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Halophytic plants grow in high salinity environments and present phytochemicals with antioxidant properties, such as phenolic compounds; due to the uncertain availability of healthy foods, there is a growing interest in their nutritional potential. However, their bioactive compounds with beneficial health effects are limited in their bioaccessibility. The objective of this study was to subject S. edulis and S. esteroa to an in vitro digestion process to evaluate the bioaccessibility and total antioxidant capacity of phenolic compounds during three phases of digestion. We determined phenolic compounds, flavonoids, and antioxidant capacity by colorimetric methods and phenolic composition by UHPLC-DAD. Total phenols, total flavonoids, and total antioxidant capacity by DPPH and TEAC in the three phases of digestion (oral, gastric, and intestinal) of S. esteroa were higher than in S. edulis, founding 4.84 % higher in total phenol content, and 0.05 % in total flavonoid content; also, and 28.94 and 23.93 % higher in total antioxidant capacity by DPPH and TEAC, respectively in the intestinal digestion phase. The bioaccessibility of S. edulis was higher than in S. esteroa; the intestinal was the phase reflecting more bioaccessible compounds. The bioaccessibility percentages of total phenols and flavonoids were 590.16 and 1012.93 %, and the percentage recovery of total antioxidant capacity by DPPH and TEAC were 181.37 and 139.74 %. We identified phenolic acids ferulic, p-Coumaric, and synaptic (hydroxycinnamic), gallic and protocatechuic (hydroxybenzoic), the flavonoids catechin (flavan-3-oles), myricetin and ruthin (flavonols), naringenin and naringin (flavonones). S. esteroa presented bioactive compounds in higher concentrations than S. edulis due to the stress imposed by its habitat; nevertheless, the determined bioactive compounds of S. edulis showed a higher bioaccessibility because it was managed under local improvement. [ABSTRACT FROM AUTHOR]

The Central American locust (CAL), Schistocerca piceifrons piceifrons (Walker) (Acrididae: Cyrtacanthacridinae), is a harmful agricultural pest from Mexico to Costa Rica. This study assessed the nutritional contents of the locust. Enzymatic digestibility of hydrosoluble proteins and the antioxidant capacities of the derived peptides were analyzed. Locust flour was used to make corn tortillas to analyze the water retention and physical properties of the tortillas. Protein content was 72.4%, and protein extract yielded 4.77 ± 0.095 mg per gram of dry weight. Trypsin provided the strongest protein digestion at 1 and 3 hours, compared to pepsin. Regarding peptide scavenging ability of free radicals, digestion with trypsin allowed detection of 0.068 and 0.055 mM TE/mg of protein, at digestive times of 1 and 3 hours, respectively. Overall, results were not statistically different. Corn tortillas displayed changes in color and consistency related to quantity of locust flour. When more locust flour was used, more water was lost during the cooking process. The research documents the potential of Central American locust as a protein source and brings the possibility of using this undervalued natural resource. Nutritional content of the CAL were compared to that of other edible insects. [ABSTRACT FROM AUTHOR]

Our aim was to evaluate a whole-grain diet containing 0 (T1) and 60% (T2) waste papaya silage in vitro, in situ and in vivo. In vitro, biogas, methane and dry matter degradation (DMDiv), neutral detergent fiber (NDFDiv) and crude protein (CPDiv) were determined at 72 h; in situ, DM (DMDis), NDF (NDFis) and CP (CPDis) digestibility was determined at 72 h; in vivo, consumption and apparent digestibility of DM (DMI and DMD) and NDF (NDFI and NDFD), daily weight gain (DWG), rumen characteristics (pH, bacterial and protozoan counts) were determined. In addition, we performed coproparasitoscopic analysis and interviews with producers. Biogas production, methane, DMDiv, CDPiv, DMDis, DMD, NDFD, pH, bacterial and protozoan counts, and parasite load of nematodes and coccidia were not different between treatments (p > 0.05). T2 showed more NDFDiv, CPDis, DMI, NDFI, DWG than T1, while T1 was higher than T2 in NDFDis (p < 0.05). The results obtained from in vitro, in situ and in vivo techniques indicate that the diet with 60% waste papaya silage (T2) showed a similar response to the control diet (T1). Therefore, waste papaya silage is a non-conventional feeding alternative for weaned calves in the Costa Chica region of the state of Guerrero, Mexico., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective: To determine the concentration of arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), and zinc (Zn) in milk and cheese by comparing the use of nitric acid (HNO3) and a mixture of nitric acid and hydrogen peroxide (HNO3-H2O2) in acid digestion. Design/Methodology/Approach: The milk for the study was collected from storage tanks in various localities of Huejotzingo, and the different types of cheese came from Santa Ana Xalmimilulco, Huejotzingo, Puebla, Mexico. Digestion was carried out in a CEM MarsX microwave. Elemental concentrations were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Results: The combination of HNO3-H2O2 in milk digestion resulted in higher concentrations of Cd, Pb, and Zn. Conversely, the concentration of As was higher when using only HNO3 for digestion. No significant differences were found for Cr and Cu between the two digestion methods. In the case of Oaxaca cheese, digestion with HNO3 resulted in higher concentrations of As. Acid digestions did not affect the concentrations of the remaining elements. The same behavior was observed for Ranchero cheese, since the digestion combining HNO3-H2O2 resulted in lower As concentrations, as compared to the digestion with only HNO3. Pb and Zn were not significantly affected by the treatments, while the concentrations of Cd, Cr, and Cu could not be determined when samples were treated with the HNO3-H2O2 combination. Limitations: In this work we were able to determine the concentration of a number of metals present in milk and cheese using nitric acid and hydrogen peroxide in acid digestion. However, we recommend more tests are carried out to establish which acid or combination of acids allows for a broader detection of metals. Findings/Conclusions: According to the results obtained in this work, we can conclude that there is specificity for metal detection, with HNO3 being the most efficient. [ABSTRACT FROM AUTHOR]

