Effect of age of growing turkeys on digesta viscosity and nutrient digestibility of maize, wheat, barley and oats fed as such or with enzyme supplementation

The effects of age of growing turkeys and beta-glucanase-xylanase activity-containing feed enzyme supplementation on digestibility and feeding value of pelleted maize, wheat, barley and oats were investigated in growing turkeys using excreta collection and ileal sampling by slaughter. Excreta were collected and turkeys were slaughtered at 4, 8 and 12 weeks of age. Viscosity of jejuno-duodenal digesta, caecal volatile fatty acid concentration, ileal crude protein digestibility, total tract fat digestibility and AMEN were assayed using titanium dioxide as an indigestible marker. The highest viscosities were observed in barley and wheat. Viscosity of wheat, barley and oats digesta decreased while caecal volatile fatty acid concentration, fat digestibility and AMEN increased with age. Ileal crude protein digestibility was highest in wheat and lowest in barley. Ileal crude protein digestibility significantly declined with age in most feeding treatments. Enzyme reduced digesta viscosity most efficiently in wheat and barley and improved ileal crude protein digestibility, total tract fat digestibility and AMEN in wheat, barley and oats, but interactions occurred, the effect of enzyme on viscosity being the most remarkable for wheat and barley and for the young birds.     

Effect of age of growing turkeys on nutrient digestibility and energy value of cereal-soybean-based diets

Ileal and total tract digestibility of protein, total tract digestibility of fat and AME_N of cereal-based diets were assayed in growing turkeys at four, seven and 12 weeks of age. Fat digestibility and AME_N improved linearly with age. Total tract protein digestibility improved with age according to a curvilinear trend, while ileal protein digestibility improved from 4?–?7 weeks of age but decreased from 7?–?12 weeks of age. It can be concluded that higher AME_N values could be applied when formulating diets for older than for younger turkeys. Regarding protein digestibility more investigation is needed but a possible fall in values after the first weeks of age may be expected.     

Digestibility and energy value of cereal-based diets in relation to digesta viscosity and retention time in turkeys and chickens at different ages estimated with different markers

Digesta viscosity, ileal transit time of digesta, apparent ileal protein digestibility and apparent metabolisable energy (AME_N) of diets based on wheat and dehulled barley (WB), oats (O) or a mixture of these (WBO) fed as such or with enzyme supplementation in three- and six-week old turkeys and broilers were investigated. In addition, differences between ileal digestibility and AME_N calculated by using titanium dioxide (TiO₂), chromic oxide (Cr₂O₃) or acid insoluble ash (AIA) as indigestible markers were compared. Digesta viscosities were generally moderate reaching from 2.5 mPa · s to 7.3 mPa · s. The highest viscosities were observed in WBO diets. Viscosities were reduced with age in broilers, and were generally higher in turkeys than in broilers, especially at six weeks of age. Digesta retention time in ileum was elongated with age of the birds, pronouncedly in broilers. Oat inclusion to the diets decreased retention time especially in broilers at six weeks of age. Apparent ileal digestibility of protein ranged from 0.64–0.83, was lower at six weeks of age than at three weeks of age and generally lowest in O diets, especially in turkeys. AME_N of the diets ranged from 11.2–13.4 MJ/kg being higher at six weeks of age than at three weeks of age. AME_N of Diets O was the lowest but AME_N of WBO diets was higher than that of WB diets indicating a synergistic interaction of cereals, this trend being more pronounced in broilers. Enzyme supplementation decreased viscosity and improved AME_N in most diets, but did not affect ileal protein digestibility. Differences between ileal digestibility estimates obtained with TiO₂ or Cr₂O₃ were small and mainly not significantly different from 0. AME_N estimates were generally higher when calculated with Cr₂O₃ than with TiO₂. AIA gave remarkably lower AME_N values than TiO₂ (the significant differences ranging from 0.24–0.94 MJ/kg). In addition, effects of markers on AME_N estimates interacted with age of the birds and dietary treatments.     

