Development Of Gastrointestinal Tract Research Articles

Effect of Triticale Grain in Diets on Performance, Development of Gastrointestinal Tract and Microflora in Crop and Ileum of Broiler Chickens.

The purpose of the research was to determine the effect of the use of a diet containing 30% triticale grain. In an experiment lasting 28 days, 180 one-day Ross-308 chickens (sex ratio 1:1) with an average initial body weight in treatment of 44.6 g were randomly assigned to 30 metabolic cages/replications, 6 birds in each. To compare the results between treatments, a one-way ANOVA was used with uneven replication numbers. The control group (I) received a standard diet containing maize and soybean meal. In the other treatments, 30% of different cereals were used: II-wheat, III-barley, and IV-triticale. Significant differences in body weight (BW) and feed conversion ratio (FCR) were observed on the 4th day of the life of broiler chickens (p < 0.05). Differences were determined between the control group (90.7 g BW and 1.32 kg of feed/kg BWG in the case of FCR) and birds receiving barley (93.0 g BW and 1.29 kg of feed/kg BWG in the case of FCR), compared to chickens fed diets with a 30% share of wheat grain (86.2 g BW and 1.53 kg feed/kg BWG in the case of FCR) and triticale (86.6 g BW and 1.53 kg feed/kg BWG in the case of FCR). Later, the differences in performance of birds between treatments did not occur (p > 0.05). In the nutrition of broiler chickens, control or 30% of the triticale diet caused a significant reduction (p < 0.01) of the number of Escherichia coli (E. coli) in the crop of broiler chickens (0 log cfu/g), compared to birds obtaining feed with 30% of wheat (1.78 log cfu/g). The diet containing triticale also reduced the number of E. coli (p < 0.05) within the ileum (0.78 log cfu/g) compared to chickens obtaining barley grain in the diet (2.12 log cfu/g). As a result of the use of triticale grain (p < 0.05), the total length of the bird intestines (199.64 cm) was compared to 30% of barley grain (209.76 cm). The increase in the length of the large intestine of broiler chickens in treatments was positively correlated (r = 0.613, p < 0.05) with the number of Lactobacillus sp. in the ileum. Triticale increased the pH in the crop of broilers chickens. The research results indicate that triticale, after longer storage, can be used in amounts of 30% of the diet without significant effect on the performance of broiler chickens, with a reduction in E. coli in crop in comparison with wheat and in ileum with barley.

Effect of dietary supplementation of two fiber sources differing on fermentability and hydration capacity on performance, nutrient digestibility and cecal fermentation in broilers from 1 to 42 d of age

A total of 378 Cobb-500 male broilers were used to evaluate the effects of 2 fiber sources, differing in hydration capacity and fermentability, on gastrointestinal tract development, apparent ileal digestibility and performance from 1 to 42d of age. There were 9 replicates per each of the 3 dietary treatments, all in mash form: a wheat-soybean control (CON) diet, CON diet diluted with 1.5% of wood lignocellulose (LC diet) as a non-fermentable insoluble fiber with high hydration capacity; and CON diluted with 1.5% of a mixture of fibers (ISFC diet) containing both lignified insoluble fiber and a prebiotic soluble fiber fraction from fructooligosaccharides. Additionally, the fermentability of both fiber sources (LC and ISFC) was determined by in vitro using cecal inoculum from broilers fed the experimental diets. Both LC and ISFC treatments impaired by 4% feed conversion ratio only during the first 7d (P = 0.003) compared with CON group. In the grower period (21-42d), the ISFC group showed the best growth (P = 0.039), and at 42d tended to show the highest body weight (P = 0.095). This agrees well with the highest ileal dry matter (P = 0.033) and organic matter (P = 0.043) digestibility observed in ISFC group and the similar trend observed for ileal protein digestibility (P = 0.099) at 42d. Also, at 42 d, absolute and relative (% body weight) digestive tract weights (P ≤ 0.041) and empty gizzard weights (P ≤ 0.034) were greater for LC and ISFC groups compared to CON. The cecal molar proportion of valeratewas greatest in ISFC group (P = 0.039). In vitro gas production was higher for ISFC than for LC substrate when using either a diet-adapted or non-adapted cecal inoculum (P < 0.05). These results show the interest in combining IF with prebiotic highly fermentable fiber, such as fructooligosaccharides, in broilers to improve nutrient digestibility and finishing performance.