Chiltepin, a wild chili mostly used in different traditional foods and traditional medicine in Northwest Mexico, represents a source of polyphenols. However, studies about the bioaccessibility of polyphenols as a parameter to measure the nutritional quality and bioefficacy of them in the fruit after consumption are scarce. Chiltepin showed phenolic acids and flavonoids contents between 387 and 65 μg/g, respectively. Nevertheless, these values decreased after the digestion process. Before digestion, gallic acid, 4-hydroxibenzoinc acid, chlorogenic acid, caffeic acid, p-coumaric acid, quercetin and luteolin were the main polyphenols found in chiltepin by HPLC-DAD and confirmed by FIA-ESI-IT-MS/MS. Gallic and chlorogenic acids were non-detected in the gastric phase, while only p-coumaric acid (5.35 ± 3.89 μg/g), quercetin (5.91 ± 0.92 μg/g) and luteolin (2.86 ± 0.62 μg/g) were found in the intestinal phase. The bioaccessibility of phenolic acids, flavonoids, and total polyphenols after the intestinal phase was around 24, 17 and 23%, respectively. Overall, results indicated that release of polyphenols from chiltepin fruit might be affected by the food matrix and gastrointestinal conditions due to the low bioaccessibility values observed. [ABSTRACT FROM AUTHOR]

Background: In January 2014, Mexico implemented a tax on sugar-sweetened beverage (SSB) purchases of 1 peso/L.Objective: We examined the heterogeneity of changes in nonalcoholic beverage (SSB and bottled water) purchases after the tax was implemented by household income, urban and rural strata, and household composition.Methods: We used 4 rounds of the National Income and Expenditure Surveys: 2008, 2010, 2012, and 2014. Changes in purchases in per capita liters per week were estimated with the use of 2-part models to adjust for nonpurchases. We compared absolute and relative differences between adjusted changes in observed purchases in 2014 with expected purchases in 2014 based on prior trends (2008-2012). The models were adjusted for sociodemographic characteristics of the households, place of residence, and lagged gross domestic product per capita.Results: We found a 6.3% reduction in the observed purchases of SSBs in 2014 compared with the expected purchases in that same year based on trends from 2008 to 2012. These reductions were higher among lower-income households, residents living in urban areas, and households with children. We also found a 16.2% increase in water purchases that was higher in low- and middle-income households, in urban areas, and among households with adults only.Conclusions: SSB purchases decreased and water purchases increased after an SSB tax was imposed in Mexico. The magnitude of these changes was greater in lower-income and urban households. [ABSTRACT FROM AUTHOR]

Introduction: Recommendations of adequate total water intake (aTWI) have been proposed by the European Food Safety Agency (EFSA) and the Institute of Medicine (IOM)of the United States of America. However, there are differences in the approach used to support them: IOM recommendation is based on average intakes observed in NHANES III (Third National Health and Nutrition Examination Survey) and EFSA recommendation on a combination of observed intakes from 13 different European countries. Despite these recommendations of aTWI, the currently available scientifi c evidence is not sufficient to establish a cut-off value that would prevent disease, reduce the risk for chronic diseases or improve health status.Objective: To compare the average daily consumption of fluids (water and other beverages) in selective samples of population from Mexico, US and Spain, evaluating the quantity of fluid intake and understanding the contribution of each fluid type to the total fl uid intake. We also aim to determine if they reached adequate intake (AI) values, as defi ned by three different criteria: IOM, EFSA and water density.Methods: Three studies were compared: from Mexico, the National Health and Nutrition Survey conducted in 2012 (NHNS 2012); from US, the NHANES III 2005-2010 and from Spain the ANIBES study leaded in 2013. Different categories of beverages were used to establish the pattern of energy intake for each country. Only adult population was selected. TWI of each study was compared with EFSA and IOM AI recommendations, as well as applying the criterion of water density (mL/kcal).Results: The American study obtained the higher value of total kcal/day from food and beverages (2,437 ± 13). Furthermore, the percentage of daily energy intake coming from beverages was, for American adults, 21%. Mexico was slightly behind with 19% and Spain ANIBES study registered only 12%. ANIBES showed signifi cantly low AI values for the overall population, but even more alarming in the case of males. Only 12% of men, in contrast with 21% of women, do satisfy the EFSA criterion. The IOM criterion reaches even less with higher recommended values for daily intake. In contrast, 60% of the American population reached the recommended intake of the IOM criterion. However, available data did not allow calculating the percentage reached by the EFSA criterion. Data from the Mexican study did not permit conducting comparisons with IOM or with EFSA. However, the water density criteria (mL/kcal) was higher than 1.Conclusion: There is a notable difference between all three populations in terms of TWI. Furthermore, within the same population, values of adequacy of TWI changed signifi cantly when they were assessed using different criteria. More scientifi c evidence is required for the production of better defined water intake recommendations in the future as well as more studies focusing on beverage consumption patterns in different settings. [ABSTRACT FROM AUTHOR]