Effect of age of growing turkeys on nutrient digestibility and energy value of cereal-soybean-based diets

Ileal and total tract digestibility of protein, total tract digestibility of fat and AMEN of cereal-based diets were assayed in growing turkeys at four, seven and 12 weeks of age. Fat digestibility and AMEN improved linearly with age. Total tract protein digestibility improved with age according to a curvilinear trend, while ileal protein digestibility improved from 4-7 weeks of age but decreased from 7-12 weeks of age. It can be concluded that higher AMEN values could be applied when formulating diets for older than for younger turkeys. Regarding protein digestibility more investigation is needed but a possible fall in values after the first weeks of age may be expected.     

Effect of ambient temperature on nutrient digestibility and nitrogen balance in sheep fed brown-midrib maize silage

The aim of the experiment was to determine the impact of heat stress on nutrient digestibility and nitrogen balance in sheep fed silages differing in fibre quality. The digestibility trial was conducted at three different ambient temperatures (15°C, 25°C and 35°C for 24 h/d). The tested brown-midrib maize (Bm) silage had a higher nutrient digestibility, except for ether extract (EE) and a higher metabolisable energy (ME) content than the control maize (Con) silage. Nitrogen (N) excretion with faeces was higher but N excretion with urine was lower for sheep fed Bm silage, subsequently N balance did not differ between the two silages. Temperature had no effect on nutrient digestibility, except for crude protein (CP), but N excretion with urine was lower at elevated temperatures. A diet by temperature interaction was found for dry matter (DM) and organic matter (OM) digestibility. When the ambient temperature increased from 15°C to 25°C, the DM and OM digestibility increased in animals fed Con silage, but decreased in animals fed Bm silage. Concomitantly, ME estimated from digestible nutrients was higher for Bm than for Con at 15°C, but no differences were found at 25°C and 35°C. Effects of diet by temperature interaction, furthermore, were observed for EE and CP digestibility. Therefore, forage quality has to be considered when feeding heat-stressed animals.     

Effects of deoxynivalenol and sodium meta-bisulphite on nutrient digestibility in growing pigs

ABSTRACT

Deoxynivalenol (DON), a mycotoxin synthesised by the Fusarium, is known to affect the growth of pigs. This effect can be attenuated with sodium meta-bisulphite (SBS). The aim of this study was to evaluate the effect of SBS with antioxidant blend on nutrient digestibility in pigs fed a diet contaminated naturally with DON. Six crossbred castrated pigs fitted surgically with single-T cannulas in the distal ileum received one of four barley-corn-soybean diets with or without SBS. After 8 d of feeding, faeces and ileal digesta were collected for 2 d. Apparent ileal digestibility (AID) of the dry matter (DM), energy, nutrients and DON, and apparent total tract digestibility (ATTD) of DM, acid detergent fibre (ADF), neutral detergent fibre (NDF), energy and DON were evaluated. The AID of phosphorus, calcium and some amino acids was increased (p < 0.05) in the DON diets whereas the ATTD of DM and energy tended to decrease (p = 0.064 and p = 0.071). SBS reduced the AID of DM, energy, ADF, ether extract, phosphorus and DON (p < 0.05) but had no effect on the ATTD of DM, energy, fibre or DON. These results show that DON improved the AID of some nutrients but tended to reduce the ATTD of energy, which could explain, although anorexia is the main effect of DON on live weight gain, the reported negative effect of DON on pig growth. Finally, SBS with antioxidant blend had reduced AID of some nutrients and intestinal absorption of DON.     