Effects of bulk tank milk, waste milk, and pasteurized waste milk on the nutrient utilization, gastrointestinal tract development, and antimicrobial resistance to Escherichia coli in preweaning dairy calves

This study aimed to assess the effect of bulk tank milk (BTM), waste milk (WM), and pasteurized waste milk (PWM) on nutrient digestibility, ruminal and cecal fermentation, gastrointestinal tract (GIT) development, and antimicrobial resistance of fecal Escherichia coli from dairy calves at 2 periods (30 and 60 d of age). Calves were grouped according to BW, serum protein levels, and breed composition. Three treatments were included: BTM (n = 21), WM from cows under antibiotic treatment (n = 21), and PWM (WM submitted to HTST pasteurization; n = 21). A total of 63 calves were used, of which 18 animals (n = 6 per treatment) were evaluated in the period of 4 to 30 d, and 45 (n = 15 per treatment) from 4 to 60 d. During the experimental period, a daily intake of 6 L of milk was divided into 2 equal meals, with ad libitum access to water and starter. Milk and feed intakes were recorded daily. Apparent total-tract digestibility and nitrogen balance were conducted from 25 to 29 d of age (n = 6) and from 53 to 57 d of age (n = 15). Animals were slaughtered at 30 ± 1 and 60 ± 1 d of age for the assessment of ruminal and cecal fermentation and GIT development. Antimicrobial susceptibility testing was conducted at 1, 30, and 60 d of age (n = 15/treatment). Statistical analysis used a linear mixed-effects model for continuous outcomes and generalized linear models for single measurements (R software). Treatments WM and PWM had lower rumen pH, higher ruminal acetate concentration, larger reticulorumen and liver, and a higher prevalence of fecal-resistant E. coli compared with BTM at both 30 and 60 d. Up to 60 d, both BTM and WM treatments exhibited higher digestibility of ether extract and gross energy compared with the PWM, whereas WM and PWM treatments showed increased nitrogen intake and retention compared with the BTM treatment. These findings suggest that pasteurization of WM negatively affects nutrient digestibility and calf performance, while also affecting rumen development. Additionally, the use of milk containing antibiotic residue leads to the selection of resistant E. coli in the GIT over time.

Growth performance, nutrient digestibility, fecal microbial diversity and volatile fatty acid, and blood biochemical indices of suckling donkeys fed diets supplemented with multienzymes

BackgroundAs the foal grows, the amount of breast milk produced by the donkey decreases. In such cases, early supplemental feeding is particularly important to meet the growth needs of the foal. Foals have an incompletely developed gastrointestinal tract with a homogenous microbiota and produce insufficient amounts of digestive enzymes, which limit their ability to digest and utilize forage. Improving the utilization of early supplemental feeds, promoting gastrointestinal tract development, and enriching microbial diversity are the hotspots of rapid growth research in dairy foals. Plant-based feeds usually contain non-starch polysaccharides (NSPs), including cellulose, xylan, mannan, and glucan, which hinder nutrient digestion and absorption. In addition, proteins and starch (both biomolecules) form a composite system mainly through non-covalent interactions. The proteins wrap around the surface of starch granules and act as a physical obstacle, thereby inhibiting water absorption and expansion of starch and decreasing the enzyme's catalytic effect on starch. Glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase added to cereal diets can alleviate the adverse effects of NSPs. The current study determined the effects of adding multienzymes (glyanase, β-mannanase, β-glucanase, cellulase, protease, and amylase) to the diet of 2-month-old suckling donkeys on their growth performance, apparent nutrient digestibility, fecal volatile fatty acid (VFA) and pH, fecal bacterial composition, and blood biochemical indices.ResultsOn day 120 of the trial, fecal samples were collected from the rectum of donkeys for determining bacterial diversity, VFA content, and pH. Moreover, fresh fecal samples were collected from each donkey on days 110 and 115 to determine apparent digestibility. The multienzymes supplementations did not affect growth performance and apparent nutrient digestibility in the donkeys; however, they tended to increase total height gain (P = 0.0544). At the end of the study, the multienzymes supplementations increased (P < 0.05) the Observed species, ACE, Chao1, and Shannon indices by 10.56%, 10.47%, 10.49%, and 5.01%, respectively. The multienzymes supplementations also increased (P < 0.05) the abundance of Firmicutes, Oscillospiraceae, Lachnospiraceae, Christensenellaceae, Christensenellaceae_R-7_group, and Streptococcus in feces, whereas decreased (P = 0.0086) the abundance of Proteobacteria.ConclusionsMultienzymes supplementations added to a basal diet for suckling donkeys can increase fecal microbial diversity and abundance.