Background: High intake of sugar-sweetened beverages (SSB) is linked to increased weight, energy intake, and diabetes. Even though the increasing interest on beverages and water intake, there are few dietary tools carefully validated. The purpose of this paper is to compare a fluid intake 7-day diary against a 24-h recall questionnaire to estimate the fluid consumption in overweight and obese women participating in a randomized controlled trial in Mexico.Methods: This cross-sectional study explored the correlation of reported fluid consumption between two methods: 3-day 24-hr recalls and 7-day diary beverage registry in overweight and obese Mexican women aged 18-45 y (n = 190).Results: There was no difference on median estimated volume (mL/d), nor the median estimated energy (kcal/d) from total beverage consumption registered by the two dietary tools. The crude and rank correlation among the two dietary instruments was high for total fluid consumption in mL/d r = 0.7, p < 0.001 (crude and rank correlation) and for fluid consumption measured as energy intake: r = 0.7; p < 0.001 crude, and r = 0.5; p < 0.001 rank correlation. By type of beverage, the more meaningful rank correlations were for fluid intake in: mL/d, water, alcohol beverages, and SSB; and in kcal/d, alcohol beverages and SSBs (rank correlation ≥ 0.6).Conclusions: Overall, the 7-day diary showed high and strong rank correlations with that reported in the 24-h recall, suggesting that the diary method is a valid dietary tool to evaluate total fluid, water and SSB intake in this population. [ABSTRACT FROM AUTHOR]

A better knowledge of the amino acid composition of foods commonly consumed in different regions is essential to calculate their scores and, therefore, to predict their protein quality. This paper presents the amino acid composition, amino acid score and in vitro protein digestibility of fifteen foods that are commonly consumed in Northwest Mexico. The foods were prepared by the traditional methods and were analyzed by reverse-phase HPLC. The chemical score for each food was determined using the recommendations for children of 1-2 years of age, and the digestibility was evaluated using a multienzyme technique. Lysine was the limiting amino acid in cereal-based products (scores 15 to 54), and methionine and cysteine were limiting in legume products (scores 41 to 47), boiled beef (score = 75) and hamburger (score = 82). The method of preparation had an effect on the content of certain amino acids, some of them increased and others decreased their content. Meat products and regional cheese provided a high amino acid score (scores 67 to 91) and digestibility (80.7 to 87.8%). Bologna, a processed meat product, had a lower digestibility (75.4%). Data on the amino acid composition of foods commonly consumed in Mexico can be used to provide valuable information on food analysis and protein quality, and to contribute to nutrition and health research and health programs. [ABSTRACT FROM AUTHOR]