Effect of excessive dietary fluoride on nutrient digestibility and retention of iron, copper, zinc, and manganese in growing pigs

Ninety-six crossbred growing pigs were used to evaluate the effects of fluoride levels on growth performance, nutrient digestibility, and the retention of minerals in tissues. Four dietary treatments were formulated by supplementing fluorine (as NaF) to a corn-soybean basal diet (39.75 mg/kg F) to provide the following added fluorine levels: 0, 50 100, and 150 mg/kg fluorine. The results showed pigs of the 100 and 150 mg/kg fluorine-added groups had decreased average daily gain (ADG) and increased feed gain ratio (F/G) compared to the control (p<0.05). Apparent digestibility of protein and calcium in 100 and 150 mg/kg fluorinetreated groups was significantly lower than that of the control (p<0.05). On the other hand, iron, copper, zinc, and manganese levels in most tissues of the 100 and 150 mg/kg fluorine groups were markedly changed compared to the control (p<0.05). However, growth performance, nutrient digestibility, and mineral concentrations in all tissues of pigs were not significantly affected by the addition of 50 mg/kg fluorine (p>0.05). Thus, this study suggested that excess fluoride levels could decrease growth performance and change the retention of iron, copper, zinc, and manganese in pigs.     

Effect of zinc supplementation from different sources on growth, nutrient digestibility, blood metabolic profile, and immune response of male guinea pigs

Forty weaned male guinea pigs of 208.20±6.62 g mean body weight were divided into 4 groups of 10 animals in a randomized block design. All of the guinea pigs were fed a basal diet [25% ground maize hay, 30% ground maize grain, 22% ground chickpea (Cicer arietinum L.), 9.5% deoiled rice bran, 6% soybean meal, 6% fish meal, 1.45% mineral supplement (without Zn) and 0.05% ascorbic acid] and available green fodder. Group I served as the control (no Zn supplementation), whereas 20 ppm Zn was added in the diet in groups II, III, and IV either as zinc sulfate (ZnSO₄), zinc amino acid complex (ZAAC), and ZnSO₄ ⁺ ZAAC in equal parts, respectively. Experimental feeding lasted for 70 d, including a 3-d digestibility trial. Blood was collected through cardiac puncture from four animals in each group at d 0 and subsequently at the end of experimental feeding. After 40 d of experimental feeding, four animals from each group were injected with 0.4 mL of Brucella abortus cotton strain-19 vaccine to assess the humoral immune response of the animals. After 10 wk of study, four animals from each group were sacrificed to study the concentration of Zn, Cu, Co, Fe, and Mn in the liver, pancreas and spleen. Results revealed no significant difference in the feed intake, body weight gain, and digestibility of the nutrients, except for crude protein (CP) digestibility, which was significantly (p<0.05) lower in group IV. Although concentrations of serum glucose, Ca, and P and the albumin:globulin (A:G) ratio were similar in the different groups, the total protein, albumin, and serum alkaline phosphatase activity were higher in all of the Zn-supplemented groups on d 70. The serum Zn levels at the end of experimental feeding were significantly higher in groups II and III, whereas serum Mn levels were found to be significantly (p<0.05) higher in groups III and IV. The organ weights (as percentage of body weights) did not show any differences among the treatment groups. Although the Mn concentration was significantly (p<0.05) higher in the pancreas, the Cu concentration was significantly (p<0.05) reduced in the spleen in all of the Zn-supplemented groups. The humoral immune response (antibody titer values) on d 14 of vaccination was significantly (p<0.05) higher in all of the Zn-supplemented groups. It was concluded that the 20-ppm level of Zn in the diet might be adequate for growth and nutrient utilization in guinea pigs, but supplementation of 20-ppm zinc significantly improved the immune response and impact was more prominent with the ZAAC (organic source) compared to ZnSO₄ (inorganic source).     

Effects of dietary supplementation of DL-methionine or 2-hydroxy-4-(methylthio)-butanoic acid on food intake,nutrient digestibility,nitrogen balance,and urinary and blood metabolites in healthy,growing dogs

Abstract

The aim of this study was to evaluate effects on nutritional responses of supplemental DL-methionine and 2-hydroxy-4-(methylthio) butanoic acid (HMTBA) in a commercial-type diet in growing dogs. A nitrogen balance study was conducted as a randomized complete block design using 30 Pointer puppies (72-d-old; 5.5 kg). A corn and poultry byproduct meal based diet was supplemented with 0.1 or 0.2% DL-methionine or HMTBA on an equimolar basis. Organic matter and gross energy tended (p < 0.10) to be less digestible by dogs fed the 0.1% HMTBA diet compared with the 0.2% DL-methionine diet, but other nutrients were unaffected. Postprandial urinary calcium tended (p < 0.10) to be lower for the basal and HMTBA treatments. Fecal ammonia tended (p < 0.10) to be lower for the 0.1% HMTBA diet than for the 0.2% DL-methionine diet. At the levels tested, DL-methionine and HMTBA appear to act similarly when included in a corn and poultry by-product meal diet fed to young dogs.     

