Indigestible Neutral Detergent Fiber Research Articles

Evaluation of internal markers in digestibility estimation for sheep and goats.

The objective of this study was to compare the indirect methods of obtaining digestibility with the direct method of total fecal collection to estimate the apparent digestibility of nutrients in sheep and goats supplemented with non-protein nitrogen. Five goats and five sheep with no defined racial pattern were used, distributed in two 5 × 5 Latin squares, with split plots, considering the diets as plots and the apparent digestibility determination methodologies as subplots. The diets were composed of buffelgrass hay and the addition, via ruminal infusion, of increasing amounts of nitrogen supplementation in order to gradually raise the CP level of the basal diet in intervals of 2% points, that is, + 2, +4, + 6 and + 8%. Samples of the feeds offered, and the leftovers were collected daily during the five days of collection to determine the nutrient intake, as well as the total collection of feces to determine the apparent digestibility of the nutrients. The amount of fecal dry matter excreted was estimated by the concentration of Indigestible Acid Detergent Fiber (ADFi), Indigestible Neutral Detergent Fiber (NDFi), Indigestible Dry Matter at 244h (DMi 244h) and Indigestible Dry Matter at 264h (DMi 264h). Among the evaluated markers, DMi 264h had the lowest accuracy in estimating fecal excretion and nutrient digestibility. For the goat species, the markers ADFi and DMi 244h proved to be able to adequately predict fecal excretion and digestibility indices, while NDFi stood out for both species. Among the evaluated markers, NDFi is the one that most accurately estimates the nutrient digestibility of the diet for goats and sheep.

Optimization of indigestible neutral and acid detergent fiber measurement protocols*

Optimization of indigestible neutral and acid detergent fiber measurement protocols*

Chemical composition of marandu palisade grass fertilized with nitrogen and potassium

The goal was to evaluate the chemical composition of Urochloa brizantha cv. Marandu through the use of fertilization with nitrogen and potassium. The experiment was carried out at the Experimental Farm of UFMT, Cuiabá Campus, from December to April 2017/2018 and 2018/2019 - rainy season; and from May to September in 2018 and 2019 – dry season. Treatments corresponded to a 5x2 factorial scheme, with five nitrogen doses (0; 25; 50; 75; 100 kg ha-¹) and two potassium doses (0; 25 kg ha-1). The sample was unified as one for each individual period.The chemical characteristics evaluated were crude protein (CP), mineral matter (MM), neutral detergent fiber (NDF), acid detergent fiber (ADF), indigestible neutral detergent fiber (iNDF),total digestible nutrients (TDN) and net energy of lactation (NEF). For CP, a positive linear effect was observed for nitrogen fertilization, with 15.87% and 11.68% for the highest dose inthe rainy and dry seasons, respectively. Likewise, a linear increase in TDN and in NEL was observed. For NDF, ADF and iNDF content there was a linear reduction in both rainy and dryseasons. For potassium fertilization, there is little influence on the chemical characteristics, in fact, only in the rainy season for fiber, TDN and NEL contents. However, nitrogen fertilizationpromoted an increase of 51.13% in the CP content at the highest applied dose. The NDE, ADF and iNDF content decrease linearly with nitrogen input, on the contrary, there was an increase in TDN and NEL.

Nutritive value of fermented soybean grains for ruminants.

Fermented soybean grain (FSBG) is considered improper to use as a protein source in animal nutrition, since it is assumed that defects cause changes on its chemical composition and favor mycotoxins production, but chemical composition data does not support this theory and in vivo studies are missing. Thus, this study aimed to evaluate the effects of FSBG in feedlot lamb diets. For that, two types of FSBG (partially fermented and completely fermented, PFSBG and CFSBG) and one standard soybean grain (SSBG) were obtained and evaluated alone or as a component of experimental diets by in vitro and in vivo studies, where FSBG totally replaced SSBG in feedlot lamb diets, which was included in the experimental diets in 17.4% on dry matter basis as protein source. Before the studies, both soybeans were sent to a specialized laboratory where no mycotoxins were detected. As a result, lower DM and carbohydrate contents but higher crude protein, fiber, and indigestible NDF contents were measured in CFSBG than in SSBG. Furthermore, both types of FSBG showed lower digestibility in vitro dry matter (IVDMD) than SSBG when evaluated separately; however, when evaluated in experimental diets, the substitution of SSBG for FSBG did not affect IVDMD. It was also observed that FSBG also had less rumen-degradable protein than SSBG (mean 47.9 vs 86.4%). In the in vivo study, FSBG did not affect nutrient intake, apparent digestibility, or animal performance (i.e., average daily gain and carcass gain). Thus, mycotoxins-free FSBG may be an alternative to totally replace SSBG in feedlot lamb diets.

