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The accurate estimation of basal endogenous losses (BEL) of amino acids at the ileum is indispensable to improve nutrient utilization efficiency. This study used a quantitative proteomic approach to identify variations in BEL in the ileal digesta of growing pigs fed a nitrogen-free diet (NFD) or a casein diet (CAS). Eight barrow pigs (39.8 ± 6.3 kg initial body weight (BW)) were randomly assigned to a 2 × 2 crossover design. A total of 348 proteins were identified and quantified in both treatments, of which 101 showed a significant differential abundance between the treatments (p < 0.05). Functional and pathway enrichment analyses revealed that the endogenous proteins were associated with intestinal metabolic function. Furthermore, differentially abundant proteins (DAPs) in the digesta of pigs fed the NFD enriched terms and pathways that suggest intestinal inflammation, the activation of innate antimicrobial host defense, an increase in cellular autophagy and epithelial turnover, and reduced synthesis of pancreatic and intestinal secretions. These findings suggest that casein diets may provide a more accurate estimation of BEL because they promote normal gastrointestinal secretions. Overall, proteomic and bioinformatic analyses provided valuable insights into the composition of endogenous proteins in the ileal digesta and their relationship with the functions, processes, and pathways modified by diet composition.

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This article follows-up on our recently published work, which evaluated the impact of the addition of an alfalfa leaf-derived adsorbent in the aflatoxin B1 (AFB1)-contaminated diet in regard to the production parameters, blood cell count, serum biochemistry, liver enzymes, and liver histology of turkey poults. This paper presents complementary results on microbial community, ileal morphology, barrier function, and immunity. For this purpose, 350 1-day-old female turkey poults were randomly distributed into five groups: (1) Control, AFB1-free diet; (2) AF, AFB1-contaminated diet at 250 ng/g; (3) alfalfa, AFB1-free diet + 0.5% (w/w) adsorbent; (4) alfalfa + AF, AFB1-contaminated diet at 250 ng/g + 0.5% (w/w) adsorbent; and (5) YCW + AF, AFB1-contaminated diet at 250 ng/g + 0.5% (w/w) commercial yeast cell wall-based adsorbent (reference group). In general, in the AF group, the growth of opportunistic pathogens was promoted, which lead to gut dysbacteriosis, mainly influenced by Streptococcus lutetiensis. Conversely, a significant increase in beneficial bacteria (Faecalibacterium and Coprococcus catus) was promoted by the addition of the plant-based adsorbent. Moreover, the AF group had the lowest villus height and a compromised barrier function, as evidenced by a significant (p < 0.05) increase in fluorescein isothiocyanate dextran (FITC-d), but these negative effects were almost reversed by the addition of the alfalfa adsorbent. Furthermore, the AF + YCW and alfalfa + AF groups exhibited a significant increase in the cutaneous basophil hypersensitivity response compared to the rest of the experimental groups. Taken together, these results pointed out that the alfalfa counteracts the adverse effects of AFB1 in poults, facilitating the colonization of beneficial bacteria and improving the barrier function of the turkey poults.

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Vermicompost was used for humic acid (HA) preparation, and the adsorption of aflatoxin B1 (AFB1) was investigated. Two forms of HA were evaluated, natural HA and sodium-free HA (SFHA). As a reference, a non-commercial zeolitic material was employed. The adsorbents were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), energy-dispersive X-ray spectroscopy (EDS), zeta potential (ζ-potential), scanning electron microscopy (SEM), and point of zero charge (pHpzc). The adsorbent capacity of the materials when added to an AFB1-contaminated diet (100 µg AFB1/kg) was evaluated using an in vitro model that simulates the digestive tract of chickens. Characterization results revealed the primary functional groups in HA and SFHA were carboxyl and phenol. Furthermore, adsorbents have a highly negative ζ-potential at the three simulated pH values. Therefore, it appears the main influencing factors for AFB1 adsorption are electrostatic interactions and hydrogen bonding. Moreover, the bioavailability of AFB1 in the intestinal section was dramatically decreased when sorbents were added to the diet (0.2%, w/w). The highest AFB1 adsorption percentages using HA and SFHA were 97.6% and 99.7%, respectively. The zeolitic material had a considerable adsorption (81.5%). From these results, it can be concluded that HA and SFHA from vermicompost could be used as potential adsorbents to remove AFB1 from contaminated feeds.

