Chemical Composition and In Vitro Ruminal Fermentation Characteristics of Native Grasses from the Floodplain Lowlands Ecosystem in the Colombian Orinoquia.

Grasses from lowland ecosystems in flooded savannahs are useful to feed extensive grazing animals; however, scarce information about its agronomic and fermentation characteristics exists. This study aims to determine the chemical composition and fermentation parameters of native grasses from the floodplain lowlands ecosystem in the Colombian Orinoquia. Three native grasses (Leersia hexandra, Acroceras zizanioides and Hymenachne amplexicaulis) and a "control" grass (introduced Urochloa arrecta-Tanner grass) were sown and sampled at 30, 40 and 50 days of age. On each sampling date, biomass production in a 1 m2 frame was estimated, and the chemical composition and fermentation parameters were analyzed using near-infrared spectroscopy and the in vitro gas production technique, respectively. Data were analyzed using a mixed model for repeated measures and the least significant difference (LSD) was used for mean differentiation (p < 0.05). The grasses' nutritional characteristics varied as follows: dry matter (DM, 0.7-2.0 ton/ha), crude protein (CP, 6.1-12.2%), neutral detergent fiber (NDF, 56.6-69.6%), ash (5.8-15.8%) and dry matter digestibility (DMD) between 20.8 and 60.6% from 12 to 48 h of fermentation. Native plants such as L. hexandra and A. zizanioides presented higher biomass production, CP, ash, cellulose, and Ca levels than the control plant. During the experimental period (30 to 50 days), the grasses did not present significant nutrient availability changes. In terms of fermentation characteristics, L. hexandra increased ammonia concentrations and total volatile fatty acids (TVFA) and butyric acid. This latter effect was also observed in A. zizanioides grass. L. hexandra and A. zizanioides grasses constitute a valuable alternative forage resource during the flooding times of the studied ecosystem.

Dairy goats fed sunflower hay intercropped with chickpea in small-scale systems. Part II: Cheese yield and composition, sensory analysis, and economic performance / Cabras lecheras alimentadas con heno de girasol intercalado con garbanzo en sistemas de pequeña escala. Parte II: Rendimiento y composición del queso, análisis sensorial y desempeño económico / Cabras leiteiras alimentadas com feno de girassol consorciado com grão de bico em sistemas de pequena escala. Parte II: Rendimento e composição do queijo, análise sensorial e desempenho econômico

Abstract Background: Goat production has grown worldwide as a way to improve the quality of rural life and reduce the environmental footprint; nevertheless, there is a need to increase productivity through improved feeding strategies. The market demands healthier products with organoleptic characteristics similar to the traditional ones; thus, it is necessary to evaluate the effect of new forages for goats and its acceptance by consumers. Chemical and organoleptic composition of goat milk vary according to the diet which, in turn, affects the characteristics of cheese. Cheese texture, taste and smell are the most important sensory attributes for consumers. Objective: To evaluate the effect of substituting corn straw with sunflower hay associated with chickpea for dairy goats on yield, chemical composition and sensory acceptability of cheese, as well profitability. Methods: Twenty-eight Saanen dairy goats were randomly assigned to two treatments in a 30-day experiment on a small farm. The daily ration per goat in the MZST treatment (control treatment) consisted of alfalfa hay (200 g/goat/day) and concentrate (400 g/goat/day) plus 600 g/goat/day (50% of the ration) of corn straw. The SFCP treatment substituted corn straw with sunflower-chickpea hay; it had the same alfalfa and concentrate content, but with no corn straw and was added with 600 g/goat/day of sunflower-chickpea hay. The yield, composition and sensory evaluation of fresh cheese made with milk from each treatment were recorded, and the feeding costs and returns evaluated. Variables for the chemical composition of cheese were analyzed following a completely randomized design. Results: Significant differences were observed in cheese yield and all chemical composition variables. According to sensory evaluation, SFCP cheese had significantly higher scores for texture and odor but lower for taste and overall acceptability compared to MZST. In terms of profitability, SFCP increased feed costs by 5% but resulted in higher margins over feed costs of 12 and 24% for milk and cheese, respectively, compared to MZST. Conclusion: In spite of favorable performance and economic returns of MZST treatment (control treatment), the organoleptic characteristics of the cheese reduced its general acceptance.

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Resumo Antecedentes: A produção de caprinos em todo o mundo tem crescido como forma de melhorar a qualidade de vida rural e reduzir a pegada ambiental; pero há uma necessidade de aumentar a produtividade através de estratégias de alimentação melhoradas. A crescente procura dos consumidores por produtos mais saudáveis mas com características organolépticas semelhantes aos tradicionais, tornou necessário desenvolver estratégias para satisfazer esta necessidade, pelo que é necessário avaliar o efeito de novas forrageiras nas dietas na sua aceitação pelos consumidores. A composição química e organoléptica do leite de cabra varia de acordo com a dieta, o que por sua vez afeta as características do queijo de leite de cabra. Entre os atributos sensoriais mais importantes para os consumidores estão textura, sabor e cheiro. Objetivo: Avaliar o efeito da substituição da palha de milho por feno de girassol associada ao grão-de-bico na alimentação de cabras leiteiras, em termos de rendimento, composição química e aceitabilidade sensorial do queijo, bem como desempenho econômico. Métodos: Vinte e oito cabras leiteiras Saanen foram distribuídas aleatoriamente em dois tratamentos em um experimento de 30 dias em uma fazenda de pequena escala. A ração diária por cabra no tratamento MZST (tratamento controle) consistia em feno de alfafa (200 g/cabra/dia) e concentrado (400 g/cabra/dia) mais 600 g/cabra/dia (50% da ração) de a palha de milho e o tratamento SFCP (tratamento substituiu o feno de girassol-grão moído) continham os mesmos teores de alfafa e concentrado, mas com 600 g/cabra/dia de feno de girassol-grão. O rendimento, a composição e a avaliação sensorial dos queijos in natura feitos com leite de cada tratamento foram registrados e os custos de alimentação e retornos avaliados. As variáveis de composição química dos queijos foram analisadas seguindo um delineamento inteiramente casualizado. Resultados: Houve diferenças significativas no rendimento do queijo e para todas as variáveis de composição química. A avaliação sensorial mostrou que o queijo SFCP teve pontuações significativamente mais altas para textura e odor, mas significativamente mais baixas para sabor e aceitabilidade geral em comparação com o MZST. Em termos econômicos, o SFCP aumentou os custos com alimentação em 5%, mas resultou em margens mais altas sobre os custos com alimentação de 12 e 24% para leite e queijo, respectivamente, em comparação com o MZST. Conclusão: Apesar do desempenho favorável e do retorno econômico com o tratamento MZST (tratamento controle), mudanças nas características organolépticas do queijo reduziram sua aceitação geral.

