Intake and apparent nutrient digestibility, ruminal parameters, and nitrogen balance of lambs fed with corn and forage-free diets with sodium bicarbonate / Consumo e digestibilidade aparente dos nutrientes, parâmetros ruminais e balanço de N de cordeiros confinados recebendo dietas com milho e sem forragem com bicarbonato de sódio

This study evaluated forage-free diets supplemented with sodium bicarbonate (SB) based on ground flint corn on intake, apparent nutrient digestibility, ruminal parameters, and N balance. Four rumen-cannulatedDorper × Santa Inês lambs, with a body weight of 43.4 ± 0.85 kg (mean ± standard deviation) were used. The experimental design was a 4×4 Latin square. Each experimental period lasted 21 days. Experimental diets were: positive control, a diet without SB containing 400 g/kg DM of soybean hulls (CONT), and three diets based on ground flint corn, containing 10 (10SB), 20 (20SB) or 30 (30SB) g/kg DM of SB. Intake of neutral and acid detergent fiber was greater for CONT (P < 0.01) when compared to SB. Intake and apparent nutrient digestibility of dry and organic matter, ether extract, and crude protein did not differ. Intake (P = 0.01) and digestibility (P < 0.01) of non-fiber carbohydrates were greater for SB diets and neutral detergent fiber digestibility was greater (P = 0.03) for CONT. The total digestible nutrients and metabolizable energy were greater for SB (P = 0.04). Rumen concentrations of acetate (P < 0.01), isobutyrate (P < 0.01), butyrate (P < 0.01), isovalerate (P < 0.01), and total short-chain fatty acids (P < 0.01) were greater for CONT. Ruminal pH showed a quadratic (P = 0.05) response to SB levels, with greater values for 20SB. Sodium bicarbonate was efficient in increasing ruminal pH at the level of 20 g/kg DM without interfering with the intake and apparent nutrient digestibility characteristics.

O presente estudo avaliou a suplementação de bicarbonato de sódio (BS) em dietas sem forragem à base de milho moído sobre o consumo e a digestibilidade aparente dos nutrientes, os parâmetros ruminais e o balanço de N. Foram utilizados quatro cordeiros Dorper × Santa Inês, com um peso corporal inicial de 43,4 ± 0,85 kg (média ± desvio padrão). O delineamento experimental foi quadrado latino 4×4. Cada período experimental durou 21 dias. As dietas experimentais foram: controle positivo, sem BS, contendo 400 g/kg de MS de casca de soja (CONT) e três dietas à base de milho moído, sem casca de soja, contendo 10 (10BS), 20 (20BS) ou 30 (30BS) g/kg de MS de BS. O consumo de fibra em detergente neutro e ácido foi maior (P < 0,01)para o CONT quando comparado com BS. O consumo e a digestibilidade aparente da matéria seca, matéria orgânica, extrato etéreo e proteína bruta não diferiram entre os tratamentos. O consumo (P = 0,01) e digestibilidade (P < 0,01) dos carboidratos não fibrosos foram superiores para as dietas contendo BS e a digestibilidade da fibra em detergente neutro foi maior para o CONT. Os teores de nutrientes digestivos totais e energia metabolizável foram superiores para as dietas contendo BS (P = 0,04). A concentração ruminal de acetato (P < 0,01), isobutirato (P < 0,01), butirato (P < 0,01), isovalerato (P < 0,01) e ácidos graxos totais de cadeia curta (P < 0,01) foram mais elevadas para o CONT. O pHruminal apresentou resposta quadrática (P = 0,05) em relação aos níveis de BS, sendo observado maior pH para os animais alimentados com a dieta 20BS. O BS foi eficiente em aumentar o pHruminal no teor de 20 g/kg MS sem interferir no consumo e na digestibilidade aparente dos nutrientes. Portanto, 20 g/kg de MS é a dose indicada de BS em dietas sem forragem para terminação de cordeiros em confinamento.

