Indigestible Acid 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.

89 Performance of iADF as an internal marker for evaluating forage digestibility in horses

Total fecal collection (TFC) is considered the gold standard for evaluating diet digestibility; however, this method is time consuming, labor-intensive, and requires horses to wear collection harnesses and/or be confined to stalls for prolonged periods. Less frequent sampling of feces can be more practical and less disruptive to the management and routines of certain types of horses (e.g., horses in training, lactating mares, growing horses) but requires the use of a marker to estimate daily fecal output. Indigestible acid detergent fiber (iADF) is routinely used to determine dry matter digestibility (DMD) in cattle but evidence of its effectiveness as an internal marker in horses is limited. This study used 5 mature Quarter Horse geldings to compare fecal output and DMD determined with TFC to that estimated using iADF. Horses were fed alfalfa (Medicago sativa, ALF) or bermudagrass (Cynodon dactylon ‘Coastal’, CBG) hays at 1.6% BW/d in a crossover design. Hays were chosen to represent a large span in fiber concentration (ALF: 38% NDF, 30% ADF; CBG: 70% NDF, 35% ADF). Each period consisted of an 8-d diet adaptation followed by a 3-d TFC. Hays and daily composited fecal samples were analyzed for iADF using 2 methods: in situ incubation in a rumen-cannulated cow and in vitro incubation using equine fecal inoculum from a non-study donor. Samples were incubated for 288 h and sequentially analyzed to determineresidual neutral and acid detergent fibers, with the latter representing iADF. Data were compared using mixed model ANOVA and linear regression. Marker recovery of iADF averaged 98% (SEM 4%) and was similar between iADF methods and hays. Use of fecal inoculum yielded higher estimates of iADF intake (P < 0.01) and iADF excretion in feces (P < 0.01) than the rumen in situ iADF method. Daily fecal output and DMD estimated by rumen in situ iADF (P = 0.27, P = 0.29) and fecal inoculum iADF (P = 0.71, P = 0.79) both agreed with direct determination by TFC. Linear regression of DMD showed a strong relationship between TFC and both iADF methods (P < 0.001), with slightly better prediction when iADF was determined by rumen in situ (y = 0.81x + 7.1; R2 0.85; RMSE 4.8) than equine fecal inoculum (y = 0.79x + 10.0; R2 0.71; RMSE 7.0). Both equations approached a slope of unity and an intercept not different from zero (P > 0.10). Across all methods, DMD of ALF was higher (P < 0.01) than CBG. Findings support use of iADF as a marker to predict DMD of hays in horses. This study measured iADF in samples representing all feces excreted; thus, future work should verify the suitability of iADF as a marker when applied to fecal spot sampling.

Digestibility of diets with passion fruit by-product estimated through external and internal markers in dairy heifers

This study examined the influence of the external markers chromium oxide (CO), titanium dioxide (TD), isolated, purified and enriched lignin (LIPE®) and isolated, purified, enriched lignin in nanoparticles (NANOLIPE®) as well as the internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in diets with inclusion of passion fruit by-product for dairy heifers on the estimation of fecal output and nutrient digestibility. Sixteen Holstein × Zebu crossbred heifers at an average live weight of 363 ± 28 kg were randomly distributed in a completely randomized design where they received diets in which Tifton 85 (Cynodon sp.) hay was replaced with passion fruit by-product (0, 12, 24 and 36%, as-fed basis). The CO, LIPE®, NANOLIPE® and iNDF markers did not differ from the total collection method (p &gt; 0.05) in the estimation of fecal output and nutrient digestibility. The TD and iDM markers overestimated, while iADF underestimated fecal output. Under the presented conditions, we recommend using the CO, LIPE®, NANOLIPE® and iNDF markers to estimate fecal output and nutrient digestibility in diets with inclusion of passion fruit by-product for dairy heifers.

A comparison of methods for estimating forage intake, digestibility, and fecal output in red deer (Cervus elaphus).