Potential Forage Hybrid Markets for Enhancing Sustainability and Food Security in East Africa.

The cattle sector is strategic for both the economic development and food security of Africa, but the low availability and quality of forage puts the most vulnerable population at risk. Hybrid forages are an alternative for enhancing both food security and sustainability of the sector but adoption levels are still low in Africa, which is related to various factors such as the availability of seeds. This document analyzes potential markets for new interspecific hybrids of Urochloa and potential hybrids of Megathyrsus maximus, adapted to the environmental conditions of eastern and partially western Africa, applying a four-step methodology based on estimating (i) required forage amounts for each country according to its dairy herd, (ii) potential hectares for forage cultivation based on (i), (iii) hectares that can be covered by the two hybrids of interest according to a Target Population of Environment approach, and (iv) potential market values for each country and hybrid. The results show a potential market of 414,388 ha for new interspecific hybrids of Urochloa and 528,409 ha for potential hybrids of Megathyrsus maximus, with approximate annual values of 73.5 and 101.1 million dollars, respectively. Ethiopia, Tanzania, and Kenya hold a market share of 70% for Urochloa, and South Sudan, Ethiopia, and Tanzania a 67% market share for Megathyrsus maximus. The results will help different actors in decision-making, i.e., regarding private sector investments in forage seed commercialization or public sector incentives supporting adoption processes, and thus contribute to increasing food security and sustainability in the region.

Use of near-infrared reflectance spectroscopy on feces to estimate digestibility and dry matter intake of dietary nutritional characteristics under grazing conditions in Colombian creole steers.

Digestibility and intake are parameters difficult and expensive to estimate under grazing conditions; therefore, the aim of this study was to develop near-infrared reflectance spectroscopy (NIRS) calibrations applied to feces (F-NIRS) and evaluate their accuracy to predict dry matter digestibility (DMD) and dry matter intake (DMI) of Colombian creole cattle. Five digestibility trials using creole steers were conducted; indigestible neutral detergent fiber (iNDF) was used as internal marker and Cr2O3 and TiO2 as external markers. A total of 249 forage and 396 fecal samples from individual animals were collected, dried, and grinded for conventional chemical analysis. For spectral analysis, fecal samples were pooled across collection periods (77 samples). Chemometric analysis was performed using WinISI V4.10 software applying the modified partial least squares method. Cross-validation was performed to avoid overfitting the models. The goodness-of-fit statistics considered were the coefficient of determination in cross-validation and prediction sets (R2cv and r2, respectively) and the ratio performance deviation (RPD). Fecal NIRS calibrations developed for forage and supplement DMD showed a satisfactory fit (R2cv =0.87 and RPD=2.77 and R2cv=0.92 and RPD=3.50, respectively). The accuracy of fecal output equations using chromium (Cr) and titanium (Ti) was similar in terms of R2cv (0.92) and RPD (3.63 vs. 3.57). Total DMI equations using Ti performed better compared to Cr (R2cv = 0.82 vs. 0.78; RPD=2.41 vs. 2.17, respectively). The F-NIRS models were validated using a completely independent set of fecal samples showing a moderate fit (r2>0.8 and RPD>2.0). This study showed that F-NIRS is a feasible tool to predict DMD and DMI of creole steers under grazing conditions. However, previous to socialization, this requires an improvement in accuracy of the calibrated equations related to grazing animals in different production contexts.

Reproductive and Agronomic Characterization of Novel Apomictic Hybrids of Paspalum (Poaceae).

The tetraploid germplasm of Paspalum contains a large diversity that can be used to generate better forages. The objective was to evaluate a group of Paspalum notatum and Paspalum simplex apomictic hybrids for a set of agronomic traits and apomixis expressivity. Forage yield, cold tolerance, winter regrowth, and seed yield were evaluated. The expressivity of apomixis was evaluated in P. simplex hybrids by flow cytometry. Progeny testing with molecular markers was used to determine the genotypic variability in the progeny. Differences within P. notatum and P. simplex hybrids were observed for all traits, and some of them were superior in comparison with the controls. The accumulated forage yield during three years was 988 g m-2 in the P. notatum hybrids, whereas, in P. simplex, the average forage yield per harvest (40 days of regrowth) was 180 g m-2. In P. simplex, the apomixis expressivity varied between 0 and 100%, and 65% of the hybrids showed high apomixis expressivity (superior to 70%). The genotypic mean homogeneity in the progeny was 76% and 85% in P. notatum and P. simplex, respectively. The generation of hybrids with high apomixis expressivity that combine good agronomic performance and homogeneity in the offspring is possible in tetraploid P. notatum and P. simplex.

