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This study aimed to evaluate the ruminal degradation and intestinal digestion of nutrients of two cultivars of oat grains (CDC Nasser and CDC Seabiscuit) in comparison with a barley grain (CDC Meredith that was considered the control treatment) in dairy cows. Nasser showed higher rumen undegradable protein (RUP; P < 0.01) and intestinal digestible protein (P < 0.01) than Seabiscuit or control. However, the total digestible protein was not different among grain varieties (P = 0.25). The in vitro intestinal digestibility of RUP (dIBP) for Nasser was higher than control (P = 0.02); however, the dIBP in Seabiscuit did not differ from other cultivars. The intestinal digestible rumen bypass starch and total digestible starch were lower in the oat grain varieties than in the control (P < 0.01). The truly absorbed protein supplied to the small intestine (DVE) was highest for control, intermediate for Seabiscuit, and lowest for Nasser (P < 0.01). Moreover, control showed a higher estimated feed milk value than oat varieties (P < 0.01). In conclusion, Seabiscuit shared similar rumen degradation and intestinal digestibility with control suggesting that Seabiscuit oat grain could in some extension replace barley grain in diets for dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this study was to characterize ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from canola feedstock (canola seeds) and coproducts (meal and pellets) from bio‐oil processing which were impacted by source origin. The feedstocks and coproducts (mash, pellet) were randomly collected from five different bio‐oil processing plants with five different batches of samples in each bio‐processing plant in Canada (CA) and China (CH). In situ rumen degradation kinetics were determined using four fistulated Holstein cows with incubation times at 0, 2, 4, 8, 12, 24 and 48 h. Intestinal digestions were determined using the three‐step in vitro method with preincubation at 12 h. The DVE/OEB and National Research Council systems were applied to evaluate the truly absorbable nutrient supply to dairy cows and feed milk values (FMVs). The results showed that in situ undegradable fractions (U) (p = 0.025) were higher in CA meals, and potentially degradable fraction of D was higher (p = 0.016) in CH meals. CH meals had higher total digestible dry matter (TDDM, p = 0.018) and intestinal digestibility of protein (dIDP, p = 0.016). Canola meals from CA had lower MREE (microbial protein synthesized in the rumen based on available rumen degradable protein; p = 0.011) and DVME (rumen synthesized microbial protein digested in the small intestine; p = 0.011) and had higher ECP (endogenous protein in the small intestine, p = 0.001) and absorbed endogenous crude protein (truly absorbed ECP in the small intestine) than CH (p = 0.001). The FMV evaluated based on the metabolic protein and net energy showed no differences between CA and CH in both coproducts and feedstocks. [ABSTRACT FROM AUTHOR]

Tannins can be utilized to increase rumen undegradable protein (RUP) by their capacity to form complexes with diverse nutrients present in the feed. In that regard, high-performance ruminants demand elevated RUP levels. The objective of this study was to evaluate the effects of incorporating varying levels of tannin into three protein sources (cottonseed, peanut, and soybean meals) on ruminal kinetic parameters, ruminal fermentation, and intestinal digestibility. Thus, three in situ experiments were conducted to investigate the ruminal degradation kinetics, where Fraction A represents the soluble portion, Fraction B relates to the portion potentially degraded in the rumen, and kd denotes the degradation rate of Fraction B, for both dry matter (DM) and crude protein (CP) in the rumen. Additionally, the study assessed dry matter effective degradability (ED), rumen undegradable protein (RUP), and intestinal digestibility (ID). These experiments utilized three cannulated animals for the in situ incubations. Regarding cottonseed meal in terms of DM degradation kinetics, tannin inclusion had a quadratic effect on fraction A (p < 0.01), B (p = 0.10, trend), kd (p = 0.03), and ED (p < 0.01). Fraction A of CP had a cubic effect (p = 0.03), being greater for the control compared with the other treatments. The inclusion of tannin linearly increased RUP (p < 0.01). The RUP proportion increased 29, 33, and 45% when 20, 40, and 60 g/kg tannin were used, respectively, compared to the control. For peanut meal, the A fraction of protein and RUP responded quadratically as tannin was included in peanut meal (p < 0.01). However, tannin levels did not affect fraction B of protein and ID. Regarding soybean meal, fractions A and B of DM and ED had cubic effects (p < 0.01), being greater for the control compared with the other treatments, and responded quadratically as tannin increased. Also, tannin inclusion had a cubic effect on fractions A and B of protein, RUP, and ID (p < 0.01). The cubic behavior showed greater B fraction and ID and lower A fraction and RUP for the control compared other treatments (p < 0.01). Tannins offer a promising avenue for elevating RUP levels in diets featuring cottonseed and peanut meals. Nevertheless, no advantages were observed when treating soybean meal with tannin.

Tannins can be utilized to increase rumen undegradable protein (RUP) by their capacity to form complexes with diverse nutrients present in the feed. In that regard, high-performance ruminants demand elevated RUP levels. The objective of this study was to evaluate the effects of incorporating varying levels of tannin into three protein sources (cottonseed, peanut, and soybean meals) on ruminal kinetic parameters, ruminal fermentation, and intestinal digestibility. Thus, three in situ experiments were conducted to investigate the ruminal degradation kinetics, where Fraction A represents the soluble portion, Fraction B relates to the portion potentially degraded in the rumen, and kd denotes the degradation rate of Fraction B, for both dry matter (DM) and crude protein (CP) in the rumen. Additionally, the study assessed dry matter effective degradability (ED), rumen undegradable protein (RUP), and intestinal digestibility (ID). These experiments utilized three cannulated animals for the in situ incubations. Regarding cottonseed meal in terms of DM degradation kinetics, tannin inclusion had a quadratic effect on fraction A (p < 0.01), B (p = 0.10, trend), kd (p = 0.03), and ED (p < 0.01). Fraction A of CP had a cubic effect (p = 0.03), being greater for the control compared with the other treatments. The inclusion of tannin linearly increased RUP (p < 0.01). The RUP proportion increased 29, 33, and 45% when 20, 40, and 60 g/kg tannin were used, respectively, compared to the control. For peanut meal, the A fraction of protein and RUP responded quadratically as tannin was included in peanut meal (p < 0.01). However, tannin levels did not affect fraction B of protein and ID. Regarding soybean meal, fractions A and B of DM and ED had cubic effects (p < 0.01), being greater for the control compared with the other treatments, and responded quadratically as tannin increased. Also, tannin inclusion had a cubic effect on fractions A and B of protein, RUP, and ID (p < 0.01). The cubic behavior showed greater B fraction and ID and lower A fraction and RUP for the control compared other treatments (p < 0.01). Tannins offer a promising avenue for elevating RUP levels in diets featuring cottonseed and peanut meals. Nevertheless, no advantages were observed when treating soybean meal with tannin. [ABSTRACT FROM AUTHOR]

