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Dairy factories annually generate an increasing amount of wastewater, which can cause eutrophication due to high concentrations of amino acids and lipids. To address this issue, membrane technology has emerged as a promising solution, but membrane fouling remains a significant challenge, since it can cause decreased flux, decrease membrane rejection performance, and increased energy demand. This study aimed to reduce membrane fouling by integrated a three-dimensional printed (3DP) turbulence promoter into an ultrafiltration dead-end cell and varying stirring speeds. Two mathematical models, Hermia and resistance-in-series, were used to analyze the fouling process. According to both models, the cake layer formation model indicated the most prevalent fouling mechanism. Specific energy demand, permeate flux, membrane rejection, and membrane reversible and irreversible resistances were measured, calculated, and compared. The results suggest that the combination of an integrated 3DP turbulence promoter and high stirring speeds can effectively reduce membrane fouling in a dairy wastewater treatment module., (© 2023. The Author(s).)

A simple T-cannula was surgically inserted into the ileum of growing female Large White x Dutch Landrace swine. Chymus samples collected with the help of the cannula were analysed to determine the apparent digestibility of different dietary nutrients such as dry matter, crude protein and starch, as well as of some essential amino acids. The following three experiments were conducted: (I) of the cereals, the "Tewo" triticale variety fed alone and in 1:1 concentrate mixtures with wheat or maize was studied; (II) waxy maize hybrids and maize hybrids of normal endosperm were compared without treatment and after treatment by the Bocchi technology; (III) untreated and extruded maize supplemented either with extracted soybean or with extracted sunflower was also tested. The ileal digestibility of protein, amino acids and starch was determined and compared with values obtained by conventional (faecal) analysis. When feeding triticale alone or in combination with wheat or maize, the ileal digestibility of crude protein and amino acids increased as a result of feeding the cereal combinations (e.g. crude protein 72-79%, lysine 75-79%, threonine 63-78%, methionine 74-86%). Comparison of the two maize hybrids revealed that, with the exception of methionine, lysine and tyrosine, the amino acids of the waxy hybrid had higher ileal digestibility. Treatment of the normal hybrid by the Bocchi technology caused a significant improvement in the ileal digestibility of cystine, isoleucine, lysine, valine, and dry matter. This treatment also improved the faecal digestibility of all test nutrients but methionine. Bocchi treatment of the waxy hybrid significantly improved the ileal digestibility of isoleucine, leucine, methionine, tyrosine and valine, and the faecal digestibility of cystine, dry matter, and crude protein. No major variety- or treatment-related differences were found in the digestibility of starch. As a result of extrusion, the digestibility of nutrients of the soybean + maize mixture increased from 61.6% to 70.3% (crude protein), from 41.1% to 59.4% (threonine), from 60.1 to 72.0% (methionine), and from 70.7% to 82.7% (lysine). The same treatment of the sunflower + maize mixture increased the digestibility of crude protein from 80.6% to 84.5%, that of threonine from 78.1% to 80.6%, that of methionine from 79.7% to 84.3%, while that of lysine from 61.4% to 72.3%. The ileal digestibility of starch was 97-98% for both mixtures. As a result of extrusion, most of the faecal digestibility values showed a significant improvement for both the soybean- and the sunflower-containing mixtures. The favourable effect exerted by extrusion on the digestibility of nutrients is markedly influenced by the feed components.

Male rats weighing 100 g were used in a 19-day trial. The rats received diets containing varying proportions of methionine. Their absolute liver weight was lower, due to the high methionine levels, than that of the animals fed optimum rations, whereas the relative liver weight was found to be lower only in the pair-fed group. No essential differences were observed between the levels of dry matter, protein, and fat. Glycogen levels were found to be lowered only in cases when high methionine doses were administered. Pathologically low levels of glycogen were found in animals of the pair-fed group. High methionine consumption reduced the percentages of 12 glucogenetic amino acids in the liver. This, in turn, suggests an increased rate of glucose formation from amino acids, a process which was not observed in animals of the pair-fed group. High methionine doses produced a condition of hyperglycaemia, while in the pair-fed group hypoglycaemia was observed. The highest rate of secretion of thyroid hormones was found in animals receiving the optimum ration; a lower rate of secretion was observed in the animals consuming less or more methionine. In animals receiving high methionine levels the rate of hormone secretion decreased in a stepwise manner with increasing methionine supplementation. Only the highest methionine doses (5,3%) were found to have a negative effect on the maximum rate of iodine incorporation into the thyroid gland. These findings were also substantiated by histological investigations because a true pathological picture was only found in histological sections of thyroid tissue from animals fed the highest methionine doses (5,3%) The thyroid tissue of these animals consisted predominantly of small glandular alveoli whose colloid was slightly coloured. The epithelial cells of these alveoli were degenerated; some cases of liver cell disintegration and, more rarely, cellular necrosis were noted.