PSIV-7 Optimization of Indigestible Neutral and Acid Detergent Fiber Measurement Protocols

Abstract Dry matter digestibility (DMD) is a factor that impacts nutrient use efficiency and growth performance of beef cattle. Indigestible neutral (INDF) and acid detergent fiber (IADF) are internal markers commonly used to estimate DMD. The objective of this experiment was to optimize existing protocols for determination of INDF and IADF in feedlot rations and feces. This experiment implemented a 2×2×4 factorial arrangement with a starter or finisher diet, with or without a pepsin and HCl pre-digestion of the diets, and with four ruminal incubation lengths (72, 96, 120, or 288 h). The samples used in this experiment were from diets fed and total fecal collections obtained from 6 steers consuming the starter or finisher diet. Fecal and diet marker concentrations were analyzed using a mixed model ANOVA with ruminally canulated steer (n = 2) as a random effect and diet, pre-digestion, marker, time, and possible interactions as fixed effects. A two-sided t-test was used to test if marker fecal recoveries differed from 100%. When diets were pre-digested, a plateau in dietary marker concentration was achieved, where concentrations of both markers were not different (P ≥ 0.10) when incubated for 120 h compared with 288 h. When diets were not predigested, the dietary content of both markers continued to decrease with increasing ruminal incubation length so that marker content of 120-h incubations were significantly greater (P < 0.01) than 288-h incubations, except for IADF content of the finisher diet where the 120 and 288 h were not different (P = 0.77). The dietary content of INDF and IADF for samples that were not pre-digested and incubated for 288 h were not different (P ≥ 0.64) from the samples that were pre-digested and incubated for 120-h. For the INDF marker across both diets, fecal concentrations were lowest (P ≤ 0.01) when ruminally incubated for 288 h compared with all other ruminal incubation durations. The fecal concentrations of IADF were less (P < 0.01) when incubated for 288 h compared with those incubated for 120 h for the starter diet, but only tended (P = 0.07) to be less at those same time points for the finisher diet. When pre-digestion was conducted, only 120-h ruminal incubations had fecal recoveries that were not different (P ≥ 0.26) from 100% for all markers and diet types. If a pre-digestion was not conducted, then only the 288 h length provided fecal recoveries that were not different (P ≥ 0.12) from 100% for all diets and markers. Based on these results, using a pepsin and HCl pre-digestion followed by a 120-h ruminal incubation shortens time requirements and provides acceptable measurements of INDF and IADF concentrations in feeds and feces. If pre-digestion of diet samples is not possible then a 288-h ruminal incubation length is required.

Nutritional uniformity of cell wall and lignin fractions in grass and red clover silage evaluated by the Lucas test with application to forage feed evaluation

The objective of this study was to investigate relationships between different cell wall (CW) fractions and in vivo digestibility of grass and red clover silages. The material consisted of 28 silages (6 primary growth grass, 16 regrowth grass and 6 red clover). Different fibre fractions predicted organic matter (OM) and neutral detergent fibre (aNDFom) digestibility reasonably well among the three forage types, but uniformly the digestibility predictions were not accurate enough for estimating the feeding value. Isolation of total CW did not improve digestibility predictions compared with aNDFom. The fraction insoluble in CW isolation, but soluble in aNDFom extraction was a uniform feed fraction with almost complete true digestibility. Isolation of CW fraction from faecal samples was not able to solubilize endogenous and metabolic components. True crude protein (CP) digestibility was higher than 0.90 when estimated by the Lucas test and by assuming that only N bound to neutral detergent fibre in faeces was of feed origin. Acid detergent lignin was more closely related to digestibility than lignin isolated from neutraldtergent fibre or CW (but all were inferior compared to indigestible NDF (iNDF) determined by 12-d ruminal in situ incubation. Lignin to iNDF ratio varied both within and between forage types. For evaluating nutritive value of forages actual measurements of iNDF (or undigested NDF) is recommended over detailed analysis of fibre and lignin fractions. Despite some CW fractions are solubilized in ND extractions, analysis of total CW is not a useful tool in ruminant nutrition research.