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.

Applying assisted reproductive technology and reproductive management to reduce CO2-equivalent emission in dairy and beef cattle: a review

Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane. In addition to enteric methane (CH4) produced by the rumen, cattle production also contributes carbon dioxide (CO2) (feed), nitrous oxide (N2O) (feed production, manure) and other CH4 (manure) to the total greenhouse gas (GHG) budget of beef and dairy production systems. The relative contribution in standard dairy systems is typically enteric CH4 58%, feed 29% and manure 10%. Herds with low production efficiency can have an enteric CH4 contribution up to 90%. Digestibility of feed can impact CH4 emission intensity. Low fertility herds also have a greater enteric CH4 contribution. Animals with good feed conversion efficiency have a lower emission intensity of CH4/kg of meat or milk. Feed efficient heifers tend to be lean and have delayed puberty. Fertility is a major driver of profit in both beef and dairy cattle, and it is highly important to apply multi-trait selection when shifting herds towards improved efficiency and reduced CH4. Single nucleotide polymorphisms (SNPs) have been identified for feed efficiency in cattle and are used in genomic selection. SNPs can be utilized in artificial insemination and embryo transfer to increase the proportion of cattle that have the attributes of efficiency, fertility and reduced enteric CH4. Prepubertal heifers genomically selected for favourable traits can have oocytes recovered to produce IVF embryos. Reproductive technology is predicted to be increasingly adopted to reduce generation interval and accelerate the rate of genetic gain for efficiency, fertility and low CH4 in cattle. The relatively high contribution of cattle to anthropogenic global methane has focussed attention on strategies to reduce enteric CH4 without compromising efficiency and fertility. Assisted reproductive technology has an important role in achieving the goal of multiplying and distributing cattle that have good efficiency, fertility and low CH4.(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)

Effects of antibiotic growth promoters and concentrate on intake, digestibility, degradability, and ruminal variables in beef steers / [Efeitos de antibióticos promotores de crescimento e do concentrado sobre o consumo, digestibilidade, degradabilidade e variáveis ruminais de novilhos de corte]

The objective of this study was to evaluate the addition of antibiotic growth promoters to concentrate on intake, digestibility, in situ degradability and ruminal variables in steers. Four steers in a Latin square design were fed hay (ad libitum), concentrate [10g kg-1 of body weight (BW)] and mineral mix (0.272g kg-1 of BW). The additives (0.75mg kg-1 of BW) were incorporated in the mineral mix as follows: Control (no antibiotics), lasalocid (LASA), salinomycin (SALI) or virginiamycin (VIRG). Antibiotic did not affect intake, pH, volatile fatty acids (VFA) and digestibility of dry matter (DM), organic matter, crude protein, ethereal extract, and non-fibrous carbohydrates. The LASA and SALI tended (P=0.09) to reduce the digestibility of neutral detergent fiber (NDF). The SALI and VIRG tended (P=0.09) to reduce the DM disappearance, and VIRG tended (P=0.06) to reduce the NDF disappearance in the rumen. The SALI and VIRG reduced the effective degradation and only SALI reduced the concentration of N-NH3 in the rumen. Thus, the antibiotics did not affect intake, pH, VFA and digestibility, but decreased the degradation of fiber and only SALI reduced the concentration of ammonia nitrogen (N-NH3) in the rumen.