Maize silage is appreciated for dairy cows due to its high energy content. Mexico is a centre of origin for maize and small-scale dairy farmers use landrace 'criollo' maize silages to feed their herds. However, the characteristics of landrace 'criollo' maize silages in terms of starch content, which defines their nutritional value in terms of energy, are not known. The objective was to characterise criollo maize silages in terms of starch content. Seventy-seven silage samples from 2011 to 2015 were analysed for contents of dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP), in vitro dry matter digestibility (IVDMD), and starch content. A factor analysis using principal component analysis as an extraction method was undertaken, and a hierarchical cluster analysis performed. Five factors affected the starch content of silages and five maize silage clusters identified. There was a positive association between IVDMD and metabolisable energy and between crude protein and acid detergent fibre; moreover, a positive relation was found between dry matter and maize starch contents. Significant differences were found (P < 0.001) for the contents of IVDMD, ME, ashes, OM, DM, and starch. The DM content of group 1 silage did not show any significant differences from other groups, except with group 2 silage, which had the lowest contents of DM and starch. Therefore, group 1 and 5 silage had the highest DM and starch contents, while group 3 silage had the highest IVDMD values and ME contents; finally, group 4 had the highest ash contents. Starch content in criollo maize silages was higher that reports for other maize races and is influenced by climate conditions and dry matter content., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The objective of this work was the measure the in situ and ruminal degradability and dry matter digestibility of three fattening diets for lambs, used by lamb producers in the central area of Tamaulipas, México. The nylon bag technique was used to determine in situ dry matter digestibility, using three lambs with cannulas in the rumen, distributed in a Latin Square design. The ruminal incubation times were 0, 4, 8, 12, 24 and 48 h. All treatment diets (T) used ground sorghum grain (Sorghum vulgare) as a base. T1 included rice (Oryza sativa) polishing with 7.53% on a dry matter basis (DM) of sorghum straw as forage; T2 had 5% DM of sorghum straw as forage; and T3 had 5% DM of buffel grass (Cenchrus ciliaris) hay plus 3% DM of alfalfa hay (Medicago sativa). In T1, the highest (P<0.05) value of digestibility at 0 and 4 h was observed. For 24 h, the highest (P<0.50) digestible fraction was obtained with T2. At 48 h, no difference (P>0.05) was observed between treatments. The washing loss and the degradation constant were higher (P<0.05) for T1 than T2 and T3. The diet of T1, containing rice polishing, produced the highest digestible fraction at the fi rst hours of incubation in rumen (0 and 4 h). T3 was digested in smaller proportion, although it could be the best diet for feedlots of lambs because of the lower acidosis risk. [ABSTRACT FROM AUTHOR]

The article reports on developing a new methodology that, in addition to an acid digestion, will incorporate a basic solution to dissolve organic matter resistant to strong acids to ensure a complete digestion of the algal tissues. This technique was compared to three other methods described in the scientific literature using a certified standard. Once validated, the new methodology was applied to selected seaweed samples collected from pristine zones of Baja California, Mexico, and compared with measurements from other noncontaminated areas of the world described in the literature.

Provides information on a study that examined the digestibility of fish meal and soybean meal by Litopenaeus vannamei at different temperatures and salinities using practical diets based on ingredients available in Mexico. Methodology of the study; Results and discussion on the study.

Apple has phenolic compounds that provide it antioxidant capacity, but during the digestion process, these compounds can undergo changes that modify their bioaccessibility and subsequently decrease the beneficial effects on human health. The present study aimed to analyze the effect of in vitro gastrointestinal digestion on bioaccessibility (B) of the total content of phenolic compounds (PC), flavonoids (TF), anthocyanins (TA), and antioxidant capacity (ABTS, DPPH) of five different apple varieties. Samples were subjected to static in vitro digestion model following the InfoGest consensus protocol. After the in vitro digestion, the PC, TF, TA, ABTS, and DPPH content were significantly different (p≤ 0.05) in each digestion stage. The intestinal stage released higher content of PC (20.79–81.43 %) and TF (43.08–83.41 %), while the gastric stage released higher content of TA (126.49–204.23 %) (p ≤ 0.05). The Principal Component Analysis (PCA) indicated that Red Delicious variety was mainly correlated with higher content of PC, TF, and TA before and after in vitro digestion. At the gastric stage, TA presented correlation with ABTS (r: 0.83) and DPPH (r: 0.87), while, in the intestinal stage, PC and TF presented the highest correlation with ABTS (r: 0.97–0.98) and DPPH (r: 0.86–0.92). Though in vitro digestion favors the release of PC, TF, and TA, their content was lower than that obtained before in vitro digestion, which suggests that chemical extraction could overestimate the bioavailability of phenolic compounds. [ABSTRACT FROM AUTHOR]

Animal foods in general are considered to be foods with high protein qualities, although their qualities are not always similar because of differences in essential amino acids. The purpose of this study was to compare the protein quality of different animal foods and of their mixtures with vegetable foods, mainly cereals, at the 30:70 animal:vegetable protein proportion with experiments performed under the same conditions. The animal foods were eggs, beef, pork, barbecued lamb, chicken, ham, sausage and milk powder. The vegetable foods used in the mixtures were rice, lime-treated corn flour, wheat flour and cooked black beans. The protein concentrations in the raw and cooked materials were analyzed. The protein efficiency ratios (PER) and digestibilities were determined in Fisher 344 weanling rats. Based on the corrected PER, the foods with the best protein quality were egg (3.24), sirloin beef (3.16), lamb (3.11) and chicken breast (3.07), which were significantly different (P < 0.05) from milk powder (2.88) and beef liver and beef round (2.81 and 2.70, respectively). The ham (2.63) and the pork loin (2.57) had a similar protein quality to that of casein (2.50). The lowest protein quality was found in sausages (2.14). In most of the mixtures of animal and vegetable protein (30:70), the PER was similar to or higher than that of the animal food alone. Beans were the vegetable food that showed the lowest response to the addition of animal food. The conclusion of the study is that some 30:70 mixtures of animal:vegetable protein, such as chicken, beef round and pork with cereals could be utilized for regular meals because of their high PER and low cost. [ABSTRACT FROM AUTHOR]