Dairy goats fed sunflower hay intercropped with chickpea in small-scale systems. Part I: Animal performance / Cabras lecheras alimentadas con heno de girasol intercalado con garbanzo en sistemas de pequeña escala. Parte I: Desempeño animal / Cabras leiteiras alimentadas com feno de girassol consorciado com grão de bico em sistemas de pequena escala. Parte I: Desempenho dos animais

Abstract Background: Small-scale livestock systems provide quality food for a growing demand of animal protein worldwide. Although these systems help to improve rural living standards and reduce the environmental footprint new feeding strategies should be tested to improve animal productivity. Sunflower -which is native to México- and chickpea -also common in the study area- may be used as feed alternatives for dairy goats. Objective: To evaluate the effect of substituting corn straw with sunflower-chickpea hay on yield and nutrient composition of goat milk. Methods: In this participatory study, a total of 28 multiparous Saanen dairy goats were randomly assigned to two treatments (14 goats each) during a 30-day experiment in a small farm. Two weeks prior to the experiment all goats received an adaptation diet. One treatment (MZST) received a conventional diet of lucerne hay (200 g/goat/day) and concentrate (400 g/goat/day), plus 600 g/goat/day (50% of the ration) of corn straw. The second treatment (SFCPT) contained the same lucerne and concentrate content with 600 g/goat/day of sunflower-chickpea hay. Milk yield and composition, and live weight and body condition of the goats were recorded for each treatment. Results: SFCPT significantly increased milk yield, protein, and solids content, but no difference was observed in milk fat. Conclusion: Dietary supplementation of goats with sunflower and chickpea hay increases milk production, protein, and total solids content compared with corn hay.

Resumen Antecedentes: Los sistemas de producción animal en pequeña escala proveen alimentos de calidad para una demanda mundial creciente de proteina animal. Aunque estos sistemas ayudan a mejorar la calidad de vida rural y reducen la huella ambiental, se deben buscar nuevas estrategias de alimentación para incrementar la productividad animal. El girasol -originario de México- y el garbanzo -común en la zona de estudio- pueden usarse como alternativa para la alimentación de cabras lecheras. Objetivo: Evaluar el efecto de sustituir el heno de maíz con heno de girasol y garbanzo sobre el rendimiento y composición nutricional de la leche de cabra. Métodos: En este estudio participtivo, un total de 28 cabras multíparas lecheras Saanen fueron asignadas aleatoriamente a dos tratamientos (14 cabras a cada uno) durante 30 días en una finca pequeña. Dos semanas antes del experimento todas las cabras recibieron una dieta de adaptación. Un tratamiento (MZST) recibió una dieta convencional de heno de alfalfa (200g/cabra/día) y concentrado (400 g/cabra/día), más 600 g/cabra/día (50% de la ración) de heno de maíz. El segundo tratamiento (SFCPT) tuvo el mismo contenido de alfalfa y concentrado, pero con 600 g/cabra/día de heno de girasol-garbanzo. Se registraron los rendimientos y composición de leche, peso vivo y condición corporal de las cabras para cada tratamiento. Resultados: SFCPT incrementó significativamente el rendimiento de leche, y contenido de proteína y sólidos, pero no hubo diferencias en contenido de grasa. Conclusión: La suplementacion dietaria de cabras con heno de girasol y garbanzo aumenta la producción de leche y su contenido de proteína y sólidos totales en comparacion con el heno de maiz.

Resumo Antecedentes: Os sistemas de produção animal em pequena escala têm um papel importante no fornecimento de alimentos de qualidade para atender uma demanda mundial crescente desses produtos, para melhorar a subsistência rural e para reduzir a pegada ambiental. Há uma necessidade, porem, de aumentar a produtividade através de estratégias de alimentação melhoradas. O girassol é nativo do México e o grão-de-bico é uma cultura comum na área de estudo que podem representar uma alternativa na alimentação de caprinos leiteiros. Objectivo: Avaliar através de investigação participativa na exploração o efeito da substituição da palha de milho tradicionalmente utilizada na alimentação de cabras leiteiras por uma forragem alternativa adaptada à região, mas não utilizada até o momento, em termos de rendimento, composição química de leite fresco de cabras. Métodos: Vinte e oito cabras leiteiras Saanen multipares foram designadas aleatoriamente a dois tratamentos (14 cabras/tratamento), em um experimento de 30 dias numa fazenda de pequena escala. Duas semanas antes do experimento, todos os caprinos receberam uma dieta de adaptação. Um tratamento (MZST) recebeu a dieta convencional de feno de alfalfa (200 g/caprino/dia) e concentrado (400 g/caprino/dia) mais 600 g/caprino/dia (50% da ração) de palha de milho. O segundo tratamento (SFCPT) tinha a mesma proporção de alfalfa e concentrado, mas com 600 g/caprino/dia de feno de girassol e grão-de-bico. O rendimento e composição do leite, o peso vivo e a condição corporal das cabras foram registrados de cada tratamento. Resultados: SFCPT aumentou significativamente o rendimento do leite e o conteúdo de proteínas e sólidos, mas não houve diferença no conteúdo de gordura láctea. Conclusão: O tratamento com girassol e feno de grão de bico aumentou a produção de leite, o teor de proteína e os sólidos totais.

