Effect of D‐mannitol on nitrogen retention,fiber digestibility and digesta transit time in adult rabbits

The aim of the current study was to elucidate the effect of gastrointestinal retention time of digesta on fiber digestibility in adult rabbits fed indigestible, but fermentable, sugar D‐mannitol. Six adult rabbits were fed alternately a commercial diet containing 5% glucose and a diet containing D‐mannitol. Total feces and urine were collected during the experimental period. Nitrogen (N) balance, digestibility of nutrients, and gastrointestinal mean retention time (MRT) were measured. The results indicated that urinary excretion was significantly lowered, whereas N retention and N accumulation rates were significantly increased in the D‐mannitol group compared with the glucose group (P < 0.05). However, fecal N excretion was unaffected. Absorption of crude ash (CA) and acid detergent fiber (ADF) digestibility were significantly higher in the D‐mannitol group compared with the glucose group (P < 0.05). The addition of D‐mannitol to the diet did not affect the MRT of liquid digesta, but increased the MRT of solid digesta compared with the glucose group (P < 0.05). These results suggest that the addition of D‐mannitol to the diet stimulates cecal bacterial growth, thereby increasing N utilization and digesta retention time.     

Effect of fructo‐oligosaccharides on nutrient digestibility and digesta retention time in adult guinea pigs

A previous study suggested that addition of fructo‐oligosaccharides (FOS) to the diet improved nitrogen (N) utilization and decreased acid detergent fiber (ADF) digestibility in guinea pigs. The present study was conducted to clarify the relationship between ADF digestibility and gastrointestinal mean retention time (MRT) in guinea pigs under FOS supplementation. Adult male guinea pigs were fed a commercial diet (50 g/day) with either 5% glucose (glucose group) or 5% FOS (FOS group) for 12 days in individual metabolism cages. Unlike the glucose group, N utilization improved, but ADF digestibility significantly (P < 0.05) decreased in the FOS group. MRT of solid digesta also significantly (P < 0.05) decreased in the FOS group compared with that in the glucose group. We concluded that reduction of MRT of solid digesta containing FOS decreased ADF digestibility in guinea pigs.     

Comparison of rumen bacteria distribution in original rumen digesta,rumen liquid and solid fractions in lactating Holstein cows

Background: Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods: To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet(HFD) or a high energy diet(HED) were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results: Rumen bacterial diversity was mainly affected by diet and individual cow(P 0.05) rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers(using LEf Se analysis) were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions: Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.     

Low ambient temperature elevates plasma triiodothyronine concentrations while reducing digesta mean retention time and methane yield in sheep

Ruminant methane yield (MY) is positively correlated with mean retention time (MRT) of digesta. The hormone triiodothyronine (T₃), which is negatively correlated with ambient temperature, is known to influence MRT. It was hypothesised that exposing sheep to low ambient temperatures would increase plasma T₃ concentration and decrease MRT of digesta within the rumen of sheep, resulting in a reduction of MY. To test this hypothesis, six Merino sheep were exposed to two different ambient temperatures (cold treatment, 9 ± 1 °C; warm control 26 ± 1 °C). The effects on MY, digesta MRT, plasma T₃ concentration, CO₂ production, DM intake, DM digestibility, change in body weight (BW), rumen volatile fatty acid (VFA) concentrations, estimated microbial protein output, protozoa abundance, wool growth, water intake, urine output and rectal temperature were studied. Cold treatment resulted in a reduction in MY (p < 0.01); digesta MRT in rumen (p < 0.01), hindgut (p = 0.01) and total digestive tract (p < 0.01); protozoa abundance (p < 0.05); and water intake (p < 0.001). Exposure to cold temperature increased plasma T₃ concentration (p < 0.05), CO₂ production (p = 0.01), total VFA concentrations (p = 0.03) and estimated microbial output from the rumen (p = 0.03). The rate of wool growth increased (p < 0.01) due to cold treatment, but DM intake, DM digestibility and BW change were not affected. The results suggest that exposure of sheep to cold ambient temperatures reduces digesta retention time in the gastrointestinal tract, leading to a reduction in enteric methane yield. Further research is warranted to determine whether T₃ could be used as an indirect selection tool for genetic selection of low enteric methane‐producing ruminants.     

