Crude Protein Degradability Research Articles

Linkage of in situ ruminal degradation of crude protein with ruminal degradation of amino acids and phytate from different soybean meals in dairy cows

The objectives of this study were to determine the range in ruminal degradability of crude protein (CP) and intestinal digestibility of rumen undegradable protein in commercial soybean meal (SBM) and to investigate the range in in situ ruminal AA and phytate (InsP6) degradation and their relationship to CP degradation. An in situ study was conducted using 3 lactating Jersey cows with permanent rumen cannulas. Seventeen SBM variants from Europe, Brazil, Argentina, North America, and India were tested for ruminal CP and AA degradation, and in vitro intestinal digestibility of rumen undegradable protein. Nine variants were used to investigate the ruminal degradation of InsP6. The estimated rapidly degradable fraction (a) of CP showed an average value of 4.5% (range: 0.0%-9.0%), the slowly degradable fraction (b) averaged 95% (91%-100%), and the potential degradation was complete for all 17 SBM variants. The degradation of fraction b started after a mean lag phase of 1.7 h (1.1-2.0 h) at an average rate (c) of 10% per hour, but with a high range from 4.5% to 14% per hour. Differences in the degradation parameters induced a considerable range in CP effective degradation at a rumen passage rate of 6% per hour (CPED6) from 38% to 67%; hence, the concentration of rumen undegradable protein varied widely from 33% to 62%. The range in AA degradation between the SBM variants was high, with Ser showing the widest range, from 28% to 96%, and similar for the other AA. The regression equations showed close relationships between CP and AA degradation after 16 h of in situ incubation. However, the slopes of the linear regressions were significantly different between AA, suggesting that degradation among individual AA differs upon a change in CP degradation. The concentrations of InsP6 and myo-inositol pentakisphosphate in bag residues in the in situ study decreased constantly with longer ruminal incubation times. The ruminal degradation parameters of InsP6 ranged from 11% to 37% for fraction a, 63% to 89% for fraction b, and from 7.7% to 21% per hour for degradation rate c, with average values of 21%, 79%, and 16% per hour, respectively. The calculated InsP6 effective degradation at a rumen passage rate of 6% per hour (InsP6ED6) varied from 61% to 84% among the SBM variants. Significant correlations were detected between InsP6ED6 and CPED6 and between InsP6ED6 and chemical protein fractions A, B1, B2, B3, and C. Linear regression equations were developed to predict ruminal InsP6 degradation using CPED6 and chemical protein fractions B3 and C chosen by a stepwise selection procedure. We concluded that a high range in CP, AA, and InsP6 degradation exists among commercial SBM, suggesting that general degradability values may not be precise enough for diet formulation for dairy cows. Degradation of CP in SBM may be used to predict rumen degradation of AA and InsP6 using linear regression equations. Degradation of CP and InsP6 could also be predicted from the chemical protein fractions.

232 In Vitro Digestibility of Dry Matter and Nitrogen of Napier Grass Silage Is Affected By Fertilization with Cow-Dung Bio-Digester Slurry and Fermentable Carbohydrate Additives at Ensiling