Dynamics of starch digestion in dairy cows fed extruded pellets differing in physical functional properties were investigated by measuring starch digestibility, post‐prandial rumen fermentation patterns, and post‐prandial duodenal starch appearance. Additionally, starch digestion effects on neutral detergent fiber (NDF) digestibility and methane (CH4) emission were studied. Pure barley was extruded to produce three treatments having pellets of either low‐density (LD), medium‐density (MD) or high‐density (HD). The experiment was conducted in a 3 × 3 Latin square design using three lactating Danish Holstein cows fitted with ruminal, duodenal and ileal cannulas. After the allocation of experimental concentrate directly into the rumen through the rumen cannula, cows were fed a basal diet low in starch. Eight samples were collected on equal time intervals (9 h) from duodenal digesta, ileal digesta and feces (grab sample) to determine digestibility. For post‐prandial rumen fermentation patterns, four sample sets of rumen dorsal, medial and ventral fluid were taken from each cow, whereas for post‐prandial duodenal starch appearance, 14 samples of duodenal chyme were obtained from each cow relative to morning feeding of experimental concentrate at 07:00 h. Ruminal, small intestinal, hindgut and total tract digestibility of starch did not differ among treatments. Similarly, NDF digestibility and CH4 emission also remained unaffected by treatments. However, compared with the LD and MD treatments, the HD treatment showed higher acetate: propionate ratio at all positions in the rumen and a higher post‐prandial duodenal starch appearance. This indicates lower ruminal starch degradation (RSD) and higher starch flow into the small intestine for HD treatment. In conclusion, the current study indicates that pellets' physical properties can manipulate RSD, where pellets with high density and fluid stability can partly shift starch digestion from the rumen to the small intestine. Indeed, further investigations are needed. [ABSTRACT FROM AUTHOR]

Simple Summary: Scientists constantly seek techniques that may improve animal-feed usage, because they can reduce environmental impact and increase the profitability of feedlot systems. In beef-cattle production systems, high-performance animals need a greater protein supply that escapes rumen fermentation to be digested in the intestine compared to low-performance animals. This fraction is called rumen undegradable protein (RUP). Cottonseed meal is a possible protein source with an excellent amino-acid profile; however, cottonseed meal has low RUP content, which can be increased by applying heat and xylose. Thus, we submitted this feed to different heat techniques (autoclave, conventional, and microwave ovens), with and without xylose treatment, to increase its RUP content. Our results suggest that the evaluated processing methods may increase cottonseed meal RUP. The best treatments under the experimental conditions were: for the autoclave, xylose-treated cottonseed meal with 8 and 16 min heating; for conventional oven, 90 min heating for xylose-treated cottonseed meal; and for the microwave oven, xylose-treated cottonseed meals with 2, 4, and 6 min heating. Further studies are necessary to confirm the results found here and evaluate the effects of these processed ingredients on ruminal fermentation parameters, animal performance, and economic viability. The ruminal kinetics of protein sources may be changed by heat and sugar treatments. Thus, these processing methods may be used as alternatives to increase beef-cattle diets' rumen undegradable protein (RUP). We aimed to evaluate the effects of processing cottonseed meals with autoclave, conventional, and microwave ovens, with and without using xylose, on the ruminal kinetics degradation parameters and intestinal digestibility (ID). In situ studies were conducted, and each sample was incubated in the rumen to determine dry matter (DM) and crude protein (CP) rumen degradation kinetics. In vitro studies were also conducted to evaluate ID. The control treatment had a greater soluble fraction for DM and CP than processed cottonseed meals (p < 0.05). The addition of xylose decreased both DM and CP water-soluble fractions (fraction A) of cottonseed meal heated in a conventional oven (p < 0.05). Compared to the control, we observed a decrease in effective degradability and increased RUP for all processed methods (p < 0.05). Furthermore, conventional and microwave ovens showed greater ID than the control. Moreover, xylose-treated groups heated in the autoclave and conventional ovens had greater ID than xylose-untreated cottonseed meal. Under these experimental conditions, cottonseed RUP was increased by the evaluated processing methods. [ABSTRACT FROM AUTHOR]

Simple Summary: Protein is a nutrient with a high cost in beef production. Thus, it is crucial to study techniques that improve animal protein utilization. Furthermore, the more productive the animal, the higher its rumen undegradable protein (RUP) requirements. This protein escapes ruminal fermentation to be digested in the intestine. Peanut meal is a feasible byproduct with excellent protein content but low RUP. This problem is commonly solved by submitting the feed to heat processing methods (such as autoclaves or conventional and microwave ovens) with or without treatment with sugars (such as xylose). Thus, here, we submit peanut meal to these different heat techniques, with and without xylose treatment, aiming to increase its RUP content. Overall, our results suggest that the tested methods effectively increased the RUP content of the peanut meal. The best treatments were as follows: for an autoclave, xylose-treated peanut meal with 24 min of heating; for a conventional oven, 60 min of heating for both xylose-treated and -untreated peanut meals; and for a microwave oven, xylose-treated peanut meals with 4 and 6 min of heating. Nevertheless, further research is recommended to evaluate the effects of these ingredients on the parameters of ruminal fermentation and animal performance. Peanut meal has an excellent total protein content but also has low rumen undegradable protein (RUP). High-performance ruminants have high RUP requirements. We aimed to evaluate the effects of processing peanut meal with an autoclave and conventional and microwave ovens, with and without using xylose on its ruminal kinetics degradation parameters and intestinal digestibility (ID). In situ studies were conducted to determine dry matter (DM) and crude protein (CP) rumen degradation kinetics. In vitro studies were conducted to evaluate intestinal digestibility (ID). The control treatment had a greater fraction A for DM and CP than peanut meals processed with an autoclave or conventional oven. The control had greater kd for CP compared with the microwave. The addition of xylose decreased fraction A, the degradation rate of fraction B (kd) and RUP, and increased the protein B fraction of autoclaved peanut meal. We observed a decrease in effective degradability (ED) and increased RUP for processed treatments in all experiments compared with the control. Processing methods did not affect the protein ID of autoclaved peanut meal compared to the control. An interaction between xylose and heating time was observed, where increasing heating time linearly reduced the ID of xylose-untreated treatments. Overall, these results suggest that the tested methods effectively increased the RUP content of peanut meal. [ABSTRACT FROM AUTHOR]

Byproducts in livestock diets have the potential to reduce the environmental impact of food production and the cost of animal feeding. The objective was to evaluate the extent and rate of nutrient degradability of potato and other byproducts by rumen microorganisms in vitro. Byproducts included barley malt sprouts, fries, dry peel, and hopper, which were supplied by Performix Nutrition Solutions (Nampa, ID). Two in vitro incubators (DAISYII, ANKOM Technology) each with four incubation jars were used to evaluate ruminal degradability of dry matter (DM) and neutral detergent fiber (NDF). Each jar contained 1,600 mL buffer solution (ANKOM Technology), 400 mL rumen contents (collected from two ruminally cannulated cows), 14 filter bags (F57, ANKOM Technology) with 0.5 g of ground byproduct, 14 filter bags with 0.5 g of ground corn (standard), and 14 blank bags. Each jar was purged with CO2 and filter bags were incubated at 39°C for 0, 3, 6, 9, 12, 24, and 48 h, then removed, rinsed, dried at 55˚C for 48 h, weighed, and analyzed for DM and NDF. Each byproduct was incubated in 3 jars on two different d (6 replicates). Degradation of DM was separated into fractions A (disappearance at 0 h), C (DM remaining after 48 h) and B (100%-A-C). Rate of degradation for fraction B was the slope of the natural logarithms of the DM disappearance. All byproducts were compared with standard corn grain as the control. Fraction A for DM was not different (P > 0.40) for barley malt sprouts (35.4%) and hopper (33.7%), and less (P < 0.05) for dry peel (27.8%) and fries (13.2%) when compared with corn grain (33.4%). Fraction B for DM was greater (P < 0.05) for fries (74.0%), not different (P = 0.44) for hopper (56.1%), and less (P < 0.05) for dry peel (43.6%) and sprouts (37.0%) when compared with corn grain (53.9%). Rate of DM degradation for fraction B was greater (P < 0.05) for fries (9.9%/h) and hopper (7.0%/h), and not different (P > 0.16) for dry peel (4.6%/h) and sprouts (3.0%/h) when compared with corn grain (3.8%/h). Fraction C for DM was greater (P < 0.05) for dry peel (28.6%) and sprouts (27.6%), and not different (P = 0.20) for fries (12.9%) and hopper (10.3%) when compared with corn grain (12.7%). The indigestible frac- tion of NDF after 48 h of incubation was greatest for dry peel (58.5%), intermediate for sprouts (40.1%) and hopper (36.7%), and least for fries (25.4%; P < 0.05). These results demonstrate that the extent and rate of ruminal DM degradability of various potato and other byproducts differ and may be more or less degradable in the rumen compared with corn grain. [ABSTRACT FROM AUTHOR]

