Degradable Crude Protein Fraction Research Articles

Tiempos de cosecha sobre el valor nutritivo del forraje verde hidropónico de cebada

The aim of this study was to evaluate the effect of harvest days (16, 18, 20 and 22 after germination) on the nutritional value of hydroponic green forage (HGF) of barley in terms of chemical composition: dry matter (DM ), organic matter (OM), crude protein (CP), mineral matter (MM) and neutral detergent fibre (NDF), and the determination of the kinetic parameters of the in situ degradation of DM and CP, using three cattle with fistula rumen. The incubation times were: 0, 6, 12, 24, 48 and 72 hours. The DM and MM were similar (p>0.05) in the cultures, while the highest CP concentration was observed on day 16 and 18 (15.07 and 14.66%, respectively). NDF decreased linearly due to the effect of harvest days. The day factor quadratically influenced the degradation of the soluble fraction (SF) of the DM and PC, estimating 60 and 62.53% as maximum degradation of SF at 17 and 15 days of harvest, respectively. On the contrary, the potentially degradable fraction (PFD) of DM and CP decreased by 15.91 and 12.88% at 19 and 13 days of germination, respectively. The potential degradability of the DM was high and different on days 16 and 18, and with higher and similar values ​​in the effective degradability for the passage rates of 2, 5 and 8%/hour in relation to the other days. The same behaviour was recorded in the CP passage rates. The FVH of barley at 16 and 18 days after germination has a higher CP content, lower indigestible fractions of DM and CP and high effective degradability, which allows these crops to be classified as feeds of high nutritional quality that favour their use as a supplement for ruminants.

Effect of extrusion with molasses on the rumen undegradable protein fraction of canola oilcake meal and sweet lupins

The effect of the extrusion of canola oilcake meal (COM) and crushed sweet lupins (CSL) with molasses on the dry matter (DM) and crude protein (CP) degradability was determined in situ. Locally sourced (SOILL Moorreesburg, South Africa) COM and CSL, with the addition of 6% molasses, were extruded at a maximum temperature of 116 °C. A total of six Dohne Merino wethers (± 80 kg), fitted with rumen cannula, were used in this trial. Samples in polyester bags (5 g) were incubated in the rumen of the sheep at intervals of 0, 2, 4, 8, 16, 24, and 48 h. The DM and CP disappearances from the rumen were determined and degradability parameters were estimated. Extrusion increased the potentially degradable CP fraction by 43.5%. At each outflow rate, the average CP effective degradability of COM (68.2%) was lower than that of CSL (78.0%). Extrusion substantially lowered the CP effective degradability for both protein sources at every outflow rate tested. The biggest effect was seen at 0.08/h, where effective degradation was lowered by 25.6%. Extrusion with molasses was found to modify ruminal degradation parameters of both canola oilcake meal and crushed sweet lupins, while also decreasing the effective rumen degradation, especially at faster outflow rates. Thereby, the rumen undegradable protein fraction was increased by 85.4%. This study shows that COM and CSL extruded with 6% molasses can substantially increase RUP.

Chemical Composition and In Situ Degradability of Desmanthus spp. Forage Harvested at Different Maturity Stages

This study evaluated the change in nutritive value and in situ degradability of Desmanthus spp. (desmanthus) cultivars JCU2; D. virgatus, JCU4; D. bicornutus and JCU7; D. leptophyllus harvested at varying maturity stages to test the hypothesis that the nutritive value and in situ degradability of desmanthus differ between cultivars and with maturity stage at harvest. In Experiment 1, desmanthus was harvested at 11, 38, 72 and 103 days of regrowth (maturity), separated into the leaf and stem portion, dried and analysed for dry matter (DM) and chemical composition. In Experiment 2, desmanthus was harvested 78, 122 and 168 days after planting (maturity). Samples were dried, and DM, crude protein (CP) and neutral detergent fibre (NDF) and acid detergent fibre (ADF) degradation were determined using the in situ technique with three fistulated Droughtmaster steers. The results showed an interaction between cultivar and maturity on the leaf to stem mass ratio, leaf CP, stem NDF and the leaf ADF (p ≤ 0.04). The leaf-to-stem mass ratio declined more steeply with maturity in JCU7 compared to JCU2 and JCU4 (p = 0.04), while there was a higher decline in leaf CP of JCU4 than JCU2 and JCU7 (p < 0.01). The total potentially degradable fraction of DM and CP did not differ between cultivars (p ≥ 0.30) but declined with maturity (p ≤ 0.04). However, the effective DM degradability at a high particle outflow rate was higher in JCU4 than in JCU7. Taken together, these results indicate that differences exist between cultivars, and higher livestock production may be achieved by utilising the different cultivars in a blend and at earlier maturity stages. Therefore, the hypothesis that nutritive value and in situ degradability of desmanthus differ between cultivars and with maturity stage at harvest was accepted.