Exposure of insects and host plants to different concentrations of CO2 affects the performance of Mahanarva spectabilis (Hemiptera: Cercopidae) in successive insect generations / A exposição de insetos e plantas hospedeiras às diferentes concentrações de CO2 afeta o desempenho de Mahanarva spectabilis (Hemiptera: Cercopidae) em sucessivas gerações do inseto

Abstract The performance of three successive generations of Mahanarva spectabilis (Distant) (Hemiptera: Cercopidae) fed on four forages exposed to environments with different CO2 concentrations was evaluated. In the first bioassay, we utilized the following scenarios: A) plants and insects were kept at high and constant CO2 (700 ppm) and B) the insects were kept at CO2 700 ppm and fed on plants from the greenhouse (average of 390 ppm). In the second bioassay, we utilized the following scenarios: C) plants and insects were kept in a greenhouse and D) the insects were kept in the greenhouse and fed on plants kept at CO2 700 ppm. The survival and duration of the nymphal and adult stages and the number of eggs/female of M. spectabilis were evaluated. It was only possible to evaluate the cumulative effects of the increase of CO2 on three successive generations of M. spectabilis kept in a greenhouse, due to the reduced survival of the insects in the first generation in the laboratory. A greater direct than indirect effect of the CO2 level on the performance of M. spectabilis was observed. Furthermore, it should be considered that the effect of CO2 elevation on the survival, periods of development, and fecundity, when taken together, can significantly impact the population dynamics of M. spectabilis in future climate scenarios.

Resumo Avaliou-se o desempenho de três gerações sucessivas de Mahanarva spectabilis (Distant) (Hemiptera: Cercopidae) alimentadas com quatro forrageiras expostas à ambientes com diferentes concentrações de CO2. No primeiro bioensaio, utilizamos os seguintes cenários: A) plantas e insetos foram mantidos em fitotron com CO2 alto e constante (média de 700 ppm) e, B) os insetos foram mantidos em nível de 700 ppm de CO2 e alimentados com plantas advindas da casa de vegetação (média de 390 ppm). No segundo bioensaio, utilizamos os seguintes cenários: C) plantas e insetos foram mantidos em casa de vegetação e, D) os insetos foram mantidos em casa de vegetação e alimentados com plantas mantidas em fitotron. A sobrevivência e duração das fases ninfal e adulta e o número de ovos/fêmea de M. spectabilis foram avaliados. Só foi possível avaliar os efeitos cumulativos do aumento do CO2 em três gerações sucessivas de M. spectabilis mantidas em casa de vegetação, devido à reduzida sobrevivência dos insetos na primeira geração quando mantidos em fitotron. Observou-se maior efeito direto do que indireto do nível de CO2 sobre o desempenho de M. spectabilis. Além disso, deve-se considerar que o efeito da elevação de CO2 sobre a sobrevivência, períodos de desenvolvimento e fecundidade, quando tomados em conjunto, podem impactar significativamente a dinâmica populacional de M. spectabilis em cenários climáticos futuros.

Effect of tropical forage species in silvopastoral arrangements on methane production and in vitro fermentation parameters in a RUSITEC system / Efecto de especies forrajeras tropicales en arreglos silvopastoriles sobre la producción de metano y parámetros de fermentación in vitro en un sistema RUSITEC / Efeito de espécies forrageiras tropicais em arranjos silvipastoris sob a produção de metano e parâmetros de fermentação in vitro em um sistema RUSITEC

Abstract Background: Supplementation of grazing cattle with native and naturalized forages using silvopastoral systems has been suggested as an affordable strategy to reduce methane production and improve nutrition, diminishing the environmental impact of cattle production. Objective: To evaluate the effect of three tropical forage species in a silvopastoral arrangement on methane production and fermentation parameters using an in vitro ruminal simulation system (RUSITEC). Methods: Four diets were evaluated. The control treatment was a basal diet of colosuana grass (COL; Bothriochloa pertusa), while the other diets consisted of 70% COL complemented with 30% shrub forage from either Leucaena leucocephala (CL), Guazuma ulmifolia (CG), or Crescentia cujete (CT). A randomized complete block design with repeated measurements over time was used. Results: The inclusion of shrub forage did not affect pH, organic matter degradation (OMD) or volatile fatty acids (VFA). The inclusion of shrub forage affected the degradation of structural components. The concentration of N-NH3 increased in the CL diet compared to COL (p<0.05). In general, methane production in terms of mL/day, mL/g DMi, mL/g DMd, and mL/gOMd was reduced for CL compared to COL (p<0.05). Conclusions: Based on these results, inclusion of Leucaena leucocephala, Guazuma ulmifolia or Crescentia cujete on B. pertusa-based diets improves ruminal fermentation parameters and reduces in vitro methane production.

Resumen Antecedentes: Suplementar ganado en pastoreo con forrajes nativos y naturalizados en sistemas silvopastoriles se ha sugerido como estrategia para reducir la producción de metano y mejorar la nutrición, disminuyendo el impacto ambiental de la ganaderia. Objetivo: Evaluar el efecto de tres especies forrajeras tropicales en arreglos silvopastoriles sobre la producción de metano y parámetros de fermentación utilizando un sistema de simulación ruminal in vitro (RUSITEC). Métodos: El tratamiento control consistió en una dieta basal de pasto Colosuana (COL; Bothriochloa pertusa), mientras que las demás dietas consistieron de 70% COL complementado con 30% de forraje arbustivo de Leucaena leucocephala (CL), Guazuma ulmifolia (CG) ó Crescentia cujete (CT). Se utilizó un diseño de bloques completos al azar con mediciones repetidas en el tiempo. Resultados: La inclusión de forrajes arbustivos no afectó (p>0.05) el pH, la degradación de la materia orgánica (DMO), ni los ácidos grasos volátiles (AGV). La inclusión de recursos arbóreos afectó la degradación de los constituyentes estructurales. La concentración de N-NH3 aumentó en la dieta CL en comparación con el control (p<0.05). En general, la producción de metano en términos de mL/día, mL/g DMi, mL/g DMd y mL/g OMd se redujo en CL respecto a COL (p<0.05). Conclusiones: Con base en estos resultados, la inclusión de Leucaena leucocephala, Guazuma ulmifolia o Crescentia cujete en dietas a base de B. pertusa mejora algunos parámetros de fermentación ruminal y reduce la producción in vitro de metano.