O objetivo foi avaliar a adição de antibióticos promotores de crescimento ao concentrado sobre o consumo, digestibilidade, degradabilidade in situ e variáveis ruminais de novilhos. Quatro novilhos em um delineamento quadrado latino foram alimentados com feno (ad libitum), concentrado [10g kg-1 do peso corporal (PC)] e mistura mineral (0,272g kg-1 do PC). Os antibióticos (0,75mg kg-1 do PC) foram incorporados à ração: Controle (sem antibióticos), lasalocida (LASA), salinomicina (SALI) ou virginiamicina (VIRG). Os antibióticos não afetaram o consumo, pH, ácidos graxos voláteis (AGV) e digestibilidade da matéria seca (MS), matéria orgânica, proteína bruta, extrato etéreo e carboidratos não fibrosos. A LASA e a SALI tenderam (P=0,09) a reduzir a digestibilidade da fibra em detergente neutro (FDN). A SALI e a VIRG tenderam (P=0,09) a reduzir o desaparecimento da MS, e a VIRG tendeu (P=0,06) a reduzir o desaparecimento da FDN no rúmen. A SALI e a VIRG reduziram a degradação efetiva e somente a SALI reduziu a concentração de nitrogênio amoniacal (N-NH3) no rúmen. Assim, os antibióticos não afetaram o consumo, pH, AGV e digestibilidade, mas diminuiram a degradação da fibra e somente a SALI reduziu a concentração de N-NH3 no rúmen.

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)

Nutritional and metabolic parameters of ewe lambs fed yeast in the diet containing fibrolytic enzyme / Parâmetros nutricionais e metabólicos de borregas alimentadas com leveduras na ração contendo enzima fibrolítica

This study aimed to evaluate the dry matter digestibility, intake and metabolic profile of ewe lambs fed active or inactive yeasts in the diet containing fibrolytic enzyme. Twenty crossbred animals with an average weight of 33.4kg and an average age of six months were distributed in a completely randomized design. The treatments consisted of yeasts: Control (no yeast), Milk Sacc X® (active yeast), Active Flora®(active yeast + inactive yeast) and Rumen Yeast®(inactive yeast). Analysis of variance and SNK test were applied with a significance level of 5% for type I error. There was no difference for dry matter intake between treatments (P>0.05). There was a significant trend (P=0.0596) for dry matter digestibility, with higher values for the control treatment. There was a significant trend for blood metabolites (P=0.0705), in which the diet containing Milk Sacc® was superior to the other treatments for total protein concentration. In addition, there was a statistical difference (P<0.05) for urea concentration, in which control and Active Flora® treatments were superior to the others. The inclusion of active or inactive yeasts in the diet for ewe lambs containing fibrolytic enzyme reduces dietary digestibility, without affecting the dry matter intake, in addition, it increases urea and total protein levels without causing liver or kidney damage in ewe lambs.

Objetivou-se avaliar a digestibilidade da matéria seca, consumo e perfil metabólico de borregas alimentadas com leveduras vivas e inativadas na ração contendo enzima fibrolítica. Foram utilizados vinte animais mestiços com peso médio de 33,4kg e idade média de seis meses, distribuídas em delineamento inteiramente casualizado. Os tratamentos consistiram nas leveduras: Controle (sem levedura), Milk Sacc X® (levedura ativa), Active Flora®(levedura viva mais levedura inativada) e Rúmen Yeast® (levedura inativa). Foi realizada à análise variância e teste SNK com nível de significância de 5% para o erro tipo I. Não houve diferença entre tratamentos para consumo de matéria seca com uso ou não de levedura na dieta (P>0,05). Houve tendência significativa (P=0,0596) para a digestibilidade da matéria seca sendo superior para com o tratamento sem inclusão de leveduras. Para os metabólitos sanguíneos houve tendência significativa (P=0,0705) sendo o Milk Sacc® superior aos demais tratamentos para concentração de proteínas totais. Além disso, houve diferença estatística (P<0,05) para concentração de ureia cujos tratamentos controle e Active Flora® foram superiores aos demais. A inclusão de leveduras vivas ou inativadas na dieta para borregas contendo enzima fibrolítica diminui a digestibilidade da dieta, sem afetar o consumo de matéria seca, além disso, aumenta teores de ureia e proteínas totais sem causar prejuízos hepáticos ou renais as borregas.

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.