A200 EXPOSURE TO CANNABIS SMOKE IN UTERO AFFECTS THE DEVELOPMENT OF THE ENDOCANNABINOID SYSTEM IN THE GASTROINTESTINAL TRACT

Abstract Background Recreational use of cannabis has been legalized in Canada since 2018. Increasing numbers of women are using cannabis while pregnant, with reported rates ampersand:003E10%. There is a disconnect with societal perceptions, with up to one third of women believing that cannabis is safe for use in pregnancy, but with preclinical and clinical studies demonstrating negative neurodevelopmental outcomes. A key component of gut-brain axis regulation is found in the endocannabinoid system (ECS), of which receptors, ligands and enzymes are extensively distributed throughout the gastrointestinal (GI) tract and are actively involved in GI motility and sensation. Aims We tested the hypothesis that exposure to cannabis smoke in utero could influence the expression of ECS components in the developing GI tract. Methods We developed a “real world” cannabis smoke inhalation model in which CD-1 pregnant mouse dams were exposed daily to a delta-9-tetrahydrocannabinol (THC)-dominant strain of cannabis in a smoking chamber unit, from embryonic days 6 (E6) to E18. Control mice were placed in a restraining cage and exposed to room air for the equivalent time-period. Dams were sacrificed at E18, fetuses removed and the fetal GI tract (from stomach to distal colon) collected for RNA extraction. Key components of the ECS were investigated by developing a NanoString Custom CodeSet, including receptors (cannabinoid receptors 1 and 2; CB1 and CB2, transient receptor potential vanilloid type 1; TRVP1, GPR55) and enzymes (diacylglycerol lipase; DAGL, fatty acid amide hydrolase; FAAH, monoacylglycerol lipase; MAGL, N-acylphosphatidyletanolamine phospholipase D; NAPE-PLD). Samples (n=per litter; 7 cannabis-exposed and 8 control) were processed in the Farncombe Metagenomics Facility and NanoString data analyzed using nSolver Analysis Software. Results We found a significant increase in the expression of ECS receptors in the cannabis-exposed compared to control GI tract at E18, including CB2 (pampersand:003C0.05), TRPV1 (pampersand:003C0.05) and GPR55 (pampersand:003C0.0005). Interestingly, no significant change in mRNA expression was detected for CB1. We also found a significant increase in mRNA encoding the full panel of ECS enzymes, including DAGL (pampersand:003C0.005), FAAH (pampersand:003C0.05), MAGL (pampersand:003C0.05) and NAPE-PLD (pampersand:003C0.005) in cannabis-exposed compared to control GI tract. Conclusions In conclusion, we have found a significant increase in mRNA expression in a panel of key ECS receptors and enzymes in the GI tract at a point of maximal exposure to cannabis in utero. Future research will be needed to further characterize potential impacts on postnatal GI development and function. Funding Agencies CIHRThe Azrieli Foundation

Effects of Supplementing Milk Replacer with Sodium Butyrate on Dairy Calves.

Diarrhea and respiratory diseases pose significant challenges in the rearing of pre-weaned calves, motivating the investigation of tools to improve gastrointestinal tract development, health, and overall performance in young calves. Consequently, the primary objective of this study was to assess the effectiveness of an additive incorporated into milk replacer to promote the development and health of the animals. Forty-six dairy calves were randomly assigned into two treatments: control (CON, n = 23; with 15 females and 8 males), and sodium butyrate (SB, n = 23; with 15 females and 8 males). The calves in the SB treatment group were supplemented with 4 g/d of unprotected sodium butyrate (Adimix, Adisseo, China), added to the milk replacer from 4 to 60 days of age. Water and starter were fed ad libitum. The study evaluated several parameters, including feed intake, nutrient digestibility, ruminal pH, ammonia and volatile fatty acids, blood metabolites (glucose, insulin-like growth factor type 1, urea, β-hydroxybutyrate), hemogram, health scores, performance, and feed efficiency. Bull calves were euthanized at 60 days of age for organ comparison, while heifer calves were assessed for carryover effects up to 90 days of age. Data were analyzed independently using linear mixed models using the nlme package in R, and the Artools package for non-parametric categorical outcomes. Although the feed intake and performance variables exhibited differences within weeks, no divergence was observed between treatment groups. Notably, a positive treatment-by-week interaction was identified for starter feed intake (p = 0.02) and total dry matter intake (p = 0.04) during pre-weaning for CON animals. Ruminal parameters, blood metabolites, and hemogram values such as glucose, urea, insulin-like growth factor type 1, mean corpuscular value, lymphocytes, and neutrophils displayed differences within weeks during the pre-weaning stage, but similar results within groups. No differences between supplemented and non-supplemented calves were found across nutrient digestibility, organ development, and histology. Regarding health scores, differences were noted within weeks for fecal and respiratory scores during the pre-weaning stage, and only the respiratory score during the post-weaning stage. Consequently, butyrate supplementation did not elicit improvements or negative effects in the body development or health status of dairy calves.