Digestive physiology of captive giant anteaters (Myrmecophaga tridactyla): determinants of faecal dry matter content

Giant anteaters (Myrmecophaga tridactyla) are specialized insectivores and consume mainly ants and termites in the wild. In captivity, giant anteaters are either fed a complete diet, or a combination of a domestic carnivore diet with leaf eater pellets, or a traditional gruel‐type diet. Soft faeces are a frequently encountered problem with this type of feeding. In the present study, we analysed diet and faeces composition, calculated digestibility and measured mean retention time on various diets in eight giant anteaters (total of n = 64 experiments). The results suggest that the digestive physiology of giant anteaters is similar to that of domestic dogs and cats in terms of nutrient digestibility and digesta retention. When testing correlations between faecal dry matter content and other variables, no relationship with dietary crude fibre content or mean digesta retention time could be detected. However, acid insoluble ash intake was significantly and positively correlated with faecal dry matter content. The amount of acid insoluble ash excreted with the faeces was higher than that ingested with the diet offered, indicating that the giant anteaters ingested soil from their enclosure of up to 93 g per day. This finding is consistent with observation of faeces of wild giant anteaters that contain soil or sand most likely due to indiscriminate feeding. It also corresponds to reports that indigestible materials such as peat, soil, chitin or cellulose contribute to a firmer faecal consistency in various carnivore species. Therefore, offering giant anteaters the opportunity to voluntarily ingest soil from their enclosure might be beneficial.     

Effect of feeding Bacillus subtilis on rumen fermentation,blood metabolites,nutrient digestibility,and energy and nitrogen balances in non-lactating crossbred cows

The purpose of this study was to investigate the effects of feeding Bacillus subtilis on rumen fermentation, blood metabolites, nutrient digestibility, and energy and nitrogen balances in non-lactating crossbred (Holstein-Friesian × Bos indicus) cows. Four cows were assigned to the control and B. subtilis diets in a crossover design, and respiratory and metabolic experiments were conducted. For the B. subtilis diet, B. subtilis DSM15544 spores were added at the rate of 1.0 × 10¹⁰ CFU/head/day to the control diet. At 4 hr after feeding, cows fed the B. subtilis diet had increased levels of i-butyric acid in the rumen fluid and tended to have lower concentrations of plasma non-esterified fatty acids when compared with cows fed the control diet. This suggests that feeding B. subtilis could improve energy efficiency. However, there was no effect on energy retention in this study. Although there were no effects on nutrient digestibility, nitrogen balance, or methane production, heat production was significantly higher in cows fed the B. subtilis diet than in those fed the control diet.     

The effect of fructose supplementation on feed intake,nutrient digestibility and digesta retention time in Reeves’s muntjac (Muntiacus reevesi)

The aim of the study was to determine the effect of fructose supplementation in the diet on feed intake, nutrient digestibility and digesta retention time in Reeves's muntjac (Muntiacus reevesi), a browsing cervid. In Experiment 1, six adult males of Reeves's muntjac were used in a replicated 3 × 3 Latin square design and fed a diet consisting of dehydrated chopped lucerne (ad libitum), high‐fibre pellet (120 g/day) and wheat bran (30 g/day) without (F0) or with addition of 12 and 24 g fructose/day (F12 and F24, respectively). In Experiment 2, the same six adult muntjacs were used in crossover design and fed F0 or F12. Doses of supplemental fructose were set to increase intake of water‐soluble carbohydrates (WSC; ≈40 g/day; ≈8% of WSC in consumed dry matter [DM]) by 25 and 50% relative to F0. Feed intake was controlled daily (Experiment 1 and 2) and total tract digestibility and digesta retention time were determined (Experiment 2). In Experiment 1, DM intake of chopped dehydrated lucerne decreased with fructose supplementation (F0 vs. F12 and F24; p = .01) but was not different between F12 and F24 (p = .76). Total DM intake was also not different between treatments (p ≥ .13). In Experiment 2, DM intake of lucerne, total DM intake and nutrient digestibility was not affected by fructose supplementation (p ≥ .17), but mean retention time of long particles in the whole GIT tended to be longer for F12 compared to F0 (p = .09). Under conditions of the current study, additional fructose intake (resulting in a range of WSC content in consumed DM from 8.6% to 13%) had only minor impact on feed intake and investigated functions of the gastrointestinal tract of Reeves's muntjac.     