Background and Objectives: The imbalance between the production of rumen degradable protein (RDP) and microbial protein (MP) decreases animal performance and increases environmental pollution. Therefore, to meet the requirements for microbial protein without excessive N, rations must also be balanced for RUP and RDP. Sunflower meal (SFM) is a protein source for ruminants. However, its use in ruminant nutrition is often limited by the high protein degradability in the rumen. Irradiation is a new method that is considered in the processing of protein sources. The aim of this study was to investigate the effect of irradiation on rumen degradation kinetics and in vitro digestibility of SFM. Materials and Methods: SFM samples were irradiated with the use of the gamma-ray (GR) in doses of 20 and 40 KGy and microwave (MV) at 800 W for 3 and 5 minutes. The irradiation of samples was done at the Radiation Application Research Institute affiliated with the Atomic Energy Organization. The chemical composition of unirradiated and irradiated SFM was determined. Degradability parameters of the samples were measured by nylon bag technique using three rumen-fistulated Dashtyari cattle for 0, 2, 4, 8, 16, 24, and 48 hours. The two-step digestion technique was used to determine the digestibility of SFM. Statistical analysis of data was performed using SAS software. Results: GR irradiation decreased DM of SFM. Irradiation of SFM caused a reduction in EE, NDF, ADF, and Ash and increased CP compared to unirradiated SFM. GR irradiation decreased washout fraction degradation, the rate constant of degradation of b fraction and ERD, and increased potentially degradable fraction of SFM. MV irradiation for 5 minutes increased the washout fraction of CP and decreased the potentially degradable fraction (P<0.05). Treatment of SFM by MV for 5 minutes caused a reduction in the potential degradability of CP (P<0.01). Processing of SFM with MV for 3 minutes decreased ERD of CP at a rumen outflow rate of 0.02h-1(P<0.05). GR irradiation decreased RDP and increased RUP and metabolizable protein (MP) (P<0.01). Irradiation of SFM with GR increased ERD of CP at rumen outflow rates of 0.05h-1 and 0.08h-1 (P<0.01). Irradiation of SFM with MV increased RDP (P<0.01) and increased ERD and MP at a rumen outflow rate of 0.02h-1 (P<0.01). MV irradiation for 3 minutes at rumen outflow rates of 0.02h-1 and 0.05h-1 increased RUP (P<0.05). The coefficient of crude protein conversion into RDP and RUP in GR- irradiated SFM was decreased and increased respectively (P<0.01). MV irradiation for 3 minutes at rumen outflow rate of 0.02h-1 coefficient of crude protein converts into RDP and RUP decreased and increased respectively (P<0.05). The in vitro digestibility of SFM was unaffected by irradiation (P>0.05). Conclusion: The experiment results indicated that irradiation of SFM with GR had a better effect on increasing RUP and improving the quality of SFM for use in diets of lactating cows. [ABSTRACT FROM AUTHOR]

BACKGROUND The effects of growth stage (GS) and ensiling were assessed on whole‐crop oat's (Avena sativa L. cv. Cantara) chemical composition, silage fermentation quality and in situ ruminal degradability. Oat was harvested and ensiled at six GS: boot, heading, water ripe, early milk, early dough and grain ripe (144, 151, 178, 234, 362 and 512 g kg−1 of dry matter (DM) of whole‐crop forage, respectively). RESULTS: GS influenced chemical composition, silage fermentation quality and ruminal degradability of whole‐crop oat. Lower DM and higher water‐soluble carbohydrates (WSC) contents lead to adequate forage compaction and fermentation at early GS; however, effluent was produced until the dough stage (L and Q; P ≤ 0.003). Advancing in maturity increased (P < 0.001) crop yield (4.5 to 9.4 t DM ha−1), DM (144 to 512 g kg−1), neutral detergent fibre (NDF; 537 to 571 g kg−1 DM), lignin (44.6 to 71.3 g kg−1 DM) and starch contents (26.4 to 201 g kg−1 DM), and reduced (P < 0.001) crude protein (107 to 60 g kg−1 DM) and WSC (115 to 17.5 g kg−1 DM). DM and NDF ruminal degradability declined with maturity for fresh and ensiled forages (L and Q; P < 0.05). Density and buffering capacity decreased with GS (L and Q; P < 0.001), whereas pH and soluble protein increased (L and Q; P ≤ 0.004). CONCLUSION: The growth stage of oat influenced the nutritive value and ruminal degradation to a greater extent than ensiling, and thus it can play a paramount role in whole‐crop oat silage quality. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Grasslands / Forrajes Tropicales is the property of International Centre for Tropical Agriculture - CIAT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peanut meal has an excellent total protein content but also has low rumen undegradable protein (RUP). High-performance ruminants have high RUP requirements. We aimed to evaluate the effects of processing peanut meal with an autoclave and conventional and microwave ovens, with and without using xylose on its ruminal kinetics degradation parameters and intestinal digestibility (ID). In situ studies were conducted to determine dry matter (DM) and crude protein (CP) rumen degradation kinetics. In vitro studies were conducted to evaluate intestinal digestibility (ID). The control treatment had a greater fraction A for DM and CP than peanut meals processed with an autoclave or conventional oven. The control had greater kd for CP compared with the microwave. The addition of xylose decreased fraction A, the degradation rate of fraction B (kd) and RUP, and increased the protein B fraction of autoclaved peanut meal. We observed a decrease in effective degradability (ED) and increased RUP for processed treatments in all experiments compared with the control. Processing methods did not affect the protein ID of autoclaved peanut meal compared to the control. An interaction between xylose and heating time was observed, where increasing heating time linearly reduced the ID of xylose-untreated treatments. Overall, these results suggest that the tested methods effectively increased the RUP content of peanut meal.

The ruminal kinetics of protein sources may be changed by heat and sugar treatments. Thus, these processing methods may be used as alternatives to increase beef-cattle diets’ rumen undegradable protein (RUP). We aimed to evaluate the effects of processing cottonseed meals with autoclave, conventional, and microwave ovens, with and without using xylose, on the ruminal kinetics degradation parameters and intestinal digestibility (ID). In situ studies were conducted, and each sample was incubated in the rumen to determine dry matter (DM) and crude protein (CP) rumen degradation kinetics. In vitro studies were also conducted to evaluate ID. The control treatment had a greater soluble fraction for DM and CP than processed cottonseed meals (p < 0.05). The addition of xylose decreased both DM and CP water-soluble fractions (fraction A) of cottonseed meal heated in a conventional oven (p < 0.05). Compared to the control, we observed a decrease in effective degradability and increased RUP for all processed methods (p < 0.05). Furthermore, conventional and microwave ovens showed greater ID than the control. Moreover, xylose-treated groups heated in the autoclave and conventional ovens had greater ID than xylose-untreated cottonseed meal. Under these experimental conditions, cottonseed RUP was increased by the evaluated processing methods.