The objective of this experiment was to determine appropriate methods for estimating fecal output, digestibility, and intake in red deer (Cervus elaphus). Dry matter intake (DMI), digestibility, and fecal output were estimated using the dual-marker (titanium dioxide; TiO2 and indigestible acid detergent fiber) technique, double n-alkane ratio technique (ALK) and the pulse dose (Yttrium; Y) technique to determine a suitable method to estimate DMI, fecal output, and digestibility measurements. Four male and four female deer were stratified by sex and randomly assigned either fresh-cut perennial ryegrass (Lolium perenne L.) or fresh-cut plantain (Plantago lanceolata) ad libitum in a cross-over design experiment. Actual DMI (mean ± SD: 1.5 ± 0.36 kg DM/d), digestibility (0.70 ± 0.06), and fecal output (0.45 ± 0.1 kg DM/d) were measured daily over the collection periods, and the average of each period was used for methods' comparison. The ALK method adequately estimated digestibility and fecal output of plantain; however, overestimated digestibility (P < 0.05) and DMI of ryegrass, so that there was no statistical agreement (P > 0.10) in DMI when diets were pooled. The overestimated DMI of the ryegrass diet led to ALK predicting greater intake when deer consumed ryegrass than plantain, which was the opposite of actual measurements. The pulse dosed Y overestimated (P < 0.05) fecal output and consequently DMI for both plantain and ryegrass, however, indicated similar trends to actual values. The dual-marker technique using TiO2 was able to detect the statistical differences between plantain and ryegrass as the actual measurements, had moderate to strong precision (r = 0.50 to 0.66) and statistical agreement (P < 0.05) with the pooled diet data. Therefore, the dual-marker technique provided the best alternative estimation method to actual measurements of forage DMI of grazing red deer.

Use of indigestible markers to estimate the apparent dry matter digestibility of diets containing a cocoa by-product

Fecal production and apparent dry matter digestibility (ADMD) were evaluated using external markers (chromium oxide; titanium dioxide; isolated, purified, and enriched lignin (LIPE®); and isolated, purified, and enriched lignin nanoparticles (NANOLIPE®) and internal markers (indigestible DM (IDM), indigestible neutral detergent fiber (INDF), and indigestible acid detergent fiber (IADF) in diets based on Tifton 85 bermuda grass (Cynodon sp.) hay containing different concentrations of a cocoa by-product. Sixteen crossbred (Holstein × Zebu) dairy heifers with a mean live weight of 363.00 ± 27.70 kg were evaluated and distributed in a completely randomized block design with a split-plot arrangement. The plots corresponded to the diets, which differed in the substitution of bermuda grass hay with different concentrations (0, 8, 16, and 24% of DM) of the cocoa by-product, whereas the splitplots represented the indigestible markers. Chromic oxide, LIPE®, NANOLIPE®, and INDF accurately estimated ADMD and fecal production whereas titanium dioxide, IDM, and IADF did not accurately estimate these parameters.

Internal markers for predicting dry matter intake and digestibility in Santa Inês ewes on a pasture

AbstractAssessing feed intake is a valuable tool for herd management decisions. The use of markers is one of the most widely used techniques for estimating dry matter intake (DMI) in ruminants. Thus, internal markers (IM) were evaluated to predict DMI and digestibility (DMD) in ewes supplemented on a pasture during pre‐ (75, 105 and 135 days of gestation) and postpartum periods (30 and 60 days of lactation). The animals were kept on a pasture, and they were put into individual stalls to receive their supplementation. Twelve ewes were distributed in a completely randomized design: (a) Two supplementation levels (SL; 5 and 15 g/kg body weight, BW) and three IM (indigestible neutral detergent fiber, iNDF; indigestible acid detergent fiber, iADF; and rumen‐undegradable dry matter; RUDM) were used and analyzed as mixed models. (b) The DMI and DMD, which were estimated by the best marker, were analyzed as repeated measures using the mixed procedure in SAS. Fecal output was estimated using an external marker (LIPE®; isolated, purified and enriched lignin). The DMI and DMD estimated by RUDM were greater and better than iADF and iNDF, which were similar. The effects of SL and physiological stages for DMI and DMD were evaluated by the values obtained from RUDM. As expected, regardless of the physiological stage, DMI and DMD were greater in the animals that received 15 g/kg BW. Considering the physiological stage, the animals fed 15 g/kg BW had greater DMI and DMD at 75 days of gestation and 30 days of lactation and the least DMI was observed at 135 days of gestation and 60 days of lactation. In conclusion, RUDM provides the best estimates for DMI and DMD, which were greater in animals receiving 15 g/kg BW of concentrate at the beginning of gestation and lactation.