Effects of temporary intensive feed restriction on performance,nutrient digestibility and carcass criteria of growing male Californian rabbits

The aim of the study was to evaluate the effect of a temporary quantitative feed restriction on growth performance, nutrient digestibility and carcass criteria of rabbits. A total of 80 weaned male Californian rabbits (30 d of age) were randomly assigned to four treatments of 20 rabbits each. The Control group was fed ad libitum during the whole experimental period (days 30–72 of age). For the three restricted fed groups the feed intake was reduced by 15%, 30% and 45% compared to the Control group, respectively. The feed restriction was applied after weaning and lasted for 21 d. Thereafter, at 51 d of age, in all treatments the feed supply returned to ad libitum intake till 72 d of age (AL period). The feed restriction decreased the body weight gain of rabbits (during the restriction period and the whole experimental period, p < 0.001) and improved feed conversion ratio during all tested periods (p < 0.001). In the AL period, the daily body weight gain of all groups was similar. After the AL period, the digestibility of all measured nutrients was significantly higher for animals fed restrictively. Furthermore, feed restrictions significantly decreased the proportion of perirenal and scapular fat and increased relative weight and length of the gastrointestinal tract. Therefore, it can be concluded that the applied feed restriction improved feed conversion, nutrient digestibility and reduced fat at the slaughter age of Californian rabbits, but the reduced body weight gain could not be compensated by a subsequent ad libitum feeding for 3 weeks.     

Effect of niacin supplementation on digestibility,nitrogen utilisation and milk and blood variables in lactating dairy cows fed a diet with a negative rumen nitrogen balance

The aim of the present experiment was to determine if a niacin supplementation of 6 g/d to lactating dairy cow diets can compensate negative effects of a rumen nitrogen balance (RNB) deficit. A total of nine ruminally and duodenally fistulated lactating multiparous German Holstein cows were successively assigned to one of three diets consisting of 10 kg maize silage (dry matter [DM] basis) and7 kg DM concentrate: Diet RNB– (n = 6) with energy and utilisable crude protein at the duodenum (uCP) according to the average requirement of the animals but with a negative RNB (–0.41 g N/MJ metabolisable energy [ME]); Diet RNB0 (n = 7) with energy, uCP and a RNB (0.08 g N/MJ ME) according to the average requirement of the animals and, finally, Diet NA (n = 5), which was the same diet as RNB–, but supplemented with 6 g niacin/d. Samples of milk were taken on two consecutive days, blood samples were taken on one day pre- and post-feeding and faeces and urine were collected completely over five consecutive days. The negative RNB reduced milk and blood urea content and apparent total tract digestibility of DM, organic matter (OM) and neutral detergent fibre (NDF). Also N excretion with urine, the total N excreted with urine and faeces and the N balance were reduced when the RNB was negative. Supplementation of niacin elevated plasma glucose concentration after feeding and the N balance increased. Supplementing the diet with a negative RNB with niacin led to a more efficient use of dietary N thereby avoiding the negative effects of the negative RNB on the digestibility of DM, OM and NDF.     