Exogenous enzymes in sheep diet: nutritional and physiological parameters

The objective of this study was to evaluate the effect of adding exogenous enzymes to the diet on nutrient intake and digestibility, nitrogen balance, ingestive behavior and rumen movement of ewe lambs. Five ewe lambs, Dorper x Santa Inês crossbred, with an average age of 7 ± 1 months, average weight of 36.40 ± 2.36 kg were assigned in a 5x5 Latin square design. The treatments consisted of adding exogenous enzymes to the concentrate: Allzyme, Fibrozyme®, Amaize®, Mix and Control. Analyses of variance were applied and means were compared by the SNK test, and non-parametric Kruskal Wallis test at 5% significance. The dry matter intake in relation to body weight, crude protein intake and nitrogen intake were higher with the use of amylolytic enzyme compared to the other treatments (p <0.05). Nitrogen balance was higher with the use of amylolytic enzymes and the Allzyme® enzyme complex (p <0.05). A longer time spent in total chewing was observed with the inclusion of fibrolytic and amylolytic enzymes without changes in rumen movement. The use of exogenous enzymes promotes better use of nutrients, with high digestibility of dry matter, neutral detergent fiber and crude protein.(AU)

Soybean meal from damaged grains replacing standard soybean meal in diets of feedlot lambs

Two studies were carried out to evaluate the effects of levels of soybean meal produced from damaged soybean grains replacing normal soybean meal on in vitro and in situ digestibility of ruminant diets as well as on intake, digestibility, and animal performance of growing/finishing lambs. In trial 1, we evaluated the in vitro digestibility of each soybean meals (normal and damaged), as well as diets containing levels of the damaged replacing the normal (0, 333, 667 and 1,000 g.kg−1) soybean meal on kinetic parameters of in vitro cumulative gas production, in vitro dry matter and crude protein digestibility, in situ rumen-degradable protein, rumen-undegradable protein, and in vitro intestinal digestibility of rumen-undegradable protein. In trial 2, we used 48 growing/finishing lambs to evaluate the effects of damaged soybean meal levels (0, 333, 667, and 1,000 g.kg−1) replacing normal soybean meal in feedlot diets (20:80 roughage:concentrate ratio) on intake and digestibility of nutrients and on animal performance. The damaged soybean meal presented lower values for total gas production and in vitro dry matter digestibility than normal soybean meal. Higher rumen-undegradable protein was estimated for damaged soybean meal than for the normal and consequently lower rumen-degradable protein for damaged compared to normal. Because of the lower rumen-degradable protein, damaged soybean meal promoted lower in vitro ammonium nitrogen (NH3 -N) concentrations than the normal in feedlot diets. In the in vivo trial, there were no effects of damaged soybean meal levels in the diets on intake and digestibility of nutrients (dry matter, organic matter, crude protein, and fiber) as well as on total weight gain, average daily gain, carcass yield, or feeding efficiency. Thus, damaged soybean meal can fully replace the normal one in lamb feedlot diets (in up to of 1,000 g.kg−1 of the normal soybean meal) without causing adverse effects on intake and digestibility of nutrients and on animal performance.

Which non-fibrous carbohydrates: neutral detergent fiber ratio optimizes the use of cactus cladodes in diets of growing heifers? / Qual relação carboidratos não fibrosos: fibra em detergente neutro otimiza o uso de palma forrageira em dietas para novilhas em crescimento?