Sheep production is traditional for rural communities in Mexico, based on natural grasslands and semi-stabled feeding. Quality forages are necessary to improve productivity in these systems. Weeds are an alternative to feed ruminants and to manage crops. Also, many plants have secondary metabolites beneficial for livestock. The objective was to assess the nutritive value in vitro and the antioxidant activity of three weeds (Tithonia tubiformis, Cosmos bipinnatus, and Tagetes lucida) and four treatments (T0 = control diet, T1 = diet + 5% T. tubiformis, T2 = diet + 5% C. bipinnatus, and T3 = diet + 5% T. lucida). Nutritive value was determined from chemical composition by standard methods and mineral contents by inductively coupled plasma analyses. Secondary compounds, total phenols (TP), total tannins (TT), condensed tannins (CT), and phenolic compounds, were determined by high-performance liquid chromatography, and total antioxidant activity was determined by measuring the oxygen radical absorbance capacity. Rumen fermentation kinetics and in vitro digestibility of dry matter (IVDMD), organic matter (IVOMD), and neutral detergent fibre (IVNDFD) were determined per species and treatment by in vitro gas production. T. tubiformis had the highest CP and TP contents (P < 0.05), and C. bipinnatus had the highest fibre and CT contents (P < 0.05). Inclusion of T. lucida in the diet resulted in an 18% increase in TP content and a 30% increase in antioxidant activity in comparison to the control diet. No significant differences (P > 0.05) were found in rumen kinetics parameters, IVDMD, IVOMD, IVNDFD, or metabolizable energy, indicating that the tested weeds can be used as additives to increase antioxidant activity in sheep diets without negative effects., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

The aim of this investigation was to evaluate the use of ripe mango as a source of energy in an integral diet consisting of regional products for fattening lambs. Twenty-seven Creole lambs were used and given a 10-day period to adapt to the diet. Three treatments were evaluated: T1 = 40% mango; T2 = 50% mango; and T3 = control diet. In the in vitro analysis, partial and accumulated production of biogas and methane, degradation of dry matter, and neutral detergent fiber were determined. In the in vivo analysis, dry matter intake (DMI), daily weight gain (DWG), apparent digestibility of nutrients, and ruminal characteristics were estimated. The experimental design was completely random. The in vitro results helped hypothesize that the diets with low fiber content would not affect potential dry matter intake. With the exception of the protozoa count, ruminal characteristics were not different among diets (p > 0.05). In productive response, T3 was 13.73% higher DMI than T1, which was 32.24% higher than T2. T3 promoted 61.22% more DWG than T1 and T2. T2 displayed better digestibility of dry matter, organic matter, neutral detergent fiber, and crude protein than T3 (p < 0.05). Fattening lambs fed rations that contain 40% and 50% mango reduces the dry matter intake and daily weight gain relative to the control, although apparent digestibility is higher than for the control diet.

In the semi-arid highlands of central Mexico, triticale (× Triticosecale L.) is emerging as an alternative, less water-demanding forage crop than alfalfa for dairy cattle. Studies reported here were aimed at evaluating triticale hay (TH) relative to alfalfa hay (AH) for lactating cow performance, apparent digestibility, N partition, and ruminal degradation kinetics of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF). Study 1 was conducted on a privately owned farm. Four barns were used to conduct 4 replicated 3 × 3 Latin squares (1 barn = 1 square), where each barn included 3 pens (experimental units) receiving 1 of 3 dietary treatments. Each pen had 62 Holstein dairy cows. All diets included a forage-to-concentrate ratio of 42:58 (DM basis), which is typical for intensive dairy farms of the region. Dietary treatments were formulated to replace AH with TH on a CP basis, and included (DM basis) 15.1% AH and 0% TH, 9.0% AH and 7.4% TH, and 0% AH and 16.4% TH. Diets were iso-energetic (1.64 Mcal of net energy for lactation/kg of DM) and iso-nitrogenous (17.9% CP). Pen-level DM intake and milk production were from all cows in the pen, but pen-level milk composition, apparent digestibility, and N partitioning were from 8 cows (observational units) randomly selected in each pen. Orthogonal contrasts were used to determine linear and quadratic effects of increasing TH from 0 to 7.4, and 16.4% of dietary DM. Although DM intake was not affected, there was a tendency for CP intake to decline linearly and for NDF intake to increased linearly as TH replaced AH in the diet. Milk production declined linearly by 0.077 kg/d for each additional percentage unit of TH in the diet, which amounted to a 3.5% decline when TH replaced AH entirely. However, no effect was observed on energy-corrected milk production because of a compensatory linear effect of increasing milk fat concentration with the incorporation of TH in the diet. Total-tract NDF digestibility tended to increase linearly by 18.5%, but no differences were detected for urinary urea-N excretion and for N utilization estimated as milk N/(fecal N + urinary N + milk N). Study 2 was an in situ trial conducted to determine the degradation kinetics of AH and TH used in study 1. In spite of differences in degradation kinetics parameters for DM, CP, and NDF, only NDF effective ruminal degradation tended to be greater for TH than AH. Replacing AH with TH at the level typically found in intensive dairy farms of the semi-arid regions of Mexico had minimal effects on milk production and N utilization., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to evaluate the influence of tree foliage species supplemented in ruminant diets based on Pennisetum purpureum on the in vitro digestibility and fermentation, microbial biomass synthesis and enteric methane production. Seven experimental diets were evaluated, including a control treatment based on P. purpureum (PT) grass, and six additional treatments supplemented with 30.0% foliage from Neomillspaughia emargiata (NE), Tabernaemontana amygdalifolia (TA), Caesalpinia gaumeri (CG), Piscidia piscipula (PP), Leucaena leucocephala (LL) and Havardia albicans (HA). A randomised complete block design repeated in two periods (block) was used. The highest gas production (P < 0.05) was recorded in treatments TA and PT (237 and 228 mL g -1 , respectively). The highest in vitro digestibility of dry matter (IVDMD) and organic matter (IVOMD) (P < 0.05) was recorded in the control treatment PT (57.9% and 66.1%, respectively). Treatments LL, NE, TA and PP promoted greater microbial biomass synthesis (290, 223, 220 and 213 mg g -1 , respectively) (P < 0.05). The proportion of propionic acid also increased in these latter treatments and in treatments CG and HA (P < 0.05). Additionally, treatments LL, PP, NE and TA decreased methane production (25.8, 29.5, 30.6 and 31.8 L kg -1 of digested dry matter, respectively). In conclusion, supplementation with L. leucocephala, P. piscipula, N. emargiata and T. amygdalifolia in ruminant diets based on P. purpureum is one feed alternative that can promote greater efficiency and synthesis of microbial biomass, increase the proportions of propionic and butyric acid and decrease the production of enteric methane by 15.6 to 31.6%.

