Exogenous amylase increases gas production and improves in vitro ruminal digestion kinetics of sorghum and corn grains / Amilase exógena aumenta a produção de gases e melhora a cinética de digestão ruminal in vitro de grãos de sorgo e milho

The aim of this study was to evaluate the effect of exogenous amylase on gas production, in vitro dry matter digestibility (IVDMD), and in vitro digestion kinetics of sorghum (Sorghum vulgaris) and two corn hybrids of different grain textures. Ruminal fluid was collected from two rumen-fistulated cows receiving or not exogenous amylase (0.7g kg-1 of dry matter (DM basis)), provided to achieve 396 kilo Novo units kg-1 for amylase activity (DM basis). Gas production was measured after 1, 3, 6, 9, 12, 15, 18, 21, 24, 30, 36, 42 e 48 hours of incubation. Amylase increased gas production (mL) by 5.4%. Corn hybrids have higher in vitro dry matter digestibility than sorghum. Exogenous amylase increased the potential of gas production (A) (P=0.01). There was an effect of hybrid for IVDMD (P<0.01). The addition of exogenous amylase increases the in vitro gas production, improves fermentation kinetics, and increases the production of the ammonia nitrogen of corn and sorghum grains, but does not affect in vitro and dry matter digestibility or the short-chain fatty acids production.

O objetivo deste estudo foi avaliar o efeito da amilase exógena na produção de gases, a digestibilidade in vitro da matéria seca (DIVMS) e a cinética de digestão in vitro de sorgo (Sorghum vulgaris) e de dois híbridos de milho de diferentes texturas de grãos. O líquido ruminal foi coletado de duas vacas fistuladas no rúmen recebendo ou não amilase exógena (0,7g kg-1 de matéria seca (MS)), fornecida para atingir 396 kg Novo unidades kg-1 para atividade de amilase (base na MS). A produção de gás foi medida após uma, três, seis, nove, 12, 15, 18, 21, 24, 30, 36, 42 e 48 horas de incubação. A amilase aumentou a produção de gás (mL) em 5,4%. Híbridos de milho apresentam maior DIVMS que o sorgo. A amilase exógena aumentou o potencial de produção de gás (A) (P=0,01). Houve efeito de híbrido para DIVMS (P<0,01). Amilase exógena aumenta a produção de gás in vitro, melhora a cinética da fermentação e aumenta a produção de nitrogênio amoniacal de grãos de milho e sorgo, mas não afeta a digestibilidade in vitro da matéria seca ou a produção de ácidos graxos de cadeia curta.

Association of additives in supplemented grazing cattle during the finishing phase at the rainy season

The objectives were to evaluate the effects of monensin and virginiamycin, alone or combined, on supplemented Nellore cattle grazing tropical grass during the rainy season. Two experiments were conducted simultaneously to evaluate intake, digestibility, CH4 emissions, blood parameters, performance, and carcass characteristics (Exp. 1), and ruminal fermentation and relative abundance of ruminal microorganisms (Exp. 2). Animals (n = 92 Exp. 1 and n = 12 Exp. 2) were distributed in a completely randomized design and allocated in twelve paddocks composed of Urochloa brizantha (A. Rich.) Stapf. cv. Xaraés. A protein-energetic supplementation of 3 g/kg of BW per day was provided to all animals. Supplements were: without additives (WA), monensin alone at 80 mg/kg of product (MN), virginiamycin alone at 150 mg/kg of product (VM), and monensin (80 mg/kg of product) combined with virginiamycin (150 mg/kg of product; MNVM). Treatments did not affect intakes of total dry matter (DM), supplement DM, and nutrients. However, the intakes of forage DM and crude protein decreased in cattle fed MNVM compared with animals fed WA, MN, and VM. Total volatile fatty acids increased in animals fed VM. Ruminal NH3-N decreased, and pH increased in animals fed MN, VM, and MNVM. Relative abundance of total F. succinogenes and S. ruminantium decreased and R. flavefaciens increased in animals fed MN and VM at d 118. Treatments had no effect on enteric CH4 emissions. The average daily gain (ADG) and total gain were greater in cattle fed MNVM than in cattle fed MN. Combination of monensin and virginiamycin altered the rumen microbial populations but did not decrease enteric CH4 emissions. However, it decreased forage dry matter intake without altering the ADG and total weight gain, leading to an increase in feed efficiency. Results from this study indicate an advantage in including feed additives combined in the diet of supplemented Nellore cattle grazing tropical grass during the rainy season.

Exploring the rumen microbial community in Guizhou White goats at different ages

This study evaluated the changes in rumen microbiome during the process of age development of farming Guizhou White goats from Southwest China. We conducted high-throughput 16S rRNA gene sequencing to investigate the diversity, structure, and composition of goat rumen microbiota (RM) of 21 goats of different age groups (1, 6, and 12 months). We found that volatile fatty acids (i.e., acetate, propionate, and butyrate) fermented by microbes were found to increase significantly in the sixand one-month-old goats. Results of the genera abundance analysis showed that abundance of eight and seven taxa decreased in six- and one-month-old goats, respectively, compared with that in 12-month-old goats. Additionally, differences in six taxa in six-month-old goats and in one taxon in one-month-old goats were found. In addition, specific gut microbiome was found, which was significantly correlated with rumen fermentation parameters in Guizhou White goats. These results revealed the signature microbiota in RM during various developmental stages in goats raised in Southwest China and can also provide a guiding tool for evaluating rumen health of ruminants worldwide.(AU)

Nutritional quality of wet distillers grains coensiled with wholeplant maize and its feeding value for lambs