Intake, digestibility, rumen fermentation and performance of beef cattle fed diets based on whole-crop wheat or barley harvested at two cutting heights relative to maize silage or ad libitum concentrates

This experiment aimed to quantify the relative intake, digestibility, rumen fermentation, performance and carcass characteristics of beef cattle fed diets based on good quality whole-crop wheat and barley silages, each harvested at two cutting heights, and to rank these relative to good quality maize silage and an ad libitum concentrates-based diet. Ninety beef steers, initial live-weight 438 ± 31.0 kg, were allocated to one of the following dietary treatments in a randomised complete block design: maize silage (MS), whole-crop wheat harvested at a normal cutting height (WCW) (stubble height 0.12 m) or an elevated cutting height (HCW) (stubble height 0.29 m), whole-crop barley harvested at a normal cutting height (WCB) (stubble height 0.13 m) or an elevated cutting height (HCB) (stubble height 0.30 m), each being supplemented with 3 kg concentrates/head/day, and ad libitum concentrates (ALC) supplemented with 5 kg grass silage/head/day for the duration of the 160-day study. Mean dry matter (DM) of the maize silage, whole-crop wheat, head-cut wheat, whole-crop barley and head-cut barley was 301, 488, 520, 491 and 499 g/kg, respectively. There were no differences in total DM intake among treatments, or in rumen fermentation characteristics (except ammonia), or in DM digestibility among the forage-based treatments. Neutral detergent fibre digestibility was lower (P<0.05) for whole-crop wheat than head-cut barley, and starch digestibility was lower (P<0.05) for whole-crop barley and head-cut barley than maize silage. Steers fed ALC had a higher carcass gain (P<0.001) and carcass weight (P<0.05) than all other treatments, but there were no differences between any of the forage-based treatments. Steers fed MS had a better feed conversion efficiency (FCE) than those on WCW or WCB (P<0.05) but were similar to HCW and HCB. The FCE was better for ALC versus any of the other treatments, particularly compared to WCW or WCB (P<0.001). Subcutaneous fat from steers fed ALC was more yellow (P<0.01) than that from steers fed the other treatments. Neither intake nor performance were altered by raising the cutting height of cereals or by replacing whole-crop wheat by barley. However, head-cut cereals numerically favoured DM intake, carcass gain and feed conversion efficiency values nearer to that of maize than whole-crop cereal silages. Ad libitum concentrates supported superior levels of growth by steers compared to all other treatments.     

Effect of enzyme extracts isolated from white-rot fungi on chemical composition and in vitro digestibility of wheat straw

A series of in vitro experiments were completed to evaluate the potential of enzyme extracts, obtained from the white-rot fungi Trametes versicolor (TV1, TV2), Bjerkandera adusta (BA) and Fomes fomentarius (FF), to increase degradation of cell wall components of wheat straw. The studies were conducted as a completely randomized design and analysed using one-way ANOVA. Enzyme activities of the extracts, previously obtained from a liquid culture medium, were characterized in terms of laccase and peroxidase for ligninolytic activity. Carboxymethyl cellulase (CMCase) and avicell digesting cellulase (Avicelase) were used for cellulolytic enzyme assays. Wheat straw samples were incubated with enzyme extracts in a citrate buffer (pH 5.0) in a forced air oven at 25 °C for 6 days. In vitro NDF digestibility (IVNDFD), and the rate and extent of NDF fermentation, without and after incubation with the white-rot enzyme extracts, were determined using a gravimetric microbiological method and a gas production technique, respectively. Results from cell wall chemical composition showed that TV2 and BA enzyme extracts decreased NDF concentration (P<0.05) and that TV1 had higher activity (P<0.05) towards cellulose. There was an increase in IVNDFD (P<0.05), resulting from treatment of wheat straw with enzyme extracts from BA, TV1 and TV2, reaching a difference of 13% for TV2 (P<0.05), versus the non-treated straw control. Treatment with enzyme extract from TV2 caused increased gas production (P<0.05) after the first 20 h of incubation, and also increased the maximum rate of gas production, thus enhancing fermentation kinetics. This study indicates that enzyme extracts from white-rot fungi can be used to develop new approaches to overcome low digestibility of some plant cell walls. Utilization of different substrates to produce enzyme extracts can lead to production of viable ligninolytic complexes which could improve the nutritive value of fibrous feeds.     