Effects of grass hay proportion in a corn silage‐based diet on rumen digesta kinetics and digestibility in dairy cows

In this study, we aimed to evaluate the effects of six levels of orchardgrass hay (GH) proportion (0%, 10%, 20%, 30%, 40% or 50% of dry matter) in finely chopped corn silage (CS)‐based diets on digesta kinetics of CS and GH in the rumen. Six non‐lactating, rumen‐cannulated Holstein cows were used in a 6 × 6 Latin square design. Ruminal digesta kinetics was measured by ruminal dosing of feed particle markers (dysprosium for CS, erbium for GH) followed by fecal sampling. The increase of GH proportion had a quadratic effect (P < 0.01) on total tract digestibility of neutral detergent fiber (NDF) and acid detergent fiber. The proportion of GH did not affect the particle size distribution of rumen digesta, total weight of dry matter or NDF in the rumen. The rates of large particle size reduction in the rumen for CS tended to increase linearly with increasing GH proportion (P = 0.077). A quadratic effect (P < 0.05) was found with increasing the GH proportion for the ruminal passage rate of small GH particles, but not for CS particles. The results suggested that associative effects between CS and GH could be generated on rumen digesta kinetics when cows were fed a CS‐based diet with an increased proportion of GH.     

Extruded urea could reduce true protein source in beef cattle diets

Rumen micro‐organisms are capable of producing microbial protein from ammonia and carbon skeleton, and non‐protein nitrogen (NPN) may be one of the sources of ammonia. Alternative source of NPN is the slow release of ammonia sources in which the product is the extrusion of starch with urea. This work aimed to determine the effects on nutrient intake, ingestive behaviour, digestibility, nitrogen balance, ruminal pH, rumen ammonia nitrogen, volatile fatty acids (VFA) and blood parameters with increased levels of extruded urea (50, 60, 70 and 80 g/100 kg of body weight [BW]) in beef cattle diet. Four rumen cannulated crossbred steers with initial mean weight of 336 ± 47 kg in a 4 × 4 Latin square design were distributed. Diets were formulated with 400:600 g/kg roughage:concentrate ratio on dry matter based and provided once per day, being used whole corn silage as roughage. There were no effects on nutrient intake (kg/day), ingestive behaviour, apparent digestibility, nitrogen balance, volatile fatty acid (VFA) and blood parameters in extruded urea treatment groups. Similar results were observed on time spent on feeding, rumination and idleness. There were positive linear effects (p = 0.022) on rumen pH in the time of 8 hr after feeding and also on plasma concentration of the extruded urea levels (p = 0.039); whereas a linear negative effect (p = 0.030) was observed on ammonia nitrogen for the collection time of 2 hr after feeding. Increased levels of extruded urea could maintain nutrient intake, digestibility, ingestive behaviour, rumen pH and blood parameters in normal conditions. In conclusion, we recommend the extruded urea use with values up to 80 g/100 kg BW in confined beef cattle that receive balanced diets with 140 g/kg of crude protein.     

Relationships between chewing behavior, digestibility, and digesta passage kinetics in steers fed oat hay at restricted and ad libitum intakes