Evaluation of Stockpiled Perennial Forage Compared to Grass-legume Hay for Chemical Composition and Rumen Degradation Kinetics

The objective of this study was to determine the chemical composition and in situ degradability of dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) of stockpiled perennial forage (SPF) or sun-cured hay (HAY) when collected at the start or end (October vs. December) of fall grazing. Selected 6, 4-ha paddocks consisting of meadow bromegrass and alfalfa, were randomly assigned to 1 of 2 replicated (n = 3) winter feeding systems (SPF and HAY). Sampling was done twice per year at the beginning (October) and end (December) from (a) stockpiled perennial forage (SPF) in field paddocks and from (b) harvested round bale hay (HAY) over 2 consecutive years. Selected 6, 4-ha paddocks consisting of meadow bromegrass and alfalfa, were randomly assigned two winter feeding systems (SPF (n=3) and HAY (n=3)). Sampling were done twice per year at the beginning (October) and end (December) from (a) SPF (b) HAY over 2 consecutive years. To evaluate in situ degradability, duplicate nylon bags from each experimental unit were incubated for 0, 3, 6, 10, 13, 25, 48, 72, and 96 h in five Hereford heifers fitted with rumen cannula. Relative to HAY, SPF had greater (p = 0.01) OM (906 vs. 916 g/kg DM) and NDF (653 vs. 631 g/kg DM) concentrations. Sampling date had no effect (p > 0.05) on CP, OM, and ADF in both forages, whereas the NDF was greater (p = 0.01) in forages sampled in December. The in situ soluble fraction (S) of DM was greater (p = 0.01) for SPF collected in October, HAY collected in October, and HAY collected in December s (156, 138, and 152 g/kg DM, respectively) relative to SPF collected in December (106 g/kg DM). The potentially degradable fraction (D) of CP was less (p < 0.05) for HAY December samples compared to SPF December and HAY October samples (257 vs. 522 and 523 g/kg CP, respectively). The SPF had a greater (p < 0.05) potentially degradable ADF (749 vs. 587 g/kg ADF) and potentially degradable NDF (770 vs. 591 g/kg NDF) compared to HAY. The effect of forage type and sampling date did not affect (p > 0.05) effective degradability of NDF. Regardless of the forage type the potentially degradable fraction of NDF decreased from October to December (SPF: 770 to 730 g/kg NDF) (HAY: 680 g/kg to 491 g/kg NDF). These findings suggest SPF grazing is a robust substitute to hay feeding systems for beef cows.

Effect of replacing soybean meal with marula nut meal on rumen dry matter and crude protein degradability.

In situ rumen degradability of dry matter (DM) and crude protein (CP) in ruminant diets composed of graded inclusion levels of marula nut meal (MNM) as a protein source to replace soybean meal were evaluated. The five diets denoted as diet 1 (0.0gkg-1 MNM: control), diet 2 (45.5gkg-1 MNM), diet 3 (91.7gkg-1 MNM), diet 4 (138.4gkg-1 MNM), and diet 5 (185.9gkg-1 MNM) were tested. Three cannulated mid-lactating Holstein cows were used to incubate triplicate subsamples of each diet for 2, 4, 8, 16, 24, and 48h in polyester bags. The soluble fractions of DM and CP increased (P < 0.05) with increasing levels of MNM (138.4-185.9gkg-1 MNM). However, the insoluble but degradable fractions of DM and CP increased (P < 0.05) with decreasing levels of MNM (45.5-0.0gkg-1 and 91.7-0.0gkg-1 MNM, respectively). While the degradation rate of fraction and the effective degradability of DM increased (P < 0.05) with decreasing levels of MNM (91.7-0.0gkg-1), those of CP increased with increasing levels of MNM (138.4-185.9gkg-1 MNM) in the diet. These results suggest that dietary inclusion of MNM up to 91.7gkg-1 in ruminant diets can provide undegradable protein to be absorbed in the small intestines and used for metabolic function, while an inclusion of up to 185.9gkg-1 can be degraded in the rumen for microbial protein synthesis.