This study aimed to evaluate the effect of different non-fibrous carbohydrate (NFC):neutral detergent fiber (NDF) ratios (0.70:1, 0.90:1, 1.14:1, 1.42:1, and 1.85:1) in diets containing cactus cladodes on intake, digestibility, ruminal parameters, ingestive behavior, and microbial protein of growing heifers. Five rumencannulated heifers (194 ± 70 kg of body weight) were distributed in a Latin square design (5 x 5). There was a quadratic effect on the intake of dry matter (DM) (Kg day-1 and %BW) and crude protein (CP) with the increase in non-fibrous carbohydrate (NFC): neutral detergent fiber (NDF) ratio, with maximum values of 7.07 kg day-1, 2.86%, and 0.949 kg day-1, estimated for 1.37:1, 1.39:1, and 1.27:1 ratios. When the intake of NDF decreased, in turn, the intakes of NFC and TDN increased. The NDF digestibility decreased with increasing NFC levels in diets. The other nutrients were not influenced. The ruminal pH showed the lowest values at 4 hours after feeding, mainly for animals fed the 1.85:1 ratio. There was a quadratic effect for rumination time with maximum values estimated for an NFC:NDF ratio of 0.88:1. The time spent idle increased linearly, while total chewing time and feeding efficiency of NDF decreased. The urinary volume increased linearly. However, microbial protein synthesis and the efficiency of the synthesis were not influenced. The number of protozoa increased by 64.5% with the elevation of the NFC:NDF ratio. We recommend a NFC:NDF ratio of 1.37:1 in diets containing cactus cladodes, to improve the use of nutrients, without negatively affecting ruminal parameters.(AU)

Este estudo teve como objetivo avaliar o efeito de diferentes relações carboidratos não fibrosos (CNF): fibra em detergente neutro (FDN) (0,70: 1; 0,90: 1; 1,14: 1; 1,42: 1 e 1,85: 1) em dietas contendo palma forrageira sobre o consumo, digestibilidade, parâmetros ruminais, comportamento ingestivo e proteína microbiana de novilhas em crescimento. Cinco novilhas, fistuladas no rúmen (194 ± 70 kg de peso corporal) foram distribuídas em um delineamento em quadrado latino (5 x 5). Houve efeito quadrático sobre o consumo de matéria seca (MS) (kg dia-1 (% PC) e proteína bruta (PB) com o aumento da relação carboidratos não fibrosos (CNF): fibra em detergente neutro (FDN), com valores máximos de 7,07 kg dia-1, 2,86% e 0,949 kg dia-1, estimado para 1,37: 1; 1,39: 1 e proporção de 1,27: 1. Enquanto a ingestão de FDN diminuiu, a ingestão de CNF e NDT aumentou. A digestibilidade da FDN diminuiu com o aumento dos teores de FDN nas dietas. Os demais nutrientes não foram influenciados. O pH ruminal apresentou os menores valores 4 horas após a alimentação, principalmente para os animais alimentados na proporção de 1,85: 1. Houve efeito quadrático para o tempo de ruminação com valores máximos estimados para uma relação CNF: FDN de 0,88: 1. O tempo de ócio aumentou linearmente, enquanto o tempo total de mastigação e a eficiência alimentar da FDN diminuíram. O volume urinário aumentou linearmente. No entanto, a síntese de proteína microbiana e a eficiência da síntese não foram influenciadas. O número de protozoários aumentou 64,5% com a elevação da relação CNF: FDN. Recomenda-se a relação CNF:FDN de 1,37: 1 em dietas contendo palma forrageira, para melhorar o aproveitamento dos nutrientes, sem afetar negativamente os parâmetros ruminais.(AU)

Effect of ensiling time on apparent total tract starch digestibility in Southern Brazilian dairy herds