Resumo Antecedentes: A suplementação do gado em pastejo com forragens nativas e naturalizadas usando sistemas silvipastoris, tem sido sugerida como uma estratégia acessível para reduzir a produção de metano e melhorar a nutrição, diminuindo os impactos ambientais da produção de gado. Objetivo: Avaliar o efeito de espécies forrageiras tropicais de arranjo silvipastoril na produção de metano e parâmetros de fermentação usando um sistema de simulação ruminal in vitro (RUSITEC). Métodos: O controle do tratamento (COL) consistiu em uma dieta basal de Colosuana (Botrhiochloa pertusa) sozinha, enquanto as outras dietas, CL, CG e CT, foram complementadas com 30% de Leucaena leucocephala, 30% Guazuma ulmifolia ou 30% Crescentia cujete, respectivamente. Um desenho de blocos completos randomizados com medições repetidas ao longo do tempo foi aplicado. Resultados: A inclusão de forragem arbustiva não afetou o pH (p>0,05), a degradação da matéria orgânica (OMD) e os ácidos graxos voláteis (AGV). A degradação dos componentes estruturais foi afetada pela inclusão de forragem arbustiva. A concentração de N-NH3 aumentou no CL em comparação ao COL (p<0,05). Em geral, a produção de metano em termos de CH4 (mL/dia), CH4 (mL/g DMi), CH4 (mL/g DMd) e CH4 (mL/gOMd) reduziu (p<0,05) no CL em relação ao COL. Conclusões: Com base nos resultados e considerando as condições experimentais avaliadas, a inclusão de Leucaena leucocephala, Guazuma ulmifolia ou Crescentia cujete em dietas à base de B. pertusa melhora alguns parâmetros de fermentação ruminal e reduz a produção de metano in vitro.

Relationship between Chemical Composition and In Vitro Methane Production of High Andean Grasses.

The present study aims to establish the relationship between chemical composition and in vitro methane (CH4) production of high Andean grasses. For this purpose, eight species were collected in dry and rainy seasons: Alchemilla pinnata, Distichia muscoides, Carex ecuadorica, Hipochoeris taraxacoides, Mulhenbergia fastigiata, Mulhenbergia peruviana, Stipa brachiphylla and Stipa mucronata. They were chemically analyzed and incubated under an in vitro system. Species such as A. pinnata and H. taraxacoides were characterized by high crude protein (CP. 124 g/kg DM) and low neutral detergent fiber (NDF. 293 g/kg DM) contents in both seasons, contrary to Stipa grasses. This same pattern was obtained for H. taraxacoides, which presented the highest values of gas production, organic matter digestibility (DOM), metabolizable energy (ME) and CH4 production (241 mL/g DM, 59% DOM, 8.4 MJ ME/kg DM and 37.7 mL CH4/g DM, on average). For most species, the content of CP, acid detergent fiber (FDA) and ME was higher in the rainy season than in the dry season, which was the opposite for CH4 production (p ≥ 0.05). In general, the nutritional content that most explained the behavior of CH4 production was the NDF content (R2 = 0.69). Grasses characterized by high NDF content produced less CH4 (R = -0.85).

Deep Learning Regression Approaches Applied to Estimate Tillering in Tropical Forages Using Mobile Phone Images.

We assessed the performance of Convolutional Neural Network (CNN)-based approaches using mobile phone images to estimate regrowth density in tropical forages. We generated a dataset composed of 1124 labeled images with 2 mobile phones 7 days after the harvest of the forage plants. Six architectures were evaluated, including AlexNet, ResNet (18, 34, and 50 layers), ResNeXt101, and DarkNet. The best regression model showed a mean absolute error of 7.70 and a correlation of 0.89. Our findings suggest that our proposal using deep learning on mobile phone images can successfully be used to estimate regrowth density in forages.

Greenhouse gas emissions from cattle dung depositions in two Urochloa forage fields with contrasting biological nitrification inhibition (BNI) capacity.

Grazing-based production systems are a source of soil greenhouse gas (GHG) emissions triggered by excreta depositions. The adoption of Urochloa forages (formerly known as Brachiaria) with biological nitrification inhibition (BNI) capacity is a promising alternative to reduce nitrous oxide (N2O) emissions from excreta patches. However, how this forage affects methane (CH4) or carbon dioxide (CO2) emissions from excreta patches remains unclear. This study investigated the potential effect of soils under two Urochloa forages with contrasting BNI capacity on GHG emissions from cattle dung deposits. Additionally, the N2O and CH4 emission factors (EF) for cattle dung under tropical conditions were determined. Dung from cattle grazing star grass (without BNI) was deposited on both forage plots: Urochloa hybrid cv. Mulato and Urochloa humidicola cv. Tully, with a respectively low and high BNI capacity. Two trials were conducted for GHG monitoring using the static chamber technique. Soil and dung properties and GHG emissions were monitored in trial 1. In trial 2, water was added to simulate rainfall and evaluate GHG emissions under wetter conditions. Our results showed that beneath dung patches, the forage genotype influenced daily CO2 and cumulative CH4 emissions during the driest conditions. However, no significant effect of the forage genotype was found on mitigating N2O emissions from dung. We attribute the absence of a significant BNI effect on N2O emissions to the limited incorporation of dung-N into the soil and rhizosphere where the BNI effect occurs. The average N2O EFs was 0.14%, close to the IPCC 2019 uncertainty range (0.01-0.13% at 95% confidence level). Moreover, CH4 EFs per unit of volatile solid (VS) averaged 0.31 g CH4 kgVS-1, slightly lower than the 0.6 g CH4 kgVS-1 developed by the IPCC. This implies the need to invest in studies to develop more region-specific Tier 2 EFs, including farm-level studies with animals consuming Urochloa forages to consider the complete implications of forage selection on animal excreta based GHG emissions.