The effect of pistachio by-product extracts treatment in protecting soybean meal and canola meal protein from rumen microbial degradation.

The industrial de-hulling of fresh pistachio generates a large quantity of pistachio by-products (PBP). The present study aimed to investigate the effects of treating soybean meal (SBM) and canola meal (CM) with tannin extracts derived from PBP on the protein fractions according to the Cornell Net Carbohydrates and Protein System (CNCPS), rumen degradability, and ruminal and post-ruminal crude protein (CP) disappearance in an in situ trials using three fistulated steers. The extracts of PBP were obtained via different solvents and then added to SBM and CM, so that the final concentrations of added tannins were 0, 5 and 10 g kg-1 dry matter. The CNCPS soluble proteins (fractions A + B1 ) of CP and B1 fraction of CP were lower (P < 0.01) in SBM and CM treated with PBP extracts than untreated meals. Treating SBM with different PBP extracts (except 5 g kg-1 tannin water extract) and CM with 5 g kg-1 tannin water extract and 10 g kg-1 tannin ethanol extract decreased (P < 0.01) ruminal disappearance of CP. From the in situ results, the rapidly degradable fraction (a) of CP decreased (P < 0.01) by treating SBM with different PBP extracts and CM with 5 and 10 g kg-1 tannin water extracts, whereas the slowly degradable fraction (b) of CP remained unchanged in SBM. Treatment of SBM and CM with PBP extracts decreased (P < 0.01) the effective degradability of crude protein estimated with different outflow rates. Some of the tannin extracts derived from PBP by water, ethanol and methanol could be effective with respect to protein protection of SBM and CM from degradation in the rumen; however, the use of tannin from water extracts can be more economical and practical. © 2020 Society of Chemical Industry.

Effect of heat-treated canola meal and glycerol inclusion on performance and gastrointestinal development of Holstein calves

The objectives of this study were to assess the effect of using heat-treated canola meal (CM) and glycerol inclusion in starter mixtures on starter intake, growth, and gastrointestinal tract development in Holstein bull calves. In the first study, a protocol for the heat treatment of CM was evaluated by comparing commercial CM that was exposed to 0, 100, 110, or 120°C of heat treatment for 10 min. Following heat treatment, in situ crude protein (CP) ruminal degradability and estimated intestinal CP digestibility were assessed. It was observed that the degradable fractions of dry matter and CP in CM decreased linearly with increasing temperature of heat treatment. The estimated intestinal CP digestibility was greatest when CM was heated to 110°C. In the second study, 28 bull calves were used in a randomized complete block design. Calves were fed pelleted starters containing CM or CM that was heat-treated to 110°C for 10 min. Diets also contained 0 or 5% glycerol on a dry matter basis. The study lasted 51 d, ending on the first day of weaning. Starter intake, average daily gain (ADG), ruminal short-chain fatty acid concentrations, morphology of the rumen and small intestine, gene expression (MCT1, GPR41, GPR43, UTB, AQP3, PEPT1, PEPT2, ATB0+, and EAAC1) in the ruminal, jejunal, and ileal epithelium, and brush border enzyme activities in the duodenum, jejunum, and ileum were investigated. Few interactions between heat-treated CM and glycerol inclusion were observed. Feeding heat-treated CM did not affect starter intake. However, feeding heat-treated CM to calves tended to reduce ADG and decreased the weight of ruminal and jejunal tissue. Heat treatment did not affect gene expression or brush border enzyme activities in the small intestine. Glycerol inclusion tended to increase cumulative starter intake and increased cumulative body weight gain. Use of glycerol reduced ruminal pH and increased the concentration of ruminal short-chain fatty acids. Additionally, glycerol inclusion increased abomasal, duodenal, jejunal, and cecal digesta weights and tended to increase the weight of the jejunal tissue. Glycerol supplementation tended to downregulate the expression of MCT1 in the ruminal epithelium, and upregulated the expression of MCT1 in the epithelium of proximal jejunum. In conclusion, heat treatment of CM may negatively affect calf growth and gastrointestinal tract development. Glycerol inclusion may increase starter intake, ADG, ruminal fermentation, and intestinal development in calves when CM is used as a main source of protein in pelleted starter mixture.