PSVI-3 Effects of Different Concentrate Inclusion Levels in Diets Containing Agri002E Sorghum Silage on Intake and Digestibility in Growing Nellore Bulls

Abstract The sorghum hybrid, AGRI002E, sorghum was developed for high dry matter (DM) production per area. However, there are no reports in the literature evaluating the use of this silage with different inclusion levels of concentration on the ingestive and digestive variables of beef cattle. Therefore, this study aimed to access the effects of different concentrate levels in diets containing AGRI002E sorghum silage (SS) on feed intake, ruminal and apparent total tract digestibilities of organic matter (OM), neutral detergent fiber corrected for contaminant ash and protein (apNDF), and starch. Nellore rumen-cannulated bulls (n = 5; BW = 242 ± 5 kg) were used in a 5×5 Latin square design. The experimental treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg of diet DM) in SS-based diets. The concentrates used in the experimental diets were based on corn, soybean meal, sulfated urea, virginiamycin, and mineral supplement. The diets were formulated to provide approximately 120 g of crude protein per kg dietary DM. In the 0% concentrate diet, the protein level was adjusted with sulfated urea. All diets contained the same amount of virginiamycin and mineral supplement. Each experimental period lasted 24 d, with 17 d adaptation, 4 d of total feces collection, and 3 d collection to obtain omasal flow using a double marker technique (indigestible NDF and Co-EDTA). Data were analyzed using MIXED-SAS. Starch and OM intake linearly increased (P < 0.001) with increasing concentrate inclusion. Intake of apNDF decreased linearly (P = 0.018) and tended to be quadratically influenced (P = 0.022) with increasing concentrate inclusion (Table 1). Ruminal digestibility of OM increased linearly (P < 0.001) with increasing concentrate inclusion. Starch ruminal digestibility decreased linearly (P = 0.003) and tended to be influenced quadratically (P = 0.0015) with increasing concentrate inclusion. Ruminal digestibility of apNDF tended to decrease linearly (P = 0.057) with increasing concentrate inclusion. Total apparent digestibility of OM increased linearly (P < 0.001) and apNDF and starch total apparent digestibility decreased linearly (P ≤ 0.002) with increasing concentrate inclusion. Increasing inclusion of concentrate in AGRI002E sorghum silage-based diets increased OM and starch intake, and ruminal and total apparent OM digestibility and decreased apNDF intake and ruminal and apNDF and starch total apparent digestibility.

Metabolic responses and performance of Holstein × Gyr heifers grazing Brachiaria decumbens supplemented with varied crude protein levels.

We aimed to evaluate the effect of supplemental CP on the nutritional characteristics and performance of Holstein × Gyr crossbreed heifers grazing intensively-managed Brachiaria decumbens throughout the year. Thirty-eight heifers with average initial body weight of 172.5 ± 11.15 kg (mean ± SE) and 8.2 ± 0.54 mo of age were randomly assigned to four treatments: three protein supplements (SUP) composed of soybean meal and ground corn fed at 5g/kg of BW, plus a control group (CON). The supplements had 12, 24 and 36% of CP for treatments S12 (n = 9), S24 (n = 10), and S36 (n = 9), respectively. The experiment latest one year, subdivided into four seasons: rainy, dry, rainy-dry transition (RDT), and dry-rainy transition (DRT). Feces and pasture samples were collected for 4 days in each season, using chromium oxide, titanium dioxide, and indigestible neutral detergent fiber (NDF) to estimate fecal excretion, supplement, and pasture intake, respectively. The data were analyzed using PROC GLIMMIXED of the SAS with repeated measures. No effects of supplementation were detected on pasture and NDF intake. However, SUP animals had a greater intake of DM, metabolizable energy, and metabolizable protein. A positive linear response on metabolizable protein intake was observed among SUP animals. We observed an interaction between treatment and season for all digestibility variables, with a positive linear response in CP digestibility among SUP animals during all seasons. For neutral detergent fiber (NDF) digestibility, we observed a positive linear response in RDT and rainy seasons and a quadratic response during the dry season. Furthermore, SUP animals had greater average daily gain (ADG) than non-supplemented animals, and among SUP animals, there was a quadratic response to ADG, with the greatest gain observed in S24. We observed greater nitrogen retention coefficient in SUP animals than in non-supplemented animals and a positive linear effect among SUP animals. Supplemental CP did not affect microbial protein production and efficiency. We observed an interaction between treatment and season for blood glucose, with SUP animals having greater glucose concentration in all seasons than non-supplemented animals. Additionally, we observed a quadratic response among SUP animals only during RDT and dry season, with the greatest glucose concentration in S24. SUP animals had greater blood concentrations of urea and IGF-1. In conclusion, SUP animals had greater intake, digestibility, and performance than non-supplemented animals, with the 24% CP supplement demonstrating the best metabolic responses and performance.

