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The effect of dietary fats differing in fatty acid (FA) composition on the metabolism of saturated FA (SFA) and monounsaturated FA (MUFA) in growing pigs was investigated. The deposition of FA in the body and the fate of individual dietary FA were assessed after slaughter. Gilts with an initial body weight (BW) of 60 kg were used as experimental animals. Six pigs were slaughtered at 60 kg BW, while further 18 pigs received three isoenergetic and isonitrogen experimental diets containing linseed oil, rapeseed oil or beef tallow at 50 g/kg diet until they reached 105 kg (six pigs per group). The chemical composition and the content of FA in the whole body were determined and compared across groups. Regardless of dietary treatment, the whole body contained similar amounts of protein, fat and total FA. The total accumulation (percentage of net intake and de novo production) of SFA and MUFA was similar in all groups, but the processes of elongation and desaturation of SFA and MUFA depended upon the type of FA added to the diet. A high dietary content and intake of MUFA inhibits desaturation compared to SFA- and PUFA-rich diets, whereas a high SFA content and intake lowers elongation rate. The increasing net intake of total SFA and MUFA was associated with a lower total de novo production of these FA in the whole body of pigs.

The effects of indigestible carbohydrates, protein type, and protein level on large intestine health were examined in rats. For 21 days, 12 groups of six 12-week-old male Wistar rats were fed diets with casein (CAS), or potato protein concentrate (PPC), providing 14% (lower protein level; LP), or 20% (higher protein level; HP) protein, and containing cellulose, resistant potato starch, or pectin. Fermentation end-products, pH, and β-glucuronidase levels in cecal digesta, and ammonia levels in colonic digesta were determined. Cecal digesta, tissue weights, cecal and colon morphology, and colonocyte DNA damage were also analyzed. Digesta pH was lower, whereas relative mass of cecal tissue and digesta were higher in rats fed pectin diets than in those fed cellulose. Cecal parameters were greater in rats fed PPC and HP diets than in those fed CAS and LP diets, respectively. Short-chain fatty acid (SCFA) concentrations were unaffected by protein or carbohydrate type. Total SCFA, acetic acid, and propionic acid concentrations were greater in rats fed LP diets than in those fed HP. Cecal pool of isobutyric and isovaleric acids was greater in rats fed PPC than in those fed CAS diets. PPC diets decreased phenol concentration and increased ammonia concentration in cecal and colonic digesta, respectively. Cecal crypt depth was greater in rats fed PPC and HP diets, and was unaffected by carbohydrates; whereas colonic crypt depth was greater in rats fed cellulose. Myenteron thickness in the cecum was unaffected by nutrition, but was greater in the colon of rats fed cellulose. Colonocyte DNA damage was greater in rats fed LP diets than in those fed HP diets, and was unaffected by carbohydrate or protein type. It was found that nutritional factors decreasing cecal digesta weight contribute to greater phenol production, increased DNA damage, and reduced ammonia concentration in the colon.

Autoclaving diminishes the nutritional value of rat diets, depending on the duration and temperature of the process and the type of dietary protein. We evaluated in vivo and in vitro the effects of autoclaving on the protein and energy values of soy-free and soy-containing rat diets. The true digestibility and biological value of the dietary protein were determined in a 10-d experiment involving 28-d-old Wistar Crl:WI(Han) male rats fed casein- or soy-containing diet that was autoclaved for 20 min at 121 °C (T1), 10 min at 134 °C (T2), or not autoclaved (T0). The apparent protein digestibility and metabolizable energy concentration of experimental diets were assayed during an 18-d trial involving 6-wk-old Wistar-Crl:WI(Han) male rats and compared with a commercial diet. The neutral detergent fiber (NDF) content, amount of protein bound to NDF, protein solubility, and in vitro ileal protein digestibility were determined. Autoclaving decreased protein solubility, with the T2 condition having a greater effect than that of T1, and decreased the protein parameters determined in vivo, except for the apparent digestibility of the standard rat diet. Autoclaving decreased metabolizable energy slightly. The Atwater formula yielded higher values than those determined in rats, in vitro, and calculated according to the pig equation. We conclude that autoclaving diets according to the T1 program was less detrimental to dietary protein than was T2 and that the NDF content and protein solubility may be helpful in assessing the effect of autoclaving. The pig formula and in vitro method appear to be valid for estimating the metabolizable energy of rat diets.