Competing Interests: There is no conflict of interest among the authors in the publication of this article

1. Predicting the diet diversity of animals is important to basic and applied ecology. Knowledge of diet diversity in animals helps us understand niche partitioning, functional diversity and ecosystem services such as pollination, pest control and seed dispersal. 2. There is a negative relationship between the length of the digestive tract and diet diversity in animals; however, the role of digestive physiology in determining diet diversity has been ignored. This is especially important in vertebrates with powered flight because, unlike non-flying vertebrates, they have limitations that may constrain gut size. 3. Here, we evaluate the relationship between digestive capacity and diet diversity in Carollinae and Stenodermatinae frugivorous bats. These bats disperse the seeds of plants that are key to Neotropical forest regeneration. 4. Our results show that digestive capacity is a good predictor of diet diversity in Carollinae and Stenodermatinae frugivorous bats (R(2) = 0·77). 5. Surprisingly, the most phylogenetically closely related species were not similar in their digestive capacity or diet diversity. The lack of a phylogenetic signal for the traits evaluated implies differences in digestive physiology and diet in closely related species. 6. Our results highlight the predictive usefulness of digestive physiology for understanding the feeding ecology of animals., (© 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.)

The high diversity of carotenoids and chlorophylls in foods contrasts with the reduced number of pigments that typically are investigated in micellarization studies. In this study, pepper samples (raw and heat-treated) contained 68 individual pigments, but only 38 of them were micellarized after in vitro digestion. The micellarization of pigments was majorly determined by the interaction effect of processing style (food matrix effect) and fat type (saturated and unsaturated). The highest micellarization was observed with raw peppers. Unsaturated fat increased the micellarization of carotenoid esters, while the impact of fat on the micellarization of free carotenoids seemed to be dependent on pigment structure. The micellarization efficiency was diminished as the esterification level of carotenoids increased. The type of fatty acid moiety and the polarity of the carotenoids modulated their micellarization. Chlorophylls were transformed into pheophytins by heat-processing and digestion, with the pheophytins being stable under gastrointestinal conditions. Micellarization of pheophytins was improved by fat.

Chemical composition, in vitro gas production with and without polyethyleneglycol (PEG-4000 MW), and in vitro digestibility of dry matter (IVDMD) and organic (IVOMD) foliage from Pithecellobium dulce, Gliricidia sepium and Haematoxylum brasiletto were determined. The preference test was run for 15 days: the first 10 days as adaption period and the 5 days served as evaluation period. It was conducted in ten developing female Creole goats of 6 months old, weighing 14 ± 2.0 kg in order to determine goat preference for any of the three foliages. Productive performance of 35 male creole kids of 6 months old (14 ± 3.0 kg) was also determined by ad libitum feeding of the foliage of the tree: the 30 and 15 % of each of the P. dulce (T1, T2), G. sepium (T3, T4), and H. brasiletto (T5, T6) foliages were added to the experiment diets, while T7 served as control diet that did not contain any foliage. The crude protein (CP), total phenols (TP), condensed tannins (CT), IVDMD, and IVOMD were different among the foliages. The PEG determined the biological activity of the TP and CT of H. brasiletto. Goats preferred to consume the foliage of P. dulce because of its higher content of CP and IVDMD and low content of TP and CT. In the productive response, dry matter intake (DMI) was higher in kids fed T1 diet and was stimulated by higher IVDMD and IVOMD, which resulted in the higher daily weight gain (DWG). The contribution with TP and CT of H. brasiletto to T5 and T6 and the rejection by the animals of G. sepium in T3 and T4 explain the negative effects on the DMI and the DWG. Findings of the study suggested higher kid performance for P. dulce foliage. Possible attributes may include its better CP, low TP and CT, and higher digestibility.