Effects of lactoferrin supplementation on ileal and total tract nutrient digestibility,gastrointestinal microbial populations,and immune characteristics of ileal cannulated,healthy, adult dogs

Abstract

Orally supplemented lactoferrin derived from bovine milk is purported to have beneficial effects on gut health of animals. Bovine lactoferrin (0, 60, or 120 mg/d) was fed to ileal cannulated, adult dogs in a replicated 3 × 3 Latin square design with 14 d periods. Control dogs tended (p = 0.06) to have higher fecal DM concentrations compared with dogs supplemented with 120 mg/d lactoferrin (34.5 vs. 32.9%). Fecal scores ranged from 3.0 – 3.3, suggesting that feces of all dogs was near the desired consistency, with dogs supplemented with 120 mg/d lactoferrin tending (p = 0.08) to have higher fecal scores. Ileal azoreductase activity tended (p < 0.10) to be higher in dogs supplemented with 60 or 120 mg/d lactoferrin (609 vs. 592 nmol/h per g ileal DM, respectively) as compared with unsupplemented dogs (272 nmol/h per g ileal DM). The following bacterial groups were measured: bifidobacteria, Campylobacter spp., Clostridium spp., eubacteria, Escherichia coli, Lactobacillus spp., Staphylococcus spp., and Streptococcus spp. Fecal streptococci concentrations were lower (p < 0.05) for dogs receiving 60 mg/d lactoferrin (8.60 log₁₀ cfu/g fecal DM) as compared with unsupplemented dogs (9.19 log₁₀ cfu/g fecal DM) or dogs receiving 120 mg lactoferrin/d (9.43 log₁₀ cfu/g fecal DM). Dogs supplemented with 120 mg/d lactoferrin tended (p = 0.08) to have higher fecal indole concentrations as compared to unsupplemented dogs (1.80 vs. 1.46 μmol/g fecal DM). Because most bacterial groups measured were unaffected, it appears that lactoferrin did not exhibit prebiotic activity, and based on the data collected, lactoferrin also did not appear to have major effects on indices of health in the dog.     

Influence of physical treatment of rape expeller,wheat, maize and maize gluten feed on degradability in the rumen and on the enzymatic in vitro digestibility of non degraded crude protein

The influence of physical treatment‐expansion and flaking‐on crude proteins degradability in the rumen was studied in maize, maize‐gluten feed, rape extracted meal and in the expanded one at 120°C and 150°C, rape cake, wheat and flaked wheat by in sacco method. The enzymatic digestibility of crude protein in the rumen undegraded residues of the above mentioned feeds was determined by an enzymatically in vitro method.

The treatment of feed decreased significantly the original solubility and theoretical degradability of crude proteins, and the amount of undegraded crude proteins was increased. Positive influence on the amount of enzymatically digested crude protein was determined in rape expanded at 120 °C and 150 °C (60, 61 and/or 68%). Flaking of wheat had a similar effect. Enzymatic digestibility at undegraded rests where increased by 8–10% after the heat treatment and it remained almost unchanged in expanded maize‐gluten feed.     

Effects of dietary addition of cellulase and a Saccharomyces cerevisiae fermentation product on nutrient digestibility,rumen fermentation and enteric methane emissions in growing goats

This study was designed to assess the effectiveness of dietary cellulase (243 U/g, derived from Neocallimastix patriciarum) and a Saccharomyces cerevisiae fermentation product (yeast product) on ruminal fermentation characteristics, enteric methane (CH₄) emissions and methanogenic community in growing goats. The experiment was conducted in a 5 × 5 Latin square design using five Xiangdong black wether goats. The treatments included a Control and two levels of cellulase (0.8 g and 1.6 g/kg dry matter intake (DMI), i.e. 194 U/kg and 389 U/kg DMI, respectively) crossed over with two levels (6 g or 12 g/kg DMI) of the yeast product. There were no significant differences regarding feed intake, apparent digestibility of organic matter, neutral detergent fibre and acid detergent fibre among all the treatments. In comparison with the Control, the ruminal ammonia N concentration was decreased (p = 0.001) by cellulase and yeast product addition. The activities of carboxymethylcellulase and xylanase were decreased after cellulase addition. Moreover, dietary cellulase and yeast product addition led to a significant reduction (p < 0.05) of enteric CH₄ emissions although the diversity and copy numbers of methanogens among treatments were not dissimilar. The present results indicate that the combination of cellulase and yeast fermentation product can reduce the production of CH₄ energy and mitigate the enteric CH₄ emissions to a certain degree.     