Background: Simultaneous quantification of liposoluble vitamins is not a new area of interest, since these compounds co-determine the nutritional quality of food and feed, a field widely explored in the human and animal diet. However, the development of appropriate methods is still a matter of concern, especially when the vitamin composition is highly complex, as is the case with feed designated for laboratory animals, representing a higher health and microbiological status., Results: A method combining microemulsion electrokinetic chromatography (MEEKC) with liquid-liquid extraction was developed for the determination of four fat-soluble vitamins in animal feed. A separation medium consisting of 25 mmol L⁻¹ phosphate buffer (pH 2.5), 2-propanol, 1-butanol, sodium dodecyl sulfate and octane allowed the simultaneous determination of vitamins A, D, E and K within a reasonable time of 25 min. The polarity of the separation voltage was reversed in view of the strongly suppressed electro-osmotic flow, and the applied voltage was set at 12 kV. The fat-soluble vitamins were separated in the order of decreasing hydrophobicity., Conclusion: It was proved that the proposed MEEKC method was sufficiently specific and sensitive for screening fat-soluble vitamins in animal feed samples after their sterilization., (© 2013 Society of Chemical Industry.)

Forty-eight gilts were submitted to a 30% restriction of feed (groups F and F1) or protein intake (group P) from 90 to 118 days of age, followed by realimentation from 119 to 168 days of age. Control pigs (C) were fed during the whole experiment according to a semi ad libitum scale. During realimentation all animals were fed according to semi ad libitum scale except pigs F1 which were fed ad libitum. Six pigs from each group were slaughtered at the end of restriction and realimentation. Restriction decreased the weight of musculus longissimus dorsi (MLD) and increased shear force. Restriction of feed intake depressed MUFA concentration and increased n-6/n-3 ratio while protein restriction decreased n-6/n-3 and PUFA:SFA ratios. Structure of fibers was not affected. After realimentation MLD mass was still lower in all previously restricted pigs, shear force was the lowest in F1 pigs. Only percentage of fast twich oxidative fibers was significantly greater in F1 pigs than in others. Significant correlations between parameters investigated during the study were found., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Nutritional value of diets containing 10% potato fibre or cellulose (diets MPF and MC, respectively) and their long-term effects on parameters related to potential health benefits were studied in rats. In a first experiment nutrient digestibility and metabolisable energy of the diets were determined. In a second experiment, each diet was fed to 20 male and 20 female rats aged nine weeks old during 12 (Lot W12) or 24 (Lot W24) weeks. Feed intakes per cage and body weight of rats were registered. In all animals organ weight was determined and in animals of Lot W12 and in males of Lot W24 biochemical blood parameters were analysed. In males of Lot W24, caecal SCFA concentration and body composition were also determined. Testosterone blood concentration was determined in males of Lots W12 and W24. Protein and fat digestibilities were lower, while those of ash, crude fibre and NFE were higher in the MPF than the MC diet. The energy value of the MPF diet was greater but energy intake was similar for both diets. Body weight, body protein and fat contents in males of Lot W24 did not differ between the groups, while body ash was significantly greater in MPF than MC rats (2.64 vs. 2.17 g/100 g BW). SCFA concentration and pool were considerably greater in MPF than MC rats, the SCFA profile being similar. Potato fibre did not affect total cholesterol, whereas it decreased triglycerides and very low density lipoproteins (VLDL) in Lot W12 of both genders, and tended to decrease them in males of Lot W24. Blood glucose and testosterone concentrations and relative mass of prostate were significantly depressed by the MPF diet in males of Lot W24. It can be concluded that feeding potato fibre stimulates caecal fermentation, improves mineral absorption and does not affect total cholesterol levels. The concentration of lipids, VLDL, glucose and testosterone depended on potato fibre in an age-dependent way.

