Ouabain-sensitive respiration and protein synthesis in duodenal mucosa and liver in rats fed increasing levels of pea fibre or protein and housed in 18 or 28°C environments

Seventy‐two Wistar rats were used in two studies to investigate the effect of environmental temperature (18 or 28°C), and increasing levels of dietary fibre (low, 68 g/kg dry matter (DM); medium 110 g/kg DM; high, 157 g/kg DM) and protein (low, 91 g/kg DM; medium, 171 g/kg DM; high, 262 g/kg DM) on respiration attributable to Na⁺,K⁺‐ATPase activity and protein synthesis in duodenal mucosa and liver of rats. In vitro O₂ consumption in tissues was measured polarographically using a Clark‐style YSI biological O₂ monitor. Whole‐body O₂ consumption was measured with two open‐circuit respiration chambers. Whole‐body O₂ consumption was higher (p < 0.05) at 18°C than at 28°C. Rats fed the low protein diet had significantly higher (p < 0.05) whole‐body O₂ consumption than those fed the medium or high protein diet. Compared with 28°C, the environmental temperature of 18°C caused an increase (p < 0.05) in total O₂ consumption and O₂ consumption attributable to Na⁺,K⁺‐ATPase activity in duodenal mucosa. There was no effect (p > 0.05) of environmental temperature on total O₂ consumption, Na⁺,K⁺‐ATPase activity attributable to protein synthesis dependent on O₂ consumption in the liver. Total O₂ consumption and O₂ consumption attributable to Na⁺,K⁺‐ATPase activity increased (p < 0.05) in duodenal mucosa in rats fed the low level of dietary fibre compared with rats fed the medium level of dietary fibre. In vitro O₂ consumption determined in duodenal mucosa and in liver did not always correspond to whole‐body O₂ consumption. This may indicate that respiration in the duodenum and liver adapts differently and may not reflect changes in whole‐body respiration in response to dietary modification and changes in thermal environment.     

ORIGINAL ARTICLE: Impact of feeding level on digestibility of a haylage‐only diet in Icelandic horses

Eight mature Icelandic geldings were used in an experiment arranged as a change‐over design to evaluate the effect of feeding level on the digestibility of a high‐energy haylage‐only diet. The horses were fed a low feeding level 10.7 g dry matter (DM)/kg body weight (BW) (maintenance) and a high feeding level 18.1 g DM/kg BW (1.5 × maintenance) during two 23 days experimental periods. Total collection of faeces was performed for 6 days at the end of each period to determine the coefficient of total tract apparent digestibility (CTTAD). The CTTAD for DM, organic matter, neutral detergent fibre (NDF), acid detergent fibre and energy was higher in horses fed at the low level of feed intake, while feeding level did not affect the CTTAD of crude protein. The largest difference in CTTAD between feeding levels was found for NDF. The content (/kg DM) of digestible energy in the haylage was 11.3 MJ at the low level of feed intake and 10.6 MJ at the high level of feed intake. It can be concluded that feeding level has a large impact on the digestibility and energy value of early cut haylage in Icelandic horses.     

Effect of Environmental Temperature on Digestive Tract,Visceral Organ Size,Digestibility and Energy Metabolism in Rats Fed Different Levels of Pea Fibre

Abstract

A study was performed to investigate the effect of environmental temperature (18°C or 28°C) and increasing levels of pea fibre in the diet on digestive tract, visceral organ size, digestibility and energy metabolism in rats. Thirty-six male Wistar rats, initial liveweight (LW) 77-79 g, were allocated to six groups and housed at either 18°C (three groups) or 28°C (three groups). Three wheat starch, fish meal and pea fibre-based diets were prepared to contain 100, 200 and 300 g pea fibre kg^?1 (68, 110 and 157 g dietary fibre kg^?1 DM) and 160 g protein (N × 6.25) kg^?1. One group of rats at each temperature was fed one of the diets for four balance periods. Gas-exchange measurements were made and urine and faeces were quantitatively collected. Food to gain ratio was higher (P <.05) at 18°C than at 28°C and increased (P <.05) as the level of fibre was increased. The weight of the visceral organs from rats housed at 18°C was higher (P<.05) than at 28°C. The empty weight of the small intestine, caecum and colon increased (P <.05) as the level of pea fibre was increased. The digestibility of DM, protein and dietary fibre (DF) was lower (P <.05) at 18°C than at 28°C. As the level of pea fibre was increased, the digestibilities of nutrients and energy decreased (P <.05). However, the digestibility of DF increased (P <.05) as the level of pea fibre was increased. The partial digested energy value for pea fibre was 11.9 kJ g^?1. The metabolizable energy (ME) intake and heat production at 18°C (1128 and 974 kJ (W^0.75 day)^?1 respectively) were higher (P<.05) than at 28°C (831 and 674 kJ (W^0.75 day)^?1 respectively). As the level of pea fibre was increased, ME intake (W^0.75 day)^?1 and heat production (W^0.75 day)^?1 decreased (P <.05). Heat production as a percentage of ME was higher (P <.05) at 18°C than at 28°C: 86.6% and 81.2%, respectively. Heat production as a percentage of ME was higher (P <.05) for rats fed the 100 g pea fibre kg^?1 diet than the 200 or 300 g pea fibre kg^?1 diet. In conclusion, environmental temperature as well as DF influenced digestive tract and visceral organ size, digestion and protein and energy metabolism.     