Abstract To effectively utilize the tropical cassava (Manihot esculenta Crantz) foliage (CF) resources, the CF silages were prepared with microbial additives, including Chikuso-1 (CH1, Lactobacillus plantarum), Snow Lact L (SN, L. rhamnosus), Acremonium cellulase (CE), SN + CE and CH1 + CE. Silage fermentation, chemical composition and ruminal degradation were studied in Hainan, China. CF silages prepared with lactic acid bacteria (LAB) and CE were well preserved, with a higher (P

The main of this work was to evaluate the nutritional value of three agroindustrial co-products in finishing diets for sheep using the technique of in vitro gas production. The experimental treatments consisted of the inclusion of three different co-products in the diets: corn germ meal, corn germ meal and sunflower meal at levels of 0, 10, 20 and 30%. The kinetics of cumulative gas production was analyzed using the bicompartmental logistic model. The parameters were analyzed through analysis of variance, and when significant, orthogonal contrasts were used for specific partitioning of the effects of dietary inclusion levels on diets. The addition of maize germ meal in the diets, a quadratic behavior (P <0.05) was observed for the gas production and the rate of degradation of the fast digestion fraction, linear reduction (P <0.05) for the production of gas from the slow digestion fraction and no significant difference (P> 0.05) for the degradation rate of this same fraction. In vitro ruminal digestibility reduced linearly (P <0.05) with inclusion of the levels of this co-product. When dry corn distillery was included in the diets, the production of gases of the fast digestion fraction showed a linear reduction (P <0.05), the degradation rate of this same fraction did not show a significant effect (P> 0.05) (P <0.05) and the rate of degradation of this fraction did not change (P> 0.05). In vitro ruminal digestibility of DM did not change (P> 0.05) with inclusion of this coproduct. The inclusion of sunflower meal resulted in a linear reduction (P <0.05) in the gas production of the fast digestion fraction, a non significant effect (P> 0.05) for the degradation rate of this same fraction, 0.05) for the production of slow digestion fraction and quadratic effect (P <0.05) for the degradation rate of this fraction. There was no significant effect (P <0.05) for ruminal digestibility of dry matter in vitro. It was concluded that although the inclusion of the co-products in the diets altered one or more kinetic parameters of ruminal fermentation, ruminal digestibility in vitro did not change significantly. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the nutrient intake, digestibility, degradability, and ruminal characteristics of Sindhi heifers fed diets that contained a combined total of 75% oldman saltbush hay (hereafter saltbush hay) and prickly pear cactus. Eight 12-month old intact male red Sindhi calves (four fistulated and four non-fistulated) with an initial mean weight of 170 ± 5 kg were assigned to 4 × 4 Latin squares, where factors consisted of four diets, namely 15% hay and 60% cactus; 30% hay and 45% cactus; 45% hay and 30% cactus; and 60% hay and 15% cactus, and four times at which rumen fluid was collected. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes in kg/day and NDF in percentage live weight (LW), water intake, salinity, and conductivity increased with hay level. Intake and digestibility of nonfibrous carbohydrates were curvilinear with higher values in diets containing 30% saltbush hay. The apparent digestibility of dry matter (DM) and organic matter decreased linearly as the concentration of saltbush hay increased in the diet. The pH of the rumen fluid was within the acceptable range for favourable microbial growth. The low temperature and high salinity and conductivity indices in the diets should be viewed with caution at higher concentrations of saltbush hay, because of a possible decrease in nutrient absorption and the development of health problems in the animals. Apparent degradability coefficients of DM and NDF were affected significantly by inclusion of prickly pear and saltbush hay in the diets. [ABSTRACT FROM AUTHOR]

Enteric methane (CH4) emitted by ruminant species is known as one of the main greenhouse gases produced by the agricultural sector. The objective of this study was to assess the potential the potential for CH4 mitigation and additionally the chemical composition, in vitro gas production, dry matter degradation (DMD), digestibility and CO2 production of five tropical tree species with novel forage potential including: Spondias mombin, Acacia pennatula, Parmentiera aculeata, Brosimum alicastrum and Bursera simaruba mixed at two levels of inclusion (15 and 30%) with a tropical grass (Pennisetum purpureum). The forage samples were incubated for 48 h, and a randomized complete block design was used. Crude protein content was similar across treatments (135 ± 42 g kg−1 DM), while P. purpureum was characterized by a high content of acid detergent fiber (335.9 g kg−1 DM) and B. simaruba by a high concentration of condensed tannins (20 g kg−1 DM). Likewise, A. pennatula and P. aculeata were characterized by a high content of cyanogenic glycosides and alkaloids respectively. Treatments SM30-PP70 (30% S. mombin + 70% P. purpureum) and BA30-PP70 (30% B. alicastrum + 70% P. purpureum) resulted in superior degradability at 48h than P. purpureum, while in the AP30-PP70 (30% A. pennatula + 70% P. purpureum) was lower than the control treatment (p ≤ 0.05). At 24 and 48 h, treatments that contained P. aculeata and B. alicastrum yield higher CH4 mL g−1 DOM than P. purpureum (p ≤ 0.05). The inclusion of these forage species had no statistical effect on the reduction of CH4 emissions per unit of DM incubated or degraded at 24 and 48 h with respect to P. purpureum although reductions were observed. The use of fodders locally available is an economic and viable strategy for the mitigation of the environmental impact generated from tropical livestock systems.

Abstract Background Very limited information exists on the ruminal degradation kinetics of nutrients in garlic stalk. The present study aimed to survey the annual yield of garlic stalk in Korea and determine its feed-nutritive value for ruminants. Methods In Experiment 1, garlic stalk was incubated in situ in the rumen of two Hanwoo steers (360 ± 15 kg body weight) and removed after 12, 24, or 48 h to determine the ruminal degradation kinetics of DM and NDF. Rice straw was also included for comparison. In Experiment 2, In Experiment 2, six male Corriedale sheep were randomized to two dietary treatments to determine the apparent digestibility of nutrients in garlic stalk. Diets included a control ration without garlic stalk (60% concentrate mix +40% ryegrass) or a treatment ration (70% control diet +30% garlic stalk). Results The Korean national yield of garlic stalk (sun-dried basis) in 2016 was estimated to be 31,910 tons, with the southern coastal regions producing the highest quantity. Compared with rice straw, garlic stalk had lower NDF, higher ADF, and greater effective degradabilities of DM and NDF, resulting in a greater TDN value (56.3%), which was higher than that obtained for rice straw (43.7%). Conclusion These results provide basic information on the ruminal DM and NDF degradation kinetics of garlic stalk, which would be helpful for the efficient utilization of this by-product in ruminant diets.