Evaluation of particle size and feed form on performance, carcass characteristics, nutrient digestibility, and gastrointestinal tract development of broilers at 39 d of age

The objective of this study was to evaluate combined effects of corn particle size and feed form on performance, carcass characteristics, nutrient digestibility, and gastrointestinal tract development of broilers from 1 to 39 d of age. A total of 1,800 days old, male Cobb 500 broilers were randomly assigned to 9 dietary treatments with 8 replicate pens (25 birds/pen). The experiment consisted of a factorial arrangement of 3 corn particle sizes (750, 1,150, and 1,550 μm) and 3 feed forms (mash, 3- and 4-mm pellets) provided from 1 to 39 d. Titanium dioxide (TiO2) was added as an indigestible marker (0.5%) during the finisher phase (27-39 d) to determine nutrient digestibility. Feed intake (FI), body weight (BW), and feed conversion ratio (FCR) were determined at 17, 27, and 39 d of age, with FCR adjusted for mortality. On d 40, 10 birds/pen were randomly selected and processed for meat yield determination. Data were analyzed as a 3×3 factorial (particle size x feed form) arrangement of treatments. Broilers fed 3- and 4-mm pellets had increased (P < 0.05) BW, FI, and lower FCR than broilers fed mash diets at 39 d of age. At 39 d of age, broilers fed diets with 750 µm corn particle size had heavier (P < 0.05) BW and increased FI than broilers fed diets with corn particle sizes of 1,150 and 1,550 µm. At 39 d of age FCR was unaffected by corn particle size. Heavier (P < 0.05) carcass and breast weights were observed for broilers fed 3-mm pellets. Broilers fed diets with corn particle size of 750 µm had heavier (P < 0.05) carcass and breast weight than broilers fed diets with 1,550 µm. Digestibility of nutrients was higher (P < 0.05) in pelleted diets, particularly when corn particle size was increased from 750 to 1,550 µm. Breast myopathies such as wooden breast (WB) and spaghetti meat (SM), were greater (P < 0.05) in broilers fed 3-mm pellets compared to mash diets. In conclusion, broilers fed 3- and 4-mm pelleted diets had greater nutrient digestibility and improved broiler performance compared to broilers fed mash diets.

A comparative analysis of gastrointestinal tract barrier function and immune markers in gilt vs. sow progeny at birth and weaning.

Progeny born to primiparous sows (gilt progeny; GP) have lower birth, weaning and slaughter weights than sow progeny (SP). GP also have reduced gastrointestinal tract (GIT) development, as evidenced by lower organ weights. Therefore, the aim of this experiment was to quantify changes in GIT barrier function that occur in birth and weaning, representing two major challenges to the young piglet. The effects of parity (GP vs. SP) in GIT barrier integrity function were quantified at four timepoints: birth (~0h), 24h after birth (24h), 1-d preweaning (PrW), and 1-d postweaning (PoW) in commercially reared piglets. Due to inherent differences between newborn and weanling pigs, the results were analyzed in two cohorts, birth (0 vs. 24h, n = 31) and weaning (PrW vs. PoW, n = 40). Samples of the stomach, jejunum, ileum, and colon were excised after euthanasia and barrier integrity was quantified by measuring transepithelial resistance (TER), macromolecular permeability, the abundance of inflammatory proteins (IL-8, IL-1β, and TNF-α) and tight junction proteins (claudin-2 and -3). Papp was characterized using a dual tracer approach comprising 4 KDa fluorescein isothiocyanate (FD4) and 150kDa tetramethyl rhodamine isothiocyanate (T150)-labeled dextrans. Characteristic effects of the initiation of feeding and weaning were observed on the GIT with the initiation of feeding, such as increasing TER and reducing Papp at 24h, consistent with mucosal growth (P = 0.058) This was accompanied by increased cytokine abundance as evidenced by elevations in TNF-α and IL-1β. However, GP had increased IL-8 abundance (P = 0.011 and 0.063 for jejunum and ileum respectively) at birth than 24h overall. In the weaning cohort, jejunal and ileal permeability to FD4 was higher in GP (P = 0.05 and 0.022, respectively) while only higher ileal T150 was observed in GP (P = 0.032). Ileal claudin-2 abundance tended to be higher in SP overall (P = 0.063), but GP ileal claudin-2 expression was upregulated weaning while no change was observed in SP (P = 0.043). Finally, other than a higher jejunal TNF-α abundance observed in SP (P = 0.016), no other effect of parity was observed on inflammatory markers in the weaning cohort. The results from this study indicate that the GIT of GP have poorer adaptation to early life events, with the response to weaning, being more challenging which is likely to contribute to poorer postweaning growth.

Physiological and immunological aspects of feed restriction and its beneficial impacts in fattening rabbits' productivity-an updated review.

Two feed restriction (FR) regimens are utilized with weaned rabbits including a quantitative FR (amount-limited feed or time-restricted admission to feed) and a qualitative FR (modulation of diet content especially protein and energy). The use of post-weaning FR may help in preventing post-weaning digestive disorders, stimulating compensating growth, improving feed efficiency, and decreasing carcass fat content. Interestingly, FR may contribute to changing meat's chemical composition and its physical quality attributes by regulating the morphological and biochemical characteristics of muscle fibers. Also, FR could enhance the gastrointestinal tract development, its histomorphology, and improve feed digestibility and absorption. Furthermore, FR regimens are involved in establishing gut microbial balance and enhancing the host immunological response. It might be concluded that post-weaning FR is involved in influencing the physiological and immunological aspects of growing rabbits. It might be documented that light to mild FR (i.e., 80-90% AL), early (i.e., at the first 2 weeks post-weaning), and relatively short in duration (i.e., for 2-3 weeks) had no negative effects on live body weight, while severing FR reduced live body weight in comparison with ad libitum rabbits.