Effect of Dietary Fibre on Digestibility and Energy Metabolism in Pregnant Sows

This study was undertaken to provide information on the effect of two levels of dietary fibre (DF) [184 vs. 407 g DF kg^-1 dry matter (DM)] on the digestibility of nutrients and energy metabolism in pregnant sows during different stages of pregnancy. The amount of DF in the high-fibre diet was supplied by dried sugar beet pulp (20%) and oats, wheat bran and grass pellets. The intake of metabolizable energy (ME) was similar for both the low-fibre and the highfibre diet, with an average daily intake of 30.74 MJ. Digestibility of DM, organic matter, protein, fat and energy was significantly decreased by a high DF level, but no effect of the diets was observed on the stage of pregnancy. A high fibre level significantly increased the digestibility of DF, indicating that fibre from sugar beet pulp is more fermentable than fibre from cereals. Protein utilization increased during the pregnancy, but at a very low level, indicating that the protein level in diets for pregnant sows could be lower. Inclusion of extra DF in the diet significantly increased the amount of energy excreted as CH₄. Heat production was affected by diet, although not significantly (28.77 vs. 29.72 MJ day^-1 in the low-fibre and highfibre diets, respectively). The utilization of ME for energy retention was lower for the high-fibre diet as a result of increased hind-gut fermentation. There was similar relation between the net energy of the standard and the high-fibre diet either calculated using the official Danish feed evaluation (0.77) or experimental estimated value (0.81).     

Nutrient digestibility and feedlot performance of lambs fed diets varying protein and energy contents

Thirty-six Thalli male growing lambs were used in a completely randomized design with 2 × 2 factorial arrangement of treatments to evaluate the effect of varying levels of energy and protein on nutrient intake, digestibility, weight gain, and gain to feed ratio. Four experimental diets, i.e., low energy–low protein (LE-LP), low energy–high protein (LE-HP), high energy–low protein (HE-LP), and high energy–high protein (HE-HP) were formulated. The low- and high-energy diets contained 2.3 and 2.7 MJ/kg dry matter (DM) with 12% and 14% of crude protein. The lambs were fed ad libitum. Dietary energy and protein levels and their interactions influenced the nutrient intake. Maximum dry matter intake was noted in animals fed LE-HP diet followed by LE-LP, HE-HP, and HE-LP diets. Digestibility of DM and N increased (P < 0.01) and that of neutral detergent fiber decreased (P < 0.01) linearly with increasing levels of dietary energy and protein. Digestibility of N was only affected by protein level and interaction between energy and protein levels. Average daily gain was higher (P < 0.01) in lambs fed HE-HP diet followed by LE-HP, LE-LP, and HE-LP diets. Dietary energy and protein levels and their interaction had significant effect (P < 0.01) on gain to feed ratio.     