In situ ruminal degradation kinetics and blood metabolites as affected by feeding different sources of tannin and flavonoids to small-tailed Han rams

The objective of this study was to determine the effects of feeding two kinds of alfalfa varieties, Gannon No. 3 (G3) and Gannon No. 9 (G9), with variable contents of tannin and flavonoids and compare their effects to dietary supplements of tannin and flavones on ruminal degradation kinetics and serum metabolites. Fifteen ruminally cannulated small-tailed Han rams were divided into five groups and fed the following diets for 30 days as follows: CONT (basal diet), G3 (200 g of G3 + basal diet), G9 (200 g of G9 + basal diet), TAN (2 g of hydrolysable tannin (HT) + basal diet) and FLV (2 g of Puerariae flavones + basal diet). Animals were weighed, serum samples were collected, and in situ ruminal incubation of soybean was performed to determine the degradation kinetics of the dry matter (DM), crude protein (CP), and organic matter (OM). Animals’ weight increased significantly at the end of the experiment in all groups. The greatest serum total protein concentration was found in the TAN group. Also G9 and FLV increased the ruminal degradation of DM and CP. Meanwhile CONT followed by TAN and G3 decreased the rumen degradable fractions of CP and increased significantly the undegradable CP fraction. We concluded that G9 had a similar effect as Puerariae flavone, while G3 followed the same effect of HT on the ruminal degradation. However, they showed different impacts on serum metabolites.

High Fiber Cakes from Mediterranean Multipurpose Oilseeds as Protein Sources for Ruminants.

Simple SummaryRecovery and valorization of residues are key factors for agro-industry to progress towards circular-economy models and more sustainable productions. In the vegetable oils industry, large quantities of spent seed cakes are produced downstream of the oil extraction processes, and their use as animal feedstuffs, mainly as protein supplements for ruminants, is a possible valorization strategy. In this study, we analyzed chemical composition and in vitro digestibility of spent cakes from sunflower, pomegranate, cardoon, tobacco and hemp that are multipurpose cultures emerging in Mediterranean area. The results showed that the cakes of tobacco, cardoon and hemp might be interesting alternative protein feeds for ruminants. The valorization of these cakes may potentially improve economic and environmental sustainability of the emerging vegetable-oil production chains.Fifteen oilseed cakes from sunflower, pomegranate, cardoon, tobacco and hemp were characterized with regard to chemical composition, Cornell Net Carbohydrate and Protein System (CNCPS) fractionation, in vitro digestibility of dry matter, neutral detergent fiber, and crude protein. All the cakes presented low moisture, rather variable ether extract contents and medium to high levels of crude protein and neutral detergent fiber. The cakes significantly differed in terms of CNCPS partitioning and in vitro digestibility. Tobacco and hemp cakes presented high contents of slow degradable fractions of crude protein and carbohydrate joined to good post-ruminal protein digestibility. Cardoon cakes presented the highest rumen protein degradability. Based on crude protein content and intestinal digestibility of rumen undegraded protein, cakes of tobacco and hemp showed the better potential as alternative protein supplements for ruminants, while pomegranate appears to be the least suitable for ruminant feeding.

Nutrient evaluation and ruminal degradation of dry matter and protein from amarula (Sclerocarya birrea), macadamia (integrifolia) and baobab (Adansonia digitata L.) oilcakes as dietary supplements for ruminants.

Inadequate availability of feed ingredients significantly contributes to reduced animal production. Nutritional evaluation of feed ingredients for potential use in feed ration is key. Triplicate samples of oil extraction by-products viz.: amarula (Sclerocarya birrea), macadamia (integrifolia) and baobab (Adansonia digitata L.) oilcakes were analysed for proximate, mineral and amino acids content. To determine the in situ rumen degradability of dry matter (DM) and crude protein (CP) from the oilcakes, polyester bags were used to incubate triplicate subsamples of each oilcake in the ventral rumen of each of the three cannulated mid-lactating Holstein cows for 2, 4, 8, 16, 24, or 48h. Amarula oilcake (AOC) had higher (P < 0.05) CP, ether extract and essential amino acid content than macadamia (MOC) and baobab (BOC) oilcakes. Fibre fractions were higher (P < 0.05) in MOC and BOC than in AOC. While calcium (Ca) and potassium (K) concentrations were high (P < 0.05) in MOC and BOC, phosphorus (P) concentration was high (P < 0.05) in AOC. The effective degradability of DM and water-soluble, rapidly degradable fractions of DM and CP were high (P < 0.05) in AOC. Insoluble but degradable fraction of CP was high (P < 0.00) in BOC and effective degradation of CP was high (P < 0.05) in AOC and BOC. The AOC with its high CP, EE and essential AA can be used as both protein and energy source for ruminants. Seemingly, MOC and BOC can be used as supplements for fibre as well as Ca and K in ruminant diets. Hence, these non-conventional oilcakes have the potential to partially replace conventional oilcakes in ruminant diets. Evaluation of growth performance, nitrogen digestion and carcass characteristics in ruminants fed diets containing the AOC, BOC and MOC are recommended.