Variability in feed intake the first days following weaning impacts gastrointestinal tract development, feeding patterns, and growth performance in nursery pigs.

The present study investigated the effects of voluntary feed intake (FI) the first days after weaning on gastrointestinal development and protein fermentation the first week after weaning and growth performance and feeding patterns during the nursery phase. A total of 144 mixed-sex weaned pigs (24 ± 2 d old; 7.2 ± 0.8kg body weight [BW]) were allocated to 12 pens with 12 pigs/pen. Each pen was equipped with an electronic feeding station for monitoring individual FI during a 40-d study. Pigs were classified based on their cumulative FI over the initial 3 d after weaning (FId1-3) being above or below their pen median FId1-3 (high = 919 ± 244g or low = 507 ± 222g FId1-3). Similarly, weaning BW classes (BW0; high = 7.72 ± 0.59kg or low = 6.62 ± 0.88kg BW) were created to study interactions with FId1-3. Two female pigs with either a high or a low FId1-3 per pen (n = 24) were selected for sampling at d6 and were used to study gastrointestinal development and fermentation products in the small intestine. Feeding patterns per day, FI, and growth performance were measured individually. Low FId1-3 pigs had lower (P < 0.05) daily FI during d0 to d8, d8 to d15, and d22 to d28, BW on d15, d22, d29, and d40, and average daily gain during d0 to d8, d22 to d29, and d29 to d40 compared to high FId1-3. High FId1-3 pigs increased (P < 0.05) the number of visits to the feeder between d1 to d13 and d31 to d35, and the time spent per visit only for d1 to d4 (P < 0.05). The daily rate of FI (g/min) was higher (P < 0.05) for High FId1-3 pigs on d6, d8, d9, and d10, and again several days later (d20 to d39). In addition, the high FId1-3 × high BW0 interaction improved daily FI during d18 to d40 compared to low FId1-3 × low BW0 class (P < 0.05). For the sampling on d6, low FId1-3 pigs had a lighter small intestine, colon, and pancreas, and reduced villi length, smaller villi surface area, and a lower number of goblet cells size in jejunum (P < 0.05), while concentrations of lactic acid, histamine, and cadaverine in small intestinal content were increased (P < 0.05). In conclusion, pigs with high FId1-3 became faster eaters with higher FI and growth rates toward the second half of the nursery, which was similar and additive for pigs with higher weaning BW. High FId1-3 was also associated with greater development of the gastrointestinal tract and a reduced protein fermentation 1-wk after weaning.

Effects of particle size of corn and stocking densities on the performance, carcass traits and gastrointestinal tract development of Muscovy ducks in housing.

The current investigation was conducted to investigate the effects of different particle sizes of corn and stocking densities on performance, carcass traits and gastrointestinal tract (GIT) development of Muscovy ducks in housing. 200 Muscovy ducks were distributed in a factorial scheme (2 × 2) where the treatments were constituted by two stocking densities (2 or 3 birds/m2) and two particle sizes of corn (6 or 8mm), with five replicates of 10 birds each. At 1, 35, 70, and 90days old, Muscovy ducks were slaughtered to evaluate the development of heart and GIT. Muscovy ducks managed in the density of 3 birds/m2 presented higher (P < 0.05) GIT development, performance and carcass traits regardless of age evaluated. In the same way, Muscovy ducks fed diets using a particle size of corn of 6mm (Mean Geometric Diameter (MGD) = 781μm) presented higher (P < 0.05) GIT development, performance and carcass traits regardless of age evaluated. Conclusively, the stocking density of 3 birds/m2 and the particle size of corn of 6mm (MGD = 781μm) were considered ideal recommendations for Muscovy ducks, providing higher GIT development, which resulted in better performance and carcass traits.

Effect of type of fiber and its physicochemical properties on performance, digestive transit time, and cecal fermentation in broilers from 1 to 23 d of age