Influence of combined yeast culture and enzymatically hydrolyzed yeast on in vitro ruminal fermentation in contrasting feed substrates.

BACKGROUND: Feed additives such as live yeast cultures have increasingly been used in ruminant feeds to improve animal performance and feeding efficiency. However, it is not clear how inactive combined yeast cultures affect ruminal gas production, fermentation kinetics and efficiency. Therefore, this study was done to determine the influence of incubating different substrates with a combined yeast culture + enzymatically hydrolyzed yeast (YC + EHY) on in vitro ruminal gas production, fermentation kinetics and metabolizable energy. Six contrasting substrates (Trichantera gigantea and Glircidia sepium leaves, Brachiaria hybrid (cv. Mulato II) leaf + stem and leaf only, Cynodon nlemfuensis and a commercial concentrate dairy feed) were incubated with and without YC + EHY in buffered rumen fluid and gas production measured at 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48 and 72 h post incubation. RESULTS: In vitro fermentation parameters (a, b, a + b and c) were unaffected by YC + EHY except for the lag phase in T. gigantea, which that reduced by 31.3% when it was incubated with YC + EHY. Supplementation with YC + EHY also did not affect metabolizable energy, 72 h organic matter digestibility, 24 h gas or CH4 production within substrate. However, cumulative gas and methane production at peak fermentation in the commercial concentrate feed was reduced by 20% when incubated with YC + EHY. CONCLUSION: It was concluded that YC + EHY has the potential to improve microbial colonization of T. gigantean substrates and reduce gas and methane production at peak fermentation in commercial concentrate feeds. © 2021 Society of Chemical Industry.

Mitigation of ruminal methane production with enhancing the fermentation by supplementation of different tropical forage legumes.

The aim of this research was to evaluate the influence of forage species adapted to the tropical region of Ecuador on gas production, enteric methane, digestion, and ruminal fermentation. The tree forage evaluated were C. arborea, E. fusca, B. forficata, E. poeppigiana, C. argentea, G. sepium, C. tora, and F. macrophylla. Ruminal fluid of four adult sheep fistulated with permanent cannulas in the rumen was used in the in vitro gas production technique. The in vitro gas production parameters were lower (P < 0.05) in the C. arborea (A = 41.68 mL gas/g DM, c = 0.044%/h and Lag = 1.654 h) and the average gas production rate for B. forficata was 1.017 mL/h (P < 0.05). C. arborea presented higher (P = 0.0001) effective degradation and real DM digestibility (40.461 g/kg and 82.51 mg/g, respectively). With respect to VFA, the highest (P < 0.05) proportion of acetic, propionic, and butyric was observed in C. arborea, G. sepium, and E. poeppigiana (72.52, 23.09, and 7.44 mol/100 mol, respectively) and the lowest (P = 0.0001) ratio: acetic/propionic was observed in G. sepium (2.92 mol/100 mol). The content of NH3-N (mg/L) showed no difference. The lowest (P = 0.0001) methane production was observed in C. arborea (1.23 mL CH4/g DM). The use of forage species of tropical climate rich in secondary metabolites in ruminant diets has the capacity to reduce the gas production and enteric methane; however, this is at the expense of the reduction of the fermentation of organic matter in the rumen.

Physiological response of WAD sheep fed different combinations of Guinea grass and ensiled Alternanthera brasiliana (L.) O. Kuntze based diets: Intake, haematology and serum biochemical indices.

Animal feed shortages characterize the long dry season in most Sub-Saharan African countries. Studies exploring alternative feedstuffs with similar or complementary nutritional efficacy to the conventional ones are seriously canvassed. Therefore, this study aimed to evaluate the effect of feeding West African Dwarf (WAD) sheep with different combinations of guinea grass and ensiled A. brasiliana based diets on their intake, haematology, and biochemical indices. A total of 30 growing female WAD sheep (BW =10.5 ± 0.92 kg; mean  ± SD), 12-18 months of age were allocated to five dietary treatments containing different inclusion levels of ensiled A. brasiliana (0%, 30%, 45%, 60% and 90%) in a trial that lasted for 90 days. Intakes were estimated daily and body weight changes taken weekly. Blood concentrations of haemoglobin, packed cell volume, white blood cells, differential white blood counts (lymphocytes, monocytes, neutrophils, eosinophils), red blood cells, total protein, albumin, globulin, creatinine and cholesterol were also determined. The total dry matter intake (DMI) increased (P < 0.05) with increasing inclusion levels of A. brasiliana. While the feed conversion ratio decreased (P < 0.05), the final weight and average daily gain significantly increased (P < 0.05) with increasing levels ensiled A. brasiliana. The red blood cell, creatinine, globulin, cholesterol, white blood cell and its differentials were not affected (P > 0.05) by the inclusion levels of A. brasiliana. However, the total protein and albumin were influenced (P < 0.05) by inclusion levels of A. brasiliana. The inclusion levels of A. brasiliana up to 90% promote growth and were not harmful to the ewes.

Grazed rain-fed small-grain cereals as a forage option for small-scale dairy systems in central Mexico.