Evaluating internal and external markers versus fecal sampling procedure interactions when estimating intake in dairy cows consuming a corn silage-based diet

Feed intake assessment is a valuable tool for herd management decisions. The use of markers, either internal or external, is currently the most used technique for estimating feed intake in production animals. The experiment used 10 multiparous Holstein cows fed a corn silage-based diet, with 55:45 forage-to-concentrate ratio, the average fecal recovery (FR) of TiO2 was higher than FR of Cr2O3, and both FR were more than unity. With internal markers, acetyl bromide lignin and cutin FR were lower than unity, and average FR for indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) was 1.5. The FR was unaffected by the fecal sampling procedure and appears to be an intrinsic property of each molecule and how it interacts with digesta. Of the 2 external markers, only Cr2O3 produced accurate fecal output (FO) estimates and the same happened to dry matter digestibility (DMD) when iNDF and iADF were used. Estimates for DMD and FO were affected by sampling procedure; 72-h bulk [sub-sample from total feces collection (TFC)] sampling consistently produced accurate results. The grab (sub-samples taken at specific times during the day) sampling procedures were accurate when using either of the indigestible fibers (iNDF or iADF) to estimate DMD. However, grab sampling procedures can only be recommended when concomitant TFC is performed on at least one animal per treatment to determine FR. Under these conditions, Cr2O3 is a suitable marker for estimating FO, and iNDF and iADF are adequate for estimating DMD. Moreover, the Cr2O3+iADF marker pair produces accurate dry matter intake estimates and deserves further attention in ruminant nutrition studies. The method of dosing the external markers is extremely important and greatly affects and determines results. Whichever the method, it must allow the animals to display normal feeding behavior and not affect performance. The grab sampling procedures can replace TFC (once FR is established), which may open new possibilities for pasture-based or collectively housed animals.

Dietas para ovinos contendo capim elefante maduro e raspa de mandioca: estimativa de digestibilidade aparente por meio de indicadores

Objetivou-se a avaliar a estimativa da digestibilidade aparente (DA) em dietas para ovinos por meio dos indicadores internos MSi (matéria seca indigestível), FDNi (fibra em detergente neutro indigestível) e FDAi (fibra em detergente ácido indigestível) e o indicador externo LIPE®. Utilizou-se oito ovinos machos Santa Inês, castrados, fistulados no rúmen, com peso médio corporal de 50 kg. Os animais receberam dietas a base de raspa de mandioca e do capim elefante maduro (120 dias). Os indicadores internos (MSi, FDNi e FDAi) foram estimados após 288 horas de incubação in situ das amostras de alimentos e fezes. O indicador externo LIPE® foi fornecido na forma de cápsulas na dosagem de 250 mg/animal/dia. Os resultados de DA estimados pelo indicador externo LIPE® diferiram estatisticamente (P0,05) entre o método da coleta total de fezes e os indicadores internos FDNi e FDAi. Os indicadores internos FDNi e FDAi podem ser utilizados em estudos de digestibilidade em ovinos, pois, permitem estimar de forma semelhante ao método da coleta total de fezes.