The objective of this study was to evaluate the relationships between chewing behavior, digestibility, and digesta passage kinetics in steers fed oat hay at restricted and ad libitum intakes. Four Hereford steers, with an initial average BW of 136 kg, were used in an experiment conducted as a balanced 4 × 4 Latin square with 4 treatments (levels of intake) and 4 periods. Animals were fed lopsided oat hay (Avena strigosa Schreb.) at 4 levels of intake (as a percentage of BW): 1.5, 2.0, 2.5, and ad libitum. Digestibility, chewing behavior, and digesta passage kinetic measurements were recorded during the experimental period. Chewing rates during eating and ruminating [(chews?min(-1))/g of DMI?kg(-1) of BW?d(-1)] decreased (P = 0.018 and P = 0.032, respectively) with increased DMI (g?kg(-1) of BW?d(-1)), whereas total chewing and total time spent on each chewing activity increased. Calculated total energy expended by the chewing activity was 4.2, 4.4, 5.2, and 5.3% of ME intake for DMI of 1.5, 2.0, and 2.5% of BW and ad libitum, respectively, indicating that adjustments in animal chewing behavior may be a mechanism of reducing energy expenditure when forages are fed at restricted intake. Hay digestibility decreased (P < 0.001) with increased DMI (r = -0.865). Digesta mean retention time (h) was strongly correlated with DMI (r = -0.868) and OM digestibility (r = 0.844). At reduced intake, hay digestibility was enhanced (P < 0.001) by extending digesta retention time and by increasing chewing efficiency, highlighting the relationship between chewing behavior and the digestive process. Fractional outflow rate of particulate matter from the reticulorumen (k(1)) was positively correlated with total chews, emphasizing that the decrease in particle size caused by chewing facilitates particle flow through the digestive tract. Increased hay intake also increased (P < 0.001) k(1), whereas passage rate of the liquid phase, transit time, and rumen fill were not affected (P > 0.05). The latter was correlated with rumen volume (r = 0.803). In conclusion, the results of this study indicate that animals fed at restricted intake increased chewing rate when eating and ruminating, which, along with a longer digesta retention time, contributed to enhance feed digestibility.     

Comparison of Nutrient Digestibility Between Adult and Aged Horses

There is little published work comparing digestibility in healthy adult versus healthy aged horses. Researchers hypothesized that there would be no differences in macronutrient digestibility between eight adult (5–12 years) and nine aged (19–28 years) horses fed three diets in a Latin square design. Seventeen stock-type mares were randomly assigned for a 5-week period to one of three diets: hay only (HAY), hay plus a starch- and sugar-rich concentrate (CHO), or hay plus a fat- (oil) and fiber-rich concentrate (FF). Each diet period comprised 3 weeks of outdoor group drylot feeding, 2 weeks of indoor stalled individual feeding, followed by a 72-hour digestibility trial including total urine and fecal collection. Feed, fecal, and/or urine samples were analyzed to determine dry matter, crude protein, fat, energy, calcium, and phosphorus apparent retention as well as apparent digestibility. Neutral detergent fiber digestibility was also determined. Mean body weight was lower in aged than in adult horses (455 ± 12 kg vs. 500 ± 13 kg; P = .02), but body condition score (BCS) did not differ between groups (aged horses, 4.8 ± 0.2 BCS and adult horses, 5.1 ± 0.2 BCS; P = .20). No age differences in digestibility, apparent digestibility, or apparent retention were seen for any of the variables measured. Based on the results of this study, total tract macronutrient digestibility appears to be similar between healthy adult and aged horses.     

Effect of feeding Acacia nilotica pods to sheep on nutrient digestibility,nitrogen balance,ruminal protozoa and rumen enzymes activity

This study was conducted to evaluate the effect of supplying two levels of Acacia nilotica (A. nilotica) pods to rations of sheep on nutrient digestibility, nitrogen balance and rumen liquor parameters (pH, total protozoa count, protein concentration and enzymes activity). Twelve mature rams (50 ± 1.25 kg B.W.) were distributed into three groups, each with four rams. Animals in group one were considered as a control which fed a basal diet, consisting of concentrate mixture and Egyptian clover. The second group and the third one received the same basal diet with supplying the concentrate mixture by 1.5% and 3.0% of A. nilotica pods meal respectively. The experiment lasted for 3 weeks. It was found that supplementation of A. nilotica pods to the concentrate mixture at a rate of 1.5% and 3.0% significantly improved the total feed intake compared to the control. The digestibility of dry matter and crude fibre was significantly reduced with A. nilotica supplements, whereas the digestibility of crude protein was significantly improved. All of nitrogen intake and N‐retained were significantly increased in rams fed on concentrates with 1.5% and 3.0% A.  nilotica pods when compared to the control. The pH of ruminal fluid was not affected by the dietary treatments. Nevertheless, the total rumen protozoa count was significantly decreased in A. nilotica pods supplemented groups. Also, the rumen protein concentration and the ruminal enzymes activity, especially α‐amylase, cellulase and protease, were lower in A. nilotica pods supplemented treatments. In conclusions, inclusion of low levels of A. nilotica pods (1.5% and 3.0%) in the concentrates can be used as a natural protein protectant in ruminants by forming tannin protein complexes in the rumen to maximize the amino acids available in the lower digestive tract. Also, these levels can increase the protein digestibility as well as the N‐retained in the body .     