Detect molecular spectral features of newly developed Vicia faba varieties and protein metabolic characteristics in ruminant system using advanced synchrotron radiation based infrared microspectroscopy: A preliminary study.

Recently, advanced synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-IMS) has been developed as a rapid, direct, non-destructive and bioanalytical technique. To date, there has been very little application of this technique to study the molecular structure make-up in pulse seeds. Thus, the objectives of this study were to detect the interactive association between protein molecular structure and nutrient availability of newly developed Vicia faba varieties. Two different varieties of faba beans (CDC Snowdrop = low-tannin variety; vs. FB9-4 = high-tannin variety) were selected for this study. The molecular spectra data were collected by using SR-IMS. The ratio of both amide I to II area and height were higher (P < 0.01), while the ratio of α-helix to β-sheet was lower (P < 0.05) in CDC Snowdrop compared to FB9-4. The crude protein (CP) content and the predicted truly digestible nutrients as well as the bioenergy values did not vary between two varieties. The CDC Snowdrop had exhibited a higher (P < 0.01) rapidly degradable CP fraction (75.99 vs. 71.45% on CP) and a lower (P < 0.01) moderately degradable CP fraction (19.43 vs. 22.85% on CP), resulting in a higher (P < 0.01) rumen degradable protein and a lower (P < 0.01) rumen undegradable protein content than that of FB9-4 variety. However, the total supply of digestible rumen undegraded feed protein was higher (P < 0.05) in FB9-4 than CDC Snowdrop. Strong positive correlations were found between the ratio of α-helix to β-sheet and CP contents (R = 0.86, P < 0.01) as well as the truly digestible CP contents (R = 0.83, P < 0.01); respectively. In conclusion, the results of this study reveal that the protein are metabolized differently between different type of faba bean varieties and the advanced SR-IMS molecular spectroscopy can be used to rapidly delineate protein molecular structure motifs along with their nutritive value in ruminant livestock system.

Growth Performance and Ruminal Metabolic Variables of Goats Fed Rain Tree (Samanea saman) Pods.

The effect of rain tree pods (RTP) or acacia pods on the growth performance, rumen metabolites, and digestibility of dry matter (DM) and crude protein (CP) in goats was evaluated through feeding trial and in situ methods. Eighteen 7 month-old Philippine native goats with body weight range of 7.86±1.28 kg were divided into three groups consisting of six replicates and randomly assigned to one of treatment diets containing 0%, 50%, and 100% RTP in the concentrate portion of a ration containing 65% roughage and 35% concentrate. Three rumen-cannulated mature goats were used in the in situ studies to determine the dietary effects on rumen fluid pH, total volatile fatty acids (VFA), ammonia, and rumen DM and CP digestibilities. Differences (P values 50% RTP generally resulted in lower above-stated performance parameters. Rumen fluid pH of goats decreased after feeding and was lowest in goats fed with 50% RTP. Concentrations of VFA and ammonia were not significantly different. Slowly degradable DM of the test diets were higher in concentrate mixture without RTP. Degradable fractions of CP had highest value on concentrate mixture without RTP while lowest on 100% RTP. However, no differences were observed on potentially digestible fractions and degradability constants of DM and CP. It could be concluded that RTPs can be an alternative ingredient in concentrate mixtures given up to 50% in the mixture as part of a daily ration for goats.

In situ and in vitro evaluation of crude protein degradation and utilisable crude protein content of barley, rye and triticale grains for ruminants.