Evaluation of internal markers as determinants of fecal dry matter output and digestibility in feedlot sheep

This study aimed to evaluate the fecal recovery of the internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF), and indigestible acid detergent fiber (iADF) and to compare them as estimators of the fecal dry matter output (FDMO) and digestibility of the dry matter (DM) with values observed in total feces collection in trials with feedlot sheep. For this, 82 sampling units from two experiments were evaluated. Internal markers were quantified in the feed supplied, orts, and feces. The recovery of the markers was determined by the comparison of the amount of marker consumed and excreted. Fecal dry matter output and digestibility were determined based on the amount of marker consumed and on its concentration in the feces through individual collections directly from the rectum of the animals, with values compared with those observed in the total feces collection from orthogonal contrasts. The mean bias, the concordance correlation coefficient, and the mean squared prediction error were also evaluated. For all statistical procedures, the critical level of probability for type-I error was fixed at 0.05. The marker iDM showed complete fecal recovery (100.03%) and was efficient in estimating FDMO (482.9 g day-1) and DM digestibility (542 g kg-1) as compared with the values observed in the total feces collection (454.7 g day-1 and 561 g kg-1 for FDMO and DM digestibility, respectively). The iNDF and iADF markers did not show complete recovery in the feces and were not effective in the estimate of FDMO and DM digestibility.

608 Replacing corn grain by crude glycerol in diets of grazing dairy cows: Feed intake, pasture degradability, and milk production

Eighteen Holstein cows (6 ruminally cannulated) were used in the first 60 days of lactation to evaluate the effect of the replacement of corn grain (CG) by crude glycerol (CGly) on organic matter intake (OMI), pasture degradability and milk yield (MY). Cows were blocked [by parity (3.17±1.42), body condition score (3.0±0.3), expected caving date], and assigned randomly to two treatments (T). T1= partially mixed diet (PMR) containing sorghum silage (SS) plus concentrate (CG, wheat grain, soybean expeller, minerals and vitamins) and T2= PMR containing SS plus concentrate where CGly -76.5% glycerol, ALUR Uruguay- replacing the CG. Both groups received PMR in individual feeders and grazed during afternoon in a temperate pasture with herbage allowance-above the ground level- 60 kg DM.cow-1.day-1. Chemical composition of PMR (OM, CP, NDF, and EE in g/kgDM) respectively was for T1 [934, 117, 317, and 5] and [927, 106, 297 and 46] for T2. OMI and the ruminal degradation kinetics of DM of pasture were measured in situ in two periods. PMR intake (OMI-PMR) was measured individually as the difference between the amounts offered and refused. OMI-forage was determined with chromium oxide (Cr2O3) and indigestible acid detergent fiber as external and internal marker respectively. In situ data was fitted to nonlinear model D(t)=a+b(1-e-ct), where D= disappearance of DM , (a) soluble fraction, (b) degradable fraction, and (c) degradation rate. MY was Individual measured daily. Intake, degradability parameters, and MY were analyzed with a mixed model whit repeated measures. The model included fixed effects: T, period/week, interaction T*period and cow as a random effect. The statistical analyzes were performed with SAS (2010), data are expressed as lsmeans (s.e) and were considered to differ when P < 0.05. Treatment or interaction did not affect Total organic matter intake, OMI-PMR or OMI-f and was [23.6(1.4), 12.7(0.5) and 10.9 (1.0)] kgOM.d-1 for T1 and [20.8(1.3), 10.9(0.5) and 9.8 (0.9)] kg OM.d-1 for T2 respectively. The parameters “a”, “b” “c” of pasture were not affected by T, period or interactions and averaged 20(3.1) g/kgDM 602 (3.6) g/kgDM, 0.04(0.007) h-1. Milk yields was not affected by treatment (30.6(1.0) kg.día-1) or interaction T*week of lactation (WOL) but as expected it was affected for WOL. The absence of negative effects related to the use of CGly in substitution of CG in these conditions allows its use up to 10% DMI for dairy cows without altering the efficiency of the milk production process.