The effects of insoluble fiber (IF) sources differing on particle size and hydration capacity (HC) on growth performance, gastrointestinal tract (GIT) development, cecal fermentation, and digestive transit time were investigated from 1 to 23 d of age in 550 Ross-308 broiler males housed in 50 cages. The experimental design was based on the administration of a common corn-soybean meal nonsupplemented with additional IF sources diet in mash form (Control), and 4 dietary treatments consisting in the Control diet diluted with 1.5% of different IF: lignocellulose (LC), fine-ground straw (FS) and coarse-ground straw (CS), all characterized by high HC; and almond shell (AS) having low HC. Cecal fermentation was assessed by in vitro fermentation of the IF sources using the cecal content of 22-day broilers as inoculum. Compared with control birds, the inclusion of IF sources tended to impair the FCR (P=0.053), with birds fed the HC-IF sources (LC, FS, and CS) showing lower ADFI (P=0.005) and ADG (P=0.001) than those fed the AS diet. The relative weight of gizzard and cecum, small intestine length, and digestive transit time decreased in AS group (P ≤ 0.050) compared with the average value of the groups fed the other IF sources. The inclusion of IF reduced (P=0.006) the excreta moisture content, with no differences among IF sources. Dietary treatments had no effect either on cecal short fatty acids concentration or on intestinal morphology. As indicated by the in vitro gas production results, both LC and AS were less fermented than FS and CS, although all IF sources were low fermentable. None of the IF sources were able to influence the fermentation capacity of cecal microbiota after 22 d of feeding. In summary, animals fed AS presented smaller gizzard and cecum relative size, showed higher ADFI and ADG, and tended to improve fed conversion ratio in comparison to those fed the rest of IF sources.

The use of ascorbic acid in ovo feeding for poultry embryos and its effect on egg hatchability, embryo mortality, chicks’ weight, and gastrointestinal tract development

The use of ascorbic acid in ovo feeding for poultry embryos and its effect on egg hatchability, embryo mortality, chicks’ weight, and gastrointestinal tract development

Benefits of tributyrin on growth performance, gastrointestinal tract development, ruminal bacteria and volatile fatty acid formation of weaned Small-Tailed Han lambs

This study aimed to determine the effects of tributyrin on growth performance, gastrointestinal tract development, ruminal bacteria and volatile fatty acid (VFA) formation. Thirty healthy weaned Small-Tailed Han female lambs at 3 months old with BW 27.5 ± 4.1 kg (mean ± SD) were randomly assigned to five groups of six lambs each, and each group received tributyrin at 0, 0.5, 1.0, 2.0 and 4.0 g/kg in feed. Weights were measured before the start and end of the study. After 15 d adaptation, DMI, feed, faeces and urine were recorded every week. Lambs were sacrificed at d 75. Compared to lambs fed no tributyrin, lambs fed 4.0 g/kg tributyrin had higher average daily BW gain (P = 0.04) and DMI (P < 0.01). Tributyrin reduced nitrogen (P < 0.01), Ca (P < 0.01) and P (P < 0.01) losses derived from faeces and urine. The mostly important, tributyrin increased dorsal sac thickness (P < 0.01), papillae length (P = 0.04) and width (P < 0.01), ventral sac papillae length (P < 0.01) and width (P < 0.01), caudodorsal blind sac thickness (P = 0.02), papillae length (P < 0.01) and width (P < 0.01). Furthermore, tributyrin increased thicknesses of both the duodenum (P < 0.01) and ileum (P = 0.01), and villus heights of the duodenum (P = 0.01), ileum (P < 0.01), jejunum (P < 0.01) and caecum (P = 0.02), but tributyrin decreased duodenal (P < 0.01) and caecal crypt depths (P < 0.01). Tributyrin reduced rumen pH (P < 0.01) while promoting total VFA concentration (P < 0.01). Tributyrin improved the structure of rumen bacteria by enhancing Clostridium (P = 0.04), Butyrivibrio (P < 0.01), Streptococcus (P = 0.04), Prevotella (P = 0.04), Ruminobacter (P = 0.02) and Fibrobacter (P = 0.03). In conclusion, tributyrin could stimulate gastrointestinal tract development by enhancing colonization of rumen VFA-producing bacteria, and dietary supplementation of tributyrin at 4.0 g/kg of DM was recommended for the weaned lambs.

Ret deficiency decreases neural crest progenitor proliferation and restricts fate potential during enteric nervous system development

The receptor tyrosine kinase RET plays a critical role in the fate specification of enteric neural crest-derived cells (ENCDCs) during enteric nervous system (ENS) development. RET loss of function (LoF) is associated with Hirschsprung disease (HSCR), which is marked by aganglionosis of the gastrointestinal (GI) tract. Although the major phenotypic consequences and the underlying transcriptional changes from Ret LoF in the developing ENS have been described, cell type- and state-specific effects are unknown. We performed single-cell RNA sequencing on an enriched population of ENCDCs from the developing GI tract of Ret null heterozygous and homozygous mice at embryonic day (E)12.5 and E14.5. We demonstrate four significant findings: 1) Ret-expressing ENCDCs are a heterogeneous population comprising ENS progenitors as well as glial- and neuronal-committed cells; 2) neurons committed to a predominantly inhibitory motor neuron developmental trajectory are not produced under Ret LoF, leaving behind a mostly excitatory motor neuron developmental program; 3) expression patterns of HSCR-associated and Ret gene regulatory network genes are impacted by Ret LoF; and 4) Ret deficiency leads to precocious differentiation and reduction in the number of proliferating ENS precursors. Our results support a model in which Ret contributes to multiple distinct cellular phenotypes during development of the ENS, including the specification of inhibitory neuron subtypes, cell cycle dynamics of ENS progenitors, and the developmental timing of neuronal and glial commitment.