Abstract The use of silages during the dry season could ameliorate major nutritional constraints in ruminant livestock production in tropical regions. Napier grass (Pennisetum purpureum) is a tropical forage source that is used for silage in South Africa. The present objective was to determine the effects of fertilization with bio-digester slurry (BDS) and of carbohydrate additives [no additive (control), molasses, brown sugar, and maize meal] at ensiling on in vitro digestibility of Napier grass silage. Fresh Napier grass irrigated weekly with either BDS or water was cut after 12 weeks and ensiled for 90 days in 1 liter glass jars in a 2 (control and slurry irrigation) x 4 (no additive, molasses, maize meal and brown sugar) factorial arrangement replicated three times. The nutrient composition was determined using standard protocols. The in vitro digestibility of dry matter (DM) and crude protein (CP) were determined by the three-stage method after incubation in rumen of steers for 12, 24 and 48-hour incubation. The bags containing rumen undegradable residuals (RURs) were removed from the bags, composited by treatment, and ground through a 1 mm sieve. Approximately 1g samples of RURs of each silage sample were placed in a 0.1 N HCl solution adjusted to pH 1.9 with 1 g ℓ-1 of pepsin, and then in pancreatin solution and rinsed with deionized water and dried at 60°C for 48 h. At 24 h incubation, the no BDS, no additive (control) treatment had the least (P < 0.01) DM degradability. As incubation time progressed to 48 h, fertilization with BDS with molasses inclusion increased (P < 0.05) DM disappearance. However, the BDS fertilization and carbohydrate additive interaction had no effect (P > 0.05) on 12 incubation h, and in vitro digestibility after 12, 24 and 48 h of incubation. Fertilization with BDS reduced (P < 0.05) DM digestibility after 48 hours of rumen incubation. Carbohydrate additives increased (P < 0.01) DM disappearance at 12, 24 and 48 rumen incubation h but did not not influence in vitro DM digestibility after 12, 24, and 48 h of rumen incubation. Fertilization with BDS and carbohydrate additives at ensiling interaction had no effect (P > 0.05) on CP degradability at 12, 24, and 48 h of rumen incubation, and in vitro CP digestibility after 12, 24, and 48 h of incubation. Carbohydrate additives increased (P < 0.01) CP disappearance at 12, 24 and 48 rumen incubation h and reduced (P < 0.01) in vitro CP digestibility after 12 h of rumen incubation but did not have an effect (P > 0.05) on in vitro CP digestibility after 24 and 48 h of rumen incubation.

In vitro protein fractionation methods for ruminant feeds

Estimating protein fractions and their degradation rate are vital to ensure optimum protein supply and degradation in the digestive system of ruminants. This study investigated the possibility of using the ANKOM gas production system and preserved rumen fluid to estimate the protein fractions and in vitro degradability of protein-rich feeds. Three in vitro methods: (1) gas production method (2) Cornell Net Carbohydrate and Protein System (CNCPS), and (3) the unavailable nitrogen assay of Ross (uNRoss) were used to quantify protein fractions of four feeds (lupin meal, vetch grain, Desmanthus hay, and soybean meal). Rumen fluid mixed with 5% dimethyl sulfoxide and frozen at −20 °C was also compared against fresh rumen fluid in the gas production and uNRoss methods. All three methods ranked the feeds identically in the proportions of available (degradable or ‘a + b’) protein fractions as vetch grain, soybean meal, lupin meal, and Desmanthus hay in decreasing order. The use of fresh rumen fluid produced greater available protein fractions than preserved rumen fluid in all feeds. However, there was no difference between total gas production from lupin meal and vetch grain fermented for 16 h in either rumen fluid source. The in vitro degradable CP (IVDP) was higher for vetch grain (46 and 70%) at the 4th and 8th hours of incubation than other feeds, whereas soybean meal (85%) exceeded the other feeds after the 16th hour of incubation (P < 0.001). The greatest ammonia-N concentration was from soybean meal (1.27 mg/g) and lupin meal (0.87 mg/g) fermented for four hours using fresh rumen fluid. The proportion of fraction 'b' for soybean (82.1% CP) and lupin meals (39.4% CP) from the CNCPS method were not different (P = 0.001) from the fraction 'b' estimation of the gas production method for the same feeds (r = 0.99). Regardless of the methods, a greater water-soluble protein fraction was found from vetch grain (39.6–46.6% CP), and the proportion of fraction ‘c’ or unavailable protein in Desmanthus hay (39.1–41.5% CP) exceeded other substrates (P < 0.001). The strong positive correlation between fractions across different methods and identical ranking of feeds suggests the possibility of using ANKOM gas production apparatus for protein fractionation.

Brachiaria Hybrid and Pennisetum purpureum Supplemented with Pueraria phaseoloides Increased the Concentration of Rumen-Undegradable Protein in Forages for Ruminants