ABSTRACT: The high moisture content of wet distillers grains with solubles (WDGS) has limited its feeding value despite the relatively high nutritive value. The coensiling with wholeplant maize, as a complementary feed, was evaluated for growing lambs by formulating diets whose contents were: whole plant maize silage (WPMS) + sunflower oilcake meal (SOM) (control, WPMS + SOM), whole plant maize silage + dried distillers grains (WPMS + DDGS), and wholeplant maize (WPM) coensiled with WDGS (WPM WDGS). Rumen fermentation parameters and in situ degradability of the diets were evaluated using three cannulated Merino wethers in a cross over 3 × 3 Latin square design experiment that lasted 39 days. Concurrently, feed intake and growth performance of South Africa Mutton Merino lambs (29.7 ± 3.6 kg) were evaluated over 45 days. The WPMS + DDGS diet had a lower rate of dry matter degradation (p 0.05) compared to the WPMS + SOM and WPMWDGS diets. However, the rapidly fermentable fraction, as well as the progressively fermentable fraction of the diet dry matter, was not different (p > 0.05). No differences in rumen volatile fatty acid, ammonia nitrogen concentration nor rumen pH of the wethers as a result of diet differences were observed. Lambs consuming the WDGSbased diet had a lower average daily intake and average daily gain (p 0.05) compared to lambs consuming the DDGS and WPMSbased diets. However, the feed conversion ratio was not affected by diet differences (p > 0.05). In conclusion, coensiling WDGS with wholeplant maize provides the opportunity for the longterm storage and utilization of WDGS in lamb feeding.

Chitosan combined with technical cashew nut shell liquid improves in vitro ruminal parameters and gas production kinetics

The objective was to evaluate the inclusion of chitosan (CHI) and technical cashew nut shell liquid (CNSLt) as natural feed additives in cattle diets on nutrient digestibility, ruminal fermentation, and in vitro gas production kinetics. We conducted a completely randomized design with 5×4 factorial arrangement, with 20, 35, 50, 65, and 100% Tifton 85 hay and four additives, monensin (200 mg/kg DM), CNSLt (500 mg/kg DM), CHI (500 mg/kg DM), and CNSLt+CHI (500 mg/kg DM/each). Dry matter (DM) and organic matter (OM) digestibility showed a linear reduction according to forage levels. The highest DM digestibility was observed with CHI on cattle diets. Inclusion of CHI increased DM digestibility. The highest in vitro organic matter and crude protein (CP) digestibilities were observed for CNSLt+CHI. The in vitro dry matter digestibility increased linearly with concentrate in the diet. There was interaction of forage:concentrate ratio and the additives for neutral detergent fiber, acid detergent fiber and hemicellulose digestibility. Chitosan, CNSLt, and CNSLt+CHI promoted the lowest acetate:propionate ratio compared with monensin. Total gas production showed interaction of the forage:concentrate ratio and additives. Lag time was lowest with CNSLt+CHI. Chitosan and CNSLt can be considered alternative fermentation modulators to ionophores by improving nutrient digestibility and increasing ruminal propionate concentrations.(AU)

Effects of ricinoleic acid from castor oil and cashew nutshell liquid on nutrient digestibility and ruminal fermentation in dairy heifers / Efeitos do ácido ricinoleico do óleo de mamona e do líquido da castanha de caju sobre a digestibilidade de nutrientes e fermentação ruminal de novilhas leiteiras

This study aimed to evaluate the effects of combining functional oils (FO) [ricinoleic acid (RA) and cashew nutshell liquid (CNSL)] on nutrient intake and total-tract apparent digestibility, ruminal fermentation, nitrogen utilization, and predicted rumen microbial protein (Pmic) in heifers. Twelve Jersey heifers (14±0.6 months and 264±18.7 kg BW) were assigned to a 4 × 4 Latin square experiment with the following treatments: Control (CON), diet without feed additives; Ricinoleic acid, dietary inclusion of RA at 2 g kg-1 dry matter (DM); Cashew nutshell liquid, dietary inclusion of CNSL at 2 g kg-1 DM; and a mixture of 1 g kg-1 DM of RA and 1 g kg1 DM of CNSL (RA+CNSL). Heifers were allowed 14 d for treatment adaptation followed by 5 days of sampling. Total feces collection was performed to determine digestibility. Rumen fluid was collected to determine short-chain fatty acids (SCFA) concentration. Urine samples were collected for nitrogen and purine derivatives analyses. Feeding RA decreased intake of DM, but increased crude protein (CP) digestibility and ruminal acetate concentration. Feeding CSNL increased NDF digestibility and lowered Pmic. The association of RA+CNSL increased neutral detergent fiber (NDF) digestibility and ruminal concentration of total SCFA without affecting DM intake. Feeding RA treatment decreased N intake and N excreted in feces and urine. CNSL group had the highest values of N balance. Heifers fed RA had lower Pmic than CNSL and RA+CNSL. The association of RA+CNSL improved digestibility of fiber and increased ruminal concentration of SCFA without altering N balance and Pmic.(AU)