Factors influencing the development of gastrointestinal tract and nutrient transporters' function during the embryonic life of chickens-A review.

Intestinal morphology and regulation of nutrient transportation genes during the embryonic and early life of chicks influence their body weight and feed conversion ratio through the growing period. The intestine development can be monitored by measuring villus morphology and enzymatic activity and determining the expression of nutrient transporters genes. With the increasing importance of gut development and health in broiler production, considerable research has been directed towards factors affecting intestine development. Thus, this article reviews (1) intestinal development during embryogenesis, and (2) maternal factors, in ovo administration, and incubation conditions that influence intestinal development during embryogenesis. Conclusively, (1) chicks from heavier eggs may have a better-developed intestine than chicks from younger ones, (2) in ovo supplementation with amino acids, minerals, vitamins or a combination of several probiotics and prebiotics stimulates intestine development and increases the expression of intestine mucosal-related genes and (3) the long storage period, improper incubation temperature and imbalanced ventilation can negatively influence intestinal morphology and nutrient transporters gene expression. Finally, understanding the intestine development during embryonic life will enable us to enhance the productivity of broilers.

Body composition, gastrointestinal, and reproductive differences between broiler breeders fed using everyday or skip-a-day rearing programs

Broiler breeder feed restriction practices have intensified as broiler feed efficiency has been improved. Skip-a-day (SAD) rearing regimen has controlled breeder growth, although this practice has become questionable for the modern breeder. We compared everyday (ED) and SAD programs and evaluated their impact on pullet growth performance, body composition, gastrointestinal tract development, and reproduction. At d 0, Ross 708 (Aviagen) pullet chicks (n=1,778) were randomly assigned to 7 floor pens. Three pens were fed using the ED and 4 pens with SAD program through wk 21 using a chain-feeder system. ED and SAD grower diets were formulated to be isonutritious, with the only difference that ED diets had more crude fiber. Pullets (n=44 per pen) were moved to 16 hen pens by treatment at wk 21 with 3 YP males (Aviagen) in each pen. All birds were fed common laying diets. In addition to BW data, sampled pullets and hens were scanned using dual energy X-ray absorptiometry (DEXA) to obtain body bone density and composition. Hen performance and hatchery metrics were recorded through wk 60. ED birds were heavier with similar nutrient intake from wk 10 to 45 (P ≤ 0.013). Pullet uniformity was unaffected by feeding method (P ≥ 0.443). SAD pullets had less body fat at wk 19 (P=0.034) compared to ED pullets, likely as a metabolic consequence of intermittent feeding. SAD birds had lower bone density at wk 7, 15, and 19 (P ≤ 0.026). At 4 wk of age, SAD pullets had less intestinal villi goblet cells compared to ED pullets (P ≤ 0.050), possibly explained by the effect that feed removal has on cell migration rates. Overall egg-specific gravity (P=0.057) and hatch of fertile % (P=0.088) tended to be higher in eggs from ED hens. Altogether, ED feeding increased young pullet intestinal goblet cells and increased both bone density and body fat at wk 19. ED program improved pullet feed conversion (2.6% less feed) and increased eggshell quality and hatch of fertile.

Butyrate supplementation in the liquid diet of dairy calves leads to a rapid recovery from diarrhea and reduces its occurrence and relapses in the preweaning period