Supplementing tropical grasses with leguminous forages is known to improve the nutritive value of forage-based diets. However, it is not clear how basal grass forages supplemented with Kudzu (Pueraria phaseoloides) affect the nitrogen (N) and crude protein (CP) fractions of grass/legume forages. The aim of this study was to determine the N and CP fractions and in vitro ruminal CP degradability of Brachiaria hybrid (B. ruziziensis × B. decumbens × B. brizantha) and elephant grass (Pennisetum purpureum) supplemented with Kudzu at a target CP content of 133 ± 0.6 g/kg of dry matter (DM). The grass/legume forages were evaluated for total N, buffer-soluble N (BSN), buffer-insoluble N (BISN), non-protein nitrogen (NPN), neutral detergent-insoluble N (NDIN), acid detergent-insoluble N (ADIN), CP fractions A, B1, B2, B3, C, rumen-degradable protein (RDP), rumen-undegraded protein (RUP), and in vitro ruminal CP degradability. The CP concentration of Kudzu was 217 g/kg DM, while grass forages ranged between 79.9 and 112 g/kg DM. The BISN, CP degradability parameters b, and potential degradability were approximately 56, 41, and 74%, respectively, higher in grass forages supplemented with Kudzu. The concentrations of RUP in the grass forages (23.9–32.5 g/kg DM) were significantly improved when they were supplemented with Kudzu (72.0–79.9 g/kg DM). Therefore, we concluded that basal grass forages supplemented with Kudzu to a target CP content can improve the amount of RUP supplied by the forage portion of the diet. This can have a positive effect on forage utilization and animal performance while reducing the cost to feed for ruminants.

Evaluation of degradability of Moringa, Pineapple waste and Plantain herbs by in situ and in vitro gas production technique

Nutritional evaluation of feed ingredients is important for potential use in feed rations. It is very important to determine not only the nutrient content and quality of feeds but also their digestibility prior to adding in the ration. This study was undertaken to assess the potential nutritive value of selected shade-dried herbs of moringa, pineapple waste, and plantain through in situ degradation and in vitro gas production techniques. The study compared 4 treatments, namely moringa (MH), pineapple waste (PwH), plantain (PH) herbs, and a combination of three of them with a ratio of 1:1:1 (MxH). The rumen dry matter (DM) and crude protein (CP) degradability kinetics were analyzed by using the nylon bags (in situ) procedure and the organic matter digestibility and fermentation characteristics were analyzed by in vitro gas production technique. The results of the in situ study revealed that the ruminal dry matter disappearance differed significantly (P&lt;0.001) among herbs at all incubation periods whereas the PH had the greatest disappearance and PwH had the lowest among all herbs. Significantly (P&lt;0.05) the highest potential and effective degradability of dry matter were found in PH and the lowest in PwH among herbs. The ruminal CP disappearance differed significantly (p&lt;0.05) among herbs at all incubation periods. The MH had the greatest CP disappearance whereas PwH had the lowest. Significantly (P&lt;0.05) the highest potential and effective degradability of CP were found in MH and MxH, respectively, and the lowest in PwH among herbs. The results of the in vitro study revealed that cumulative gas production was increased with increasing the periods of incubation for all herbs. Significantly (P&lt;0.05) the highest gas production was found in PH and MH among all herbs at 48h of incubation. The organic matter digestibility and metabolizable energy were found significantly (P&lt;0.05) higher in MH &amp; PH and lower in PwH. Short-chain fatty acids were also significantly (P&lt;0.05) higher in MH &amp; PH and lower in PwH among herbs. It may be concluded that both plantain and moringa herbs showed better potential and effective degradability and also higher organic matter digestibility and metabolizable energy comparable to pineapple waste herbs. Bangladesh Journal of Animal Science 52 (3): 88-98.

Evaluation of legumes for fermentability and protein fractions using in vitro rumen fermentation