O objetivo deste estudo foi avaliar os efeitos da combinação de óleos funcionais (OF) [ácido ricinoleico (AR) e líquido da castanha de caju (LCC)] no consumo e digestibilidade de nutrientes, fermentação ruminal, utilização de nitrogênio e estimativa de proteína microbiana de novilhas leiteiras. Doze novilhas da raça Jersey (14±0,6 meses e 264±18,7 kg PV) foram alocadas em um experimento de quadrado latino 4×4 contendo os tratamentos a seguir: controle (CON), uma dieta sem aditivos; Ácido ricinoleico, inclusão de 2g kg-1 de matéria seca (MS) de AR na dieta; Líquido da castanha de caju (LCC), inclusão de 2 g kg-1 MS de LCC na dieta; e uma mistura de 1 g kg-1 MS de AR e 1 g kg-1 MS de LCC na dieta (AR+LCC). Cada período experimental tinha 14 dias para adaptação aos tratamentos e 5 dias de coleta. O consumo de alimentos foi mensurado diariamente, e uma coleta total de fezes foi realizada durante 3 dias consecutivos de cada período experimental para determinar a digestibilidade de nutrientes. Amostras de fluído ruminal foram coletadas no último dia de cada período para determinação da concentração de ácidos graxos de cadeia curta. Amostras de urina foram coletadas no dia 18 de cada período para análises de nitrogênio e derivados de purina. O fornecimento de AR diminuiu o consumo de MS e proteína bruta (PB), mas aumentou a digestibilidade de proteína bruta e concentração ruminal de acetato. O fornecimento de LCC não afetou o consumo, mas aumentou a digestibilidade da fibra em detergente neutro (FDN). A associação de AR+LCC aumentou a digestibilidade da PB e FDN como também a concentração total de ácidos graxos de cadeia curta no rúmen, sem alterar o consumo de MS. O tratamento AR diminuiu a ingestão de N como também a excreção de N pelas fezes e urina. As novilhas do grupo LCC tiveram os maiores valores de N absorvido e retido enquanto as novilhas do grupo AR tiveram os menores valores. As novilhas do grupo RA tiveram menor estimativa de proteína microbiana em comparação com aquelas no grupo LCC e AR+LCC mas não diferiram do CON. Em conclusão, a associação de AR+LCC melhorou a digestibilidade da fibra e aumentou a concentração do total de ácidos graxos de cadeia curta no rúmen sem alterar o balanço de N e estimativa da proteína microbiana no rúmen.(AU)

Nutritional quality of wet distillers’ grains co–ensiled with whole–plant maize and its feeding value for lambs

The high moisture content of wet distillers' grains with solubles (WDGS) has limited its feeding value despite the relatively high nutritive value. The co–ensiling with whole–plant maize, as a complementary feed, was evaluated for growing lambs by formulating diets whose contents were: whole plant maize silage (WPMS) + sunflower oilcake meal (SOM) (control, WPMS + SOM), whole plant maize silage + dried distillers' grains (WPMS + DDGS), and whole–plant maize (WPM) co–ensiled with WDGS (WPM – WDGS). Rumen fermentation parameters and in situ degradability of the diets were evaluated using three cannulated Merino wethers in a cross over 3 × 3 Latin square design experiment that lasted 39 days. Concurrently, feed intake and growth performance of South Africa Mutton Merino lambs (29.7 ± 3.6 kg) were evaluated over 45 days. The WPMS + DDGS diet had a lower rate of dry matter degradation (p 0.05). No differences in rumen volatile fatty acid, ammonia nitrogen concentration nor rumen pH of the wethers as a result of diet differences were observed. Lambs consuming the WDGS–based diet had a lower average daily intake and average daily gain (p 0.05). In conclusion, co–ensiling WDGS with whole–plant maize provides the opportunity for the long–term storage and utilization of WDGS in lamb feeding.

Nutritional quality of wet distillers' grains co-ensiled with whole-plant maize and its feeding value for lambs

The high moisture content of wet distillers' grains with solubles (WDGS) has limited its feeding value despite the relatively high nutritive value. The co­ensiling with whole­plant maize, as a complementary feed, was evaluated for growing lambs by formulating diets whose contents were: whole plant maize silage (WPMS) + sunflower oilcake meal (SOM) (control, WPMS + SOM), whole plant maize silage + dried distillers' grains (WPMS + DDGS), and whole­plant maize (WPM) co­ensiled with WDGS (WPM ­ WDGS). Rumen fermentation parameters and in situ degradability of the diets were evaluated using three cannulated Merino wethers in a cross over 3 × 3 Latin square design experiment that lasted 39 days. Concurrently, feed intake and growth performance of South Africa Mutton Merino lambs (29.7 ± 3.6 kg) were evaluated over 45 days. The WPMS + DDGS diet had a lower rate of dry matter degradation (p < 0.05) compared to the WPMS + SOM and WPM­WDGS diets. However, the rapidly fermentable fraction, as well as the progressively fermentable fraction of the diet dry matter, was not different (p > 0.05). No differences in rumen volatile fatty acid, ammonia nitrogen concentration nor rumen pH of the wethers as a result of diet differences were observed. Lambs consuming the WDGS­based diet had a lower average daily intake and average daily gain (p < 0.05) compared to lambs consuming the DDGS and WPMS­based diets. However, the feed conversion ratio was not affected by diet differences (p > 0.05). In conclusion, co­ensiling WDGS with whole­plant maize provides the opportunity for the long­term storage and utilization of WDGS in lamb feeding.