The present study aimed to evaluate the effect of continuous butyrate administration in dairy calves' liquid diet considering diarrhea, metabolic profile, gastrointestinal development, and corporal growth. Immediately after birth, calves were randomly allocated into 2 groups of 62 calves (50 females and 12 males), with access to water and a solid feed ad libitum. The Butyrate Group (BG) received 4 g/day of sodium butyrate (Admix® Easy - Adisseo) diluted in the whole milk, and the Control Group (CG) received whole milk with no supplementation. Sodium butyrate was administered from day one of life until the weaning at 90 d. Feces consistency was assessed daily for the first 30 d of life and characterized by scores from 0 to 4 (0 and 1 for normal, and 2, 3, and 4 for abnormal feces). Diarrhea was diagnosed when the animals had abnormal feces and fever. Morbidity, recurrence, mortality, and lethality data were recorded and compared between the groups. Average daily weight gain (ADG) and corporal growth (body weight, thoracic perimeter, height at the withers, and croup width) were evaluated weekly, from the first day to the 30th, and later at the 45th, 60th, and 90th d of life. Blood samples were taken weekly for up to 30 d to determine the circulating levels of total calcium, phosphorus, chloride, bicarbonate, glucose, β-hydroxybutyrate, and nonesterified fatty acids (NEFA). The males were euthanized at 15 (n = 6 per group) and 30 d (n = 6 per group) for morphometric, histological, and gene expression analysis of the gastrointestinal tract. The results showed that the Butyrate Group had a lower rate of morbidity (BG = 30% vs. CG = 50%) and recurrence (BG = 26.7% vs. CG = 60%) of diarrhea than the Control Group. In addition, the BG had abnormal feces for a shorter period (BG = 4.64 ± 0.47 d vs. CG = 8.6 ± 0.65 d). The ADG tended to be higher in BG than CG up to 30 and 60 d. Metabolic evaluations showed the lowest levels of glucose and highest levels of NEFA in BG. On d 30 of life, rumen papillae length, papilla area, duodenum villus length, and crypt depth were higher in BG than in CG. The duodenal gene expression at 30 d showed that animals with diarrhea episodes that did not receive butyrate had the highest levels of transcripts for the LCT and GLP2 genes. In addition, in different ways, both butyrate and neonatal diarrhea affected the gene expression of IGF1, SLC5A1 and AQP3. These results allow us to conclude that continuous supplementation with sodium butyrate improves gastrointestinal development, reduces the occurrence of diarrhea, and makes clinical conditions milder with faster recovery, favoring a higher ADG in the first 30 and 60 d of life. Based on these results, we conclude that sodium butyrate can be indicated for liquid diet supplementation to accelerate gastrointestinal tract development and prevent severe cases of neonatal diarrhea, tending to improve average daily gain until the weaning.

Feeding concentrate with hay of different qualities modulates rumen histology, development of digestive tract as well as slaughter performance and meat quality of young dairy calves

ABSTRACT Concentrate-rich starter diets are commonly fed to dairy calves to stimulate growth performance. However, feeding high amounts of starter feed with low inclusion of forage fibre may jeopardise the development of the gastrointestinal tract (GIT). Moreover, studies investigating the effects of feeding on carcass and meat quality of young calves at rearing are rare. The objective of this research was to investigate the effect of hay quality and concentrate inclusion on the traits of GIT development, slaughter performance and veal quality of young dairy calves. The feeding trial covered the first 14 weeks of life. Seventeen male and three female Holstein calves (n = 20) were randomly allocated to four experimental groups, which received besides acidified whole milk different solid feeds: (1) 100% medium-quality hay (MQH), (2) 100% high-quality hay (HQH), (3) 30% medium-quality hay and 70% concentrate (MQH+C) and (4) 30% high-quality hay and 70% concentrate (HQH+C). The acidified whole milk was fed in the first 12 weeks of life, and calves had ad libitum access to solid feed and water from birth till slaughter. Calves were kept in individual boxes equipped with straw and slaughtered at the end of week 14. After slaughter, gut development traits, rumen histology, slaughter performance and meat quality were assessed. Overall, both concentrate inclusion and hay quality showed major effects on rumen histology and development of the GIT in dairy calves with minimal effects on most carcass cuts and meat quality traits. Concentrate-fed calves had significantly higher average daily gains, final body weights, blood amounts and proportions of organs from the circulatory and respiratory systems. Proportions of liver and kidneys were lowest in MQH-fed calves. The proportion of GIT was significantly lower in groups fed concentrates, but the weight of the reticulorumen was unaffected by solid feed. Concentrate feeding led to thicker keratin layer and epithelium as well as wider papillae in the rumen. Hay quality particularly affected the width of the papilla and epithelium thickness, while feeding hay without concentrate enhanced the thickness of submucosa and muscularis, as well as the size of parotid glands. In conclusion, the type of solid feed affects the development of the GIT with concentrate feeding holding the risk to induce keratinisation of rumen epithelium while enhancing performance and carcass traits.

Effect of housing system and housing density on performance, viability, and gastrointestinal tract growth of broiler chicks during the first 2 wk of age

This experiment was conducted to study the effect of housing systems and housing densities on the performance and digestive tract growth of broiler chicks during the first 2 wk of age. A total of 3,600 Cobb500 day-old chicks were stocked at 4 densities (30, 60, 90, and 120 chicks/m2), and reared under 2 housing systems (conventional housing system and newly developed housing system), yielding a 2×4 factorial arrangement. The studied traits were performance, viability, and gastrointestinal tract development. The results indicated that housing systems and housing densities significantly (P < 0.001) affected the performance and GIT development of chicks. There were no significant interactions between housing system and housing density for body weight, body weight gain, feed intake, and feed conversion. The results also showed that the effects of housing density were age-dependent. That is, the higher the density, the lower the performance and digestive tract growth with advancing age. In conclusion, birds in the conventional system outperformed birds in the newly developed housing system, and further work is needed to improve the new housing system. To achieve the highest performance, digestive tract growth, and digesta content, a density of 30 chicks/m2 is recommended for chicks up to 14-days old.