Licury Cake in Diets for Lactating Goats: Intake, Digestibility, Feeding Behavior, Milk Production and Composition, and Nitrogen Metabolism.

The objective of this study was to determine the effects of licury cake (LC) inclusion in the diets of lactating goats on productive and metabolic performance. Twelve lactating goats, eight Saanen and four Anglo-Nubian, were distributed in a triplicate 4 × 4 Latin square design, with four treatments (0, 66.7, 133.3, and 200 g kg-1 of dry matter-DM). On the one hand, the LC inclusion increased neutral detergent fiber, indigestible neutral detergent fiber, and potentially digestible neutral detergent fiber (p < 0.001) intake. On the other hand, LC inclusion reduced ether extract and non-fibrous carbohydrate (p < 0.001) intake. There was a reduction in dry matter digestibility (p = 0.018) and an increase in neutral detergent fiber digestibility (p = 0.036). Feeding (p = 0.005) and rumination (p < 0.001) efficiencies increased with LC inclusion. The nitrogen balance was similar for all tested diets; however, we observed recycling metabolism. Based on the studied parameters, mainly milk production and composition, we recommend the LC inclusion of up to 200 g kg-1 DM in diets for lactating goats.

Propionic acid-based additive with surfactant action on the feeding value of rehydrated corn grain silage for dairy cows performance

Eighteen Holstein cows with 218 ± 106 days in milk (mean ± SD) and average daily milk yield of 22 ± 7.6 kg (mean ± SD) were assigned to six 3 × 3 Latin squares to evaluate the effects of using a propionic acid-based additive with surfactant action (Mycoflake™; Kemin South America, Indaiatuba, SP, Brazil) at the ensiling of rehydrated corn grain on its nutritional value and animal performance. Dry ground corn grain (998 μm) was rehydrated to reach 400 g/kg fresh matter of moisture, with or without the additive, and ensiled in 200-L plastic drums. Treatments were prepared as follows: rehydrated corn grain silage (RCGS) stored for 30 d as a negative control (30CON), RCGS stored for 60 d as a positive control (60CON) and RCGS treated with Mycoflake™ at 2 L/t and stored for 30 d (30MYC). The animals were offered a total mixed ration containing 399 g/kg whole-plant corn silage, 98 g/kg Tifton haylage, 207 g/kg RCGS (according to treatment), 98 g/kg citrus pulp, 173 g/kg soybean meal and 25 g/kg mineral-vitamin mix in total diet dry matter (DM). Ruminal DM disappearance (DMD) of RCGS was evaluated in situ using two canulated Holstein cows after 12, 24 and 48 h of incubation. Total tract apparent digestibility (TTAD) of nutrients was determined using the indigestible neutral detergent fiber content as a marker measured after 288 h of incubation in a canulated Holstein cow. Although no change in soluble protein content was observed for the 30MYC silage, its NH3-N content was greater than 30CON in both DM (P = 0.01) and total N (P = 0.02) basis, and did not differ from 60CON. The proportion of NH3-N in soluble N of 30MYC was the highest compared to both 30CON (P = 0.02) and 60CON (P < 0.01). The 30MYC RCGS presented lower geometric mean particle size and greater surface area than both 30CON (P < 0.01) and 60CON (P < 0.01). Although the pH of 30MYC RCGS did not differ from 30CON and 60CON, its lactic acid content (11.9 g/kg DM) was greater than both 30CON (9.28 g/kg DM; P = 0.05) and 60CON (8.10 g/kg DM; P = 0.01). No changes in ruminal DMD were observed for 30MYC RCGS against 30CON. There were no changes on dairy cows performance fed the 30MYC RCGS against 30CON. Cows fed 30MYC RCGS presented a different pattern of sorting behavior against 30CON and 60CON, resulting in lower intake of physically effective fiber than both 30CON (P = 0.01) and 60CON (P = 0.02), although no effect on ruminating and chewing activities was observed. No effect on TTAD of nutrients was observed for cows fed 30MYC RCGS against 30CON. Mycoflake™ hampered the formation of aggregates in RCGS, and did not enhance proteolysis. Despite changes in sorting behavior, the additive did not affect performance of dairy cows.