Effect of essential oils and aqueous extracts of plants on in vitro rumen fermentation and methane production

The objective of this study was to evaluate in vitro rumen fermentation and methane production under the influence of two sources of phytochemicals: essential oils (EOs) and aqueous extracts (AEs). Treatments were set up in a completely randomized block design, with 4×2+1 factorial arrangement of four species, S (garlic, G; cinnamon, C; rosemary, R; eucalyptus; EU) × two types of presentation, P (essential oil, EO; aqueous extract, AE) and a basal diet, BD (50% concentrate, 20% alfalfa and 30% corn silage). Rumen fermentation was evaluated using the in vitro gas production technique. All experimental units were incubated with 500 mg of BD for 72 hours. Treatments were added at a single dose of 900 mg/L of rumen inoculum. Gas pressure was recorded at 0, 2, 4, 6, 8, 10, 14, 18, 24, 30, 36, 42, 48, 60 and 72 h postincubation. There was an interaction effect (P × S) between plant extract presentation (P) and plant species (S) for all variables. Treatments GEO, CEO, REO decreased volatile fatty acids (mmol/200 mg), microbial mass production (mg/g), CH4 production (mL/g), in vitro dry matter digestibility (P < 0.05), and total gas production at 24 and 72 h post-incubation (P < 0.05; mL/g DM, mL/g OM). No differences (P > 0.05) were observed between AEs and BD. In conclusion, the use of EOs negatively affected rumen fermentation parameters and the production of CH4. Garlic and cinnamon EOs effectively reduced methane emissions; however, they also reduced in vitro dry matter digestibility.

Effect of mixture of herbal plants on ruminal fermentation, degradability and gas production

Reducing livestock negative environmental impacts get great interest in last years. So, present study was carried out to determine the effect of adding different levels of mixture of thyme and celery versus salinomycin on ruminal fermentation, gas production, dry, organic matter and fiber degradation. Four experimental treatments were used by in-vitro batch culture technique, as follow: 60% CFM, 40% clover hay (control), control diet + 2.5 gm thyme + 2.5 gm celery kg-1 DM (T1), control diet + 5 gm thyme + 5 gm celery kg-1 DM (T2), control diet + 10 gm thyme + 10 gm celery kg-1 DM (T3), control diet + 0.4 gm Salinomycin kg-1 DM (T4). Ruminal pH value was significantly increased (p 0.05) between control and other treatments except for T1 that recorded the lowest value (p < 0.05). It is concluded that mixture of thyme plus celery could be alternate for ionophores in the ruminant diets to enhance ruminal fermentation, reducing gas production without any negative effect on nutrients degradability.

Intake and ruminal parameters of goats fed diets supplemented with vegetable oils

The objective of this study was to evaluate the intake and ruminal parameters of goats fed diets supplemented with vegetable oils. Four rumen-cannulated Saanen goats were allocated to four treatments, which consisted of a control diet and diets with the inclusion of 30 g of canola, sunflower, or soybean oils per kilogram of diet dry matter (DM). The experiment lasted 40 days, which were divided into four 10-day periods. Forage intake was estimated using chromium oxide as an external marker, and supplement intake was determined as the difference between the daily amount supplied and orts. Rumen fermentation parameters were evaluated from samples of rumen fluid collected every 2 h, for 12 h. Rumen pH and short-chain fatty acid and ammonia nitrogen concentrations were measured. There was no effect of lipid supplementation on DM intake. Ether extract intake was highest in the treatments with oil inclusion, and the highest acid detergent fiber intake was obtained with the diet containing canola oil. The pH was highest in the group fed soybean oil and responded quadratically to the collection times. Total short-chain fatty acid and acetic acid concentrations also responded quadratically to the collection times. Propionic and butyric acid concentrations and acetic:propionic acid ratio showed a cubic behavior with the increasing collection times. Canola, sunflower, or soybean oils can be included at 30 g/kg of the diet DM as a strategy to increase the energy density of goat diets.

Effect of different levels of Ipomoea batatasflour inclusion on the ruminal pH of sheep in metabolic cages

The accumulation of industrial by-products increases the use of sweet potato waste for ruminants, but ruminal pH characteristics are still not well known. The objective was to assess the fluctuation of ruminal pH in sheep supplemented with different levels of sweet potato flour inclusion in their diet. Four rumen-fistulated sheep were used; they were fed a diet based on ryegrass haylage (Lolium multiflorum) and sweet potato flour (Ipomoea batatas), provided according to the level of inclusion in the total diet (0, 0.5, 1.0 and 1.5%). Approximately 80 ml of ruminal fluid was collected for reading on a bench pH meter. Statistical data analysis was run on Statistical Analysis System (SAS Institute INC. Cary, NC, USA), and statistical difference was considered for p < 0.05. The animals that received 1.5% of sweet potato flour in their diet presented acid rumen pH; the 1.0% group presented rumen pH acidification in the first 6 hours after feeding, and the 0.5% level of inclusion did not change the rumen environment. It is concluded that the inclusion of 0.5% sweet potato flour in sheep diet proved to be an efficient energy supplementation strategy.(AU)

Effect of different levels of Ipomoea batatasflour inclusion on the ruminal pH of sheep in metabolic cages

The accumulation of industrial by-products increases the use of sweet potato waste for ruminants, but ruminal pH characteristics are still not well known. The objective was to assess the fluctuation of ruminal pH in sheep supplemented with different levels of sweet potato flour inclusion in their diet. Four rumen-fistulated sheep were used; they were fed a diet based on ryegrass haylage (Lolium multiflorum) and sweet potato flour (Ipomoea batatas), provided according to the level of inclusion in the total diet (0, 0.5, 1.0 and 1.5%). Approximately 80 ml of ruminal fluid was collected for reading on a bench pH meter. Statistical data analysis was run on Statistical Analysis System (SAS Institute INC. Cary, NC, USA), and statistical difference was considered for p < 0.05. The animals that received 1.5% of sweet potato flour in their diet presented acid rumen pH; the 1.0% group presented rumen pH acidification in the first 6 hours after feeding, and the 0.5% level of inclusion did not change the rumen environment. It is concluded that the inclusion of 0.5% sweet potato flour in sheep diet proved to be an efficient energy supplementation strategy.