Effects of the ruminal comminution rate and microbial contamination of particles on accuracy of in situ estimates of ruminal degradability and intestinal digestibility of feedstuffs

Effects of considering the comminution rate (k_c) and the correction of microbial contamination (using ¹⁵N techniques) of particles in the rumen on estimates of ruminally undegraded fractions and their intestinal digestibility were examined generating composite samples (from rumen‐incubated residues) representative of the undegraded feed rumen outflow. The study used sunflower meal (SFM) and Italian ryegrass hay (RGH) and three rumen and duodenum cannulated wethers fed with a 40:60 RGH to concentrate diet (75 g DM/kgBW^0.75). Transit studies up to the duodenum with Yb‐SFM and Eu‐RGH marked samples showed higher k_c values (/h) in SFM than in RGH (0.577 vs. 0.0892, p = 0.034), whereas similar values occurred for the rumen passage rate (k_p). Estimates of ruminally undegraded and intestinal digestibility of all tested fractions decreased when k_c was considered and also applying microbial correction. Thus, microbial uncorrected k_p‐based proportions of intestinal digested undegraded crude protein overestimated those corrected and k_c?k_p‐based by 39% in SFM (0.146 vs. 0.105) and 761% in RGH (0.373 vs. 0.0433). Results show that both k_c and microbial contamination correction should be considered to obtain accurate in situ estimates in grasses, whereas in protein concentrates not considering k_c is an important source of error.     

The effects of concentrate added to pineapple (<Emphasis Type="Italic">Ananas Comosus linn. Mer.</Emphasis>) waste silage in differing ratios to form complete diets,on digestion,excretion of urinary purine derivatives and blood metabolites in growing,male, Thai swamp buffaloes

Four, male, growing Thai swamp buffaloes (197 ± 5.3 kg and all 1 year old) were used to evaluate the effects of concentrate added to pineapple waste silage in differing ratios, to form a complete diet, studying in vivo digestion, the rate of passage, microbial protein synthesis and blood metabolites. Animals were fed ad libitum with 4 diets, using four combinations of pineapple waste silage (P) and concentrate (C), in the proportions (on a dry matter basis) of 0.8:0.2 (P80:C20), 0.6:0.4 (P60:C40), 0.4:0.6 (P40:C60) and 0.2:0.8 (P20:C80). The results showed that the intakes of dry matter (DM), organic matter (OM), nitrogen (N), the N-balance, urinary purine derivatives (PD) excretion, the ratios of allantoin to creatinine (CR), PD to CR, the plasma urea-N (PUN) and insulin increased in the animals, but the intake of neutral detergent fiber (NDF), the coefficient of whole tract, apparent digestibility of NDF, the transit time (TT) and the mean retention time (TMRT) decreased, when the proportion of concentrate in the diet increased. This study indicated that the proportion of P40:C60 in the diet produced the best efficiency of urinary PD excretion (mmol) per digestible OM intake (kg DOMI).     