NIRS Estimation of the Nutritive Value of Megathyrsus maximus (Syn. Panicum sp.) Forages

Aimed to evaluate the estimation of the nutritive value of Megathyrsus maximus (Syn. Panicum sp.) forages by near-infrared reflectance spectroscopy (NIRS). The experimental design was completely randomized with four replications. The treatments were arranged in a split-plot arrangement, with nine cultivars of M. maximus in the main plot (Aries, Atlas, Massai, Mombasa, Paredao, Kenya, Tamani, Tanzania, and Zuri) and four harvesting ages in the subplot (30, 60, 90, and 120 days). The contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF), indigestible neutral detergent fiber (iNDF), and ash were evaluated. A reduction in CP and ash contents is observed with the advancement of age in all evaluated cultivars. In contrast, an increase in DM, NDF, ADF, and iNDF contents is observed. The nutritive value of the forages from the evaluated cultivars deteriorates as age increases, recommending grazing periods of less than 60 days for cattle. The NIRS estimations are excellent (R2cv &gt; 0.95) for CP, ash, NDF, and iNDF, demonstrating the potential of this technology for analyzing the nutritive value of M. maximus forages.

Between-individual variability on reticulorumen digesta passage rate in goats

Identifying factors that influence an individual’s ability to utilize nutrients is a strategy for enhancing livestock sustainability. Digesta passage rate (kp) is one of the most important determinants that influence nutrient utilization. However, there is limited knowledge regarding the individual’s variability on kp. The objective of this study was to investigate between-individual variability of reticulorumen (RR) kp of solutes and particles in goats, and its relationship to total NDF digestibility (NDFd). A dataset consisting of 103 individual records from two studies of castrated male (n = 36), female (n = 34), and intact male (n = 33) growing Saanen goats fed ad libitum and slaughtered at around 16.62 ± 0.96 (n = 21), 23.09 ± 1.33 (n = 19), 30.67 ± 2.25 kg (n = 29), 38.02 ± 1.61 (n = 16), and 44.12 ± 1.95 (n = 18) kg BW was used. The RR kp of solutes and particles were measured using Cr-EDTA and indigestible NDF (iNDF), respectively. Using mixed-effect models, considering sex and BW as fixed effects and study as random effect, we aimed to identify meaningful between-individual variance of RR kp of solutes and particles. Given the characteristic of our dataset (i.e., one observation per individual), our approach focused on exploring the variance between individuals described by the residuals of our fitted models. The RR kp of solutes and particles showed significant (P < 0.05) between-individual variation (CV ≈ 27%). Only 10% of RR kp of solutes variance was explained by DM intake (DMI) (g/d and g/d and g/kg BW) and NDF intake (NDFI); g/d), while 51.8% of the variance in RR kp of particles was explained by DMI and NDFI (g/d and g/kg BW), RR wet pool size, and iNDF:NDF intake ratio. The between-individual variation of RR kp of particles explained 19.5% of the between-individual variation in NDFd (P < 0.001). However, the nutritional and individual traits cited above (i.e., DMI, NDFI, RR wet pool size, and iNDF:NDF intake ratio) explained only 51.8% of the between-individual variation of RR kp of particles, while the remaining 48.2% was attributed to the individual’s inherent characteristics, which in turn explained only 1.24% of the between-individual variation of NDFd (P = 0.146). The RR kp of particles and solutes showed meaningful between-individuals variance, which was partially related to both individual inherent characteristics and nutritional and animal traits. However, the NDFd was found to be unrelated to the inherent characteristics of RR kp of particles.