Rations for dairy cows are comprised of high proportions of cereal grains. Thus, despite their low crude protein (CP) content, grains can contribute considerably to the CP intake of dairy cows. This study was conducted to describe and compare ruminal CP degradation of a broad range of barley, rye and triticale genotypes in situ and in vitro and different methods to estimate the utilisable CP at the duodenum (uCP). Twenty samples each of rye, barley and triticale were incubated in situ and in vitro. Exponential regression analyses were used to estimate in situ degradation parameters. Further, the effective degradability (ED), ruminal undegraded CP (UDP) and uCP for ruminal passage rates of 5% and 8% per hr were estimated. The uCP was estimated in vitro and based on two different approaches using in situ UDP data and estimates of microbial synthesised protein (based on fermented organic matter [fOM] or equations of the Gesellschaft für Ernährungsphysiologie). The degradation rate declined from rye (43% per hr) to triticale (27% per hr) to barley (20% per hr), and it exhibited remarkable variation between the genotypes of a single species. The maximal degradable CP fraction also differed between the species, but was overall very high (94%-99%). The lowest washout fraction (26%) and the highest variation in ED (77%-86% and 69%-80% for a passage rate of 5% and 8% per hr, respectively) were found in barley. The in situ uCP content (estimated using fOM) was lower for barley than for rye and triticale at ruminal passage rates of 5% and 8% per hr (barley: 157g/kg DM at both passage rates; rye and triticale: 168 (at 5% per hr) and 169 (at 8% per hr) g/kg DM). In vitro estimations of uCP did not differ between the grain species and uCP estimated according to GfE was higher for triticale than for barley and rye, which did not differ. The low variation within a single grain species and the weak correlations between ruminal CP degradation and nutrient concentrations suggested that differentiation of ED and uCP between the genotypes of a single grain species is not necessary.

Effects of sequence of nylon bags rumen incubation on kinetics of degradation in some commonly used feedstuffs in dairy rations

Nowadays, most available information on the degradative behaviour of feeds in ruminants is based on in situ incubation in the rumen, and it is adopted by many feed evaluation systems currently in use for ruminants. However, the outcome of this technique might be affected by many factors such as sequence of nylon bags incubation in the rumen. The objective of current study was to investigate effects of sequence of nylon bag incubation on degradative behavior of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) in some feed ingredients commonly used in dairy rations, including alfalfa haylage, corn silage, corn grain and soybean meal. Four multiparous Holstein lactating cows fitted with permanent ruminal cannulas were used. The nylon bags containing feed samples either were placed in the rumen at once and removed at designated time intervals (all in-gradually out method; AG) or were placed in the rumen at designated time points and retrieved at once (gradually in-all out method; GA). Fractional rate of degradation of potentially degradable fraction, lag time and effective rumen degradability (ED) of DM and CP were significantly higher in the AG compared to the GA method (P<0.05). Fractional rates of DM and CP degradation was higher in alfalfa haylage samples incubated in the rumen using the AG method compared to that using the GA method (0.138 h−1 vs. 0.073 h−1 and 0.002 h−1vs. 0.1125 h−1, for DM and CP, respectively; P<0.05). Due to a higher fractional rate of degradation (Kd) of DM and CP, the ED of DM and CP at different fractional passage rates were higher in the AG than those in the GA method (P<0.05). Potentially degradable fraction and lag time of NDF were higher in the AG method compared to the GA method (P<0.05). Placing all bags in the rumen at once and removing them at designated time intervals compared with introduction of bags in reverse sequence and removing them all at once led to a lower undegradable fraction (U) of NDF in alfalfa (1.8% vs. 4.0%, respectively; P<0.05) and corn silage (3.3% vs. 6.7%, respectively; P<0.05) samples. Potentially degradable fraction of ADF was significantly higher in the AG method compared with the GA method (P<0.05). Bag incubation sequence had profound effects on kinetics of degradation of DM, CP and NDF in situ in the feed samples studied. The effects were more evident in the forages (especially alfalfa haylage) than in the concentrate ingredients namely corn grain and soybean meal. This experiment is the first time to investigate effects of two methods under the same experiment conditions, providing basic data for the determination of ED.

Effects of silage crop and dietary crude protein levels on digestibility, ruminal fermentation, nitrogen use efficiency, and performance of finishing beef cattle