This study evaluated the inclusion of increasing contents (0; 35; 70; 105 and 140 g kg-1) of dried acerola fruit (Malpighia glabra, Linn.) by-product (DABP) in the ensilage of elephant grass (Pennisetum purpureum, Schum.) considering the in situ degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose. Plastic drums with 210 L capacity were used as experimental silos. After 45 days of ensiling, silos were opened and silage samples were collected for the degradability trial and laboratory analysis. For the in situ degradability trial, was used one rumen-fistulated adult male cattle. The five by-product inclusion contents were tested in three replicates, with five incubation times, in a randomized complete split-plot design in which the contents of DABP were the treatments (plots), the different silos were the replicates and the incubation times were the sub-plots. Longer incubation times significantly increased (P < 0.05) the disappearance rates of DM, CP, NDF, ADF and hemicellulose. The effective degradability of the DM, NDF and hemicellulose was higher in the silages with 35 g kg-1 of DABP in the rumen passage rates of 0.02; 0.05 and 0.08 h-1. Dried acerola fruit by-product can be added to elephant grass ensiling up to 35 g kg-1 without reducing the effective degradability of nutrients.

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We evaluated the lotus rhizome as a potential ruminant feed by investigating its compositional properties, in situ degradation profile and in vitro fermentation characteristics with ruminal microbes, in comparison with cereal grains (corn, barley and wheat). The antioxidative activities in the lotus rhizome were also estimated. The soluble fraction of dry matter in lotus tuber was >70%, which was higher than those in the grains. The insoluble fraction in lotus tuber was not degraded by ruminal microbes in accord with a first‐order reaction. In an in vitro experiment, lotus tuber showed lower fermentation at 8 hr compared to the grains, but exhibited higher productions of gas and VFA at 48 hr along with a lower lactate and higher pH. The lower value of final lactate production in lotus tuber, indicating the metabolic capacity for lactate utilization retained, suggests a lower risk of ruminal acidosis compared to grains. Lotus rhizome had high antioxidant activities, with the foliar bud showing the strongest ferric reducing antioxidant power, followed in order by the apical bud, node, residual tuber, edible tuber, and nodal root. For ruminants, the lotus rhizome could thus be not only an energy feed but also the source of natural antioxidants. [ABSTRACT FROM AUTHOR]

In order to improve the fermentation quality and nutritional value of king grass (KG) by using available local feed resources, silages were prepared using KG, KG supplemented with 10%, 20%, 30%, 40%, 50% fresh cassava foliage (CF), and CF. Their fermentation quality, chemical composition and ruminal degradation were examined after 30 days of ensiling. The results showed that CF silage contained 22.67% crude protein (CP) and 41.19% neutral detergent fiber (NDF) per dry matter (DM), while KG silage contained 8.36% CP and 60.44% NDF, indicating that KG silage had poor fermentation quality and low ruminal degradability. In addition, silage prepared with increased CF content had increased lactic acid, ether extract (EE), CP contents and relative feed value (p < 0.05), decreased butyric acid, NDF and acid detergent fiber (ADF) contents (p < 0.05) and increased ruminal degradability of DM, CP, NDF and ADF (p < 0.05). The results confirmed that CF supplementation could improve fermentation quality, chemical composition and ruminal degradation of mixed silage, and the optimal ratio of CF to KG for mixed silage was 50:50. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effect of nitrate supplementation on dry-matter (DM) degradation and ruminal fermentation parameters by using in vitro gas production and in situ technique. In vitro gas production and in situ DM degradation in the presence or absence of nitrate were recorded at all incubation times. At all incubation times, diets incubated with nitrate gave a significantly lower gas production than did the other diets, except at 2-h incubation. Ruminal DM degradation did not differ among the experimental treatments. Furthermore, at most incubation times, total volatile fatty acids in diets containing nitrate were lower than those in the other treatments. Nitrate supplementation considerably increased gas production from the insoluble fraction, whereas it decreased gas production from the quickly soluble fraction, and potential gas production. Moreover, in all incubations, there were significant correlations between gas production and in situ DM-degradation parameters. The control diet had the greatest retained nitrogen content, but the diets containing nitrate had the greatest faecal nitrogen. The results showed that nitrate addition resulted in a lower gas production and volatile fatty acid production in in vitro assay. It was concluded that considering the strong posetive relationship between the two methodologies, the degradability parameters can be predicted from obtained gas production. The present study showed that nitrate inclusion in the diet has the potential to improve fermentation in sheep, reducing gas production measured by in vitro technique. Nitrate had no effect on dry-matter degradation, an important factor of livestock yields. Also, these results suggested that there is a meaningful relationship between in vitro and in situ methods. [ABSTRACT FROM AUTHOR]

The aim was to evaluate how the fodder pre- dehydration time and its phenological stages influence on ruminal degradability and digestibility of ryegrass silage. The evaluated samples consisted of treatments: Vegetative: Cut and ensiled; cut + 4 hours pre-drying and ensiled and; cut + 7 hours pre-drying and ensiled; Pre-flowering: Silage cutting and ensiled and 4 hours pre-drying and ensiled; Flowering: cut and ensiled, no pre-drying, with four replications each treatment. Silage was storage for four months. It was carried out three in situ digestibility assays to determine the curve of ruminal degradability at different times (3, 6, 9, 12, 24, 48 and 72 hours), like in situ digestibility and other three assays of 24 hours and 48 hours to determinate in vitro digestibility of silage. The digestibility of ryegrass silage was influenced by both the pre-dehydration times and phenological stage, and the dehydration time of cut and silage had a high proportion of degradable components, with higher degradation rate by 24 hours of incubation. The in vitro digestibility of the ryegrass silage was greater than that in situ for up to 48 hours. The digestibility of the ensiled ryegrass biomass was influenced by the dehydration times, as well as the plant growth stage, regardless of the methodology used, being higher values for the treatment without previous drying of the vegetative stage.

The objective of this study was to investigate ruminal fermentation and the nutritional value of different microalgae products (MAP) for ruminants, including inter‐ and intra‐genera variability. Furthermore, the effect of mechanical cell disruption was also evaluated. Cell‐disrupted and nondisrupted MAP of four genera were investigated using the Hohenheim Gas Test. The investigations included characterization of gas production (GP), production of volatile fatty acids (VFA) and methane, organic matter digestibility, and energetic value as well as utilizable crude protein at the duodenum and ruminally undegradable crude protein (RUP). Furthermore, a three‐step enzymatic in vitro system was used to estimate intestinal digestibility of RUP (IDP). Ruminal fermentation was low for all investigated microalgae genera, as indicated by overall low GP, low production of VFA, and low ruminal protein degradation. Nevertheless, all microalgae genera were characterized by high RUP concentrations (236–407 g/kg dry matter; passage rate = 8% hr−1), indicating that microalgae might be a promising protein source for high‐performing ruminants. Low IDP (26%–49% of RUP) considerably contradicted this potential. Mechanical cell disruption in general enhanced the extent of ruminal fermentation of MAP but, as RUP was decreased and IDP was hardly affected, mechanical cell disruption appears not to be necessary when microalgae are intended for application as a protein source for ruminants. Because of the high variability in the characteristics of the nutritional value, general means are inappropriate to characterize the nutritional value of MAP. In conclusion, suitability of microalgae as a protein source for ruminants might be limited because of low IDP, although further studies are necessary to prove these findings in vivo. Ruminal fermentation of cell‐disrupted and nondisrupted microalgae and the consequences for the nutritional value for ruminants were investigated using different in vitro methods. The results showed a high variability between and within microalgae genera in the nutritional characteristics and in the effect of cell disruption. [ABSTRACT FROM AUTHOR]

