RESUMO 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.

ABSTRACT 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 kg-1 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.

RESUMO O objetivo foi avaliar as silagens de ração total com cana de açúcar e aditivos inoculante microbiano e quitosana. Foram utilizados trinta mini-silos utilizando o delineamento inteiramente casualizado, com três tratamentos e dez repetições. As silagens foram compostas por cana-de-açúcar misturada com farelo de milho, soja integral, uréia e misturas minerais na proporção de 50:50. Os tratamentos foram: silagem controle, aditivo microbiano (Lactobacillus plantarum + Pediococcus acidilactici, 4 g/t de KeraSil, Kera Nutrição Animal) e quitosana (10 g/kg da matéria natural). As silagens foram avaliadas quanto à fermentação e perfil microbiológico, perdas de fermentação, estabilidade aeróbica, composição químico-bromatológica, consumo e digestibilidade. O perfil de fermentação não mostrou diferença significativa entre tratamentos para os valores de pH, com um valor médio de 4,79. A produção de ácidos acéticos e propiônicos não mostrou diferença entre os tratamentos, com valores médios de 7,34 e 0,053 mmol/kg DM, respectivamente. A matéria seca, a matéria orgânica e a ingestão de proteína bruta da mistura total de ração silagem diferiram estatisticamente dos outros tratamentos (P<0,05), mas a ingestão de cana-de-açúcar fresca e de silagem de cana-de-açúcar não diferiram uma da outra (P>0,05). Os valores de digestibilidade de DM, OM e NDF foram maiores na silagem de ração mista total (P<0,05), enquanto a silagem de cana de açúcar e a cana de açúcar fresca não mostraram diferença entre si (P>0,05). A silagem de ração mista total aumentou a ingestão de nutrientes e a digestibilidade, com um melhor padrão de fermentação quando adicionado o inoculante microbiano.

ABSTRACT This study aimed to evaluate total mixed ration silages with sugarcane and the additives microbial inoculant and chitosan. Thirty mini-silos were used in a completely randomized design, with three treatments and ten replications. Silages were composed of sugarcane mixed with corn bran, whole soybean, urea, and mineral mixtures at a 50:50 roughage to concentrate ratio. Treatments consisted of control silage, microbial additive (Lactobacillus plantarum + Pediococcus acidilactici, 4 g/t of KeraSil, Kera Nutrição Animal), and chitosan (10 g/kg of natural matter). Silages were evaluated for fermentation and microbiological profile, fermentation losses, aerobic stability, chemical-bromatological composition, intake, and digestibility. Fermentation profile showed no significant difference between treatments for pH values, with a mean value of 4.79. Production of acetic and propionic acids showed no difference between treatments, with mean values of 7.34 and 0.053 mmol/kg DM, respectively. Dry matter, organic matter, and crude protein intake of the total mixed ration silage differed statistically from the other treatments (P<0.05), but fresh sugarcane and sugarcane silage intake did not differ from each other (P>0.05). Digestibility values of DM, OM, and NDF were higher in the total mixed ration silage (P<0.05), while sugarcane silage and fresh sugarcane showed no difference from each other (P>0.05). Total mixed ration silage increased nutrient intake and digestibility, with a better fermentation pattern when added with the microbial inoculant.

ABSTRACT This study was undertaken to determine the effects of chitosan and whole raw soybean on nutrient intake and total tract digestion, nitrogen utilization, microbial protein synthesis, blood metabolites, and energy balance of dairy heifers. Twelve Jersey heifers (6±0.5 months of age and 139.50±25.56 kg of live weight; mean ± standard deviation) were randomly assigned to a replicated Latin square design with a 2 × 2 factorial arrangement. The experimental period consisted of 14 days of adaptation to diets, six days of sampling, and five days of washout. The experimental diets were: control (CO); chitosan (CHI, inclusion of 2.0 g kg−1 DM of chitosan); whole raw soybean (WS, 163.0 g kg−1 of WS on diet DM basis); and chitosan + whole raw soybean (CHI+WS). Chitosan decreased dry matter and neutral detergent fiber intakes; however, CHI increased DM total tract digestion. An interaction effect was observed on retained nitrogen, which increased when animals were fed CHI+WS compared with CO or CHI, but did not differ from that of animals fed WS. Chitosan decreased microbial nitrogen and crude protein flow of heifers. Energy balance was improved when heifers received diets containing WS. Efficiency of energy utilization was not affected by experimental diets. An interaction effect was observed for blood high-density lipoprotein (HDL) concentration, which increased with both dietary inclusion of CHI and WS compared with the other diets, and CHI provided the lowest value of HDL cholesterol. Chitosan and whole raw soybean do not alter nutrient intake and total tract digestion; however, they decrease nitrogen urinary excretion and increase blood HDL cholesterol of heifers.

ABSTRACT The objective of this study was to evaluate the effects of polymer coated slow-release urea (SRU) in high-forage diets of beef steers on nutrient intake and digestibility, ruminal fermentation, microbial protein synthesis, and energy balance. Eight 24-mo-old rumen-fistulated castrated Nellore steers (average body weight = 418.0±40.0 kg) were used in a replicated 4 × 4 Latin square design. Animals were randomly distributed to receive one of the following diets: no urea inclusion; 1.0% inclusion of feed grade urea in the diet (dry matter [DM] basis); 1.0% inclusion of slow-release urea 1 in the diet (DM basis); and 1.0% inclusion of slow-release urea 2 in the diet (DM basis). Slow-release urea 2 had a similar composition to that of slow-release urea 1 and differed in that it contained 2.95% sulfur. A high-forage diet was provided (75% of total DM) and corn silage was used as the forage source. Diets with urea had increased crude protein (CP) intake, and CP and total digestible nutrients total tract digestion. Urea sources increased ruminal concentrations of ammonia nitrogen and acetate, and decreased butyrate concentrations. The polymer coated urea did not alter ruminal fermentation when compared with feed grade urea. Diets did not affect the energy balance of steers. Feed grade urea presented greater microbial protein synthesis than polymer coated slow-release urea. The partial replacement of soybean meal by 1% slow-release urea in a diet with 75% forage does not improve ruminal fermentation and microbial protein synthesis, and shows similar results as feeding feed grade urea to beef steers.

ABSTRACTThe objective of this experiment was to quantify the effects of feeding polymer-coated slow-release urea on nutrient intake and total tract digestion, milk yield and composition, nutrient balances, ruminal fermentation, microbial protein synthesis, and blood parameters in dairy cows. Sixteen Holstein cows (580±20 kg of live weight (mean ± standard deviation); 90 to 180 days in milk (DIM); and 28 kg/d of average milk yield) were used in a replicated 4 × 4 Latin square experimental design. The animals were assigned to each square according to milk yield and DIM. The animals were randomly allocated to receive one of the following experimental diets: 1) control (without urea addition); urea (addition of 1% on the diet DM basis); polymer-coated slow release urea 1 (addition of 1% on the diet DM basis); and polymer-coated slow release urea 2 (addition of 1% on the diet DM basis). All diets contained corn silage as forage source and a 50:50 forage:concentrate ratio. Milk and protein yield, production of volatile fatty acids, and propionate decreased when cows were fed diets containing urea. Addition of urea decreased nitrogen efficiency and nitrogen excreted in the feces. However, the diets did not change the cows' microbial protein synthesis, ruminal pH, or ammonia concentration. The inclusion of urea in cow diets decreases milk and protein yield due to lower production of volatile fatty acids. No advantages are observed with supplementation of polymer-coated slow-release urea when compared with feed-grade urea.