Feeding high fibre diets changes luminal environment and morphology in the intestine of sows

Sows were fed three diets varying in type and level of dietary fibre (DF). The low fibre diet (LF; 17% DF) was based on wheat and barley. In the two high DF diets (HF1, high in soluble DF and HF2, high in insoluble DF;  44% DF), the cereal part of the diet was substituted with different co-products (sugar beet pulp, potato pulp, pectin residue, pea hull, brewer's spent grain, and seed residue). The diets were fed for a four-week period to 12 sows (4 for each diet). Sows were stunned 4 h post-feeding, and digesta and tissue samples were collected from various parts of the small and large intestines. The carbohydrate load to the large intestine was 538–539 g/d when feeding the high DF diets and 190 g/d when feeding diet LF. Feeding sows the high DF diet containing large proportion of soluble DF resulted in a lower dry matter content of digesta (23 contra 28%), a higher tissue weight (2.9 contra 2.0 kg), and a higher crypt depth (492 contra 330 μm) and area (23,201 contra 15,751 μm²) in the colon compared with the low DF diet. In conclusion, increasing the amount of DF in the diet for sows resulted in an increased amount of digesta entering the large intestine which influences the functional properties of digesta. Furthermore, a high DF diet with a high proportion of soluble DF increases tissue weight, crypt depth and crypt area in the midcolon compared to a low fibre diet.     

不同饲养水平对瑶山鸡生产性能和胴体品质的影响

文章旨在研究不同饲养水平对瑶山鸡生产性能和胴体特征的影响.试验将400只平均体重一致的1日龄瑶山鸡随机分为2组,每组4个重复,每个重复50只.2组分别饲喂代谢能水平为3155 Kcal/kg、粗蛋白质水平为225 g/kg的高能高蛋白日粮和代谢能水平为2965 Kcal/kg、粗蛋白质水平为195 g/kg的低能低蛋白...     

Food intake and ingredient profile affect viscosity of ileal digesta of dogs

Two experiments were conducted to determine dietary factors affecting digesta viscosity. In experiment 1, six ileal-cannulated dogs were either full (607.1 kJ/BW0.67) or restricted (303.5 kJ/BW0.67) fed. In experiment 2, four dog foods were surveyed for effects on digesta viscosity based on protein source [animal protein (AP) or plant protein (PP)] or dietary fibre source [soluble dietary fibre (SDF) or insoluble dietary fibre (IDF)]. Dry matter (DM) intake was higher (p<0.05) when dogs were full (11.4 g/kg) compared with restricted fed (5.98 g/kg). Ileal digesta viscosity tended to be higher (p=0.07) for full fed [10,251 centipoise (cP)] compared with restricted-fed dogs (6677 cP). Ileal digesta viscosities were 6561, 11,074, 13,830 and 15,967 cP for dogs consuming IDF, SDF, AP and PP treatments respectively. Ileal DM concentrations were 11.4%, 13.6%, 14.8% and 14.8% for SDF, IDF, AP and PP treatments respectively. DM digestibility coefficients were lowest (71.2%) for the PP treatment and highest (88.7%) for the IDF treatment. Organic matter digestibilities followed a similar pattern. Ileal digesta viscosity of dogs appears to increase with increased diet intake, and increased ileal DM concentration. More digestible diets result in less ileal DM and lower viscosity constants.     

Effect of linseed cake supplementation on digestibility and faecal and haematological parameters in dogs

The experiment was conducted with a 6 x 4 cyclic changeover design. Six adult Alaskan huskies were assigned to diets containing 0%, 2%, 4%, 6% and 8% linseed cake. A linear decrease in the apparent digestibilities of organic matter (OM) (p < 0.020), ether extract (EE) (p < 0.003), neutral detergent fibre (p < 0.015), nitrogen-free extract (NFE) (p < 0.001) and crude carbohydrates (p < 0.001) was noted. Digestibilities of dry matter (DM) and crude protein (CP) were unaffected by the treatment. Wet weight of faeces increased (p < 0.001) and DM of faeces decreased (p < 0.001) linearly as the percentage of dietary linseed cake increased. Serum cholesterol concentration tended to decrease (p = 0.094) as the proportion of linseed cake increased. Apparent OM, EE, CP and NFE digestibility coefficients for linseed cake were 52%, 77%, 54% and 37%, respectively, and the digestible energy (DE) value was 13.22 MJ/kg DM. Our results showed that working and racing dogs fed the extruded and kibbled diet can utilize up to 4.2% linseed cake of diet DM as a fibre source without severe reductions in nutrient digestibility or feed consumption. Even higher levels of linseed cake, up to 8.5% of diet DM, can be used for normal or obese dogs, but more faeces will be excreted.     