Ten pea cultivars (four white-flowered, Pisum sativum ssp. hortense, and six colour-flowered, Pisum sativum ssp. arvense) grown in Latvia were analyzed and tested in in vitro experiments, as raw and cooked seeds. The colour-flowered (CF) had a greater proportion of hulls and a higher acid detergent fibre (ADF) content than white-flowered (WF) pea seeds (10.7 vs. 8.2% and 92.2 vs. 84.5 g/kg dry matter (DM), respectively). Three out of six CF varieties had a significantly greater amount of protein bound to neutral detergent fibre (NDF) than WF peas. The tannin content was higher in CF than in WF peas (8.46 vs. 0.37 g/kg DM). In vitro protein and amino acid digestibility was about 8% higher in WF than in CF varieties. Cooking decreased the tannin content in CF peas (8.46 vs. 5.51 g/kg DM) but had no effect on in vitro protein digestibility. Heat treatment reduced significantly trypsin inhibitor activity and amount of protein bound to NDF in CF and WF varieties (from 6.50 to 0.52 and from 6.54 to 0.46 trypsin inhibitor units (TIU)/mg DM; from 1.250 to 0.831 and 0.761 to 0.209 g N/100 g NDF, respectively). However, the protein bound to NDF content in pea DM increased in CF and decreased in WF varieties (from 1.525 to 2.145 and from 0.913 to 0.502 g N/kg DM, respectively). Cooking resulted in an increased NDF content over two times in both CF and WF pea seeds (from 122 to 259 and from 120 to 262 g/kg DM, respectively). The results suggest that colour-flowered pea may be considered as an interesting dietary alternative to white-flowered pea since cooking removes trypsin inhibitor activity (TIA), decreases tannins, and increases dietary fibre contents.

Two groups of 26 male and 26 female rats at the initial age 30 +/- 2 days were fed during 31 weeks on diets containing 20 percent of yellow lupin seeds having low (LG) or high (HG) gramine content. The animals were mated twice within nutritional groups, 1 male: 1 female, and their main reproductive parameters were recorded. In both reproductive cycles body weight of females at mating, after parturition and after 21-days lactation was lower in HG than in LG group. Fertility rate and body weight of neonates were not affected by the diet while number of neonates per litter tended to be lower by 0.7 and 0.8 pups in HG than in LG group. Body weight of weaners was also substantially smaller in dams fed on HG than LG diet. Relative weight of spleen but not of liver, kidney and heart was significantly greater in HG females. Four weeks old males and females issued from the first litters born to LG and HG animals (ten males and ten females per treatment) were fed individually on respective diets during 3 weeks. Feed intake and growth rate did not differ between the treatments. In males relative weight of liver and testicles was greater, while hematocrit and red blood count were lower in HG than in LG group. In females organ weights did not differ. Activity of liver enzymes determined in males was not affected by the diet. It may be concluded that high-gramine lupin affects negatively lactational performance, probably via lower feed intake, but it does not induce apparent teratogenic effects in the progeny.

The effects of feeding varied levels of low- and high-gramine yellow lupin seeds (LG and HG, respectively), and of synthetic gramine added to the diets in amounts ranging from 0.15 to 1.2 g per kg were investigated in one experiment on growing chicken and in two experiments on growing rats. The comparison of LG and HG lupin and the effect of 0.5 g gramine per kg of LG diet were determined in a growth-balance experiment with pigs. Organ weights and histology, blood parameters and activity of liver enzymes were determined. The response to HG lupin and gramine concentration varied among the species, the rats being more affected than chicken; no adverse effects of HG lupin or gramine were found in growing pigs. The common reaction of rats and chicken to the high levels of gramine (native or synthetic) was the decrease of feed intake and body gain. The increase of the relative weight of liver or kidney, changes in hematological parameters and liver enzymes were found only in rats. The estimated NOAEL (no-observed-adverse-effect level) of gramine was about 0.3 g/kg diet for rats, 0.65 g for chicken and at least 0.5 g for growing pigs.