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The mechanisms of action of humic substances (HS) as growth promoters in poultry are unknown. In this study, the productive performance, histology, and number of goblet cells (GC) in the intestinal villi of broilers under steady-state digestive conditions and under abrupt changes in diet with the addition of HS was evaluated. Broilers housed individually were offered three treatments from 14−28 days: 1 = diet with white corn/soybean meal, without growth promoter antibiotics (nonGPA); 2 = with GPA (GPA); and 3 = with 0.3% HS. At day 28, two diets were suddenly introduced: (A) white corn/soybean meal plus dried distillers' grains with solubles (DDGS); and (B) white/blue corn/soybean meal/DDGS, keeping the three original treatments. Diets A and B were also exchanged on day 37. FCR was lower with GPA and HS compared to nonGPA from 14−38 days (p < 0.05); at day 28, under steady-state digestive conditions, HS had a similar effect to GPA on the histology and GC number in the jejunum villi. The number of GC in the jejunum of HS-fed broilers on days 29 and 38, after diet changes, behaves similarly to that of AGP-fed broilers (p > 0.05). HS appears to strengthen the mucosal protection of the epithelium of the intestine.

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Different sources and inclusion levels of humic substances (HS) have been tested in broiler rations as an alternative to the addition of growth promoter antibiotics (GPA) with promising results. The current study was carried out to assess the influence of HS extracted from worm compost on broiler production parameters, carcass yield, tibia characteristics, lactic acid bacteria (LAB) counts, excretion of Eimeria oocysts, and antioxidant status of breast meat. A total of 1200 broilers were used, housed in groups of 30 per pen, and assigned to five treatments: 1 = basal diet with GPA (positive control), 2 = basal diet without GPA (negative control), 3-5 = basal diet with 0.15, 0.30, and 0.45% HS, respectively. The data was subjected to a variance analysis and orthogonal contrasts. The FI decreased linearly (p < 0.05) from 1-14, 29-42, and 1-42 days as the inclusion of HS in the feed increased. The FCR had quadratic responses (p < 0.01) from 29-42 and 1-42 days concerning the HS inclusion levels. Lactic acid bacteria was higher (p ˂ 0.05) in ten-day-old chicks with 0.45% HS in the diet. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity antioxidant potential decreased linearly (p < 0.05) concerning increasing HS in the feed. The results indicate that HS can be used as growth promoters in broiler feeds.

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Humic substances (HS) from different sources have been evaluated to replace or reduce the use of growth promoter antibiotics (GPA) in the feeds of broiler chickens. The objective was to evaluate the growth performance, tibia measurements, nutrient balance, meat quality, and microbiological status of broiler fed with an HS extract (EHS) under ad libitum (ADLIB) or feed restriction (REST). Individually caged broilers (n = 180, 14-35 day of age) were assigned to a factorial arrangement of three dietary treatments: (1) positive control with bacitracin methylene disalicylate (BMD) and salinomycin; (2) negative control without BMD nor salinomycin, and (3) same as negative control with 0.25% EHS, and two feeding regimens 1) ADLIB or REST for 24 h on d 1, 7, and 14. Results were subjected to ANOVA. Positive control and EHS-fed broilers showed higher carcass yield (p < 0.05) and lower oocyst excretion (p < 0.01) compared to negative control birds. Lactic acid bacteria (LAB) and Clostridium perfringens (C. perfringens) were higher in negative control and EHS-broilers compared to positive control (p < 0.01). In conclusion, higher carcass yield, lower C. perfringens and oocyst excretion were found in positive control and higher carcass yield, higher LAB and lower oocyst excretion were found in EHS-fed broilers. Broilers subjected to REST had reduced growth performance and meat quality. In conclusion, EHS could be used to increase the carcass yield and beneficial LAB in broilers.

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Management and production characteristics impact conception rate to first service (CR1S) in small-scale dairy farms, but the impact of body condition score (BCS) and milk production levels on cows' fertility is unknown. Our objective is to determine the effect of BCS and milk production on CR1S in small-scale dairy farms of western Mexico. Logistic regression models are used to determine the effect of BCS (at calving and first service), 60-d and 305-d milk production, protein and fat production, lactation number, and days at first service on CR1S. BCS at calving does not affect CR1S in cows with three or more lactations (39.5%; p > 0.1). However, first-lactation cows with BCS < 3.0 at calving and second lactation cows with BCS ≤ 2.5 at calving have higher CR1S (63.2 and 67.9%, respectively; p < 0.1). This result is perhaps due to reduced milk production, which leads to lower metabolic stress. BCS ≤ 2.5 at calving is associated (p < 0.05) with a reduced milk yield, explaining partially the observed higher CR1S in these groups. Cows with BCS ≤ 2.5 at first service in the higher quartile of 60-d milk production (≥ 28kg/day) show lower CR1S (23.9 and 51.1%, respectively; p < 0.01). In conclusion, BCS at calving and at first service, 60-d milk production, and lactation number are factors associated with CR1S.