The fermentative capacity of growing pigs and adult sows fed diets with contrasting type and level of dietary fibre

Adult sows have a more developed gastro-intestinal system than young growing pigs resulting in a superior capacity to digest fibrous components. The main objective of this study was to describe the capacity of sows and growing pigs to digest the fibre components in concentrated low dietary fibre (DF) diet and two high DF diets similar in DF but with contrasting DF solubility. Six sows and four growing pigs were fitted with a simple T-cannula at the terminal ileum. Each balance experiment consisted of a 7-day initial period followed by a 3-day collection of faeces and a 2 or 3-day collection of ileal digesta for growing pigs and adult sows, respectively. When feeding diets with high proportions of soluble non-starch polysaccharides (NSP), the difference in fermentation capacity between growing pigs and adult sows was small. The adult sows showed a higher fermentative capacity, evidenced by a higher fermentation and a higher methane production, when high fibre diet with high amount of insoluble fibre was fed.     

Digestible energy intake, dry matter digestibility and effect of increased calcium intake on bone parameters of grazing Thoroughbred weanlings in New Zealand

AIMS: To measure the nutritive value of pasture in terms of digestible energy intake (DEI) and dry matter (DM) digestibility, and the effects of increased calcium (Ca) intakes on apparent mineral absorption and bone characteristics in grazing weanling Thoroughbreds. METHODS: DM intake (DMI) and DEI were determined in 16 weanling Thoroughbreds grazing pasture from their daily faecal DM output, measured over 8 days, divided by the DM indigestible fraction (1-digestible DM) determined in a 6-day digestibility trial. The DM, gross energy content, crude protein, soluble carbohydrate, acid detergent fibre, neutral detergent fibre, lipid, Ca, phosphorus (P), sodium (Na), potassium(K), sulphur (S) and magnesium (Mg) composition of perennial ryegrass/white clover pasture and faeces were determined and their digestibility and/or apparent absorption calculated. Calcium intake and bone growth studies used 17 weanlings, randomly divided into three groups and fed perennial ryegrass/white clover pasture and 0.5 kg grain, with or without a CaCO3 supplement, for 84 days. The animals in Group 1 (n=6) were on a low Ca diet (3.5 g/kg DM) and were fed pasture only; those in Group 2 (n=5) were on a medium Ca diet (6.3 g/kg DM);and those in Group 3 (n=6) were on a high Ca diet (12.0 g/kg DM). After 44 days the apparent absorption of Ca was determined from the differences between the Ca intakes and faecal Ca outputs. At periods just before and after Ca supplementation the horses were anaesthetised and the left radius, third metacarpus(Mc3) and first phalanx of the left foreleg were scanned using a peripheral quantitative computed tomography scanner to determine cortical mineral content, density, area, periosteal circumference and bone strength. To investigate gastrointestinal tract transit time and DM digestibility, five randomly selected horses were administered Swiss screen bags on several occasions via a nasogastric tube. Each 60 x 10mm bag contained 3.21 (SE 0.37) g of frozen minced grass. Bags were recovered from the freshly passed faeces and frozen until analysis. RESULTS: The DM digestibility of the pasture was 0.62, while the DMI and DEI of weanlings (300 kg, gaining 0.7 kg/day) were 5.5 kg/day and 63 MJ/day, respectively. Increasing Ca intake had no significant effect on DEI, DM digestibility or on the apparent absorption of Ca, P, Na and K, but decreased the apparent absorption of Mg from 0.50 to 0.38. Regardless of Ca intake, the apparent absorption of Ca was 0.56. During the Ca administration trial there were significant increases overtime in the bone strength (strain stress index) of the proximal phalanx, Mc3 and radial diaphysis. However, the increase in bone strength was not associated with increase in dietary Ca, as neither the medium- nor high-Ca intake groups differed significantly from the low-Ca controls. The mean transit time for the Swiss screen bags was 25.46 (SE 0.09) h, and transit times were similar whether the horses were grazing or confined in loose boxes, being 26.64 (SE 0.23) h and 24.33 (SE 0.13) h, respectively. The DM digestibility determined using the bags was 0.54, which was significantly lower than the 0.62 determined by direct faeces collection. CONCLUSIONS: Good growth rates were achieved in Thoroughbred weanlings grazing perennial ryegrass/white clover pasture containing 3.5 g Ca/kg DM and a DE of 11.4 MJ/kg DM. Increasing dietary Ca intake 3.5-fold for 3 months had negligible impact on bone growth and development.     