In 2 two-factorial experiments, each conducted on 80 growing male rats, the effects of substituting 10% raw potato starch (PS), pectins (PEC), or cellulose (CEL) for wheat starch (WS) and the addition of tannic acid to WS (WSTA) were studied using diets differing in protein quality. Casein unsupplemented or supplemented with DL-methionine and gluten unsupplemented or supplemented with lysine, methionine and tryptophan were used as protein sources in Experiment 1 and 2, respectively. Parameters indicative of caecal fermentation intensity (pH, acetic, propionic and butyric acid contents, digesta and tissue weight) and of protein metabolism (urea blood concentration, faecal and urinary nitrogen excretion) were determined. Ten-day balance experiments were preceded by a 10-day adaption period to respective carbohydrates given in a diet containing balanced protein. In both experiments the type of carbohydrates affected the caecal concentration of individual and total SCFA and other parameters of fermentation intensity. Pectins and potato starch were fermented more intensively than cellulose. Faecal N excretion was increased by all carbohydrates substituted for cereal starch, and by tannic acid. Urinary excretion was greater on CEL than on PEC and WSTA containing casein and on other diets containing gluten. In both experiments urinary N excretion was the lowest on PEC diets. Protein quality had the greatest effect on apparent biological value and net protein utilization but all indices of protein utilization were also affected by carbohydrates. It is concluded that not only the amount of N excreted in faeces but also in urine is affected by the type and fermentability of carbohydrates.

In a two-factorial experiment on 96 young male rats, the effects of substituting 10% raw potato starch (PS), pectins (PEC), or cellulose (CEL) for corn starch (CS) were studied using an unsupplemented protein-free (PF) diet or a PF diet supplemented either with DL-methionine or urea. The pH and the short chain fatty acids (SCFA) content in caecal digesta, as well as caecal digesta and tissue weights were determined and used as the criteria of caecal fermentation intensity. Blood urea level, amount of N excreted via faeces and urine, DAPA content, and amino acid composition of faecal protein were analyzed as indices of protein metabolism. A 10-day adaptation period to the carbohydrates fed with the casein diet preceded the experimental period of feeding the respective carbohydrates with protein-free diets. Dietary carbohydrates significantly influenced total and individual SCFA content in caecal digesta, as well as other parameters related to the intensity of fermentation. Potato starch and pectins were more intensively fermented than cellulose. Supplementation of the PF diet with methionine and urea affected only caecal isobutyric and valeric acid content in a way dependent on the carbohydrates present in the diet. Carbohydrates significantly altered the routes of N excretion. Faecal excretion was increased by all carbohydrates studied compared to corn starch, pectins had the most marked effect. Urinary excretion was significantly increased by cellulose (as compared with the PEC and PS groups) and decreased by pectins as compared with all other groups. There was an interaction between the effects of carbohydrates and type of protein-free diet on faecal and urinary excretion. The sum of amino acids in faecal protein was the lowest on the PEC diet, but the amino acid composition expressed as a per cent of total amino acid content was similar in all groups. It can be concluded that dietary carbohydrates alter the excretion patterns of endogenous nitrogen in rats in different ways and that this effect is related to the intensity of their fermentation in the hind gut.

Pancreatic secretion in rats was assessed by measuring the amounts of p-aminobenzoic acid (PABH) excreted in urine after oral administration of Ac-L-Tyr-PAB, and by determination of enzyme activity in pancreas and faeces. 3 groups of 7 rats were kept on diets with casein as the main source of nitrogen without (control K0) or with two levels of trypsin inhibitor (K1 and K2). Two other groups were fed diets with 40 and 80% of casein substituted by raw soya bean protein and having trypsin inhibitor contents equivalent to those in diets K1 and K2. Urinary excretion of PABH ranged from 99 to 105% of intake and were not different between control and experimental rats. The weight of pancreas and pancreatic activities of trypsin and chymotrypsin in all experimental rats were higher than in controls. The activity of chymotrypsin in the faeces of rats of groups K1 and K2 was greater than in K0 while in groups S1 and S2 it was about five times that in groups K1 and K2. Generally, it was greater on diets with more trypsin inhibitor. The activity of trypsin in the faeces of rats K0, K1 and S1 was several times less than in K2 and S2. It has been concluded that measurement of trypsin and chymotrypsin in faeces allows to estimate differences in the secretion of pancreatic enzymes.