Effects of feeding intact,ground and/or pelleted rapeseed on nutrient digestibility and growth performance of broiler chickens

ABSTRACT

In this study, the effect of grinding or pelleting of rapeseed on the digestibility, apparent metabolisable energy (AME_N), growth performance and gizzard weight of broiler chickens was evaluated. In Exp. 1, four treatments were tested (240 broiler chickens, 20 replications, 3 birds per cage). Birds received either a basal diet or were fed with rapeseed of different sized particles (fine, medium and coarse ground, respectively). In Exp. 2, 10 treatments were assessed (360 chickens, 12 replications, 3 birds per cage), where five different diets (a basal diet and four diets with intact rapeseed, fine ground, medium ground or coarse ground rapeseed, respectively) were fed non-pelleted or pelleted. In Exp. 3, two treatments were compared (224 broiler chickens, 14 replications, 8 birds per floor pen): fine ground rapeseed (FG) and intact rapeseed (IS). Compared with medium and coarse ground rapeseed, fine grinding increased in Exp. 1 the AME_N of rapeseed and the precaecal digestibility (PD) of dry matter and ether extract (EE) (p < 0.05). In Exp. 2, the content of AME_N and the PD of EE and crude protein (CP) increased as the degree of grinding increased when diets were not pelleted (p < 0.01). In contrast, the significantly highest values for these parameters were measured after pelleting without effect of grinding, resulting in a significant interaction between pelleting and grinding (p < 0.001). In Exp. 3, performance of chickens was not affected by dietary treatments, but gizzard weight and the PD of CP were higher when IS were included in the diet (p < 0.05). The results suggested that fine grinding may be used to increase the feeding value of full-fat rapeseed for broiler chickens. Nevertheless, pelleting of diets with rapeseed seemed to be much more effective in the reduction of particle size than grinding.     

The interaction between lactose level and enzyme supplementation and form of barley processing on performance, digestibility and faecal volatile fatty acid concentration of weanling pigs fed barley-based diets

A 2×3 factorial arrangement was used to investigate the interaction between lactose level (170 g/kg versus 275 g/kg), enzyme supplementation (with or without endo-1,3 (4)-β-glucanase) and toasting (raw barley versus toasted barley) in barley-based diets (250 g/kg) on piglet performance and diet digestibility postweaning. One hundred and forty-four weaned piglets (24 days old, 6.5 kg live weight) were blocked on the basis of live weight and were assigned to one of six dietary treatments (n = 6) for 21 days as follows: (1) 170 g lactose/kg and barley (250 g/kg), (2) 275 g lactose/kg and barley (250 g/kg), (3) 170 g lactose/kg and toasted-flaked barley (250 g/kg), (4) 275 g lactose/kg and toasted-flaked barley (250 g/kg), (5) 170 g lactose/kg and barley (250 g/kg) plus β-glucanase, (6) 275 g lactose/kg and barley (250 g/kg) plus β-glucanase. There was an interaction (P<0.05) between lactose level and β-glucanase supplementation on average daily gain (ADG), food conversion ratio (FCR) and coefficient of total tract apparent digestibilities (CTTAD) of dry matter (DMD), organic matter (OMD) and nitrogen (N). Pigs offered 170 g lactose/kg and β-glucanase supplementation had an improved FCR and ADG compared to the treatment based on 170 g lactose/kg and unsupplemented barley. However, β-glucanase supplementation at 275 g lactose/kg had no significant effect on FCR and ADG compared to the 275 g lactose/kg and unsupplemented barley. Pigs offered diets containing 170 g lactose/kg plus β-glucanase had a significantly higher CTTAD for DMD, OMD and nitrogen compared to the 275 g lactose/kg plus β-glucanase diet. However, there was no significant effect of lactose level in the unsupplemented diets. Pigs offered high lactose diets showed significantly increased total VFA concentration, molar proportions of butyric acid and reduced acetic acid compared to those offered low lactose diets. Pigs offered β-glucanase supplemented diets showed reduced (P<0.05) total VFA concentration compared to unsupplemented diets. In conclusion, β-glucanase supplementation improved diet digestibility and pig performance compared to the unsupplemented diet at the low lactose level only. There was no response of β-glucanase supplementation at the high level of lactose.     