Paiaguas palisadegrass was released in order to meet the requirements of the different production systems. However, little is known about the quality of the forage. The goal of this study was to evaluate the protein and carbohydrate fractionation of the Paiaguas palisadegrass after intercropping with grain sorghum in the pasture recovery, through the integration of crop and livestock production. The experiment was conducted in the municipality of Rio Verde, State of Goias. The experimental design was a randomized complete block design with four replications. The treatments were composed of the following forage systems: Paiaguas palisadegrass in monocropped, sorghum intercropped with Paiaguas palisadegrass in the row, sorghum intercropped with Paiaguas palisadegrass in the interrow, and sorghum intercropped with oversown Paiaguas palisadegrass. The evaluations were carried out in the four climatic seasons of the year (winter, spring, summer, and fall) in the same plots, over a period of one year, in 16 paddocks under continuous stocking system. The results showed that forage systems did not influence protein and carbohydrate fractionation. The winter season presented higher values of protein and carbohydrate fractionation, negatively affecting the animal performance. [ABSTRACT FROM AUTHOR]

Highlights • Crude protein (CP) value from red clover silage (RCS) and soybean meal were studied. • Undegraded and intestinal digestibility of CP reduced with increasing level of RCS. • Increasing level of RCS shifted the site of CP utilization from rumen to intestine. • The CP value of diets reduced with each increasing level of RCS. • RCS can be included up to 0.30 without impairment of protein value of diets. Abstract The objective of this study was to evaluate the effect of replacing crude protein (CP) of soybean meal (SBM) with red clover silage (RCS) in total mixed rations (TMR) on ruminally undegraded feed CP (RUP) and intestinal digestibility (ID) of RUP. Four TMR were formulated to replace CP from SBM with RCS. The TMR was comprised of forage and concentrates (0.75:0.25), with ratios of RCS in TMR of 0.15, 0.30, 0.45, and 0.60 on a dry matter (DM) basis. The ruminal degradation of CP was determined using the nylon bag technique. For this, samples of TMR were incubated for 2, 8, 16, 24, 32 and 72 h. The RUP content of TMR was estimated using passage rates of 2, 5 and 8%/h. Additionally, samples of TMR were incubated in the rumen for 16 h, and their feed residues were used for determination of ID of RUP using the mobile-bag technique. For in situ ruminal degradation, increasing RCS and reducing SBM proportions increased linearly the rapidly degradable CP (a) from 26.2 to 212 g/kg CP (P < 0.001). The potentially degradable CP (b) decreased linearly from 810 to 676 g/kg CP (P < 0.001). Assuming a passage rate of 8%/h, RUP reduced linearly from 315 to 253 g/kg CP (P < 0.001). The ID of RUP reduced linearly from 760 to 574 g/kg CP (P < 0.001) with increasing RCS levels. Although differences in ruminal CP degradation and ID of RUP were apparently caused by differences in the proportion of RCS and SBM, neither linear nor quadratic effects on total tract digestible CP were observed (P = 0.22 and 0.21, respectively), and averaged 943 g/kg CP among all TMR tested. This suggests that increasing RCS and decreasing SBM proportion shifted the site of CP utilization. The CP degraded in the rumen increased, and the amount of intestinally absorbable RUP reduced linearly from 184 to 79 g/kg CP (P < 0.001). In general, replacing CP from SBM with RCS in the TMR reduced its protein value. It is concluded, that an almost complete replacement of CP from SBM by RCS in rations of high-yielding dairy cows cannot be recommended. However a replacement rate up to 0.30 does not lead to a substantial reduction in RUP supply and digestibility, and therefore considerably reduces the use of SBM. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the variability among animals regarding the critical time to estimate the undegradable fraction of fiber (ct) using an in situ incubation procedure. Five rumenfistulated Nellore steers were used to estimate the degradation profile of fiber. Animals were fed a standard diet with an 80:20 forage:concentrate ratio. Sugarcane, signal grass hay, corn silage and fresh elephant grass samples were assessed. Samples were put in F57 Ankom® bags and were incubated in the rumens of the animals for 0, 6, 12, 18, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240 and 312 hours. The degradation profiles were interpreted using a mixed non-linear model in which a random effect was associated with the degradation rate. For sugarcane, signal grass hay and corn silage, there were no significant variations among animals regarding the fractional degradation rate of neutral and acid detergent fiber; consequently, the ct required to estimate the undegradable fiber fraction did not vary among animals for those forages. However, a significant variability among animals was found for the fresh elephant grass. The results seem to suggest that the variability among animals regarding the degradation rate of fibrous components can be significant.

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen.

This work studied the effect of feeding glycerin in bulls that were fed high levels of concentrate on the ruminal environment and in situ degradability of feedstuffs. Four ruminally cannulated young bulls were assigned to a 4 × 4 Latin square arrangement of treatments. The diets consisted of 15% barley straw and 85% concentrate in dry matter (DM). There were four different concentrates: without glycerin, and with 20, 40 or 80 g of glycerin per kg of DM. Each diet was offered for 24 days, the ruminal fluid was sampled to evaluate the ruminal metabolism and to determine the ruminal bacterial population by quantitative real-time polymerase chain reaction analysis, and the in situ degradability of six different feedstuffs was measured. The treatment with the highest level of glycerin provided the lower pH (p < 0.001), and the acetic/propionic molar ratio decreased (p < 0.001) as glycerin increased. The incorporation of glycerin in the diet did not affect the DNA copies/µL of the total bacteria, Butyrivibrio fibrisolvens and Butyrivibrio proteoclasticus (p > 0.05) in the DNA extract of rumen fluid, but at high levels increased Selenomonas ruminantium (p < 0.01). Very few effects of glycerin incorporation were found for the in situ degradability. In young bulls that were fed high levels of concentrate, glycerin at 20 or 40 g/kg of feed could be included without affecting the ruminal pH and raising the propionic acid, but at 80 g/kg the ruminal pH dropped, despite the increase of Selenomonas ruminantium.

In order to improve the silage fermentation of stylo ( Stylosanthes guianensis) in tropical areas, stylo silages were prepared with commercial additives Lactobacillus plantarum Chikuso-1 ( CH1), L. rhamnasus Snow Lact L ( SN), Acremonium cellulase ( CE) and their combination as SN+ CE or CH1 + CE, and the fermentation quality, chemical composition and ruminal degradation of these silages were studied. Stylo silages treated with lactic acid bacteria ( LAB) or cellulase, the pH value and NH3-N ⁄ total-N were significantly ( P < 0.05) decreased while the ruminal degradability of dry matter ( DM), crude protein ( CP), neutral detergent fiber ( aNDFom) and acid detergent fiber ( ADFom) were significantly ( P < 0.05) increased compared to control. Compared to LAB or cellulase-treated silages, the DM, CP contents and relative feed value ( RFV), and the ruminal degradability in LAB plus cellulase-treated silages were significantly ( P < 0.05) higher, but the aNDFom content was significantly ( P < 0.05) lower. CH1 + CE treatment was more effective in silage fermentation and ruminal degradation than SN+ CE treatment. The results confirmed that LAB or LAB plus cellulase treatment could improve the fermentation quality, chemical composition and ruminal degradation of stylo silage. Moreover, the combined treatment with LAB and cellulase may have beneficial synergistic effects on ruminal degradation. [ABSTRACT FROM AUTHOR]