Diversifying feed with non-traditional options could minimize the dependency on traditional sources, maintain the feed supply throughout the year, and potentially reduce the cost of raising animals. A total of eight forage legumes including Peltophorum pterocarpum, Neptunia monosperma, Vachellia sutherlandii (Corkwood), Gliricidia sepium, Bauhinia hookeri and three Desmanthus species (JCU4, JCU5 and JCU9) were collected to assess their in vitro fermentability, degradable and undegradable protein fractions using in vitro gas production method. Soybean meal and lucerne hay were used as control. The total gas production ranged from 12.8 mL/g in P. pterocarpum to 127.3 mL/g in soybean meal. The total volatile fatty acid (VFA) concentration from G. sepium (117.7 mM/L) and V. sutherlandii (111.3 mM/L) were larger than other legumes except for soybean meal (157.1 mM/L) and lucerne hay (130.4 mM/L), P < 0.001. The methane gas produced from B. hookeri and P. pterocarpum (0.39 and 0.32 mL/g) was lower than other feeds, P < 0.001. The V. sutherlandii (720 g/kg crude protein (CP)) and G. sepium (745 g/kg CP) had the greatest effective CP degradation (EPD) than other legume species examined, P < 0.001, which was approaching that measured in the control samples. The amount of protein fraction ‘a’ (rapidly degradable) was larger in JCU9 (551 g/kg CP), and G. sepium (472 g/kg CP), and lower in B. hookeri (10.9 g/kg CP) and P. pterocarpum (14.8 g/kg CP), P < 0.001. The V. sutherlandii (386 g/kg CP) and G. sepium (272 g/kg CP) exceeded other legumes in the proportion of fraction ‘b’ (slowly degradable), P < 0.001, but not the controls. The undegradable fraction increased with increasing phenolic content and reached more than 940 g/kg CP for both B. hookeri and P. pterocarpum. The Desmanthus cultivars showed intermediate values among the tested legumes in fermentation characteristics and shows potential to provide slowly degradable protein while reducing methane. The findings indicate the possibility of using V. sutherlandii and G. sepium to substitute other forages for their greater slowly degradable protein content. Moreover, B. hookeri and P. pterocarpum plants emerged as candidates to assist protein protection in the rumen and reduce methane emissions. However, these legumes need to be evaluated in vivo before promoting for further use to confirm the variability reported here.

Nitrogen efficiency in cows fed red clover- or alfalfa-silage-based diets differing in rumen-degradable protein supply

Nitrogen pollution is an important issue in modern agriculture. For the dairy industry, increasing the efficiency of milk protein production may reduce the environmental impact of commercial farms. Optimal N utilization can be achieved by combining forage and concentrate varying in their degradability in the rumen. The aim of this study was to gain insight into the fate of dietary N as affected by forage type and rumen-degradable protein supply in lactating dairy cows, with an emphasis on milk N efficiency. Four rumen-fistulated Holstein cows were used in a 4 × 4 Latin square design balanced for residual effects. Four treatments consisting of a 2-by-2 factorial arrangement of alfalfa silage (AL) or red clover (RC)-based diets designed to satisfy 100 (rumen-degradable protein (RDP)-100) or 85% (RDP-85) of rumen degradable protein demand, by varying the amounts of ground and steam-flaked corn grain, as well as non-treated and heat-treated soybean meals. Dietary CP concentrations were greater in diets based on AL as compared with RC (P < 0.01). Kinetics of in sacco N disappearance revealed that the rapidly disappearing fraction was lower with RC than with AL diets, and this difference tended to be more pronounced for RDP-85 than RDP-100 (interaction, P = 0.06). On the contrary, slowly disappearing N fraction and fractional rate of disappearance were greater for RC as compared with AL diets (P < 0.01). Reducing RDP from 100 to 85% of requirements increased the slowly disappearing N fraction, but decreased the rapidly disappearing fraction and the fractional rate of disappearance of N (P < 0.01). Intakes of DM and N were lesser with RC compared with AL, and these differences were more pronounced with RDP-85 than with RDP-100 (interaction, P ≤ 0.04). As a proportion of N intake, fecal excretion tended to be greater (P = 0.09), whereas urinary excretion was lower (P = 0.04) with RC than with AL diets. Milk yield (tendency; P = 0.07) and total N secreted in milk were reduced (P < 0.01) with RC compared with AL diets. Feeding RC increased milk N efficiency (g of milk N/ kg of N intake) as compared with AL, and this difference tended to be of greater magnitude for RDP-85 than RDP-100 (interaction, P = 0.06). In conclusion, combining forage and concentrate of different CP degradability can improve milk N efficiency in dairy cows.