The aim of this study was to evaluate daily weight gain (DWG), total dry matter (DM) intake, rumen degradability of forage, and urinary excretion of mimosine metabolites by hair sheep in a silvopastoral system with high densities of Leucaena leucocephala. A completely randomized design was carried out with two treatments: treatment 1 (T1) silvopastoral system with leucaena at a density of 35,000 plants/ha and treatment 2 (T2), leucaena at a density of 55,000 plants/ha. Leucaena was associated with tropical grasses Panicum maximum and Cynodon nlemfluensis. Twenty-four male Pelibuey lambs of 23.2 ± 3.4 kg live weight (LW) were used (12 lambs per treatment). Results showed differences (P < 0.05) in DWG of T1 (106.41 ± 11.66 g(-1) sheep(-1)) with respect to that of T2 (81.33 ± 11.81 g(-1) sheep). Voluntary intake was higher in lambs from T1 (83.81 ± 04.07 g DM/kg LW(0.75)) with respect to that from T2 (71.67 ± 8.12 g DM/kg LW(0.75)). There was a difference in color of urine between sheep of T1 and T2, the latter giving positive results for the presence of metabolites derived from mimosine (3-4 dihydroxypyridine and 2-3 dihydroxy pyridone). Rumen degradability of DM of L. leucocephala was higher (P < 0.05) compared to that of P. maximum and C. nlemfluensis (72.94 ± 0.40 vs. 67.06 ± 1.50 and 63.25 ± 1.51 %, respectively). It is concluded that grazing at high densities of L. leucocephala affects daily weight gain of hair sheep, possibly due to ingestion of high amounts of mimosine which may exert an adverse effect on voluntary intake.

A study was conducted to estimate dry matter (DM) degradability in the rumen of lambs offered a basal soybean meal and sorghum grain diet with three levels of white mulberry (WM) leaves (Morus alba). Diets consisted of 90% concentrate and 10% sorghum straw, which was incrementally replaced by WM leaves at 0% (control diet, T1), 2.5% (T2), and 5% (T3) of the total ration. Crude protein (CP) in WM was 21.8% (DM basis). Diets had equal CP (14% DM basis) and metabolizable energy (10.8 MJ/kg DM) content. Three non-castrated Pelibuey male lambs fitted with permanent rumen cannula were utilized in a 3 × 3 Latin square design. Each experimental period consisted of 10 days of adaptation followed by sampling. DM degradability was determined using the nylon bag technique. Bags contained the experimental diets offered in each period and were incubated in rumen in pairs for 4, 8, 12, 24, and 48 h. The potential degradation was higher (P < 0.05) for T2, followed by T3 and T1. WM level did not influence the degradation rate or the effective degradation at the three passage rates modeled. It was concluded that WM forage may have useful application in feedlot diets for growing lambs, as this forage increases potential degradation of high-grain diets. The incorporation of WM in diets for feedlot lambs in tropics may reduce the use of expensive conventional protein supplements.

Two experiments were undertaken to evaluate the use of pods from Huizache (Acacia farnesiana), common in the arid and semiarid regions of Mexico, on the perfromance and apparent digestibility in Pelibuey Mexican hair growing ewe lambs. Twenty-four Pelibuey ewe lambs were used in the animal performance experiment, with a mean live weight of 14.91 +/- 1.48 kg, randomnly allocated to three groups which received ad libitum for 77 days (11 weeks) experimental whole rations T0 with 0%, T12 with 12% or T24 with 24% inclusión of dried and ground Huizache pods. Dry matter intakes (g/kg (0.75) daily) were 83, 95, 90 for T0, T12, and T24 respectively (P > 0.05). Mean daily live-weight gain was 90, 75, and 63 g/day for T0, T12, and T24 (P < 0.001). Nine Pelibuey ewe lambs were used to determine apparent digestibility in vivo of the experimental diets using a 3 x 3 latin square design repeated three times. There were differences in the digestibility of dry matter (P < 0.001), organic matter (P < 0.001), nitrogen (P < 0.031), neutral detergent fibre (P < 0.002), and acid detergent fibre (P < 0.001) being lower in T24. Huizache pods may be an alternative feed when included up to 12% of dry matter in the diets for sheep growing moderately.