BACKGROUND This work aimed to study the chemical composition and in vitro digestibility of seeds and pulp from grape pomace. In sacco degradability, ruminal fermentation of grape pomace fractions and plasma lipid peroxidation were also studied in sheep fed with or without grape pomace. RESULTS Seed and pulp fractions of grape pomace had different values for cell walls (523 vs 243 g kg−1 dry matter ( DM)), crude protein ( CP, 104 vs 138 g kg−1 DM), ether extract ( EE, 99.0 vs 31.7 g kg−1 DM), polyunsaturated fatty acids ( PUFA, 69.6 vs 53.3%) and extractable polyphenols (55.0 vs 32.1 g kg−1 DM). The in vitro true digestibility, DM in sacco degradability and CP degradability of seeds and pulp were also different (0.51 vs 0.82, 0.30 vs 0.45 and 0.66 vs 0.39 respectively). The ammonia-N concentration and total volatile fatty acids ( VFA) in ruminal liquid were significantly lower and plasma lipid peroxidation was also numerically lower in sheep that consumed grape pomace. CONCLUSION The nutritive value of grape pomace varies depending on the proportion of seeds and pulp. The interest of this by-product in sheep feeding could be related to its polyphenol and PUFA content, which could improve meat and milk quality. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effects of protein and/or starch supplementation on the nutritional performance of cattle grazing on low-quality tropical forage. Five crossbred steers (Holstein × Gyr) with an average body weight (BW) of 397 kg that were fitted with ruminal and abomasal cannulae were used. The animals were kept in individual signal-grass (Bracharia decumbens) paddocks. Five treatments were evaluated: 1 - control (without supplementation); 2 - supplementation with 1 g of crude protein (CP) per kg of BW; 3 - supplementation with 2.5 g of starch per kg of BW; 4 - supplementation with CP and starch as described for treatments 2 and 3; and 5 - supplementation as described for treatment 4 but replacing the corn starch with a mixture of corn starch and nitrogenous compounds, thereby resulting in an energy supplement of 150 g CP/kg of dry matter. The experiment was performed according to a 5 × 5 Latin square design in a 2 × 2 + 1 factorial arrangement. The forage intake was not affected by any of the factors evaluated in this study. The production of microbial nitrogen in the rumen was not affected by nitrogen or starch supplementation. The apparent nitrogen balance was only increased when both starch and nitrogen were supplied. Supplementation with both starch and nitrogenous compounds for cattle grazing on low-quality tropical forage is characterized by an interactive metabolic effect that increases nitrogen accretion by the animals.

To test the effects of year and processing plant on the nutritional value of canola meal (CM), 3 CM samples/ yr were collected from each of 12 Canadian production plants over 4 yr (total = 144). Samples of CM were analyzed for differences in chemical composition and for in vitro ruminal protein degradability using the Michaelis-Menten inhibitor in vitro (MMIIV) method. In the MMIIV method, protein degradation rate (kd) was estimated by 2 methods: from net release (i.e., blank corrected) of (1) ammonia plus AA determined by o-phthaldialdehyde fluorescence (OPAF) assay or (2) ammonia, AA, plus oligopeptides determined by o-phthaldialdehyde absorbance (OPAA) assay; rumenundegradable protein (RUP) was computed assuming passage rates of 0.16 and 0.06/h for, respectively, soluble and insoluble protein. Casein, solvent soybean meal (SSBM), and expeller soybean meal (ESBM) were included in all incubations as standard proteins. Differences among years and plants were assessed using the mixed procedures of SAS. Small but significant differences were found in CM among years for chemical composition, including N solubility; some of these differences may have been related to changes in our analytical methods over time. However, adjustment of degradation activity of individual in vitro incubations based on the mean degradation activity over all incubations yielded kd and RUP that did not differ by year using either assay. Simultaneously incubating CM samples from 2 yr in the same in vitro runs confirmed that no year effects existed for kd or RUP. Differences existed in chemical composition of CM among the 12 processing plants over the 4 yr of sample collection. Moreover, consistent differences in kd and RUP were observed among plants: kd ranged from 0.069 to 0.113/h (OPAA assay) and 0.075 to 0.120/h (OPAF assay), and RUP estimates ranged from 51 to 43% (OPAA assay) and 49 to 41% (OPAF assay). Regression of kd on insoluble N content of CM yielded correlation coefficients (R2) = 0.40 (OPAA assay) and 0.42 (OPAF assay), and regressions of kd on NDIN and N-fraction B3 yieldedR2 < 0.02. Mean estimates from both OPAA and OPAF assays for casein, SSBM, ESBM, and CM were, respectively, kd = 0.764, 0.161, 0.050, and 0.093/h and RUP= 18, 33, 56, and 45%. A range of 8 percentage units from lowest to highest RUP suggests that substantial differences exist in metabolizable protein content of CM produced by different processing plant. [ABSTRACT FROM AUTHOR]

The ruminal degradability and intestinal digestibility of dry matter (DM), crude protein (CP) and amino acids (AA) in three total mixed rations with different CP levels were estimated using the modified in vitro three-step procedure (TSP) and mobile nylon bag (MNB) technique on growing lambs. The ruminal effective degradability of DM and CP did not respond with increasing dietary CP level. However, the intestinal digestibility of DM was significantly increased with increasing dietary CP level estimated by TSP (P < 0.05) or MNB method (P < 0.01). Intestinal digestibility coefficients of CP determined by TSP were lower than those of the MNB method. Histidine was extensively degraded by rumen microorganisms, while tyrosine was the most anti-degradable AA among the samples. The ruminal AA degradability exhibited no significant differences except for threonine, tryptophan, alanine, aspartic acid and proline for the three diets. Similarly, only a few AAs (i.e. histidine, methionine, tryptophan, aspartic acid and cysteine in TSP; histidine, tryptophan, aspartic acid and serine in MNB) had significant differences in their intestinal digestibility; in addition, values of MNB were lower than that of the TSP method, indicating that intestinal digestibility of DM seems to be overestimated in TSP, while that of CP might be overestimated in the MNB method. [ABSTRACT FROM AUTHOR]

Rumen degradability kinetics was investigated for pelleted compound concentrates differing in physical functional properties of pellets. Six compound concentrate meals were produced containing either 100% wheat, 100% maize, 50% wheat+50% soybean meal (SBM; as is basis), 50% maize+50% SBM, 50% wheat+50% sugar beet pulp (SBP), or 50% maize+50% SBP. Meals were pelleted by either conventional pelleting, or by cooking extrusion using two distinct settings giving pellets with either high density (HD) or low density (LD). Ruminal degradation of starch, crude protein (CP) and NDF, and intestinal digestibility of CP were evaluated using in situ methods in cattle. Overall, processing (pelleting, extruding HD, or extruding LD) increased effective starch degradability (ESD) of pure maize and maize mixtures. The ESD increased with intensity of processing (Extruding LD>Extruding HD>Pelleting>Meal). In contradiction, ESD for pure wheat and wheat mixtures was reduced, though differences were minor. Conventional pelleting reduced the effective protein degradability (EPD) for pure wheat, but extrusion did not further affect the EPD. In contrast, the most intense processing with extrusion LD increased EPD for pure maize. Processing reduced EPD in both cereal+SBM mixtures, and further, the most intense processing with extruding LD led to the lowest EPD in cereal+SBM mixtures. In contrast, extruding increased EPD in both cereal+SBP mixtures as compared with meal and pelleting, but extruding with steam addition did not further increase the EPD. Compared to meal and pelleting, extruding without steam addition increased the effective NDF degradability for maize+SBP. The observed responses in EPD were not associated with decreases in CP disappearances from mobile bags. In conclusion, pelleting and extrusion affected ruminal degradability of starch, protein, and NDF differently depending on both type of cereal and composition of the concentrate mixture. [ABSTRACT FROM AUTHOR]