58 Evaluation of indigestible neutral detergent fiber methodology and its use as a marker to estimate hay digestibility in horses

Indigestible neutral detergent fiber (iNDF) is routinely used as an internal marker to estimate dry matter digestibility (DMD) of feeds in ruminants but has been applied less frequently to horses. Measurement of iNDF requires prolonged incubation of samples in microbial inoculum. Despite inherent differences in microbial fiber degradation between species, we hypothesized that bovine and equine sources of inoculum would produce similar measures of iNDF and both would yield accurate estimates of DMD in horses. The aim of this study was to directly measure fecal output and DMD in horses using total fecal collection and compare it to estimates derived from iNDF that had been quantified by different methods. Five mature Quarter Horse geldings (552 ± 14 kg) were fed 5 hays differing in fiber composition in a 5 × 5 Latin square design experiment. Hays offered at 1.6% BW included: alfalfa (Medicago sativa, ALFA), orchardgrass (Dactylis glomerata, ORCH), and bermudagrass (Cynodon dactylon) harvested at 4 (BG-4), 6 (BG-6), and 8 wk of regrowth (BG-8). Each period consisted of an 8-d diet adaptation followed by a 3-d total fecal collection (TC). Hay and fecal samples were dried and ground, placed in 25-μm filter bags, and incubated for 288 h in 4 different inocula to determine iNDF: in situ in rumen-cannulated cows, in vitro in rumen fluid (RF), in vitro in cecal fluid (CF), and in vitro in equine fecal inoculum (EF). Following incubation samples were analyzed for residual neutraldetergent fiber (ie, iNDF). Data were compared using a split plot within a Latin square whole plot design using mixed model ANOVA and linear regression. Mean iNDF recovery for in situ and EF (95%, 91%) was greater (P < 0.05) than CF and RF (88%, 85%; SEM 1.6%). Fecal output estimated by in situ and EF did not differ from that measured by TC but was overestimated by RF and CF methods (P < 0.05). An interaction of hay*method was observed for DMD (P = 0.01). For ALFA and BG-6, DMD determined by all iNDF methods aligned with DMD measured by TC. For ORCH and BG-4, only DMD estimates from in situ and EF were similar to TC. All iNDF methods underestimated DMD for BG-8. Linear regression of DMD for all hays measured by TC showed a stronger relationship with in situ and EF iNDF methods (R2 = 0.65, 0.64; RMSE 7.4, 7.2) than RF and CF iNDF methods (R2 = 0.56, 0.61; RMSE 8.6, 7.7), though all were significant (P < 0.01) and all equations approached unity (slope 1.0, intercept 0). Results show iNDF can be used in horses to estimate DMD across a variety of hays and may align better with TC when rumen in situ and EF methods are used to determine iNDF.

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

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

In situ ruminal degradability of forage cactus-based diets associated with pornunça silage

The knowledge of ruminal degradation kinetics of forage cactus-based diets associated with Euphorbiaceae species of the genus Manihot assist in understanding nutrient quality and use, contributing to the indication of combinations of these ingredients in ruminant diets. This study aimed to evaluate the in situ ruminal degradability of diets with increasing association of forage cactus Elephant Ear (MEE) and pornunça (Manihot sp.) silage, as well as to analyze and evaluate the indigestible neutral detergent fiber (FDNi) content of forage cactus MEE and pornunça silage. The treatments consisted of diets with cactus pear associated with pornunça silage in the roughage portion in the proportions of 375, 250, 125 and 0 g kg-1 of DM. The feed was composed of 50% roughage and 50% concentrate of dry matter. Incubation times of 0, 6, 12, 24, 48, 96, and 144 hours were evaluated for the ingredients and 0, 2, 4, 6, 8, 12, 24, 48, 72, and 96 hours for the diets. Incubation to obtain the iNDF was given for 288 hours. The experimental design consisted of randomized blocks, with three replications. Regarding roughage ingredients, MEE showed higher average disappearance, potential degradability (PD), and effective degradability (ED) in relation to pornunça silage, as well as lower NDFi content. The proportion of 375 g kg-1 MEE and 125 g kg-1 pornunça silage provided higher fractions a, b, and c, increasing ED considering the three passage rates, with higher PD. In conclusion, the association between MEE and pornunça silage at a proportion of 375 g kg-1 MEE and125g kg-1 pornunça silage of the roughage portion increases the in situ degradability of dry matter, crude protein, and neutral detergent fiber.