The effect on ruminal motility of NH4- or Na-acetate and Na- or K-lactate of various pH and doses infused into the jugular vein (i.v.) or carotid artery (i.a.) was studied in sheep with ruminal fistula I.v. infusion of NH4-acetate whenever it was accompanied by a considerable increase of the blood NH4 level potently inhibited the amplitude and frequency of ruminal contractions. I. a. administration produced more rapid and more apparent responses and a slightly elevated venous ammonia concentration than did the i.v. infusion. Thus the augmented blood ammonia level not only affected the smooth muscles and peripheral nerve endings but also inhibited the vegetative centres of the central nervous system. Infusion of Na-acetate and Na- or K-lactate solutions induced compensated acidosis or alkalosis which reduced the amplitude of ruminal contractions and produced respiratory disturbances. The latter were more apparent in alkalosis. In uncompensated acidosis or alkalosis, ruminal motility was permanently inhibited or abolished. The results appear to show that in not properly fed ruminants the frequently observed and long lasting compensated acidosis or alkalosis might influence the activity of the vegetative centres thus further metabolic disturbances and impaired gastrointestinal activity might follow the shifts in acid-base equilibrium.

In order to find out how short-time denutrition changes the concentration of some substances in the rumen fluid and the blood, tests with full-grown sheep were carried out. Fodder was withheld from sheep with inserted Jarrett fistulae for 48 hours after normal feeding. After 48 hours the animals were given concentrated fodder, after 52 hours exclusively hay. From the 72nd hour onwards the animals were provided with fodder as usual. Samples of the rumen fluid and blood samples were taken at the beginning of the test, after the last normal feeding and then in the 24th, 32nd, 48th, 52nd, 56th, 72nd and 96th hour. We could find out that, during the 48-hour denutrition, the pH-value of the rumen fluid turned alkaline and the concentrations of ammonia, volatile fatty acids and lactic acid decreased. The protein metabolism underwent a rapid change in the organism. The protein content of the blood plasma decreased, above all the albumin content, as well as the concentration of glycoproteins and volatile amino acids. Among the various amino acids, the concentration of glycine increased highly, that of alanine and valine just slightly. The concentration of most amino acids decreased or--of some of them remained the same. Among the paramters that are characteristic of lipid and carbohydrate metabolism, the total content of lipids and cholesterin decreased, and so did the concentration of blood sugar, lactic acid and pyruvic acid in the blood plasma. The results indicate that short-time denutrition has a considerable influence on the rumen fermentation and the intermediary metabolism of ruminants. The quickly arising lack of energy of ruminants slows down the protein synthesis and increases the glyconeogenesis from amino acids. The tissue is supplied with energy by the mobilisation of lipids.

The regulation of Na+ and water metabolism was studied in sheep with rumen fistula after water deprivation for 48 hours. Na+ and K+ concentrations were determined in blood plasma, blood, urine and saliva, with or without NaCl load. The results showed that the water content of the ruminal fluid plays an important role in the control of electrolyte and water metabolism. The absorption of water and Na+ from the rumen favours the maintenance of isosmolality and isovolaemia until the concentration of Na+ in the ruminal fluid has exceeded that in blood plasma. Thereafter the balance of water movement between rumen and extravascular space is shifted towards the rumen inhibiting thereby a further increase of Na+ concentration and ensuring the life conditions for the ruminal microbial population. During water deprivation not only water is lost but as a result of Na+ excretion relative hyponatraemia also ensues as can readily be assessed from the ratio of salivary Na+ and K+ concentrations. Upon NaCl load the salivary Na+/K+ ratio was increased indicating the extent of Na+ supply.