Effect of mixture of herbal plants on ruminal fermentation, degradability and gas production

Reducing livestock negative environmental impacts get great interest in last years. So, present study was carried out to determine the effect of adding different levels of mixture of thyme and celery versus salinomycin on ruminal fermentation, gas production, dry, organic matter and fiber degradation. Four experimental treatments were used by in-vitro batch culture technique, as follow: 60% CFM, 40% clover hay (control), control diet + 2.5 gm thyme + 2.5 gm celery kg-1 DM (T1), control diet + 5 gm thyme + 5 gm celery kg-1 DM (T2), control diet + 10 gm thyme + 10 gm celery kg-1 DM (T3), control diet + 0.4 gm Salinomycin kg-1 DM (T4). Ruminal pH value was significantly increased (p < 0.05) with T4 compared with other treatments. While, the T4 recorded the lowest value (p < 0.05) for microbial protein, short chain fatty acids concentrations (SCFA), total gas production, dry matter and organic matter degradability (DMd and OMd) compared with other treatments. Fiber fraction degradability (NDFd and ADFd) appeared no significant variance (p > 0.05) between control and other treatments except for T1 that recorded the lowest value (p < 0.05). It is concluded that mixture of thyme plus celery could be alternate for ionophores in the ruminant diets to enhance ruminal fermentation, reducing gas production without any negative effect on nutrients degradability.(AU)

Mathematical models to adjust the parameters of in vitro cumulative gas production of diets containing preserved Gliricidia / Modelos matemáticos para ajuste dos parâmetros de produção cumulativa de gás in vitro de dietas contendo Gliricídia conservada

ABSTRACT: This study examined the use of the Gompertz, Groot, monomolecular, Richards and two-compartment-logistic mathematical models to investigate the kinetics of in vitro gas production of diets composed of combinations of Gliricidia hay or silage. In addition, the effects of Gliricidia hay or silage inclusion on the in vitro cumulative gas production of these diets were evaluated. Rumen fermentation kinetics were analyzed by the in vitro cumulative gas production methodology. The model parameters were estimated using the Gauss Newton method, with the exception of the Richards model, which was used by Marquardt's algorithm. Model fit was assessed using the determination coefficient, F test for parameters identity, concordance correlation coefficient, root mean square error of prediction, and decomposition of mean square error of prediction into mean error, systematic bias and random error. The models were compared for accuracy (pairwise mean square error of prediction) and precision (delta Akaike's information criterion). All model evaluation and comparison statistics were calculated using Model Evaluation System software version 3.2.2. The Groot and Richards models did not differ from each other (P>0.05) and were the most precise and accurate (P<0.05). Therefore, the Groot model was selected due to its better accuracy and precision and easier access to the parameters. The inclusion of Gliricidia silage in the diet resulted in an increase in the time to obtain the maximum rate of degradation and in the time after incubation when half of the asymptotic level was reached. The Groot model is recommended to estimate the average curve. Dietary inclusion of Gliricidia silage alters the gas production curve due to the longer time required for the diet to reach the maximum rate of degradation, this can increase the time the diet remains in rumen and promote a reduction in the consumption.

RESUMO: Objetivou-se avaliar os modelos matemáticos Gompertz, Groot, monomolecular, Richards e logístico bicompartimental para estudar a cinética de produção de gás in vitro de dietas compostas de combinações de feno ou silagem de Gliricídia. Além disso, avaliou-se os efeitos da inclusão de feno ou silagem de Gliricídia sobre a produção cumulativa de gás in vitro destas dietas. A cinética de fermentação ruminal foi avaliada pela metodologia de produção cumulativa de gás in vitro. Os parâmetros dos modelos foram estimados usando o método de Gauss Newton, com exceção do modelo de Richards, que foi usado algoritmo de Marquardt. O ajuste dos modelos foi avaliado por meio do coeficiente de determinação, teste F para a identidade dos parâmetros, coeficiente de correlação e concordância, raiz quadrada do quadrado médio do erro da predição e a decomposição do quadrado médio do erro da predição em erro médio, vício sistemático e erro aleatório. Os modelos foram comparados quanto à acurácia (quadrado médio da predição pareado) e quanto à sua precisão (critério de informação delta de Akaike). Todas as estatísticas de avaliação e comparação dos modelos foram calculadas usando o software Model Evaluation System versão 3.2.2. Os modelos de Groot e Richards não diferiram entre si (P>0.05) e foram os mais precisos e acurados (P<0.05). Portanto, modelo de Groot foi selecionado devido apresentar melhor acurácia e precisão e apresentar maior facilidade na obtenção dos parâmetros. A inclusão da silagem de Gliricídia na dieta, resultou em elevação no tempo para obtenção da máxima taxa de degradação e no tempo após a incubação em que metade do nível assintótico foi atingido. Recomenda-se a utilização do modelo de Groot para estimativa da curva média. A inclusão da silagem de Gliricídia altera a curva de produção de gás devido o maior tempo necessário para que a dieta atingisse a máxima taxa de degradação, isso pode elevar o tempo de permanência da dieta no rúmen e promover redução no consumo.