Effect of dietary protein and lipid levels on growth,nutrient utilization and whole‐body composition of blue gourami,Trichogaster trichopterus fingerlings

Nine semi‐purified diets were prepared with three levels each of protein (300, 350 and 400 g/kg) and lipid (60, 80 and 100 g/kg) and fed ad libitum to Trichogaster trichopterus fingerlings (0.61 ± 0.03 g) in triplicate groups (10 fish/replicate) for 90 days to determine optimum dietary protein and lipid levels. Twenty‐seven flow‐through fibre‐reinforced plastic tanks (200 l capacity each with 100 l of water) were used for rearing the fish. The dietary protein, lipid and their interactions had significant effects (p < 0.05) on weight gain, feed conversion ratio, specific growth rate, nutrient retention and digestibility, but not on hepato‐ and viscerosomatic indexes (p > 0.05). Dietary protein and the interaction of protein with lipid had significant effect (p < 0.05) on whole‐body dry matter, lipid and energy contents, but not on protein and ash contents (p > 0.05). But, the dietary lipid had significant (p < 0.05) effect on whole‐body dry matter, protein, lipid and energy contents except the ash contents (p > 0.05). For each level of dietary protein, the increase in dietary lipid resulted significant increase (p < 0.05) in whole‐body lipid contents without affecting the protein and ash contents (p > 0.05). Based on better growth and dietary performances, the optimum dietary protein and lipid levels of blue gourami fingerling are 350 and 80 g/kg diet respectively.     

不同能量和蛋白质水平饲粮交替饲喂对妊娠母猪繁殖性能、血浆激素含量及抗氧化指标的影响

本试验旨在探究不同能量和蛋白质水平饲粮交替饲喂对妊娠母猪繁殖性能、血浆激素含量及抗氧化指标的影响.试验分为2个阶段,配制6种试验饲粮,妊娠前期试验饲粮:低能量低蛋白质水平饲粮(12.54 MJ/kg、15.55％)、中能量中蛋白质水平饲粮(13.27 MJ/kg、16.47％)、高能量高蛋白质水平饲粮(13.44 MJ...     

Responses to an estrogenic growth promoter in beef steers fed varying nutritional regimens

We investigated the influence of DM and(or) energy intake and dietary CP levels on the performance and nitrogen (N) retention of beef steers with and without growth promoter implants. In Exp. 1, four implanted (Synovex-S, 200 mg of progesterone plus 20 mg of estradiol benzoate) Angus steers and four Angus steers that were not implanted were assigned to concurrent 4 x 4 Latin squares. Initial BW averaged 296 kg. Each square consisted of moderate and moderately high DM intake treatments (4 and 6 kg/d) and low and adequate CP intake treatments (450 and 600 g/d) in a 2 x 2 factorial arrangement. Periods were 2 wk of adaptation, 5 wk of growth, and 1 wk of balance collection. Experiment 2 consisted of two replicates of 32 Hereford steers each (initial BW 324 kg). Each replicate was a 4 x 2 factorial in which steers were individually fed for 63 d. All steers had ad libitum access to a 60% corn-based concentrate diet containing either 7.9, 10.0, 12.1, or 14.6% CP (DM basis), and steers were either implanted or not implanted with Synovex-S. Experiment 3 was similar to Exp. 2 except that all steers (initial BW 315 kg) received a low-protein diet (7.6% CP) with calculated energy densities of either 1.86, 2.04, 2.22, or 2.42 Mcal ME/kg DM, and steers were limited to an equalized DM intake of 9.5 kg daily. In Exp. 1, gains for the low CP, moderate and moderately high DM intakes and the adequate CP, moderate and moderately high DM intakes were 240, 555, 208, and 730 g/d, respectively, for steers not implanted and 333, 643, 488, and 988 g/d, respectively, for implanted steers (SEM = 102 g/d). Respective values for retained N were .13, .18, .16, and .26 g/kg BW.75 and .13, .15, .22, and .29 g/kg BW.75 (SEM = .04 g/kg BW.75). Implant response was greater (CP x implant, P < .01) for both gain and retained N when adequate CP compared to low CP diets were fed. For Exp. 2, the lowest CP diet reduced ADG (.97 vs 1.27 kg/d) and efficiency of gain (100 vs 120 g gain/kg DM). Synovex-S was less effective in improving efficiency for the lowest protein diet than for the other diets (11.7 vs 20.2%). During Exp. 3, neither Synovex-S nor dietary energy influenced gain and efficiency. We concluded that adequate dietary protein is necessary to optimize the response to estrogenic growth promoters and that the low response under inadequate protein and energy intake is not improved by increasing the energy density of the diet.     