In situ ruminal degradability and intestinal digestibility of dry matter and crude protein of low-protein fraction from sunflower meal

The objective of this study was to evaluate rumen degradation kinetics and intestinal digestibility of low-protein fraction from sunflower meal (LPSFM). Three non-lactating Jersey cows with an average body weight of 436 ± 18 kg fitted with a rumen and T-type duodenal cannulas were used in the experiment. Five samples of LPSFM from different batches produced in 20-d intervals were collected and incubated in the rumen of the cows for 0, 2, 4, 8, 16, 24 and 48 h in 6 replicates. The average CP content of LPSFM was 175 (SD = 6.98) g/kg. Data were fitted to nonlinear regression model and analyzed statistically using SPSS. The soluble or rapidly degradable fraction а of LPSFM dry matter (DM) ranged from 105 to 137 (SD = 11.3) g/kg. The effective degradability of DM at assumed rumen outflow rate of 0.06/h ranged from 293 to 338 (SD= 16.3) g/kg. Fraction a of CP ranged from 124 to 189 (SD = 23.9) g/kg. Effective degradability of LPSFM CP at rumen outflow rate of 0.06/h ranged from 515 to 560 g/kg (SD = 16.2). Intestinal digestibility of LPSFM (after 16-h rumen incubation) DM and CP measured by the mobile bag technique varied from 318 to 349 g/kg (SD = 10.5) and from 766 to 820 g/kg (SD = 17.7), respectively. The average estimated Protein Digestible in the small Intestine (PDI) and Rumen Protein Balance (RPB) of the LPSFM samples analyzed in the current study, following equations in the Bulgarian feed evaluation system (at 0.06/h outflow rate), were 113 (SD = 1.67) g/kg and 125 (SD = 14.9) g/kg, respectively. The protein degradability and digestibility values obtained in this experiment can be effectively used in formulating rations for ruminant animals.

Extrusion of lupines with or without addition of reducing sugars: Effects on the formation of Maillard reaction compounds, partition of nitrogen and Nε-carboxymethyl-lysine, and performance of dairy cows

The extrusion of leguminous seeds induces the formation of Maillard reaction compounds (MRC) as a product of protein advanced glycation and oxidation, which lowers protein degradability in the rumen. However, the quantitative relationship between the parameters of pretreatment (i.e., addition of reducing sugars) and extrusion, and the formation of MRC has not been established yet. Moreover, the fate of the main stable MRC, Nε-carboxymethyl-lysine (CML), in the excretory routes has never been investigated in ruminants. We aimed to test the effects of the temperature of extrusion of white lupines with or without addition of reducing sugars on the formation of MRC, crude protein (CP) degradability in the rumen, N use efficiency for milk production (milk N/N intake), and performance of dairy cows. Two experiments with a replicated 4 × 4 Latin square design were conducted simultaneously with 16 (3 rumen-cannulated) multiparous Holstein cows to measure indicators of ruminal CP degradability (ruminal NH3 concentration, branched-chain volatile fatty acids), metabolizable protein supply (plasma essential AA concentration), N use efficiency (N isotopic discrimination), and dairy performance. In parallel, apparent total-tract digestibility of dry matter, organic matter, neutral detergent fibers, N, total Lys and CML, and partition of N and CML were measured with 4 cows in both experiments. The diets consisted on a DM basis of 20% raw or extruded lupines and 80% basal mixed ration of corn silage, silage and hay from permanent grasslands, pelleted concentrate, and a vitaminized mineral mix. Expected output temperatures of lupine extrusion were 115°C, 135°C, and 150°C, without and with the addition of reducing sugars before extrusion. The extrusion numerically reduced the in vitro ruminal CP degradability of the lupines, and consequently increased the predicted supply of CP to the small intestine. Nitrogen balance and urinary N excretion did not differ among dietary treatments in either experiment. Milk yield and N use efficiency for milk production increased with extrusion of lupines at 150°C without addition of reducing sugars compared with raw lupines. Nitrogen isotopic discrimination between dietary and animal proteins (the difference between δ15N in plasma and δ15N in the diet) were lower with lupines extruded at 150°C without and with addition of reducing sugars. Regardless of sugar addition, milk true protein yield was not affected, but milk urea concentration and fat:protein ratio were lower with lupines extruded at 150°C than with raw lupines. In the CML partition study, we observed that on average 26% of the apparently digested CML was excreted in urine, and a much lower proportion (0.63% on average) of the apparently digested CML was secreted in milk, with no differences among dietary treatments. In conclusion, we showed that the extrusion of white lupines without or with addition of reducing sugars numerically reduced enzymatic CP degradability, with limited effects on N partition, but increased milk yield and N use efficiency at the highest temperature of extrusion without addition of reducing sugars.