Mathematical models to adjust the parameters of in vitro cumulative gas production of diets containing preserved Gliricidia / Modelos matemáticos para ajuste dos parâmetros de produção cumulativa de gás in vitro de dietas contendo Gliricídia conservada

This study examined the use of the Gompertz, Groot, monomolecular, Richards and two-compartment-logistic mathematical models to investigate the kinetics of in vitro gas production of diets composed of combinations of Gliricidia hay or silage. In addition, the effects of Gliricidia hay or silage inclusion on the in vitro cumulative gas production of these diets were evaluated. Rumen fermentation kinetics were analyzed by the in vitro cumulative gas production methodology. The model parameters were estimated using the Gauss Newton method, with the exception of the Richards model, which was used by Marquardt’s algorithm. Model fit was assessed using the determination coefficient, F test for parameters identity, concordance correlation coefficient, root mean square error of prediction, and decomposition of mean square error of prediction into mean error, systematic bias and random error. The models were compared for accuracy (pairwise mean square error of prediction) and precision (delta Akaike’s information criterion). All model evaluation and comparison statistics were calculated using Model Evaluation System software version 3.2.2. The Groot and Richards models did not differ from each other (P>0.05) and were the most precise and accurate (P<0.05). Therefore, the Groot model was selected due to its better accuracy and precision and easier access to the parameters. The inclusion of Gliricidia silage in the diet resulted in an increase in the time to obtain the maximum rate of degradation and in the time after incubation when half of the asymptotic level was reached. The Groot model is recommended to estimate the average curve. Dietary inclusion of Gliricidia silage alters the gas production curve due to the longer time required for the diet to reach the maximum rate of degradation, this can increase the time the diet remains in rumen and promote a reduction in the consumption.

Objetivou-se avaliar os modelos matemáticos Gompertz, Groot, monomolecular, Richards e logístico bicompartimental para estudar a cinética de produção de gás in vitro de dietas compostas de combinações de feno ou silagem de Gliricídia. Além disso, avaliou-se os efeitos da inclusão de feno ou silagem de Gliricídia sobre a produção cumulativa de gás in vitro destas dietas. A cinética de fermentação ruminal foi avaliada pela metodologia de produção cumulativa de gás in vitro. Os parâmetros dos modelos foram estimados usando o método de Gauss Newton, com exceção do modelo de Richards, que foi usado algoritmo de Marquardt. O ajuste dos modelos foi avaliado por meio do coeficiente de determinação, teste F para a identidade dos parâmetros, coeficiente de correlação e concordância, raiz quadrada do quadrado médio do erro da predição e a decomposição do quadrado médio do erro da predição em erro médio, vício sistemático e erro aleatório. Os modelos foram comparados quanto à acurácia (quadrado médio da predição pareado) e quanto à sua precisão (critério de informação delta de Akaike). Todas as estatísticas de avaliação e comparação dos modelos foram calculadas usando o software Model Evaluation System versão 3.2.2. Os modelos de Groot e Richards não diferiram entre si (P>0.05) e foram os mais precisos e acurados (P<0.05). Portanto, modelo de Groot foi selecionado devido apresentar melhor acurácia e precisão e apresentar maior facilidade na obtenção dos parâmetros. A inclusão da silagem de Gliricídia na dieta, resultou em elevação no tempo para obtenção da máxima taxa de degradação e no tempo após a incubação em que metade do nível assintótico foi atingido. Recomenda-se a utilização do modelo de Groot para estimativa da curva média. A inclusão da silagem de Gliricídia altera a [...].

Mathematical models to adjust the parameters of in vitro cumulative gas production of diets containing preserved Gliricidia / Modelos matemáticos para ajuste dos parâmetros de produção cumulativa de gás in vitro de dietas contendo Gliricídia conservada

This study examined the use of the Gompertz, Groot, monomolecular, Richards and two-compartment-logistic mathematical models to investigate the kinetics of in vitro gas production of diets composed of combinations of Gliricidia hay or silage. In addition, the effects of Gliricidia hay or silage inclusion on the in vitro cumulative gas production of these diets were evaluated. Rumen fermentation kinetics were analyzed by the in vitro cumulative gas production methodology. The model parameters were estimated using the Gauss Newton method, with the exception of the Richards model, which was used by Marquardts algorithm. Model fit was assessed using the determination coefficient, F test for parameters identity, concordance correlation coefficient, root mean square error of prediction, and decomposition of mean square error of prediction into mean error, systematic bias and random error. The models were compared for accuracy (pairwise mean square error of prediction) and precision (delta Akaikes information criterion). All model evaluation and comparison statistics were calculated using Model Evaluation System software version 3.2.2. The Groot and Richards models did not differ from each other (P>0.05) and were the most precise and accurate (P<0.05). Therefore, the Groot model was selected due to its better accuracy and precision and easier access to the parameters. The inclusion of Gliricidia silage in the diet resulted in an increase in the time to obtain the maximum rate of degradation and in the time after incubation when half of the asymptotic level was reached. The Groot model is recommended to estimate the average curve. Dietary inclusion of Gliricidia silage alters the gas production curve due to the longer time required for the diet to reach the maximum rate of degradation, this can increase the time the diet remains in rumen and promote a reduction in the consumption.(AU)