Effect of a diet high in energy and protein on growth,carcase characteristics and parasite resistance in goats

The effects of a high-energy and high-protein diet on growth, parasite resistance and carcase characteristics were studied using local goats with an average initial body weight (BW) of 12.0 (SD = 0.7) kg. Thirty-two animals were allocated to a completely randomized factorial design, with four animals of each sex per treatment. The factors were: two diets (diet H with high content of crude protein (CP) and metabolizable energy (ME), and diet L with low content of CP and ME) and deworming (DW) or non-deworming (NDW). The highest dry matter (DM) intake was obtained for goats fed diet H combined with DW, but there was no significant difference between DW or NDW for goats fed diet H. The goats fed diet L and DW had significantly better total DM intake than NDW goats. The average daily gain of animals fed diet H was 86 and 92 g/day compared to 27 and 40 g/day for diet L, for NDW and DW animals, respectively. Feeding diet H resulted in higher slaughter weight and consequently also higher empty BW, carcase weight and dressing percentage and lower feed conversion ratio. Dewormed animals had significantly higher empty BW than NDW animals. There were significant effects of diet and parasite control on Faecal egg count (FEC: number of parasite eggs per gram of faeces (e.p.g.)), with NDW animals fed diet L having higher FEC than animals fed diet H.     

Effects of inclusion of whole-crop pea silages differing in their tannin content on the performance of dairy cows fed high or low protein concentrates

The effect of including high or low tannin forage peas as an alternative to soyabean meal on performance and N efficiency was investigated using 18 dairy cows in two Latin square design studies. Two varieties of forage pea; Racer (coloured flowers; high tannin) and Croma (white flowers; low tannin), were ensiled 12 weeks post sowing. The in situ degradability characteristics of the pea silages were determined using 4 cannulated sheep. The low tannin forage had a higher soluble N (a) fraction and a greater extent of degradation (a + b), resulting in a greater amount of N being predicted to be released in the rumen than the high tannin forage. In experiment 1, cows were fed one of three treatments in each of 3 periods of 28 d duration in a Latin square design; grass silage/whole-crop wheat (0.50:0.50, DM basis) and 8 kg/d of a high protein concentrate (GWH); grass silage/whole-crop wheat/high tannin forage pea silage (0.25:0.25:0.50 respectively, DM basis) and 8 kg/d of a high protein concentrate (HTH) or 8 kg/d of a low protein supplement (HTL). The inclusion of forage peas increased (P < 0.05) DM intake by 1.2 kg DM/d, but there was no effect of dietary treatment on milk yield (average of 23.0 kg/d), composition or live weight change. The efficiency of use of dietary N (N output in milk/N intake) was highest (P < 0.001) in cows when fed GWH (0.289) and lowest in HTH (0.234). In experiment 2, cows were fed one of three treatments in each of 3 periods of 28 d duration in a Latin square design; grass silage/whole-crop wheat (0.50:0.50, DM basis) and 8 kg/d of a high protein concentrate (GWH); grass silage/whole-crop wheat/low tannin forage pea silage (0.25:0.25:0.5 respectively, DM basis) and 8 kg/d of a high protein concentrate (LTH) or 8 kg/d of a low protein concentrate (LTL). Compared with GWH, the inclusion of forage peas increased (P < 0.05) DM intake by 2.0 kg/d, but there was no effect of dietary treatment on milk yield (average of 24.5 kg/d). Milk fat content was highest (P < 0.05) in cows when fed LTL (45.7 g/kg) and lowest in LTH (41.9 g/kg), but there was no effect (P > 0.05) of treatment on daily fat yield or any other milk component. The efficiency of dietary N use was highest (P < 0.001) in cows when fed GWH (0.300) and lowest in LTH (0.234). It is concluded that either high or low tannin forage pea silages can replace approximately 1.1 kg/d of soyabean meal in the diet of mid-late lactation dairy cows without affecting animal performance, but N efficiency for milk production is decreased.     