Ensiling corn for longer periods is a strategy used to increase rumen bacteria access to starch. In fact, when corn is ensiled for insufficient periods, starch digestibility decreases, as evidenced by excreted starch. This study investigates the effects of corn silage ensiling time on starch digestibility of dairy cows through fecal starch analysis. The trial was conducted during the spring of 2013 and the fall of 2014 on twenty dairy herds located in the state of Paraná, southern Brazil. Total mixed ration (TMR), whole-plant corn silage (WPCS) and fecal samples were collected for determination of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin and starch. Apparent total tract starch digestibility (ATTSD) was calculated using equations developed by Fredin et al. (2014) and Bal et al. (1997). Data were analyzed using the CORR, REG and GLM procedures of SAS. Spring and fall WPCS were ensiled for 260 and 132 days, respectively (p 0.05) in ATTSD-Fredin from season to season though there was a trend (p = 0.11) towards greater ATTSD-Bal for spring samples. ATTSD-Bal was positively correlated with ensiling days (r = 0.31). Starch digestibility was not negatively affected by WPCS harvesting maturity. Differences in post-ruminal starch digestion, variation between farms in DM intake and diets, limitations of the equations, influence of uncontrolled factors, and the small number of experimental units might have contributed to the absence of significant results. Overall, Bal et al. (1997) equation was more efficient in distinguishing ATTSD from different ensiling periods.

Effect of ensiling time on apparent total tract starch digestibility in Southern Brazilian dairy herds

Ensiling corn for longer periods is a strategy used to increase rumen bacteria access to starch. In fact, when corn is ensiled for insufficient periods, starch digestibility decreases, as evidenced by excreted starch. This study investigates the effects of corn silage ensiling time on starch digestibility of dairy cows through fecal starch analysis. The trial was conducted during the spring of 2013 and the fall of 2014 on twenty dairy herds located in the state of Paraná, southern Brazil. Total mixed ration (TMR), whole-plant corn silage (WPCS) and fecal samples were collected for determination of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin and starch. Apparent total tract starch digestibility (ATTSD) was calculated using equations developed by Fredin et al. (2014) and Bal et al. (1997). Data were analyzed using the CORR, REG and GLM procedures of SAS. Spring and fall WPCS were ensiled for 260 and 132 days, respectively (p < 0.01). There was no difference (p > 0.05) in ATTSD-Fredin from season to season though there was a trend (p = 0.11) towards greater ATTSD-Bal for spring samples. ATTSD-Bal was positively correlated with ensiling days (r = 0.31). Starch digestibility was not negatively affected by WPCS harvesting maturity. Differences in post-ruminal starch digestion, variation between farms in DM intake and diets, limitations of the equations, influence of uncontrolled factors, and the small number of experimental units might have contributed to the absence of significant results. Overall, Bal et al. (1997) equation was more efficient in distinguishing ATTSD from different ensiling periods.(AU)

Effect of replacing alfalfa hay with Leucaena leucocephala (L. Leucocephala) leaves on in vitro gas production, digestibility and in situ degradability in buffalo

This study was performed to investigate the effect of replacing alfalfa hay by L. leucocephala leaves in proportions of 25, 50 and 100% on in vitro gas production (GP) parameter, digestibility and in situ degradability in buffalo. Results showed that the volume of GP at 2 to 12 hours after incubation was significantly affected by replacing alfalfa hay with L. leucocephala leaves. In vitro digestibility of organic matter (OMD) differed significantly between treatment as it declined by increasing the alfalfa hay substitution rate from 25 to 100%. The microbial crude protein (MCP) differed significantly between treatments and was the greatest of 589 and 599 mg g-1 of dry matter (DM) when L. leucocephala leaves replaced alfalfa hay at 25 and 50%. The in vitro digestibility of DM (IVDMD) increased significantly at 50% L. leucocephala replacement rate. Moreover, substituting alfalfa hay by L. leucocephala had a significant effect on the in situ degradability parameters. The insoluble but potentially degradable fraction (B) and potential of degradability (A+B) significantly increased for treatment contain 50% L. leucocephala leaves. The effective degradability (ED) was significantly different between dietary treatments and was the greatest when alfalfa hay was replaced by 25 and 50% L. leucocephala. In conclusion, L. leucocephala leaves can substitute 25 to 50% of dietary alfalfa hay in buffalo rations without effect on rumen efficiency.(AU)

Effect of replacing alfalfa hay with Leucaena leucocephala (L. Leucocephala) leaves on in vitro gas production, digestibility and in situ degradability in buffalo