The effect of dietary supplementation with globin and spray-dried porcine plasma on performance,digestibility and histomorphological traits in broiler chickens

This study evaluated the effects of globin and spray-dried porcine plasma (SDPP) on growth performance, digestibility, nitrogen retention, energy retention efficiency (ERE) and intestinal morphology of broiler chickens. A total of 336-day-old male broiler chickens were reared from 1 to 40 days of age and fed 3 diets (8 replicates/diet, 14 birds/replicate) during 3 feeding phases: starter (1–12 days), grower (12–25 days) and finisher (25–40 days). Isonitrogenous diets were formulated by replacing gluten protein isolate contained in the control diet (C diet) with 2% (starter) or 1% (grower and finisher) spray-dried porcine plasma in the plasma diet (SDPP diet). The globin diet (G diet) was obtained by adding globin on the top of C diet at a dose of 0.08% for the whole rearing period. Total tract apparent digestibility (aD), nitrogen retention and ERE were assessed during the three growing phases. At 12  and 40 days of age, one bird per pen was slaughtered to sample gut, liver, spleen and bursa of Fabricius for histomorphological investigations. The SDPP diet increased body weights of chickens at 12 (+60 g; p < .001), 25 (+101 g; p < .001) and 40 days (+130 g; p = .018) of age compared to C and G diets. Also SDPP improved crude protein aD (+9.7%) and ERE (+12.3%) during the starter phase (p < .001). Dietary globin and SDPP inclusion did not affect either the gut morphology or the histopathological findings in birds at 12 and 40 days of age, despite a numerical (+6.90% and +7.40% respectively) villus height improvement in the SDPP group. Overall, these results confirm that dietary supplementation with SDPP and, to a lesser extent, with globin can improve growth performance and dietary protein and energy utilization in broiler chickens without effect on gut functionality.     

Efficiency of utilisation of different diets with contrasting forages and concentrate when fed to sheep in a discontinuous feeding pattern

The effects of feeding different levels of forages and concentrate, in a discontinuous feeding pattern, on the efficiency of feed utilisation and rumen function were studied using rumen fistulated sheep. Experiment 1 was a 4 × 4 latin square design to determine the whole tract digestibility and rumen characteristics of diets comprising 15% (C15), 25% (C25), 35% (C35) and 45% (C45) concentrate (energy-dense dairy pellets) with the rest of the diet being a combination of fresh short rotation ryegrass (Lolium mutiforum) and conserved (lucerne hay and maize silage) forages. In Experiment 2, the rumen degradation characteristics of feed ingredients were determined using the nylon bag technique. Daily dry matter intake (either expressed as g/kg LW or g/kg W ^0.75) was 10% lower (p = 0.03) for the C15 diet compared with C25, C35 and C45 diets. The apparent in vivo digestibility of dry matter (DM) for C15 diet was 4% higher (p = 0.04) than the C35 and C45 diets which may be attributed to the high quality of the forage (ryegrass) used.Fibre digestibility decreased as proportion of concentrate in the diet increased. However, this was unlikely due to changes in the rumen fermentation pattern, as neither pH (6.1 ± 0.23) nor ammonia concentration (24.4 ± 6 mg/dl), were different (p > 0.05) among diets. Instead, the lower fibre digestion was most likely the result of different type and proportion of fibre among diets, as total rumen degradability and rate of fibre degradation in the rumen were higher (p = 0.001) for ryegrass than for other feedstuffs. There was no significant difference in total nitrogen balance and urinary allantoin excretion among diets, which indicated similar total microbial protein synthesis (MPS). The asynchrony observed, for N and energy availability in the rumen for different diets using Sinclair et al. [Sinclair, L.A., Garnsworthy, P.C., Newbold, J.R., Buttery, P.J., 1993. Effect of synchronizing the rate of dietary energy and nitrogen release on rumen fermentation and microbial protein synthesis in sheep. J. Agric. Sci. 120, 251–263] equation, was due to the feeding pattern used in this study leading to excess of N in relation to total organic matter digested in the rumen. In conclusion, feeding concentrates in the diets as PMR with conserved forages in a discontinuous feeding pattern may be valuable to develop feeding strategies in a pasture based system for high producing dairy cows without affecting the rumen system.     