Feeding motivation and plasma metabolites in pregnant sows fed diets rich in dietary fiber either once or twice daily

The present study investigated the effects of source and level of dietary fiber (DF) and feeding frequency (once vs. twice daily) on feeding motivation and plasma metabolites at 4 different time points post feeding. Sixty pregnant sows (Sus scrofa, 4 blocks of 15 sows) were allocated to 1 of 5 diets within blocks. Four diets were restricted (approximately 35 MJ ME/d): a barley and wheat control diet (171 g DF/kg DM; 12 g DF/MJ ME), and 3 fiber diets formulated to contain 35% DF by including pectin residue (323 g DF/kg DM; 25 g DF/MJ ME), potato pulp (404 g DF/kg DM; 29 g DF/MJ ME), or sugar beet pulp (367 g DF/kg DM; 25 g DF/MJ ME). The fifth diet was a mixture including an equal amount of the 3 fiber diets offered semi ad libitum (ad libitum access to feed during 6 periods of 1 h starting at 0300, 0600, 1100, 1500, 1800, and 2300; 354 g DF/kg DM; 25 g DF/MJ ME). The experimental period included 2 periods of 4 wk each. Restricted-fed sows were fed once daily (0800 h) during the first period and twice daily (0800 and 1500 h) during the second period, or vice versa. Semi ad libitum fed sows had access to feed 6 times a day in both periods. In each period, the feeding motivation was assessed in an operant conditioning test, and samples of peripheral blood were taken in a balanced design, at 0900, 1200, 1900, and 0700 h, corresponding to 1, 4, 11, and 23 h after feeding for restricted sows fed once daily. No differences in the feeding motivation were found between the 4 restricted diets at any of the time points post feeding, but semi ad libitum fed sows had a decreased feeding motivation (P < 0.001). Among the restricted-fed sows, feeding twice daily resulted in decreased feeding motivation at 1900 h (P < 0.001) and at 0700h (P < 0.05) compared with feeding once daily, but not at 0900 and 1200 h, indicating that feeding twice daily reduced feeding motivation during the night compared with feeding once daily. Among restricted-fed sows, plasma concentrations of short-chain fatty acids (SCFA) were greater in sows fed high-fiber diets compared with the control (P = 0.02). Nonesterified fatty acid was least in sows on the control diet and greatest in sows on the potato diet, whereas sows on the pectin and sugar beet diets were intermediate (P < 0.001). Less diurnal variation in glucose (P < 0.001) was seen in sows on high-fiber diets. In spite of the found effects on plasma metabolites, the applied level of fiber in the diet of restrictedly fed sows did not reduce their feeding motivation irrespective of fiber source.     

谷物膳食纤维对高胆固醇饮食小鼠脂质代谢及肠道菌群的影响

本研究旨在探讨谷物膳食纤维(DF)对高胆固醇饮食小鼠的脂质代谢和肠道菌群的影响。选取C57BL/6J小鼠30只,并根据体重随机分为4组,分别饲喂基础饲粮(对照,CO组,n=8)、基础饲粮+5 g/kg DF(CO+DF组,n=8)、高脂高胆固醇饲粮(HF组,n=7)及高脂高胆固醇饲粮+5 g/kg DF(HF+DF组,n=7)。试验期8周,测定各组小鼠生长性能、血清和肝脏生化指标、粪便总胆固醇(TC)、短链脂肪酸(SCFA)、相关肝脏胆固醇和胆汁酸(BA)蛋白表达及肠道菌群。结果表明:1)CO+DF组的最终体重显著低于CO组(P<0.05),与HF组相比,CO组和HF+DF组的4周和最终体重均显著降低(P<0.05),肝脏和脂肪的重量显著减少(P<0.05)。且与HF组相比,DF+HF组摄食效率显著降低(P<0.05)。2)CO+DF组血清TC、甘油三酯(TG)含量及天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性以及肝脏TC和TG含量显著低于CO组(P<0.05),CO组和HF+DF组显著低于HF组(P<0.05),粪便TC含量仅在HF+DF组显著低于HF组(P<0.05)。3)DF对肝脏胆固醇调节元件结合蛋白-2(SREBP-2)、3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR)、肝脏X受体α(LXRα)、微管相关蛋白1轻链3-Ⅰ(LC3-Ⅰ)和微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)蛋白表达没有显著影响(P>0.05)。CO+DF组肝脏胆固醇7-羟化酶(Cyp7a1)的蛋白表达水平显着低于CO组(P<0.05),但HF组和HF+DF组之间没有显著差异(P>0.05)。4)HF+DF组的粪便总SCFA和丙酸盐含量显著高于HF组(P<0.05)。与相应的对照组相比,CO+DF组和HF+DF组的粪便丁酸盐含量显著增加(P<0.05)。5)在门水平上,DF组厚壁菌门(Firmicutes)相对丰度减少,HF+DF组的拟杆菌门(Bacteroidetes)相对丰度高于HF组。梭状芽孢杆菌属ⅪⅤa(ClostridiumⅪⅤ)相对丰度在CO+DF组和HF+DF组显著增加(P<0.05)。此外,与其他组相比,仅HF+DF组中阿克曼菌属(Akkermansia)相对丰度显著增加(P<0.05)。由此可见,每千克饲粮添加5 g DF可降低饲喂含脂45%饲粮小鼠的体重和肝脏脂肪含量,降低血清TC、TG含量及AST和ALT活性以及肝脏TC和TG含量,降低胆固醇合成相关蛋白Cyp7a1的表达水平,提高总SCFA含量及肠道有益菌群和优势菌群相对丰度。     