This study was performed to investigate the effect of replacing alfalfa hay by L. leucocephala leaves in proportions of 25, 50 and 100% on in vitro gas production (GP) parameter, digestibility and in situ degradability in buffalo. Results showed that the volume of GP at 2 to 12 hours after incubation was significantly affected by replacing alfalfa hay with L. leucocephala leaves. In vitro digestibility of organic matter (OMD) differed significantly between treatment as it declined by increasing the alfalfa hay substitution rate from 25 to 100%. The microbial crude protein (MCP) differed significantly between treatments and was the greatest of 589 and 599 mg g-1 of dry matter (DM) when L. leucocephala leaves replaced alfalfa hay at 25 and 50%. The in vitro digestibility of DM (IVDMD) increased significantly at 50% L. leucocephala replacement rate. Moreover, substituting alfalfa hay by L. leucocephala had a significant effect on the in situ degradability parameters. The insoluble but potentially degradable fraction (B) and potential of degradability (A+B) significantly increased for treatment contain 50% L. leucocephala leaves. The effective degradability (ED) was significantly different between dietary treatments and was the greatest when alfalfa hay was replaced by 25 and 50% L. leucocephala. In conclusion, L. leucocephala leaves can substitute 25 to 50% of dietary alfalfa hay in buffalo rations without effect on rumen efficiency.

Narasin inclusion for feedlot lambs fed a diet containing high amounts of ground flint corn

Narasin is an antibacterial agent that may change rumen fermentation. Two experiments were proposed to evaluate the efficiency of narasin inclusion for lambs fed a diet containing high amounts of ground flint corn. Thirty rumen-cannulated wethers were used to evaluate nutrient digestibility, nitrogen balance, and rumen metabolism (Exp. 1); and forty-five lambs were used to evaluate performance (Exp. 2) of animals fed with narasin for high flint corn diets. The experimental diets were: control or basal diet without additives (C); 25 mg of monensin kg-¹ of dry matter (DM) (M); and inclusion of 5 (N5), 10 (N10), and 15 (N15) mg of narasin kg-¹ of DM. The statistical analyses were performed using the MIXED procedure of SAS. Monensin increased DM digestibility compared to C (p = 0.01) and increasing doses of narasin linearly increased DM digestibility (p < 0.01). There was a quadratic effect (p = 0.10) for molar proportion of acetate peaking at N15. Monensin inclusion increased (p = 0.07) propionate compared to C; however, it did not differ from narasin. The increasing levels of narasin linearly decreased the total volatile fatty acids concentration in the rumen (p = 0.02). Monensin and C showed a similar performance. The increasing levels of narasin linearly increased (p <= 0.04) average daily gain and feed efficiency. Monensin and narasin changed rumen fermentation and improved overall nutrient digestibility. However, lambs that received narasin showed improved performance when compared with animals that received M.

Narasin inclusion for feedlot lambs fed a diet containing high amounts of ground flint corn

Narasin is an antibacterial agent that may change rumen fermentation. Two experiments were proposed to evaluate the efficiency of narasin inclusion for lambs fed a diet containing high amounts of ground flint corn. Thirty rumen-cannulated wethers were used to evaluate nutrient digestibility, nitrogen balance, and rumen metabolism (Exp. 1); and forty-five lambs were used to evaluate performance (Exp. 2) of animals fed with narasin for high flint corn diets. The experimental diets were: control or basal diet without additives (C); 25 mg of monensin kg-¹ of dry matter (DM) (M); and inclusion of 5 (N5), 10 (N10), and 15 (N15) mg of narasin kg-¹ of DM. The statistical analyses were performed using the MIXED procedure of SAS. Monensin increased DM digestibility compared to C (p = 0.01) and increasing doses of narasin linearly increased DM digestibility (p < 0.01). There was a quadratic effect (p = 0.10) for molar proportion of acetate peaking at N15. Monensin inclusion increased (p = 0.07) propionate compared to C; however, it did not differ from narasin. The increasing levels of narasin linearly decreased the total volatile fatty acids concentration in the rumen (p = 0.02). Monensin and C showed a similar performance. The increasing levels of narasin linearly increased (p <= 0.04) average daily gain and feed efficiency. Monensin and narasin changed rumen fermentation and improved overall nutrient digestibility. However, lambs that received narasin showed improved performance when compared with animals that received M.(AU)