NIRS Estimation of the Nutritive Value of Sugarcane Silage at Different Harvest Seasons and with Additives

This study aimed to evaluate the nutritive value of sugarcane silage at different harvest seasons and treated with additives, as well as its estimation by near-infrared reflectance spectroscopy. The experiment was developed in Colorado do Oeste, RO, Brazil, being adopted a completely randomized design with four repetitions. The treatments were arranged in a 3´5 factorial scheme, being: three harvest seasons (March, May and July); and five additives: 10% corn flour; 10% disintegrated straw and cob corn; 15% rice bran; 1,0% urea; no additive. Dry matter, crude protein, neutral detergent fiber, acid detergent fiber, ash, indigestible neutral detergent fiber and estimated total digestible nutrients contents were evaluated. The nutritive value of sugarcane silage improves with additives, when compared to sugarcane silage in natura. The moisture sequestering additives present better results when compared to urea, with the exception of crude protein content. The co-product rice bran provides reduced fiber content, and increased crude protein and total digestible nutrient contents of the silage. The silage produced in July and with additives provides the highest contents of total digestible nutrients. The near-infrared reflectance spectroscopy estimates are excellent (R2cv &gt; 0.95) for crude protein, neutral detergent fiber, acid detergent fiber, and ash, offering ranchers and researchers a fast and inexpensive service.

Estimation of dry matter intake by lambs managed on different leaves allowance of Brachiaria-grass using internal and external markers

ABSTRACT It aimed to estimate the forage intake by lambs managed in different leaf allowances on Brachiaria-grass using internal and external markers. Forty-eight Texel lambs with 17.52 ± 3.48 kg were evaluated which were 12 testers and 36 regulators. The lambs were kept in twelve paddocks, subdivided into four treatments based on green leaf allowance (60, 75, 90, and 105 g/kg of BW). The experimental design was completely randomised. To estimate dry matter intake (DMI), the following markers were used: indigestible dry matter (iDM); indigestible neutral detergent fibre (iNDF); indigestible acid detergent fibre (iADF); lignin in indigestible acid detergent (iADL) and titanium dioxide (TiO2). Comparisons between intake markers were made using Chromic Oxide (Cr2O3) as a control marker. The leaves allowance tested did not alter the voluntary intake by lambs kept in Brachiaria-grass pasture. Comparison between the control intake marker (Cr2O3) and the other markers by Dunnett's test showed that, regardless of green leaf allowance, the Cr2O3, TiO2 and iADL markers provided similar estimates of DMI, but with lower values than the other markers. External marker TiO2 and the internal iADL were demonstrated to be more suitable for estimating the dry matter intake in grazing lambs regardless of the leaf allowance.

Nutritional parameters and performance of crossbred heifers fed with millet and BRS 716 biomass sorghum silages

ABSTRACT This study addressed the different proportions of millet and sorghum silage biomass BRS 716 (BRS-716 silage) in the diet of crossbred heifers ¾ Holstein x ¼ Zebu on their nutrient intake, and digestibility, microbial protein synthesis, nitrogen balance, ingestive behaviour, and growth performance. Five experimental diets with 0, 25/75, 50/50, 75/25, and 100% of BRS-716 silage in compared to millet silage were evaluated. The roughage: concentrate ratio in the total dry matter (DM) of the diets was 75:25. The diets were evaluated in ten heifers with an initial body weight of 264.95 ± 19.4 kg (± SEM), following the experimental design in two 5 × 5 Latin squares, simultaneously. The total experimental period lasted 105 d, divided into five periods of 21 days, including a 17-d initial adaptation, and four for data collection, and samples. The increase of BRS-716 silage in the diet of crossbred dairy heifers did not change the dry matter intake (DMI), and indigestible neutral detergent fiber (iNDFI). For the purine derivatives, and microbial synthesis, there was no significant effect (P > 0.05). The average daily gain was 0.795 kg/d. The millet silage, and BRS-716 silage in the diet of crossbred Holstein × Zebu heifers used exclusively or combined in different proportions.

Effects of Aspergillus oryzae prebiotic on animal performance, nutrients digestibility, and feeding behavior of backgrounding beef heifers fed with either a sorghum silage- or a byproducts-based diet.