Collaborative study to evaluate the indigestible neutral detergent fiber and indigestible acid detergent fiber contents in feeds by in situ procedure

The objective of this collaborative study was to evaluate the indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) content in feeds in six laboratories from institutions linked to the National Institute of Science and Technology in Animal Science (INCT-CA). Six feeds were evaluated: signal grass hay, sugarcane, corn silage, soybean meal, corn and citrus pulp. Estimated levels of iNDF and iADF proved to be dependent on the laboratory in which the analysis was performed. It was found that differences between laboratories ranged from 2.40 percentage points for soybean meal to 8.05 percentage points for sugarcane for iNDF analysis and from 1.79 percentage points for corn to 10.06 percentage points for hay for iADF analysis. It was observed that the individual evaluation of each material, the total random variation of the results between laboratories ranged from 88.75 to 96.77% and 88.75 to 98.40% for iNDF and iADF analysis, respectively. The iNDF and iADF levels are dependent on the interaction effect between the evaluated material and laboratory and have low reproducibility; this may be a consequence of the differences between the methods practiced by each laboratory, demonstrating lack of standardization of procedures used by the laboratories.

Intake and digestibility of silages containing pineapple pulp and coast-cross hay with or without urea and markers recovery in sheep

The objective of this study was to evaluate the intake and digestibility of silages containing pineapple pulp and coast-cross hay, with or without addition of urea, and the recovery of the markers chromium oxide (Cr2O3), indigestible neutral detergent fiber (iNDF), indigestible acid detergent fiber (iADF), and indigestible dry matter (iDM), in a digestibility assay, in sheep. Treatments were as follows: two levels of pineapple pulp (818 and 758 g kg−1) and two levels of urea (with and without urea), in a completely randomized design. Twelve sheep (three per treatment) were used, kept in metabolic cages. Fecal excreta were determined by total collection or estimated by using the markers. Marker samples were obtained in morning and afternoon collections, with mean concentrations obtained for both daily activities. The level of silage pulp did not affect intake, while addition of urea increased the intake of crude protein (CP), but did not influence the intakes of dry matter, organic matter, neutral detergent fiber, or acid detergent fiber. The digestibility coefficients of all afore-mentioned fractions increased with the increase in pulp, the same happening with the addition of urea. The internal marker with lowest variability among the internal markers was iADF, with mean values near 100%. Mean recovery of Cr2O3 was approximately 107%, but with lower variability among treatments. Inclusion of pineapple pulp in silage does not influence intake, while addition of urea only increases the intake of CP. The levels of pineapple pulp in silage with or without urea increase the digestibility of the silage. Indigestible acid detergent fiber is the marker with lowest variability of recovery, with mean recovery for the four silages used very close to 100%.

Feeding behavior, nutrient digestibility, feedlot performance, carcass traits, and meat characteristics of crossbred lambs fed high levels of yellow grease or soybean oil

Twenty-four crossbred (Santa Inês×Dorper) non-castrated male lambs (initial body weigh 24.9kg±2.4kg), were used to evaluate the effects of lipid sources (soybean oil or frying soybean oil) on feeding behavior, feedlot performance, digestibility of dry matter and nutrients of finishing lamb diets. The animals were distributed in a randomized block design and assigned to one of the isonitrogenous (18.4% CP, DM basis) diets which were formulated in forage:concentrate ratio of 40:60. The control treatment (CTL) was composed of corn silage, corn grain, sunflower meal, soybean hulls, urea, limestone and minerals. The other two treatments contained 6% soybean oil (SO) or 6% residual soybean frying oil (YG) on DM basis, mainly replacing corn grain and soybean hulls. Animals were offered total mixed rations twice daily ad libitum. Animals were harvested at 35kg BW, and carcass characteristics data were recorded. Samples of Longissimus muscle were collected for centesimal composition analysis. The feeding behavior was observed for 3 consecutive days (12h period each). The apparent digestibility of DM and nutrients of experimental diets were estimated using the internal marker indigestible acid detergent fiber. The oil supplementation, regardless of the source, did not change feeding behavior and carcass characteristics. Dry matter and nutrient intake and digestibility were decreased when animals were fed oil, except for ether extract, which increased. Animals fed YG presented lesser average daily weight gain (177.7g) than SO-fed lambs (205.3g). In conclusion, the addition of soybean oil or yellow grease at 6% in diet DM for feedlot crossbred lambs has minimal effects on feeding behavior and increases feed efficiency, however decreases digestibility of DM, NDF and ADF, and tends to increase intramuscular fat. The use of yellow grease as an alternative energy source increases lambs’ days on feed.