Evaluation of a new commercial source of monensin in lactating dairy cows and continuous culture fermenters

The objective of this experiment was to evaluate a new commercial source of monensin (MON) on performance of mid-lactation dairy cows and fermentation parameters of dual-flow continuous culture fermenters. In Experiment 1, 43 Holstein cows (25 multiparous and 18 primiparous; 175 ± 97 DIM; 45.3 ± 10 kg/d milk yield; 692 ± 68 kg BW; mean ± SD) were used in a randomized block design experiment with a 15-d covariate and a 9-wk treatment period. The first 3 wk of the treatment period were considered adaptation and the last 6 wk were used for data collection and analysis. Treatments were: Control (CTR; no MON added), Rumensin® 90 (RUM; 350 mg/d MON from Elanco Animal Health Inc.), and Monovet® 90 (MVet; 350 mg/d MON from Huvepharma® Inc. US). All cows were fed the same base diet throughout the experiment and treatments were top-dressed during the treatment period. Orthogonal contrasts were used to evaluate CTR vs. MON (RUM + MVet) and RUM vs. MVet. Compared with CTR, MON tended to increase milk yield (43.8 vs. 42.3 kg/d) but did not affect DMI or feed efficiency. The MVet treatment improved feed efficiency compared with RUM (1.70 vs. 1.58). Treatments did not affect milk fat content and yield, milk protein yield, MUN concentration, or energy-corrected milk yield. In Experiment 2, nine continuous culture fermenters were used in a randomized block design experiment with two 10-d periods. Fermenters were fed once a day approximately 100 g DM of the same diet fed in Experiment 1. Treatments were: CTR, RUM (2 mg/L MON from Rumensin® 90), and MVet (2 mg/L MON from Monovet® 90). Monensin did not affect DM, OM, NDF, ADF, and CP degradability or total VFA production (mmol/d), but decreased acetate, butyrate, and isobutyrate molar proportions and increased propionate molar proportion compared with CTR. Both sources of MON decreased acetate to propionate ratio compared with CTR (1.61 vs. 2.40). Adding MON increased daily production of propionate (74.1 vs. 108 mmol/d) and decreased that of butyrate and isobutyrate compared with CTR. Monensin supplementation decreased ammonia-N production (433 vs. 545 mg/d) compared with CTR. Overall, results indicate MON tended to increase milk yield and altered VFA profile in the rumen and in vitro, and that MVet is a suitable source of MON for dairy cows.

Effect of processing with ozone on in vitro and in situ ruminal degradability and intestinal digestibility of feather meal protein

This study aimed to investigate the effect of processing feather meal (FM) with ozone (O3) gas on nutrient content, ruminal degradability, and intestinal digestion of crude protein (CP) using in vitro and in situ techniques. Experimental treatments were designed as control (not-processed), O3-processed FM for 12 h (h; treat 1), O3-processed FM for 24 h (treat 2), and O3-processed FM for 48 h (treat 3). Five Ghezel sheep equipped with ruminal cannulas were used to measure the nutrient degradability and to obtain ruminal fluid for in vitro gas production. Processing with O3 gas significantly decreased dry matter (DM), ether extract (EE), and Ash content of the FM compared to the control (P < 0.05). Processing FM by O3 increased the volume of in vitro gas production (P < 0.05). The soluble and potentially degradable fractions of the DM and CP showed a significant increase with increasing processing time (P < 0.05). Processing with O3 gas increased quickly degradable protein (QDP), rumen degradable protein (RDP), effective rumen degradable protein (ERDP), and digestible undegradable protein (DUP) content as a proportion of feather meal CP. Still, undegradable dietary protein (UDP) decreased significantly. Intestinal digestibility of rumen undegradable protein (RUP) and Metabolize Protein (MP) content of the FM was also significantly increased with increased processing time and the highest values were achieved after 48 h of processing (P˂0.05). According to the results of this experiment, it can be concluded that processing FM using O3 for 48 h increases its nutritional value in ruminant nutrition.

Silage additives improve fermentation quality, aerobic stability and rumen degradation in mixed silage composed of amaranth and corn straw.