Use of active and inactive yeasts in lamb diets: intake, digestibility, and metabolism / Uso de leveduras ativas e inativas na dieta de cordeiros: consumo, digestibilidade e metabolismo

This study aims to evaluate the use of active, inactive plus active, and inactive yeasts on the consumption of dry matter, water, and the apparent digestibility of dry matter, urinary parameters, and serum metabolites of lambs. Twenty crossbred lambs (Dorper x Santa Inês) were used, with an initial average body weight of 31.89 kg and seven months of age, distributed in a completely randomized design. Treatments were Control group (without yeasts); Active Flora® (ICC), live yeast plus inactivated yeast (Saccharomyces cerevisiae, 2.0 x 1010 UFC g-1) in the dose of 0.003 kg of animal dry matter -1 day-1,; Milk Sacc X® (Alltech®), active yeast - Saccharomyces cerevisiae strain 1026, 5.0 x 108 UFC g-1 - at the dose of 0.0015 kg of animal dry matter-1 day-1; and Rumen Yeast® (York Ag Products INC.), inactive yeast - Saccharomyces cerevisiae,1.5 x 104 UFC g-1 - in the dose of 0.0045 kg of animal dry matter-1 day-1. Variance analysis and the SNK (Student-Newman-Keuls) test were performed considering 5% significance. For glycemic concentrations over time, regression analysis at 5% significance were performed. The fecal score, as a non-parametric variable, was assessed by the Kruskal and Wallis test at a 5% significance level. There was a statistical difference (P 0.05). The average dry matter intake was 1.16 ± 0.16 kg day-1, whereas the dry matter digestibility was 85.40 ± 2.73%. It was concluded that active and/or inactive yeasts can be used as additives in the diet of lambs, maintaining the intake and digestibility of dry matter without causing metabolic disturbances.

Objetivou-se avaliar o efeito de leveduras ativas, inativas mais ativas e inativas sobre o consumo e digestibilidade aparente da matéria seca, de água, dos parâmetros urinários e dos metabólitos séricos de borregas. Utilizou-se 20 borregas mestiças Dorper x Santa Inês, com peso corporal médio inicial de 31,89 kg e sete meses de idade, distribuídas em delineamento inteiramente casualizado. Os tratamentos consistiram em Controle, sem uso de enzimas, e no uso das leveduras Active Flora® (levedura viva junto a levedura inativada - Saccharomyces Cerevisiae, com 2,0 x 1010 UFC g-1), Milk Sacc X® (levedura ativa - Saccharomyces C. 1026, 5,0 x 108 UFC g-1) e Rúmen Yeast® (levedura inativa - Saccharomyces C. com 1,5 x 104 UFC g-1). Foi realizado uma análise de variância e um teste SNK considerando 5% de significância. Para as concentrações glicêmicas ao longo do tempo foi realizada uma análise de regressão a 5% de significância. O escore fecal, por ser uma variável não paramétrica, foi avaliado pelo teste Kruskal e Wallis à significância de 5%. Observou-se a diferença estatística (P 0,05). A média de consumo da matéria seca foi de 1,16±0,16 kg dia-1, já a digestibilidade da matéria seca foi de 85,40 ±2,73%. Concluiu-se que as leveduras ativas e/ou inativas podem ser utilizadas como aditivos na dieta de borregas, mantendo o consumo e a digestibilidade da matéria seca sem causar distúrbios metabólicos.

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.