Effect of three different bariatric obesity surgery procedures on nutrient and energy digestibility using a swine experimental model

Morbid obesity is a worldwide health concern that compromises life quality and health status of obese human subjects. Bariatric surgery for treating morbid obesity remains as one of the best alternatives to promote excess weight loss and to reduce co-morbidities. We have not found studies reporting nutrients and energy balance considering digestibility trials in humans following surgery. The purpose of this study was to determine protein, lipid, fiber, energy, calcium, and phosphorous digestibility in a swine model that underwent ileal transposition (IT), sleeve gastrectomy with ileal transposition (SGIT), Roux-en-Y gastric bypass (RYGBP), and with sham operated animals (SHAM). Thirty-two pigs were randomly assigned to four laparoscopic procedures: IT (n = 8), RYGBP (n = 8), SGIT (n = 8), and Sham-operated pigs (n = 8). From day 0 postsurgery to 130, pigs were weighed monthly to determine live weight and weight gain was calculated for each month postsurgery until day 130. Food intake in a metabolic weight basis was calculated by measuring ad libitum food intake at day 130. Swine were fitted into metabolic crates to determine digestibility coefficients of dry matter, protein, fat, fiber, ash, energy, calcium, and phosphorous from day 130. A one-way ANOVA and Student–Newman–Keuls were used to detect differences in weight, food intake, and digestibility coefficients. Digestibility values for dry matter, fiber, phosphorus, and energy showed no differences among groups (P > 0.05). However, significant differences (P ≤ 0.05) were encountered among groups for fat, protein, ash, and calcium digestibilities. The RYGBP procedure, when applied to the pig model, significantly reduced calcium, fat, and ash digestibility, which did not occur with SGIT or IT procedure, when compared with Sham-operated animals.     

Effect of extrusion on trypsin inhibitor activity and nutrient digestibility of diets based on fish meal,soybean meal and white flakes

Abstract

The effects of moist extrusion processing of diets containing fish meal (FM) and conventional defatted soybean meal (SBM) or untoasted defatted soybean meal (white flakes [WF]) on amino acid composition, trypsin inhibitor activity (TIA), and apparent total tract digestibility of nutrients were studied. Three diets with the nutritional characteristics of feeds for salmonid fish were formulated: one control based on FM as protein source and two others where 40% of total amino acids from FM were substituted by either SBM or WF. Each diet was fed to mink either as an unextruded mixture of the ingredients or as extruded pellets in order to determine the effect of extrusion processing. Extrusion did not change the amino acid composition of the diets significantly, but reduced the TIA of both diets containing soy products by approximately 76%. Intake of the unextruded WF diet was only one-third compared with the other diets. The dry matter concentration in faeces from mink fed diets containing soy products was significantly lower than in mink fed the FM diet. Digestibility of crude protein, all amino acids and fat was lower, but starch higher, in the unextruded WF diet than in the FM and SBM diets, whereas no significant differences were found among the extruded diets. Extrusion of the WF diet increased digestibility of protein and all amino acids. The greatest increase in digestibility after extrusion of the WF diet was observed for cysteine followed by tryptophan. Extrusion of the FM and SBM diets had no significant effect on amino acid digestibility. Digestibility of starch was, in general, increased by extrusion. It is concluded that the heat treatment involved in typical moist extrusion processing used for fish feed may be sufficient to inactivate most of the TIA in unheated soybean meal, and to increase digestibility of the protein in WF to approximately the same level as found for SBM and FM. Still, extrusion is a lenient process with minor effects on nutrient digestibility of diets containing fish meal or toasted soybean meal as major protein sources.