The objective of this research was to investigate effects of different additives on the fermentation quality, aerobic stability and rumen degradation of mixed silage composed of amaranth and corn straw. The mixture ratio of amaranth to corn straw was 78%: 22%. Three additives were selected in this study and five groups were as follows: control group (CON, without additive), lactic acid bacteria group (LAB, 5 mg/kg, Lactobacillus plantarum ≥ 1.6×1010 CFU/g and L. buchneri ≥ 4.0×109 CFU/g), glucose group (GLU, 30 g/kg), cellulase group (CEL, 2 mg/kg) and lactic acid bacteria, glucose and cellulase group (LGC, added at the same levels as in individual group). The period of ensiling was 60 days. Fermentation quality, chemical composition and aerobic stability of mixed silage were analyzed. Four cows with permanent ruminal fistula were selected as experimental animals. Nylon bag technique was used to study rumen degradation characteristic of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of mixed silage. Compared with CON group, the addition of different silage additives could improve mixed silage quality of amaranth and corn straw to some extent. Combining three additives significantly increased (P < 0.05) the DM, CP and lactic acid contents, whereas decreased (P < 0.05) the ADF and NDF contents as well as pH and ammonia nitrogen/total nitrogen. Moreover, the aerobic stability and rumen degradation of DM, CP and NDF were significantly improved (P < 0.05) in LGC group when compared to other groups. In conclusion, the combined addition of lactic acid bacteria, glucose and cellulase increased DM, CP and lactic acid contents as well as lactic acid bacteria count, decreased NDF and ADF contents and aerobic bacteria and mold counts, improved aerobic stability and rumen degradation of amaranth and corn straw mixed silage.

Analysis of rumen degradation characteristics of forage crude protein in goat

The quality of feed given to ruminants can be determined from the degradation of nutrient content in the rumen. This study aimed to determine the pattern of forage degradation and the characteristics degradation of crude protein in the rumen using the in sacco method. The study used 4 fistulae kacang goats with an average body weight of 14.57 kg. The forage used consisted of R1: elephant grass (Pennisetum purpureum), R2: mini elephant grass (Pennisetum purpureum cv. Mott), R3: guinea grass (Panicum maximum), and R4: signal grass (Bracharia decumbens). The nylon bag is made of polyester measuring 8x4 cm with a porosity of 40 µm. Feed samples were put into the rumen and incubated for 0, 4, 8, 12, 24, 48, and 72 hours. The parameters measured were consumption, patterns, and forage degradation characteristics by calculating the values of a, b, c, a+b, lag time, and ED. Determination characteristics of feed degradation in the rumen by in sacco method will be analyzed. The results showed that the characteristics of crude protein degradation had significant differences in fraction values a, b, a+b, and lag time (P&lt;0.05), while c and ED did not have significant differences (P&gt;0.05). In conclusion the crude protein of the degradation characteristics in the rumen were: elephant grass (a: 9.88%, b: 64.37%, and c: 0.06/h-1), mini elephant grass (a: 16.50%, b: 45.24%, and c: 0.05/h-1), guinea grass (a: 7.42%, b: 68.24%, and c: 0.05/h-1), and signal grass (a: 6.79%, b: 56.19%, and c: 0.07/h-1). So, grass can provide sufficient protein for microbial growth in the rumen for ruminants.

Linkage of in situ ruminal crude protein degradation with ruminal degradation of amino acids and phytate from different soybean meals in dairy cows

Linkage of in situ ruminal crude protein degradation with ruminal degradation of amino acids and phytate from different soybean meals in dairy cows

Cultivar and Harvest Stage Effects on Nutritive Value of Whole Crop Oat (Avena sativa L.) Silages