Eighty-four Angus crossbred heifers (13 ± 1 mo of age, 329.5 ± 61.92 kg of body weight [BW]) were used in a generalized randomized block design with a 2 × 2 factorial arrangement of treatments. The factors evaluated were: 1) diet type (whole plant sorghum silage [SS] vs. byproducts-based [BP]), and 2) feed additive: Aspergillus oryzae prebiotic (AOP; 2 g/d) vs. Negative control (CTL; 0 g/d), resulting in four treatments: sorghum silage-control (SC), sorghum silage-AOP (SA), byproducts-control (BC), and byproducts-AOP (BA). Heifers were stratified by body weight (BW), randomly assigned to treatments (21 heifers per treatment) and housed in 12 pens equipped with two GrowSafe feed bunks each to measure individual dry matter intake (DMI). After a 14-d adaptation, BW was measured every 14 d for 56 d. Chewing activity was monitored through collar-mounted HR-Tags (heat-related tags). Following the performance period, apparent total tract digestibility was measured in 40 heifers, using indigestible neutral detergent fiber as a marker. Heifers fed with the BP diets had greater DMI (2.92% vs. 2.59% of BW, P < 0.01) and average daily gain (ADG; 1.16 vs. 0.68 kg, P ≤ 0.01) than heifers fed with SS diets. Compared with BP-fed animals, heifers consuming the SS diets had 23 more visits/d to the feed bunks (P ≤ 0.01), consumed 53% less dry matter on each visit (P ≤ 0.01), and spent 39% more min chewing/d and 63% more min chewing/kg of DMI (P ≤ 0.01). However, chewing measured in min/kg of neutral detergent fiber intake was not affected by treatment (average 111.3 min/kg of NDF intake). Feeding AOP improved gain:feed (GF) by 15% in BP-fed heifers (0.120 vs. 0.104 kg/kg; P < 0.05). Inclusion of AOP increased organic matter digestibility (OMD) in SS diets (55.88% vs. 49.83%; P < 0.01), whereas it decreased OMD in BP diets (61.67% vs. 65.77%; P < 0.05). In conclusion, ADG and GF of BP-fed heifers was greater than SS-fed heifers, and GF was greater with AOP supplementation in BP-fed heifers. Improvement in GF in BP-fed heifers was likely not related to differences in nutrient digestibility as AOP inclusion did not enhance digestibility in the BP diet. Additionally, the effects of the AOP inclusion appear to be diet-dependent, where the 15% improvement in GF by AOP occurred in heifers fed with the more fermentable diet. Therefore, further research should explore the mechanisms responsible for the observed improvements in growth performance when feeding AOP to BP-fed heifers.

Methane emissions and 13C composition from beef steers consuming binary C3-C4 diets.

Improvements in forage nutritive value can reduce methane emission intensity in grazing ruminants. This study was designed to evaluate how the legume rhizoma peanut (Arachis glabrata; RP) inclusion into bahiagrass (Paspalum notatum) hay diets would affect intake and CH4 production in beef steers. We also assessed the potential to estimate the proportion of RP contribution to CH4 emissions using δ13C from enteric CH4. Twenty-five Angus-crossbred steers were randomly allocated to one of five treatments (five steers per treatment blocked by bodyweight): 1) 100% bahiagrass hay (0%RP); 2) 25% RP hay + 75% bahiagrass hay (25%RP); 3) 50% RP hay + 50% bahiagrass hay (50%RP); 4) 75% RP hay + 25% bahiagrass hay (75%RP); 5) 100% RP hay (100%RP). The study was laid out using a randomized complete block design, and the statistical model included fixed effect of treatment, and random effect of block. Methane emissions were collected using sulfur hexafluoride (SF6) technique, and apparent total tract digestibility was estimated utilizing indigestible neutral detergent fiber as an internal marker. A two-pool mixing model was used to predict diet source utilizing CH4 δ13C. Inclusion of RP did not affect intake or CH4 production (P > 0.05). Methane production per animal averaged 250 g CH4/d and 33 g CH4/kg dry matter intake, across treatments. The CH4 δ13C were -55.5, -60.3, -63.25, -63.35, and -68.7 for 0%RP, 25%RP, 50%RP, 75%RP, and 100%RP, respectively, falling within the reported ranges for C3 or C4 forage diets. Moreover, there was a quadratic effect (P = 0.04) on the CH4 δ13C, becoming more depleted (e.g., more negative) as the diet proportion of RP hay increased, appearing to plateau at 75%RP. Regression between predicted and observed proportions of RP in bahiagrass hay diets based on δ13C from CH4 indicate δ13C to be useful (Adj. R2 = 0.89) for predicting the contribution of RP in C3-C4 binary diets. Data from this study indicate that, while CH4 production may not always be reduced with legume inclusion into C4 hay diets, the δ13C technique is indeed useful for tracking the effect of dietary sources on CH4 emissions.