Review: Recent advances in evaluation of bags made from different textiles used in situ ruminal degradation

Valente, T. N. P., Detmann, E. and Sampaio, C. B. 2015. Review: Recent advances in evaluation of bags made from different textiles used in situ ruminal degradation. Can. J. Anim. Sci. 95: 493–498. Textile bags are used in the laboratory to analyze the indigestible contents (internal markers) of feedstuffs after in situ ruminal incubation. Information is needed on the rate and extent of degradation in the rumen using bags made from different materials. In situ techniques have been used extensively to measure the degradation of feedstuffs in the rumen. However, in situ techniques are prone to variability. This paper reviews the effects of particle size, the material from which bags are made, pore size, tensile strength of the bags, in situ estimation of the levels of indigestible compounds [indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF), and indigestible acid detergent fiber (iADF)], rumen degradation profiles, and the use of bags made from nylon (50 µm), F57 (Ankom®), and non-woven textile (100 g m−2).

Silage or fresh by-product of peach palm as roughage in the feeding of lambs.

The objective of this study was to evaluate intake and apparent digestibility of agro-industrial by-product of peach palm in diets for lambs. Twenty castrated, crossbred Santa Ines lambs, with average age of 150 days and body weight of 22.4 ± 3.4 kg, were distributed in a completely randomized design with four experimental diets composed of the following: fresh by-product of peach palm enriched with urea + ammonia sulfate (FU); fresh peach palm by-product + concentrate (FP); silage of peach palm by-product + concentrate (SP); and silage of peach palm by-product enriched with 15% of cornmeal + concentrate (SPC). Intake was recorded daily, and the digestibility coefficients were estimated with the internal marker indigestible acid detergent fiber (iADF). Diet FU resulted in the lowest intake and digestibility of the nutrients evaluated. Animals receiving diet FP showed higher intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), total digestible nutrients (TDN), and digestible energy (DE) in relation to animals fed diets SP and SPC. Diets SP and SPC showed higher coefficients of digestibility of DM, OM, CP, and NDF than diet FP. Diet SP reduced the intakes of DM, OM, ether extract (EE), non-fibrous carbohydrate (NFC), TDN, and DE and the digestibility coefficients of DM, OM, and NFC as compared with diet SPC. Feedlot lambs fed a diet with fresh peach palm by-product + concentrate (diet FP) have higher nutrient intake.

Does sugar cane ensiled with calcium oxide affect intake, digestibility, performance, and microbial efficiency in beef cattle?