This study was carried out to investigate the effects of feed value and dry matter (DM) on rumen degradability properties of silages of oat (Avena sativa L.) cultivars (Kahraman and Kırklar) at different harvest stages (pre-flowering, flowering, milk, soft dough). Field and digestibility trials were carried out in randomized blocks, in a 2x4 factorial trial design during the 2016-2017 vegetation period. For the rumen digestibility of silages, three heads of Karayaka rams with rumen cannulated, average 50±3 kg body weight and 3 years old were used. As a result of the experiment, It was observed that the crude protein (CP) level of Kahraman cultivar was higher than that of Kırklar cultivar, and the CP content of cultivars decreased from the pre-flowering period to the soft dough period. In addition, with the progress of the growing period, the neutral detergent fiber (NDF) content of the varieties increased. Also, the net energy lactation (NEL) level of Kırklar cultivar was higher than Kahraman cultivar. However, the NEL levels of the cultivars decreased with the progression of the growing period. The water solubility of DM and CP of Kahraman cultivar was higher than that of Kırklar cultivar. In addition, effective dry matter degradability (EDMD) decreased with growth period in both cultivars. It was observed that the effective crude protein degradability (ECPD) rate of Kahraman cultivar was higher than that of Kırklar cultivar and ECPD rate of cultivars decreased with the progress of the growing period. As a result, Kahraman cultivar may be preferred more than Kırklar cultivar, since it has higher EDMD and ECPD in the rumen and also has higher RFV value.

Degradability of Vicia ervilia Grain Using In Situ and CNCPS Methods, and Model-Based Analysis of Its Ruminal Degradation

Using nylon bag techniques, Cornell net carbohydrates and protein systems (CNCPS), and scanning electron microscopy, the authors examined the digestibility and structure of Vicia ervilia (ervil, bitter vetch) after steam flaking, roasting, and microwave processing. During the in situ technique, the samples were incubated at 0, 2, 4, 6, 8, 12, 16, 24, 36, and 48 h. For the description of the ruminal DM (dry matter) and CP (crude protein) degradation kinetics of treated and untreated Vicia ervilia, different models were selected as the best fit for the dry matter (DM) and crude protein (CP) degradation parameters of steam flaked samples. The results showed that both the steam flaking and microwave treatment samples contained high levels of non-protein nitrogen and buffer soluble protein, respectively. In comparison with steam flaking and microwave treatment, roasting decreased and increased the buffer soluble protein and neutral detergent insoluble protein, respectively. The control treatments showed the highest levels of neutral detergent soluble protein and the lowest levels of acid detergent soluble protein. Moreover, steam flaking and roasting decreased and increased the amount of acid detergent insoluble protein, respectively. When using dry heat (microwave and roasting), the acid detergent soluble and insoluble protein fractions were increased. As a result of this experiment, the nitrogen fractions were altered using heat processing. Hence, protein fermented feed and ruminal fermentation conditions can be expressed using these results.

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.

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.

Linkage of in situ ruminal crude protein degradation with ruminal degradation of amino acids and phytate from different soybean meals in dairy cows

Linkage of in situ ruminal crude protein degradation with ruminal degradation of amino acids and phytate from different soybean meals in dairy cows

Evaluation of Rumen Degradation Kinetics of Low-Lignin Alfalfa 'Hi-Gest® 360' in Saskatchewan Canada.

The objective of this study was to determine rumen degradation kinetics of new low-lignin alfalfa (Medicago sativa L.) cv. Hi-Gest®360 (HiGest) in comparison with conventional alfalfa cv. AC Grazeland (Grazeland) in monoculture and binary mixtures at different maturity stages. Two cultivars of alfalfa (HiGest, and AC Grazeland) and their binary mixtures with hybrid bromegrass (HBG; cv. AC Success), grown in 2019 at two locations (Saskatoon and Lanigan), were cut at three maturity stages of alfalfa (1 = 10% bloom; 2 = 40% bloom; and 3 = 100% bloom). Rumen degradation characteristics, including rapidly degradable fraction (S), potentially degradable fraction (D), undegradable fraction (U), degradation rate (Kd), lag time (T0), and effective degradability (ED) of each component were determined using in situ technique and were analyzed by a first-order kinetic equation described by Ørskov and McDonald with lag time. Generally, in alfalfa monoculture, S or D were decreased and U was increased without affecting Kd and T0, resulting in decreased ED fraction with increasing stage of maturity. In binary mixtures, plant maturity stages have negligible effects on rumen degradation characteristics of CP. HiGest had higher effective degradability of DM (EDDM) as well as of NDF (EDNDF) than Grazeland. In conclusion, HiGest had greater DM and NDF rumen degradation potential relative to Grazeland. HiGest and Grazeland were different in DM and CP degradation patterns, with HiGest having higher EDDM and EDCP than Grazeland.