Flower-visiting bats encounter nectars that vary in both sugar composition and concentration. Because in the new world, the nectars of bat-pollinated flowers tend to be dominated by hexoses, we predicted that at equicaloric concentrations, bats would ingest higher volumes of hexoses than sucrose-containing nectars. We investigated the intake response of three species of Neotropical bats, Leptonycteris curasoae, Glossophaga soricina and Artibeus jamaicensis, to sugar solutions of varying concentrations (292, 438, 584, 730, 876, and 1,022 mmol L(-1)) consisting of either sucrose or 1:1 mixtures of glucose and fructose solutions. Bats did not show differences in their intake response to sucrose and 1:1 glucose-fructose solutions, indicating that digestion and absorption in bat intestines are designed under the principle of symmorphosis, in which no step is more limiting than the other. Our results also suggest that, on the basis of energy intake, bats should not prefer hexoses over sucrose. We used a mathematical model that uses the rate of sucrose hydrolysis measured in vitro and the small intestinal volume of bats to predict the rate of nectar intake as a function of sugar concentration. The model was a good predictor of the intake responses of L. curasoae and G. soricina, but not of A. jamaicensis.

Tortilla samples were elaborated by four small commercial factories in Mexico, employing masas prepared with the traditional nixtamalization process. Samples were stored at 4 degrees C for up to 72 hours and their chemical composition and in vitro starch digestibility features were evaluated. Chemical composition did not change with the storage time, but soluble carbohydrates decreased slightly during storage. A significant decrease in available starch content upon storage was observed, concomitant with increased resistant starch (RS) levels. These changes are possibly due to retrogradation. Retrograded resistant starch (RRS) values increased with storage time; in some samples, RRS represented more than 75% of total RS whereas in others it only accounted for 25%. The digestion rate (DR) in the freshly prepared tortillas was similar for the various samples, but after 72 h storage some differences among tortillas were found. Also, when a single tortilla sample was compared throughout the different storage times, lower DRs were determined in samples subjected to prolonged storage, which is related to the concomitant. increase in RRS. The differences found among the various tortilla samples may be due to minor variations in the commercial processing conditions and to the use of different corn varieties.

The chemical composition, digestibility and toxin contents of two wild legumes: Styphnolobium burseroides and Acacia bilimekii, collected in a semi-arid zone of Mexico, were determined. Both legumes had a high fiber content. The seeds of Styphnolobium burseroides had a low protein content (14%), and the pod a high content of reducing sugars. However the seeds of Acacia bilimekii had a high protein concentration (35%). The seed proteins were low in sulphur amino acids and tryptophan in both legumes but were rich in lysine. Trypsin inhibitors and lectins were present in low concentrations; alkaloids and cyanogenic glucosides were not detected. The in vitro digestibility for monogastric animals was low but the same test with ruminal juice showed a high digestibility for both legumes. Based on their chemical composition and digestibility, these legumes could be a good alternative source in the feeding of ruminants.

Lactose digestion capacity after ingestion of physiological doses of milk and its effect on milk intolerance and consumption were studied in rural and urban populations from three regions of Mexico with different milk intakes. All subjects (n = 926) received two treatments: whole milk (240 mL for children and 360 mL for adults) and the same amount of 90% lactose-hydrolyzed milk; 72% of the subjects also received as a third treatment a water solution containing lactulose (8 g for children and 10 g for adults). Lactose maldigestion determined by a hydrogen breath test was detected in 2 to 43% of subjects (depending on age group) and was higher in subjects from central and southern Mexico than in subjects from northern Mexico (P < 0.01). Only the experience of major symptoms of intolerance affected milk consumption, and these symptoms were present in 0 to 11% of children > 4 y old and in 7 to 17% of the 13- to 60-y-old subjects. No significant differences were found in lactose maldigestion or milk intolerance between rural and urban populations, but milk consumption was higher in urban areas (P < 0.01). Milk consumption in our study was affected primarily by factors not related to the capacity to digest or tolerate the lactose in milk.

Protein and energy value of 6 samples of "Spirulina" was studied on growing rats in 1972 and 1973. Sample RL 1(Spirulina platensis, originating from Tchad) was grown in artifical conditions in a laboratory. Others samples (Spirulina maxima) were grown in the solar evaporator near Mexico, washed and dried either on heated rollers (MR8, MR13) or by spraying (MA 7, MA10). Sample MA10 D corresponds to sample MA10, bleached by ethanol plus acetone (Baron, 1975). Each Spirulina sample was the only protein source of balanced, starch diets. The diets were supplemented in essential amino acids (E.A.A.) according to the requirements of growing rats (table 1). The ratios [(digestible nitrogen/metabolisable energy (EM] of the Spirulina diets were similar to that of the control diets containing herring meal. The diets were fed to groups of 15 to 17 growing rats. Energy and nitrogen balances were established by the comparative slaughter technique. Blood and muscle samples were taken at slaughter for the determination of free amino acids levels.