Digestion of carbohydrates and utilization of energy in sows fed diets with contrasting levels and physicochemical properties of dietary fiber

Three experimental diets were used to investigate the digestion of carbohydrates and utilization of energy in sows fed diets with different levels and physicochemical properties of dietary fiber (DF). The low-fiber diet (LF; DF, 16%; soluble DF, 4.8%) was based on wheat and barley. The high-fiber 1 diet (HF1; DF, 41%; soluble DF, 11%) was based on wheat and barley supplemented with the coproducts: sugar beet pulp, potato pulp, and pectin residue, and the high-fiber 2 diet (HF2; DF, 44%; soluble DF, 7.3%) was based on wheat and barley supplemented with approximately 1/3 of the coproducts used in diet HF1 and 2/3 of brewers spent grain, seed residue, and pea hull (1:1:1, respectively). The diets were studied in 2 series of experiments. In Exp. 1, the digestibility and ileal and fecal flow of nutrients were studied in 6 ileal-cannulated sows placed in metabolic cages designed as a repeated 3 x 3 Latin square design. In Exp. 2, energy metabolism was measured in respiration chambers using 6 sows in a repeated 3 x 3 Latin square design. The DF level influenced the ileal flow of most nutrients, in particular carbohydrates, which increased from 190 g/d when feeding the LF diet to 538 to 539 g/d when feeding the HF diets; this was also reflected in the digestibility of OM and carbohydrates (P < 0.05). The ranking of total excretion of fecal materials was HF2 > > HF1 > LF, which also was reflected in the digestibility of OM, protein, and carbohydrates. Feeding HF diets resulted in greater CH(4) production, which was related to the amount of carbohydrates (r = 0.79) and OM (r = 0.72) fermented in the large intestine, but with no difference in heat production (12.2 to 13.1 MJ/kg of DM). Retained energy (MJ/kg of DM) was decreased when feeding HF1 compared with LF and negative when feeding HF2. Feeding sows HF1 reduced the activity of animals (5.1 h/24 h) compared with LF (6.1 h/24 h; P = 0.045).     

Dietary pea protein stimulates bile acid excretion and lowers hepatic cholesterol concentration in rats

It has been shown that some dietary plant proteins beneficially influence lipid metabolism in animals. The effect of pea protein in this respect however has not yet been investigated. Therefore, we studied the effect of purified pea protein on the lipid metabolism in rats. Twenty-four rats received diets with either 200 g/kg of casein or purified pea protein for 16 days. Concentrations of triacylglycerols in liver, plasma and lipoproteins did not differ between both groups of rats. However, rats fed the pea protein diet had a lower concentration of total cholesterol in the liver and the very low density lipoproteins (VLDL) fraction than rats fed the casein diet (p < 0.05); cholesterol concentration in plasma, low density lipoproteins (LDL) and high density lipoproteins (HDL) did not differ between both groups. Rats fed pea protein moreover had an increased mRNA concentration of cholesterol-7α-hydroxylase in the liver and an increased amount of bile acids excreted via faeces compared with rats fed casein (p < 0.05). Concomitantly, mRNA concentrations of sterol regulatory element-binding protein (SREBP)-2 and its target genes 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and LDL receptor in the liver were increased in rats fed pea protein (p < 0.05). The data of this study suggests that pea protein stimulates formation and excretion of bile acids, which leads to a reduced hepatic cholesterol concentration and a reduced secretion of cholesterol via VLDL. An increased gene expression of SREBP-2 and its target genes HMG-CoA reductase and LDL receptor may be a means to compensate for the increased loss of cholesterol for bile acid synthesis.