Objetivou-se avaliar os modelos matemáticos Gompertz, Groot, monomolecular, Richards e logístico bicompartimental para estudar a cinética de produção de gás in vitro de dietas compostas de combinações de feno ou silagem de Gliricídia. Além disso, avaliou-se os efeitos da inclusão de feno ou silagem de Gliricídia sobre a produção cumulativa de gás in vitro destas dietas. A cinética de fermentação ruminal foi avaliada pela metodologia de produção cumulativa de gás in vitro. Os parâmetros dos modelos foram estimados usando o método de Gauss Newton, com exceção do modelo de Richards, que foi usado algoritmo de Marquardt. O ajuste dos modelos foi avaliado por meio do coeficiente de determinação, teste F para a identidade dos parâmetros, coeficiente de correlação e concordância, raiz quadrada do quadrado médio do erro da predição e a decomposição do quadrado médio do erro da predição em erro médio, vício sistemático e erro aleatório. Os modelos foram comparados quanto à acurácia (quadrado médio da predição pareado) e quanto à sua precisão (critério de informação delta de Akaike). Todas as estatísticas de avaliação e comparação dos modelos foram calculadas usando o software Model Evaluation System versão 3.2.2. Os modelos de Groot e Richards não diferiram entre si (P>0.05) e foram os mais precisos e acurados (P<0.05). Portanto, modelo de Groot foi selecionado devido apresentar melhor acurácia e precisão e apresentar maior facilidade na obtenção dos parâmetros. A inclusão da silagem de Gliricídia na dieta, resultou em elevação no tempo para obtenção da máxima taxa de degradação e no tempo após a incubação em que metade do nível assintótico foi atingido. Recomenda-se a utilização do modelo de Groot para estimativa da curva média. A inclusão da silagem de Gliricídia altera a [...].(AU)

Dry matter intake and ruminal fermentation parameters in goats fed sugarcane in replacement of corn silage

ABSTRACT The trial was conducted with the objective to evaluate fresh sugarcane as a replacement for corn silage on dry matter intake, ruminal parameters (pH, short chain fatty acids, and ammonia nitrogen concentration), and degradation kinetics of forages and concentrate in maintenance adult goats. Four nonlactating ruminally cannulated goats were used in a 4 × 4 Latin square design with the replacement of 0, 33, 67, and 100% of corn silage by sugarcane as the independent variable. The substitution of sugarcane for corn silage did not affect dry matter intake, daily weight gain, or ruminal pH. A quadratic effect was observed for ammonia nitrogen concentration with a maximum concentration at 74.43% of sugarcane inclusion, as well as for short chain fatty acids, with maximum concentrations of acetate and butyrate at 0.59 and 32.70% of sugarcane inclusion, respectively. The minimum concentration of propionate was verified on 10.36% of sugarcane inclusion. However, the acetate:propionate ratio linearly decreased with increased sugarcane content. No effect was observed of different rumen environments on forage dry matter and neutral detergent fiber degradability (effective and potential degradability, soluble and potential degradable fractions). Dry matter degradability was 66.79% for sugarcane and 72.62% for corn silage after 96 h of incubation. Neutral detergent fiber was 37.10 and 51.82% for sugarcane and corn silage, respectively, after 96 h of incubation. In conclusion, sugarcane can be used as a replacement for corn silage in maintenance adult goats feed without altering dry matter intake and forage degradability while increasing propionate production.

RESUMO O experimento foi conduzido para avaliar a cana-de-açúcar in natura em substituição à silagem de milho no consumo de matéria seca, parâmetros ruminais e cinética de degradação de forragens e concentrado em cabras adultas em mantença. Quatro cabras não lactantes canuladas no rúmen foram utilizadas em um delineamento em quadrado latino 4 × 4 com a substituição de 0, 33, 67 e 100% da silagem de milho por cana-de-açúcar. A substituição da cana-de-açúcar pela silagem de milho não afetou o consumo de matéria seca, o ganho de peso diário e o pH ruminal. Foi observado efeito quadrático para a concentração de nitrogênio amoniacal com concentração máxima de 74,43% de inclusão da cana, e também para ácidos graxos de cadeia curta, com concentrações máximas de acetato e butirato de 0,59 e 32,70% de inclusão da cana, respectivamente. A concentração mínima de propionato foi verificada em 10,36% de inclusão de cana-de-açúcar. No entanto, a relação acetato: propionato diminuiu linearmente com o aumento do teor de cana-de-açúcar. Não foi observado efeito de diferentes ambientes ruminais sobre a degradabilidade da matéria seca da forragem e da fibra em detergente neutro. A degradabilidade da matéria seca foi de 66,79% para a cana-de-açúcar e 72,62% para a silagem de milho após 96 h de incubação. A fibra em detergente neutro foi 37,10 e 51,82% para cana-de-açúcar e silagem de milho, respectivamente, após 96 h de incubação. Em conclusão, a cana-de-açúcar pode ser usada como substituto da silagem de milho na alimentação de cabras adultas de manutenção, sem alterar o consumo de matéria seca e a degradabilidade da forragem, aumentando a produção de propionato.

Dry matter intake and ruminal fermentation parameters in goats fed sugarcane in replacement of corn silage / Parâmetros de ingestão de matéria seca e fermentação ruminal em cabras alimentadas com cana-de-açúcar em substituição à silagem de milho

The trial was conducted with the objective to evaluate fresh sugarcane as a replacement for corn silage on dry matter intake, ruminal parameters (pH, short chain fatty acids, and ammonia nitrogen concentration), and degradation kinetics of forages and concentrate in maintenance adult goats. Four nonlactating ruminally cannulated goats were used in a 4 × 4 Latin square design with the replacement of 0, 33, 67, and 100% of corn silage by sugarcane as the independent variable. The substitution of sugarcane for corn silage did not affect dry matter intake, daily weight gain, or ruminal pH. A quadratic effect was observed for ammonia nitrogen concentration with a maximum concentration at 74.43% of sugarcane inclusion, as well as for short chain fatty acids, with maximum concentrations of acetate and butyrate at 0.59 and 32.70% of sugarcane inclusion, respectively. The minimum concentration of propionate was verified on 10.36% of sugarcane inclusion. However, the acetate:propionate ratio linearly decreased with increased sugarcane content. No effect was observed of different rumen environments on forage dry matter and neutral detergent fiber degradability (effective and potential degradability, soluble and potential degradable fractions). Dry matter degradability was 66.79% for sugarcane and 72.62% for corn silage after 96 h of incubation. Neutral detergent fiber was 37.10 and 51.82% for sugarcane and corn silage, respectively, after 96 h of incubation. In conclusion, sugarcane can be used as a replacement for corn silage in maintenance adult goats feed without altering dry matter intake and forage degradability while increasing propionate production.(AU)