Small-scale dairy systems face reduced availability of water for irrigation of pastures and disruption in the amount or pattern of rains due to climate change, so research on alternative short-cycle rain-fed forages is needed. Grazing reduces feeding costs and small-grain cereals may be an option. The objective was to assess on-farm the performance of dairy cows grazing 6 h/day of three small-grain cereals: rye (RYE), wheat (WHT), and triticale (TRT), and supplemented 4.5 kg dry matter (DM)/cow/day of concentrate. Twelve Holstein cows were used in repeated 3 × 3 Latin squares with 14-day experimental periods. Pasture variables were analysed with a split-plot design, and economic analysis was performed with partial budgets. Sampling of forage (sward height, net herbage accumulation, botanical and chemical composition of herbage) and animal variables (milk yield and composition, live weight, and body condition score) were at the end of each period. The RYE showed a trend (P > 0.05) for higher net herbage accumulation (NHA) with highly significant differences (P < 0.001) among periods. The RYE had higher DM, a lower crude protein (CP) content (P < 0.05), and no differences for other chemical components between treatments (P > 0.05). The RYE proportion in pasture was consistently higher, whilst the lowest cereal proportion was in WHT. There were no differences (P > 0.05) for any animal variable. The RYE and TRT treatments proved useful as rain-fed forage alternatives under grazing. WHT showed lower crop and economic performance. However, given the higher cereal component in pastures, regrowth potential, and post-grazing herbage mass, as well as better economic performance, the RYE treatment was better ranked by the participating farmer.

Effect of marker dosage frequency and spot fecal sampling frequency in the prediction accuracy of fecal output using chromic oxide and titanium dioxide in grazing BON steers.

This study aimed to evaluate the effect of two marker dosage frequencies and two spot fecal sampling frequencies on the variability of fecal output estimation and fecal recovery rate in grazing Blanco Orejinegro (BON) steers with chromium (Cr) or titanium (Ti) as external markers. Four steers (230.5 ± 14.4 kg BW) were used in a 4 × 4 Latin square design in a split-plot arrangement with two markers: Cr or Ti, two marker dosage frequencies: 10.0 g Cr2O3 or TiO2/steer once daily (DF1) or 5.0 g Cr2O3 or TiO2/steer twice daily (DF2), and two fecal sampling frequencies: spot sampling once daily (SF1) or spot sampling twice daily (SF2). Steers were equipped with fecal collection bags to evaluate the actual fecal output (FOR). Fecal marker concentration (FMC) was affected by marker dosage frequency × fecal sampling frequency interaction (P = 0.032): SF1DF1 allowed higher FMC (2.26 g/kg DM) than SF2DF1 (1.95 g/kg DM). Chromium marker allowed higher estimated fecal output (FOe) values when compared to FOR (P < 0.001). Both Ti mean and SD bias (+ 0.074 ± 0.160 kg) were lower than Cr mean and SD bias (+ 0.312 ± 0.272 kg). The Ti fecal output prediction showed lower both RSR (0.586 vs 1.401) and MSPE (0.029 vs 0.167) than Cr prediction. The titanium external marker allowed fecal output estimation with more accuracy in grazing beef cattle trials. A protocol including a once-daily marker dosage associated with a once-daily fecal sampling is plausible, allowing good fecal recovery rates and accurate fecal output estimation.

Associative Effects between Forages and Concentrates on In Vitro Fermentation of Working Equine Diets.

BACKGROUND: Horses are hindgut fermenters, and it is therefore important to determine the postgastric nutritive value of their feedstuffs and diets. Moreover, it has been demonstrated in other animal species that the fermentation of diets results in different values than those expected from pure ingredients. Therefore, the general objective of this work is to evaluate the gas production (GP) and volatile fatty acid (VFA) concentration, as well as the associative effects, of mixtures of different forages and concentrated foods, which are representative of the traditional diets of high-performance horses. METHODS: An in vitro gas production experiment was conducted to assess the fermentation of two forages and three concentrates that are typical in horse diets. The combination of 70% of forage and 30% concentrates was also assessed to determine potential associative effects. RESULTS: Concentrates and grains produced higher GP and VFA than forages when evaluated alone. When experimental diets were incubated, GP parameters and VFA concentrations of forage-concentrate mixtures had unexpected differences from the values expected from the fermentation of pure ingredients, suggesting the occurrence of associative effects. CONCLUSIONS: Our results indicate that there is a need to evaluate the fermentation of diets, rather than predicting from the values of pure ingredients.

Productive, economic, and environmental effects of sunflower (Helianthus annuus) silage for dairy cows in small-scale systems in central Mexico.

Small-scale dairy systems (SSDS) are important source of livelihood and socio-economic wellbeing for the rearers in general. The reduction of methane emissions with the inclusion of sunflower seed or seed-meal in rations for dairy cows has been reported in several studies. However, studies pertaining to the use of sunflower silage in dairy cattle feeding are lacking. The present study was conducted to assess the productive, economic, and environmental effects of the inclusion of graded levels of sunflower silage at 0%, 20%, 40%, and 60% (SFSL) along with maize silage (MZSL) on a dry matter basis. The silage was provided to eight Holstein cows in two 4×4 Latin-squares with 14-day periods. The study encompassed the productive performance of the cows, composition of feeds, besides the feeding costs, and enteric methane emissions estimated. The study indicated that inclusion of SFSL in the diet enhanced (P<0.001) the FCM by 3.5% and milk-fat content. SFSL increased feeding costs, but income/feeding costs ratios did not differ across the treatments. The higher inclusion of SFSL reduced methane emissions/kg of DM intake, / kg of milk, and in energy lost as methane. The inclusion of sunflower silage in feeding strategies for cows may be a viable alternative by increasing their milk yields and milk fat content and reducing methane emissions without affecting the income/feeding costs ratios.