Two trials were conducted to evaluate the effects of silage crop and levels of dietary crude protein (CP) in Nellore beef cattle. The experimental diets consisted of Stylosanthes (StS) or corn silage (CS) with two levels of dietary CP, 110 and 130g CP/kg diet on a dry matter (DM) basis. The forage to concentrate ratio was 50:50 on a DM basis. In Experiment 1, the four bulls that were used had an average initial body weight (BW) of 450±37.9kg, and were surgically cannulated in the rumen and abomasum. The bulls were assigned to a 4×4 Latin square with a 2×2 factorial design of treatments, and four 16-d periods. During this experiment, we collected ruminal fluid, abomasal digesta, feces, urine, and blood. In addition, the kinetic parameters of DM, CP, and neutral detergent fiber (NDF) degradation were estimated. In Experiment 2, 40 bulls with an average initial BW of 374±16.5kg were distributed into a 2×2 factorial in a randomized design with ten replicates. The trial lasted for 99 d and was divided into a 15-d period for adaptation and an 84-d period for data collection. The intake and digestibility of nutrients as well as animal performance were evaluated in Experiment 2. The potentially degradable fractions of DM, CP, and NDF of StS were lower than CS (P<0.004). The diets containing StS showed lower ruminal digestibility of organic matter (OM) and lower total tract digestibility of OM, CP, and NDF than diets containing CS (P<0.050). The StS-based diets showed higher values for ruminal pH in comparison with CS-based diets (P=0.010). The ruminal NH3–N concentration was higher for the level of 130g CP/kg diet in comparison with the 110g CP/kg diet (P<0.001). The dietary CP level affected urea nitrogen in blood (P<0.001) and urine (P=0.017), which were higher in the diets containing StS and CS at the level of 130g CP/kg diet. The diets containing StS showed a higher intake of DM, OM, CP, NDF, and indigestible neutral detergent fiber (iNDF) than diets containing CS (P<0.008). However, the amount of digested nutrients (kg/d) was similar between treatments (P>0.050). The silage crop and dietary CP levels had no effect on productive performance (P>0.050), but the StS-based diet tended to decrease feed efficiency (P=0.085). Thus, StS, as well as the level of 110g CP/kg diet, can be used to feed finishing beef cattle.

Variation between individual cows in in situ rumen degradation characteristics of maize and grass silages

Different numbers of animals have been used in different studies to cover the variation between individual animals in in situ rumen degradation characteristics of maize and grass silages. The objective of this study was to determine whether three cows are sufficient or not to cover the variation between individual cows in in situ rumen degradation characteristics of dry matter (DM), organic matter (OM), crude protein (CP), starch and neutral detergent fibre (NDF) for maize and grass silages. Fifteen maize and 15 grass silage samples, with a broad range in chemical composition, were selected. The maize and grass silage samples were incubated in the rumen for 2, 4, 8, 16, 32, 72 and 336h, using the nylon bag technique. Three cows were used for nylon bag incubation of maize silages and three other cows for grass silages. The variation between individual cows was found significant (P<0.05) for degradation rate (kd) of DM, OM and CP, and the effective rumen degradation (ED) of DM and CP of maize silages whereas non-significant (P>0.05) differences were found for all other parameters of DM, OM, CP, starch and NDF. The variation between individual cows was found non-significant (P>0.05) for rumen undegradable fraction (U), potentially rumen degradable fraction (D), kd and ED of DM, OM, CP and NDF of grass silages. The results of this study indicate that the use of three cows for nylon bag incubations of grass silages is sufficient whereas the use of three cows for nylon bag incubations of maize silages is not sufficient to cover variation between the individual cows.

In Situ Ruminal Degradability of Soybean Meal and Alternative Protein Feeds in Brazil – Meta-analysis

Soybean is widely produced, generating its co-product soybean meal, although other protein meal also contributes to ruminant nutrition. Thus, it aimed to compare meta-analytically the soybean meal degradability parameters with alternative meals from other plant species. They were used experiments that had parameters for ruminal degradability of protein concentrated feeds. The database was composed of 82 treatments from 15 works, comparing soybean meal with cotton seed meal, rapeseed and sunflower. The potentially degradable fraction and the effective degradability of the dry matter with 5%.h-1 were lower (P = 0.0011 and P = 0.0268 respectively) for the alternative meals. The contents of crude protein (CP) of the alternative meals are smaller (P = 0.0012) compared to soybean meal. The readily soluble fraction in water for CP was higher (P = 0.0017) for alternative meals. The potentially degradable fraction of CP was higher (P <0.0001) for soybean meal. The effective degradability to 8%.h-1 of CP was higher for alternative meals (P = 0.0357) than that for the soybean meal. Partial or total replacement of soybean meal by cottonseed meal, rapeseed and sunflower alter the ruminal degradability parameters of the dry matter and crude protein. The protein soybean meal is more available to rumen microorganisms and less available for animal compared to the protein of the alternative meals (cotton, rapeseed, and sunflower).