Two trials were conducted to evaluate how calcium oxide (CaO) as an additive in sugar cane silage affects animal performance and diet digestibility. Experiment 1 included 35 crossbred steers (Holstein×Nellore) with an average body weight (BW) of 350±18.3kg, which were distributed across a randomized block design with five treatments and seven replicates. The five treatments consisted of sugar cane ensiled with four different levels of CaO (0, 5, 10, and 15g/kg; fresh basis) and a standard diet of corn silage. The forage concentrate ratio was 50:50 and was formulated to be isonitrogenous (120g/kg DM). The dry matter intake (DMI) was measured daily and individually. Indigestible acid detergent fiber (iADF) was used as an internal marker to estimate apparent nutrient digestibility. There was a quadratic positive effect (P=0.013) of the CaO levels on DMI (gDM/kgBW), organic matter (OM; P=0.032), and non-fiber carbohydrates (NFC; P=0.014) intake. The average daily gain (ADG) of steers that were fed corn silage diets was similar (P=0.11) to that of those fed sugar cane silage with 5g/kg of CaO. There was a positive linear effect of the percentage of CaO on the apparent total digestibility of DM (P=0.012), OM (P=0.001), crude protein (CP; P=0.022) and neutral detergent fiber (aNDF; P=0.015) of the diets. In Experiment 2, four ruminally and abomasally cannulated Nellore steers (184±10.2kgBW) were used with a 4×4 Latin square design to evaluate the effect of CaO levels on apparent total and ruminal digestibility of nutrients, ruminal characteristics, and microbial efficiency. The four treatments were composed of the same sugar cane silage diets used in Experiment 1. The aNDF intake decreased linearly (P=0.032) as the percentage of CaO increased. There was a linear positive effect of the percentage of CaO on the apparent total digestibility of DM (P=0.036), OM (P=0.007), CP (P=0.042), and aNDF (P=0.025). There were no effects of CaO levels on the ruminal pH values (P=0.52), ammonia concentration (P=0.22), or microbial efficiency (P=0.283). Adding CaO to sugar cane silage reduces the silage fiber. However, the addition of more than 5g/kg CaO to sugar cane at ensiling does not improve silage intake and animal performance. Additionally, the use of 15g/kg of CaO in sugar cane at ensiling decreases diet intake and growth of beef cattle.

Effects of dietary brown propolis on nutrient intake and digestibility in feedlot lambs

The present study tested brown propolis in crude or extract form as a feed supplement for feedlot lambs to identify the type that most improves in vivo nutrient digestibility. Digestibility was assessed by both total fecal collection and internal markers and the results obtained by these techniques were compared. The completely randomized design was used to compare feed intake and nutrient digestibility of 24 male lambs aged seven months among four dietary treatments (crude brown propolis, propolis ethanol extract, monensin sodium, and control). Methods of feces collection were compared using a completely randomized split-plot design, with experimental diets corresponding to the main factor and the methods to estimate fecal production as the sub-factor. The diets had a roughage:concentrate ratio of 50:50, with Tifton-85 bermudagrass hay (Cynodon spp.) as roughage, and ground corn, soybean meal and minerals as concentrate. The lambs fed diets with crude propolis had higher feed intake than those fed diets containing monensin sodium. The different diets did not affect dry matter, organic matter, crude protein, neutral detergent fiber, or acid detergent fiber digestibility, but crude propolis supplementation provided higher ether extract digestibility than monensin sodium. Nutrient digestibility, as indicated by indigestible neutral detergent fiber, indigestible acid detergent fiber and sequentially-determined indigestible acid detergent fiber, was lower than that found with the fecal collection method. The addition of brown propolis has the same effect as monensin, but neither maximized nutrient availability in the diet of feedlot lambs at 7 months of age. Digestibility assessment using the internal markers indigestible neutral detergent fiber, indigestible acid detergent fiber and sequentially-determined indigestible acid detergent fiber is not an efficient method compared with total feces collection.

Intake, milk production and weight change curves for lactating Holstein x Zebu cows under grazing

The purpose of this study was to evaluate feed intake and develop lactation and weight change curves for Holstein x zebu cows under grazing. Eighteen F1 cows were used, divided into three treatments; 6 were Holstein x Gir (HGI), 6 were Holstein x Guzerat (HGU), and another 6 were Holstein x Nelore (HNE), under the feeding conditions of pasture plus concentrate with 22% of crude protein (CP). To estimate individual feed intake at pasture, 2 markers were used: titanium dioxide to estimate fecal dry matter (DM) excretion, and the indigestible acid detergent fiber (iADF) to estimate individual pasture intake. The Wood (1967) model was used to evaluate milk yield and the parameters were estimated for each genetic group, as follows: HGI = 17.2667*t0.0652*e-0.00424t; HGU = 18.1470*t0.0332*e-0.00408t; and HN = 14.2836*t0.1059*e-0.00552t. The NEFA contents varied according to different genetic groups (P&lt;0.001). It was concluded that the estimated peak DMI occurs during the sixth week of lactation, when the DMI by the different genetic groups was stabilized. The HGI cows have greater cumulative production at 305-d.