Reduction in the in vitro ruminal methane production with the inclusion of Cucurbita foetidissima / Reducción en la producción ruminal de metano in vitro con la inclusión de Cucurbita foetidissima

ABSTRACT Objective. This research aimed to evaluate the inclusion of Cucurbita foetidissima (BG) leaves as a partial or total substitution of alfalfa hay (AH) in beef cattle diets on in vitro methane output, gas kinetics and volatile fatty acids production. Materials and Methods. Five experimental treatments were formulated with the inclusion of BG as alfalfa hay (AH) substitute at 0, 25, 50, 75 and 100% in experimental treatments denominated CON (control), BG25, BG50, BG75 and BG100, respectively. Results. Lignin and organic matter decreased with BG inclusion (p<0.05). However, NDF, CT and TPC increased with higher levels of BG (p<0.05). Maximum gas production diminished with BG inclusion (p<0.05); whereas, microbial protein production, specific gas production rate and latency period were not affected (p>0.05). Methane production decreased linearly with BG inclusion (p<0.05). Nevertheless, CO2 production showed no changes with inclusion of graded levels of BG in the experimental treatments (p>0.05). Additionally, acetate and butyrate were not affected by BG inclusion (p>0.05); although, propionate increased linearly among treatments (p<0.05). Furthermore, inclusion of 75% of BG reduced 31% in vitro methane production without changes in CO2 production, suggesting an inhibition of endogenous methanogenesis. Conclusions. These results promote the inclusion of BG leaves as a potential and environmentally friendly forage source for beef cattle feeding.

RESUMEN Objetivo. El objetivo de este estudio fue evaluar la inclusión de hojas de Cucurbita foetidissima (BG) como sustituto parcial o total de la alfafa (AH) en la dieta de ganado de engorda sobre la cinética de producción de gas y producción ruminal in vitro de metano y ácidos grasos volátiles. Materiales y Métodos. Se formularon cinco dietas con la inclusión de BG como sustituto de heno de alfalfa a 0, 25, 50, 75 y 100% en los tratamientos experimentales que se denominaron CON (control), BG25, BG50, BG75 y BG100, respectivamente. Resultados. La lignina y la materia orgánica disminuyeron con la inclusión de BG (p<0.05). La máxima producción de gas disminuyó con la inclusión de BG (p<0.05); mientras que la producción de proteína microbiana, la tasa específica de producción de gas y el tiempo de latencia no mostraron cambios(p>0.05). La producción de metano disminuyó linealmente con la inclusión de BG (p<0.05). No obstante, la producción de CO2 no mostró cambios con la inclusión de BG en los tratamientos (p<0.05). Adicionalmente, el acetato y el butirato no fueron afectados por la inclusión de BG (p>0.05); a pesar de que el propionato se incrementó linealmente (p<0.05). Además, la inclusión de BG en un 75% redujo la producción de metano 31% sin afectar la producción de CO2, lo que sugiere una inhibición de la metanogenesis endógena. Conclusiones. Estos resultados promueven la inclusión de hojas de BG como una fuente de forraje potencial y amigable con el ambiente en la alimentación de ganado de engorda.

Nutritive value of elephant grass hay ammoniated by urea / Valor nutritivo do feno de capim elefante amonizado por uréia

The aim of this study was to evaluate the effect of ammoniation by urea on the nutritional value of elephant grass hay harvested after flowering. A completely randomized design, in double factorial designs with an additional treatment: 4 urea doses (2, 4, 6 and 8%) x 2 treatment periods (30 and 45 days) + 1 (Control) with four replicates each, was employed. Dry matter, ash, ether extract, neutral detergent fiber, acid detergent fiber, cellulose, lignin, neutral detergent fiber corrected for the ash and the protein, total nitrogen, acid detergent insoluble nitrogen, neutral detergent insoluble nitrogen, non-protein nitrogen, in vitro gas production and carbohydrates fractionation were analyzed. The treatments influenced the contents of DM, EE, NDF, ADF, lignin, cellulose, NDFap, fraction A + B1, fraction B2, fraction C, TN, NPN, ADIN, NDIN, L and Vf2. There was a positive linear effect of urea dose for NDF, ADIN, NDIN and L, positive linear effect on fraction A + B1, NT and NPN, and positive quadratic effect for Vf2, with absolute maximum point of 4.5%. Elephant grass hay harvested after flowering has its nutritional value improved, with a minimum dose of 4.5% urea on a dry matter basis.(AU)

Objetivou-se avaliar o efeito da amonização com ureia sobre o valor nutritivo do feno de capim elefante colheitado após florescimento. O estudo foi delineado, em esquema fatorial duplo com um tratamento adicional: 4 doses de ureia (2, 4, 6 e 8%) x 2 período de tratamento (30 e 45 dias) + 1 tratamento controle, com 4 repetições cada. As variáveis analisadas foram: matéria seca (MS), cinzas, extrato etéreo (EE), fibra em detergente neutro (FDN) e ácido (FDA), FDN corrigida para cinzas e proteínas (FDNcp), celulose, lignina, nitrogênio total (NT), nitrogênio insolúvel em detergente ácido (NIDA) e neutro (NIDN), nitrogênio não proteico (NNP). Produção de gases in vitro proveniente dos carboidratos não fibrosos (Vf1) e fibrosos (Vf2), taxa de fermentação dos carboidratos não fibrosos (k1) e fibrosos (k2) e tempo de colonização bacteriana do substrato (L), além do fracionamento de carboidratos. Os tratamentos influenciaram os teores de MS, EE, FDN, FDA, lignina, celulose, FDNcp, fração A + B1, fração B2, fração C dos carboidratos, NT, NNP, NIDA, NIDN, L e Vf2. Houve efeito linear decrescente de dose de ureia para FDNcp, NIDA, NIDN e L, crescente para fração A+B1, NT e NNP, e, quadrático crescente de dose de ureia para Vf2, com ponto máximo absoluto de 4,5% de ureia obtido após derivar a equação de regressão aos 45 dias de tratamento do feno. Concluindo que feno de capim elefante colheitado após florescimento tem seu valor nutricional melhorado, com dose mínima de 4,5% de ureia em base da matéria seca.(AU)