O experimento foi conduzido para avaliar a cana-de-açúcar in natura em substituição à silagem de milho no consumo de matéria seca, parâmetros ruminais e cinética de degradação de forragens e concentrado em cabras adultas em mantença. Quatro cabras não lactantes canuladas no rúmen foram utilizadas em um delineamento em quadrado latino 4 × 4 com a substituição de 0, 33, 67 e 100% da silagem de milho por cana-de-açúcar. A substituição da cana-de-açúcar pela silagem de milho não afetou o consumo de matéria seca, o ganho de peso diário e o pH ruminal. Foi observado efeito quadrático para a concentração de nitrogênio amoniacal com concentração máxima de 74,43% de inclusão da cana, e também para ácidos graxos de cadeia curta, com concentrações máximas de acetato e butirato de 0,59 e 32,70% de inclusão da cana, respectivamente. A concentração mínima de propionato foi verificada em 10,36% de inclusão de cana-de-açúcar. No entanto, a relação acetato: propionato diminuiu linearmente com o aumento do teor de cana-de-açúcar. Não foi observado efeito de diferentes ambientes ruminais sobre a degradabilidade da matéria seca da forragem e da fibra em detergente neutro. A degradabilidade da matéria seca foi de 66,79% para a cana-de-açúcar e 72,62% para a silagem de milho após 96 h de incubação. A fibra em detergente neutro foi 37,10 e 51,82% para cana-de-açúcar e silagem de milho, respectivamente, após 96 h de incubação. Em conclusão, a cana-de-açúcar pode ser usada como substituto da silagem de milho na alimentação de cabras adultas de manutenção, sem alterar o consumo de matéria seca e a degradabilidade da forragem, aumentando a produção de propionato.(AU)

Dry matter intake and ruminal fermentation parameters in goats fed sugarcane in replacement of corn silage / Parâmetros de ingestão de matéria seca e fermentação ruminal em cabras alimentadas com cana-de-açúcar em substituição à silagem de milho

The trial was conducted with the objective to evaluate fresh sugarcane as a replacement for corn silage on dry matter intake, ruminal parameters (pH, short chain fatty acids, and ammonia nitrogen concentration), and degradation kinetics of forages and concentrate in maintenance adult goats. Four nonlactating ruminally cannulated goats were used in a 4 × 4 Latin square design with the replacement of 0, 33, 67, and 100% of corn silage by sugarcane as the independent variable. The substitution of sugarcane for corn silage did not affect dry matter intake, daily weight gain, or ruminal pH. A quadratic effect was observed for ammonia nitrogen concentration with a maximum concentration at 74.43% of sugarcane inclusion, as well as for short chain fatty acids, with maximum concentrations of acetate and butyrate at 0.59 and 32.70% of sugarcane inclusion, respectively. The minimum concentration of propionate was verified on 10.36% of sugarcane inclusion. However, the acetate:propionate ratio linearly decreased with increased sugarcane content. No effect was observed of different rumen environments on forage dry matter and neutral detergent fiber degradability (effective and potential degradability, soluble and potential degradable fractions). Dry matter degradability was 66.79% for sugarcane and 72.62% for corn silage after 96 h of incubation. Neutral detergent fiber was 37.10 and 51.82% for sugarcane and corn silage, respectively, after 96 h of incubation. In conclusion, sugarcane can be used as a replacement for corn silage in maintenance adult goats feed without altering dry matter intake and forage degradability while increasing propionate production.

O experimento foi conduzido para avaliar a cana-de-açúcar in natura em substituição à silagem de milho no consumo de matéria seca, parâmetros ruminais e cinética de degradação de forragens e concentrado em cabras adultas em mantença. Quatro cabras não lactantes canuladas no rúmen foram utilizadas em um delineamento em quadrado latino 4 × 4 com a substituição de 0, 33, 67 e 100% da silagem de milho por cana-de-açúcar. A substituição da cana-de-açúcar pela silagem de milho não afetou o consumo de matéria seca, o ganho de peso diário e o pH ruminal. Foi observado efeito quadrático para a concentração de nitrogênio amoniacal com concentração máxima de 74,43% de inclusão da cana, e também para ácidos graxos de cadeia curta, com concentrações máximas de acetato e butirato de 0,59 e 32,70% de inclusão da cana, respectivamente. A concentração mínima de propionato foi verificada em 10,36% de inclusão de cana-de-açúcar. No entanto, a relação acetato: propionato diminuiu linearmente com o aumento do teor de cana-de-açúcar. Não foi observado efeito de diferentes ambientes ruminais sobre a degradabilidade da matéria seca da forragem e da fibra em detergente neutro. A degradabilidade da matéria seca foi de 66,79% para a cana-de-açúcar e 72,62% para a silagem de milho após 96 h de incubação. A fibra em detergente neutro foi 37,10 e 51,82% para cana-de-açúcar e silagem de milho, respectivamente, após 96 h de incubação. Em conclusão, a cana-de-açúcar pode ser usada como substituto da silagem de milho na alimentação de cabras adultas de manutenção, sem alterar o consumo de matéria seca e a degradabilidade da forragem, aumentando a produção de propionato.