Nutritive value and methane production potential of energy and protein rich feedstuffs fed to livestock in India

Four protein-rich (groundnut cake-GNC, mustard seed cake-MSC, cotton seed cake-CSC and coconut cake- CNC) and 8 energy-rich (wheat grain-WG, barley grain-BG, oat grain-OG, maize grain-MG, wheat bran A-WBA, wheat bran B-WBB, rice bran-RB, chickpea husk/chuni-GC) feedstuffs were evaluated for their carbohydrate and protein fractions, in vitro dry matter degradability, in vitro methane production and energy loss as methane. Crude protein (CP) and ether extract contents were higher in protein-rich feedstuffs than in energy feedstuffs. High lignin content was noted in CSC, GNC, MSC and RB. Degradable CP fractions of total CP ranged from 0.61 to 0.97 and were higher for protein-rich than energy-rich feedstuffs. On an average, protein-rich feedstuffs had more undegradable CP fraction than the grains or brans. Starch content was highest (P&lt; 0.001) in WBB and least in CSC with values of 369 and 37.3 g/kg DM, respectively. Rapidly degradable carbohydrate fraction (CA) was highest in WG, OG, MG (all energy-rich feedstuffs) and least in RB (6.7 g/kg DM). Similar to the observation made in the protein fractions, protein-rich feedstuffs had more unavailable CHO. Feedstuffs energy loss as methane was highest (P&lt; 0.001) from GC (1.90 Mj/kg DM) and least from MG (1.19 Mj/kg DM). Methane production of the feedstuffs could be predicted from the chemical composition, CP and CHO fractions. On an average, chemical composition and protein fractions were better predictors of CH4 production versus CHO fractions with mean R2 values of 0.94 and 0.80, respectively. Data on relative methane emission from energy and protein rich feeds could be utilized to prepare diets that will lead to less methane production from ruminants.

Effects of season and species on in sacco degradability of forages in the sub-humid subtropical savannah

Effect of season and plant species on in sacco dry matter (DM) and crude protein (CP) degradability of five plant species were investigated. Plant species were Acacia natalitia, Acacia nilotica, Dichrostachys cinerea, Scutia myrtina and Chromolaena odorata. Leaves were harvested during dry, early wet and late wet seasons, subjected to degradation in cows’ rumen using nylon bags technique. Season affected potential DM degradability and effective degradation of DM and CP. Species affected all parameters except slowly degradable fraction of CP. Interaction between season and species affected the parameters except potential and slowly degradable fraction of CP. Chromolaena odorata had highest estimated parameters of degradation among seasons compared to others. Based on potential and effective degradation, plants followed this decreasing order: C. odorata, A. nilotica, A. natalitia, S. myrtina and D. cinerea. These plants have a potential as feed supplements. C. odorata has the highest potential as feed protein source in ruminants. It concluded that season and species affected in sacco degradability of DM and CP of browse species. Key words: Dry matter, crude protein, Chromolaena odorata, ruminants, nutritive value.

Relationship between chemical composition and in situ rumen degradation characteristics of grass silages in dairy cows

The DVE/OEB2010 system in the Netherlands uses a large database of in situ rumen incubations with grass silage and grass hay samples to derive prediction formulas to estimate the rumen degradation characteristics of a number of feed value parameters. These in situ rumen incubations were not performed for this specific purpose and the data were generated at different research institutes over more than 40 years, using different grass management and fertilization practices and using different protocols. The objectives of this study were to 1) generate a new database on the rumen degradability of dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fibre (NDF) of grass silages, 2) compare this new database with the old database used in the DVE/OEB2010 system, and 3) derive regression equations using the new database to investigate the relationships between chemical composition and in situ ruminal degradation characteristics of DM, OM, CP and NDF of the grass silages. Sixty nine grass silages, with a broad range in chemical composition and quality parameters, were selected and incubated using the nylon bag technique in the rumen of three lactating Holstein Friesian cows for 2, 4, 8, 16, 32, 72 and 336h. There was a large range in the rumen degradable fractions of DM, OM, CP and NDF of the grass silages at each rumen incubation period. The data on the rumen degradation characteristics of DM, OM, CP and NDF in the present study were determined using the same standard incubation protocol, the same cows, and the same chemical analysis procedures for all the grass silage samples. Regression analysis, using the new database, showed relationships between the washable (W) fraction, rumen undegradable (U) fraction, potentially rumen degradable (D) fraction and effective rumen degradation (ED) of DM, OM, CP and NDF, respectively, and the chemical composition of the grass silages.