Crude glycerin in diets for feedlot Nellore cattle

Two studies were conducted to evaluate the effects of crude glycerin on feed intake, performance, carcass characteristics, and total digestibility of Nellore bulls. In experiment 1, cattle (n = 30) were fed a control diet without crude glycerin and diets containing 7.5, 15, 22.5, and 30% crude glycerin, for 103 d. Animals were harvested and data of carcass characteristics were collected. In experiment 2, a digestibility trial was performed using indigestible acid detergent fiber (iADF) as internal marker, and five rumen-cannulated steers. Both experiments were conducted as a randomized complete block design and data were analyzed using mixed procedures. In experiment 1 no differences were observed among treatments on dry matter intake, and performance variables. Regarding carcass characteristics, no effect was observed, except for carcass fat estimates, which were greater in treatments with crude glycerin. In experiment 2, crude glycerin promoted a decrease in digestibility of fibrous fractions NDF and HEM, and increased digestibility of crude protein by 6%. Although it caused negative effect on digestibility of fibrous fraction of diets, crude glycerin can be a good energy source for Nellore bulls, since no losses are observed on performance and carcass characteristics when animals are fed up to 30% of this by-product.

Daily and alternate day supplementation of urea or soybean meal to ruminants consuming low-quality cool-season forage: II. Effects on ruminal fermentation

Five ruminally cannulated steers (initial BW=464±26kg) consuming low-quality forage (5% CP; 78% NDF; DM basis) were used in an incomplete 5×4 Latin square with four 18-d periods to determine the influence of supplemental N source and supplementation frequency (SF) on ruminal fermentation dynamics. Treatments, arranged as a 2×2 factorial with a negative control, consisted of urea or soybean meal (SBM) supplements offered daily (D) or alternate days (2D) plus an unsupplemented treatment (CON). Urea supplements were provided to meet 100% of the degradable intake protein requirement while SBM supplements were provided on an isonitrogenous basis. All supplemented treatments received an equal quantity of supplemental N over a 2-d period. Ruminal indigestible acid detergent fiber (IADF) passage rate was increased with supplementation (P≤0.03) on the days when D and 2D supplements were provided, as well as when only D supplements were provided. In contrast, ruminal liquid fill and dilution rate were not affected by supplementation, N source, or SF on the days when D and 2D supplements were provided (P≥0.24). However, when only D supplements were offered, ruminal liquid dilution rate was greater (P=0.03) for SBM supplemented steers compared with cohorts receiving supplemental urea, whereas ruminal liquid fill was greater (P=0.03) for steers fed urea supplements. Nitrogen supplementation increased (P<0.01) ruminal NH3–N by 122% and 70%, compared with the CON, on the days when both D and 2D supplements were provided and when only D supplements were provided, respectively. We noted a N source×SF interaction for ruminal NH3–N on the days when D and 2D supplements were provided (P=0.02), as well as when only D supplements were provided (P<0.01). On the days when D and 2D supplements were provided, urea increased NH3–N by 61% (2.93 vs. 4.73mM for D and 2D, respectively), whereas the increase in NH3–N with SBM was only 15% (2.23 vs. 2.58mM for D and 2D, respectively). However, when only D supplements were provided, NH3–N was almost 36% less for the 2D compared with the D urea treatment (2.76 vs. 1.81mM, respectively), whereas an 11% increase was noted for SBM 2D compared with SBM D (1.99 vs. 1.79mM, respectively). Total concentration of VFA was increased on the days when both D and 2D supplements were provided (P=0.03), but not influenced by treatments on the days when only D supplements were provided (P≥0.50). In summary, providing a urea-based supplement, as infrequently as every-other-day, was an effective alternative to a SBM-based supplement in maintaining acceptable ruminal fermentation of steers consuming low-quality, cool-season forage.