matter. Iron deficiency is very often caused by a reduced absorption in the intestinal tract because of components in the feed forming complexes with iron of very low solubility or inhibitors reducing the absorption processes. The immune status of the organism and its resistance against infections depends on the iron supply. Iron deficiency inhibits the myeloperoxidase activity and thus decreases the bacteriocide effect of the leucocytes. In spite of this, when exposed to infections the physiological mechanisms reduce the blood concentration of available iron. By this mode of action, invading pathogens, needing iron like the host animals, will be restrained. The low content of iron in milk (Table II) combined with a high content of iron binding lactoferrin, is ideal to protect newborn and milk fed young animals against intestinal infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