Influence of exogenous acid protease in broiler chickens fed corn–soybean meal-based diets

This study was conducted to determine the influence of exogenous acid protease (EAP) on growth performance, blood profiles, excreta noxious gas emissions, ileum digesta viscosity and apparent ileal digestibility in broilers. A total of 600 1-d-old broilers with average initial body weight of 47.0 ± 0.2 g were used in a 5-week feeding trial. The broilers were randomly allotted to 1 of 4 treatments with 10 replicate pens per treatment and 15 birds per cage. Dietary treatments consisted of: CON, basal diets; EAP1, CON + 2,700 exogenous acid protease unite (APU)/kg; EAP2, CON + 5,400 APU/kg; EAP3, CON + 8,100 APU/kg. The body weight gain (BWG) had a linear improvement when chicks fed 8,100 AP/kg diets from d 18 to 35 and overall (p < .05). Lower feed conversion ratio (FCR) was obtained in broilers fed 5,400 APU/kg and 8,100 APU/kg as compared with the CON during overall (p < .05). Birds fed diets supplemented with EAP diet led to a linear increase in the ileal digestibility of crude protein, energy and amino acids (lysine, methionine, cystine, threonine, isoleucine, leucine, histidine and tryptophan) compared with CON group (p < .05). In conclusion, based on our results, we suggest that supplementation with EAP diet was effective in improving growth performance through increasing ileal digestibility of some nutrients (crude protein, energy and amino acids) in broilers.     

Effects of soybean meal supplementation on ruminal kinetics of feed particle size reduction and passage in dairy cows fed rice straw

Six ruminal-cannulated nonlactating Holstein Friesian cows (mean body weight:660 ± 42.9 kg) were used to investigate the effect of soybean meal (SBM) supplementation on voluntary rice straw (RS) intake, feed particle size reduction, and passage kinetics in the rumen. They were allocated to two dietary treatments: RS alone or RS supplemented with SBM. Voluntary dry matter intake of RS and total tract fiber digestibility was increased by SBM supplementation (p < 0.05). Supplementation with SBM decreased rumination time per dietary dry matter (DM) and neutral detergent fiber (NDFom) intake (p < 0.01). Particle size distribution in the rumen and total ruminal NDFom digesta weights were not affected by SBM supplementation. However, the disappearance rates of total digesta and large and small particles from the rumen were increased by SBM supplementation (p < 0.01). Moreover, SBM supplementation increased the rate of size reduction in ruminal particles (p < 0.05). In situ disappearance of DM and NDFom of RS in the rumen was greater in SBM-supplemented cows than in nonsupplemented cows (p < 0.05). This study clearly showed that increased ruminal RS particle size reduction, passage, and fermentation due to SBM supplementation accelerated the RS particle clearance from the rumen and resulted in increased voluntary RS intake of dairy cows.     

The effect of Lupinus albus seeds on digestibility,performance and gastrointestinal tract indices in pigs

The effect of soya bean meal (SBM) substitution in the diet with white lupine (WL) seeds on performances and some parameters of the digestive tract of pigs were studied. The digestibility experiment was performed on 30 pigs using difference method combined with marker method, where one group was offered basal diet and in diet of experimental groups 25% of the basal diet was substituted with SBM or WL meal. The growth experiment was conducted on 48 pigs of approximately 20 kg body weight. The animals from the control group were fed with diet containing SBM, whereas in the experimental groups 50% or 100% of SBM was substituted with WL seeds. At the end of the experiment, eight pigs from each group were euthanized, and digesta and tissues were sampled. The apparent total tract digestibility of crude protein and dry matter was higher (p < 0.05), but crude fibre and ether extract were lower (p < 0.05) in the WL seeds than in SBM. Substituting 50% of SBM in the control diet with WL seeds did not affect significantly pig performance. Total substitution of SBM with WL seeds impacted negatively pigs growth and feed intake (p < 0.05), but it did not affect the length of villi and crypt depth. It also significantly increased ileum digesta viscosity and ammonia concentration in the ileum and caecum digesta. In the ileal digesta of animals offered WL seeds, an increased (p < 0.05) total bacterial and Enterobacteriaceae numbers were found, whereas reduced number of yeast and mould was found in the caecal digesta. The substitution of 50% SBM with WL seeds in the growing pig diet did not affect pigs' results, but the total substitution significantly decreased the performance of pigs and affected intestinal ecology.