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The purpose of this study was to evaluate the effect of humic acids (HA) on intestinal viscosity, leaky gut and ammonia excretion in a 24 hr feed restriction (FR) model to induce intestinal permeability in chickens. One-day-old male Cobb-Vantress broilers were randomly allocated to one of two groups (n = 25 chickens), with or without 0.2% of isolated HA from worm-compost, and placed in brooder batteries. Chicks had ad libitum access to water and feed for 14 days. Intestinal permeability was induced by 24 hr FR starting at 14 days. At 15 days of age, chickens in both groups were given an appropriate dose of fluorescein isothiocyanate dextran (FITC-d) by oral gavage. Intestine and liver samples were also collected to evaluate viscosity and bacterial translocation (BT), respectively. An increase (p < .05) in intestinal viscosity was observed in the experimental group consuming 0.2% of HA and was confirmed in a published in vitro digestion model that simulates the chemical and physical conditions of the crop, proventriculus and intestine of chickens. Furthermore, the treated group also showed a significant reduction in FITC-d, liver BT and ammonia in the manure. These results suggest that HA have a positive impact in intestinal integrity in chickens.

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Mantled howler monkeys (Alouatta palliata) occupy a wide variety of tropical habitats and are the most folivorous of New World primates. However, their diet may include fruits, buds, petioles, and flowers, as well as leaves, suggesting they must cope with variations in the nutrient composition of their food. We studied the physiological basis of the dietary flexibility of these monkeys by comparing food choice, digestive performance and patterns of digesta flow in six adults, fed diets of either leaves or a mixture of fruit and leaves. Although monkeys ate similar amounts of the two diets, they ingested more digestible protein when offered the leaf diet, on which they lost body mass, but they ingested much more soluble sugars when offered fruit and leaves on which they gained mass. Digestibilities of dry matter, fat, energy and fibre did not differ between diets, but those of crude protein, soluble sugars and minerals were higher on the fruit-leaf diet. Mean retention times in the gut of solute (Co-EDTA) and particulate markers (Cr-mordanted cell walls) did not differ between diets, but on both diets the monkeys retained the particulate marker (mean retention time ca 55 h) for longer than they did the solute marker (MRT ca 50 h). A lack of selective retention of solutes and small particles in the gastro-intestinal tract of howler monkeys probably restricts them to mixed diets but their digestive strategy is sufficiently flexible to allow them to feed on a diet of leaves when fruit is unavailable.

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The objective of this study was to evaluate, during the whole productive cycle, the use of three energy sources with different unsaturated (UFA) and saturated (SFA) fatty acid profiles with two levels of metabolizable energy (ME), in diets for broilers, vaccinated or not against infectious bursal disease (IBD). Two experiments were conducted evaluating the three energy sources with different UFA and SFA profiles corresponding to soybean crude oil (SCO), a mixture of 46.8% pig fat with 53.2% bovine fat (PBF), and a mixture of 39.2% animal fat with 60.8% of vegetable oil (AVF). In the first Trial, diets contained two levels of ME (3 000 and 3 200 kcal/kg) for vaccinated and non vaccinated broilers against IBD. The second Trial used SCO, PBF, AVF, SCO/PBF and SCO/AVF in the diets, substituting SCO with PBF and AVF in the last two treatments on day 22. In Trial 1, SCO group showed higher growth and IgA concentration than PBF and AVF (P < 0.05), the broilers fed with 3 200 Kcal/kg ME (P < 0.05) were heavier and had higher titers of antibodies against IBD. At 21 days of age, vaccinated birds had a higher productive performance along with highest IgA and IgG concentrations, and larger length of villi in duodenum and jejunum (P < 0.05). In Trial 2, higher concentration of unsaturated fatty acids in SCO enhanced feed conversion the first 21 days of age (P > 0.05); later on, during growing and finishing there were no differences among energy sources. As a conclusion, it can be said that in broilers, during the growing stage, there is a positive effect on performance and immune protection according to the source and concentration of energy.

El objetivo del trabajo fue evaluar el uso de tres fuentes energéticas con diferente perfil de ácidos grasos insaturados (AGI) y saturados (AGS) en dietas para pollos de engorda con dos niveles de energía metabolizable (EM), vacunados o no contra la infección de la bolsa de Fabricio (IBF) y el uso durante todo el ciclo productivo. Se realizaron dos experimentos evaluando la inclusión de las tres fuentes energéticas con distinto perfil de AGI y AGS que correspondieron al aceite crudo de soya (ACS), combinación de grasa de cerdo (46.8%) y bovino (53.2%) (GCB), combinación de grasa animal (39.2%) y aceite vegetal (60.8%) (GAV). En el Experimento 1 se incluyeron en las dietas a dos niveles de EM (3 000 y 3 200 kcal/kg) en pollos vacunados o no contra IBF. Para el Experimento 2 se utilizaron en las dietas ACS, GCB, GAV, ACS/GCB y ACS/GAV, sustituyendo ACS con GCB y GAV en los últimos dos tratamientos el día 22. En el Experimento 1 el grupo con ACS presentó mayor crecimiento y concentración de IgA en comparación con los de GCB y GAV (P < 0.05), los pollos alimentados con 3 200 kcal/kg de EM (P < 0.05) fueron más pesados y tuvieron títulos más elevados de anticuerpos contra la IBF. Las aves vacunadas tuvieron un mayor rendimiento productivo, concentración de IgG e IgA, así como mayor longitud de vellosidades en duodeno y yeyuno a los 21 días (P < 0.05). En el Experimento 2 la inclusión de ácidos grasos insaturados en ACS mejoró la conversión alimenticia en los primeros 21 días de edad (P > 0.05); posteriormente, durante el crecimiento y finalización no existió diferencia entre las fuentes concentradas de energía. Se concluye que, por la fuente en la etapa de iniciación, concentración energética y vacunación, existe un efecto sobre la productividad y protección inmunitaria de los pollos.

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The nitrogen and energy utilization of finishing pigs allocated individually or in groups of two was evaluated. Thirty two castrated males were used with an initial weight of 68.6 ± 1.0 kg that were assigned in a randomized complete block design with a split-plot arrangement in three treatments: a pig allocated individually with free access to feed and 0.81 m² of floor space (D1AL); two pigs allocated in group with free access to feed and 0.405 m² of floor space/pig (D2AL); a pig allocated individually paired-fed to the average consumption of pigs in D2AL and floor space similar to D1AL (D1P). The experiment was divided in two periods of excreta collection: days 1-4 and 18-21, respectively. There were eight repetitions per treatment. The nutrient consumption in period 1 was higher in D1AL compared to D2AL and D1P (density x period, P < 0.01); in period 2, the nutrient consumption was higher in D1AL, intermediate in D1P and lower in D2AL. The nitrogen (P < 0.05) and energy (P < 0.10) retained in period 1 was similar among densities (density x period interaction); in period 2 it was higher in D1AL compared to D2AL. The pigs housed in groups of two with free access to feed had lower nutrient consumption and retention at the end of the trial, probably as a consequence of chronic stress due to the competition for the feed, complicated by the restriction of available floor space.

Se evaluó la utilización de nitrógeno y energía en cerdos en finalización, alojados individualmente y en grupos de dos. Se usaron 32 machos castrados con un peso inicial de 68.6 ± 1.0 kg que fueron asignados al azar, en un diseño de bloques completos con arreglo en parcelas divididas en tres tratamientos: un cerdo alojado individualmente con libre acceso al alimento y 0.81 m² de espacio de piso (D1AL); dos cerdos alojados en grupo con libre acceso al alimento y 0.405 m² de espacio de piso/cerdo (D2AL); un cerdo alojado individualmente con consumo pareado con base en el consumo de los cerdos en D2AL y espacio de piso similar a D1AL (D1P). El experimento se dividió en dos periodos de recolección de excretas: días 1-4 (periodo 1) y 18-21 (periodo 2). Se tuvieron ocho repeticiones por tratamiento. El consumo de nutrimentos en el periodo 1 fue mayor en D1AL con respecto a D2AL y D1P (densidad x periodo, P < 0.01); en el periodo 2, el consumo de nutrimentos fue mayor en D1AL, intermedio en D1P y menor en D2AL. La retención de nitrógeno (P < 0.05) y de energía (P < 0.10) en el periodo 1 fue similar entre densidades (interacción densidad x periodo); en el periodo 2 fue mayor en D1AL comparado con D2AL. Los cerdos alojados en grupos de dos con alimentación a libertad tuvieron menor consumo y retención de nutrimentos en la fase final de la prueba, probablemente como consecuencia del estrés crónico debido a la competencia por el alimento, complicado por la restricción de espacio disponible de piso.