Objetivou-se neste trabalho avaliar a divergência nutricional de genótipos de cana-de-açúcar para uso na alimentação de animais ruminantes. Foram avaliados os genótipos: RB72454, RB835486, SP80-1842, IAC86-2480, RB977512, RB867515, RB935566, RB925345, RB977625, SP79-1011, SP80-1816, SP81-3250 e SP91-1049, colhidos em soca aos 11 meses de idade, quanto às variáveis FDN, hemicelulose, lignina, relação FDN x carboidratos solúveis, fração indegradável da FDN, taxa de degradação da FDN e taxa de degradação da matéria seca. A aplicação da análise de agrupamento segundo o método de Tocher, utilizando a matriz de distâncias euclidiana média, permitiu o estabelecimento de três grupos de genótipos. A FDN e a taxa de degradação da MS foram as variáveis de maior importância para a discriminação dos grupos, contribuindo cada uma com 25,64% do poder de discriminação total. A fração indegradável da FDN foi a variável que apresentou a menor contribuição para discriminação dos grupos (11,54%). A variáveis FDN, fração indegradável da FDN, hemicelulose, taxa de degradação da MS e taxa de degradação da FDN mostraram-se eficazes para o estudo da diversidade nutricional da cana-de-açúcar. O grupo III, constituído pelo clone RB977512, apresentou as melhores médias para as variáveis avaliadas e, portanto, pode ser considerado de melhor qualidade nutricional para alimentação de ruminantes.The objective of this trial was to study the nutritional divergence of sugarcane genotypes for feeding ruminants. The following sugarcane genotypes were evaluated: RB72454, RB835486, SP80-1842, IAC86-2480, RB977512, RB867515, RB935566, RB925345, RB977625, SP79-1011, SP80-1816, SP81-3250, and SP91-1049 all harvested at 11 months of age. The discriminatory variables were: neutral detergent fiber (NDF), hemicellulose, lignin, NDF to soluble carbohydrate ratio, NDF undegradable fraction, and rates of NDF and DM degradation. Application of the cluster analyses according to the Tocher approach, using the mean Euclidian distance matrix, yielded three groups of genotypes. Neutral detergent fiber and DM degradation rates were the most important variables for group discrimination contributing individually with 25.64% of the total discrimination power while the least contribution was observed with NDF undegradable fraction (11.54%). The variables NDF, NDF undegradable fraction, hemicellulose, and rates of DM and NDF degradation all showed to be effective to evaluate sugarcane nutritional divergence. Group III formed by the clone RB977512 showed the best responses for the studied variables and as such can be considered of higher nutritional quality for ruminants.

Parâmetros cinéticos da degradação ruminal de alguns alimentos utilizados para ruminantes de zoológicos foram estimados mediante incubação in vitro com líquido ruminal de audade (Ammotragus lervia), cervo sambar (Cervus unicolor), elande (Taurotragus oryx), bovino (Bos taurus), bubalino (Bubalus bubalis), caprino (Capra hircus) e ovino (Ovis aries). Os parâmetros cinéticos foram estimados pela técnica da produção de gás, cujos dados foram ajustados pelos modelos de um e de duplo compartimento. Não foram detectadas diferenças nos parâmetros cinéticos que permitissem agrupar os alimentos (fibrosos × não fibrosos) e os animais (domésticos × silvestres). O modelo de duplo compartimento foi o mais adequado para a estimação dos parâmetros cinéticos da degradação ruminal. Inóculo microbiano oriundo de ruminantes domésticos não é recomendado para estimar parâmetros cinéticos da degradação ruminal de alimentos utilizados para ruminantes silvestres de zoológicos.The estimation of the ruminal kinetic parameters of pumpkin, potato-sweet, beet, broccoli, carrot, alfalfa hay, alfalfa pellet and bean, currently used for feeding wild and domestic ruminants raised in the Rio de Janeiro Zoo, was made through in vitro incubation of the feedstuffs together with ruminal fluid obtained from aoudad (Ammotragus lervia), sambar deer (Cervus unicolor), eland (Taurotragus oryx), cattle (Bos taurus), buffalo (Bubalus bubalis), goat (Capra hircus) and sheep (Ovis aries). The gas production technique was used to obtain gas profiles, and the data were fitted by the mono or double compartmental model. The kinetic parameters were discrepant among both, animals and feedstuffs, and the double compartmental model gave the best estimation. Ruminal inocula from domestic ruminants can not be used to estimate the kinetic parameters of ruminal degradation of feedstuffs for wild ruminants.

Com o objetivo de avaliar a degradabilidade ruminal da matéria seca (MS) e da proteína bruta (PB) de diferentes alimentos concentrados utilizados na alimentação de bovinos, pela técnica in situ, foram utilizados três novilhos Nelores, inteiros, com 24 meses e peso aproximado de 350 Kg, fistulados no rúmen. As amostras referentes aos alimentos foram pesadas e colocadas no interior de sacos de náilon (6,5 x 4,0 cm de área livre), com porosidade conhecida de 50 micras, na quantidade de 1,0 grama de MS; esses foram incubados em ordem decrescente no rúmen nos tempos de 48, 36, 24, 12, 6, 3 e 0 horas. Foram avaliados seis alimentos: glúten de milho, polpa cítrica, farelo de soja, farelo de trigo, milho moído e o farelo de amendoim. Os dados foram ajustados por regressão não-linear, segundo o modelo p = a + b(1-e-ct). As degradabilidades efetivas (DE) da matéria seca dos alimentos foram, respectivamente, de 29,3; 76,6; 71,3; 60,5; 59,6; e 60,8, para a taxa de passagem de 5%/h, e da proteína bruta foram de 8,5; 56,1; 57,4; 67,9; 30,1; e 85,2, para a mesma taxa de passagem, respectivamente. A polpa cítrica apresentou alto valor para a degradabilidade efetiva de MS (76,6%); o milho, uma lenta degradação ruminal da PB, com uma taxa de degradação para a fração “b” de 2,9%; o glúten de milho apresentou uma fração “a” de 11,9% para a MS, sendo uma fonte de proteína de alto escape ruminal, apresentou DE de 8,5%; o farelo de amendoim apresentou valor, para a fração “b”, de 67,3%, o valor nutritivo desse alimento é semelhante ao farelo de soja, mas teve a maior DE de PB superior 48% ao farelo de soja. O glúten de milho apresentou baixa degradação ruminal, enquanto a polpa cítrica e o milho tiveram uma lenta degradação ruminal, principalmente quando comparados ao farelo de amendoim.With the objective of evaluating the ruminal degradation of the dry matter and the crude protein of different concentrated feed used when feeding bovine, through the in situ technique, we used three young Nelore steers, rumen fistulated, with 24 months old, and weighting approximately 350 kg. The feed samples were weighted and put inside of nylon bags (6,5 x 4,0 cm of free area) with 50 micras porosity in the quantity of 1,0 g of dry matter, and they were put in decreasing order in the rumen with intervals of 48, 36, 24, 12, 6, 3 and 0 hours. Six feeds were analysed: corn gluten, citrus pulp, soybean meal, wheat meal, ground corn and peanut meal. The data were adjusted by non linear regression, according to the model p = a + b(1-e-ct). The effective degradability of the dry matter were, in order, 29, 3, 76, 6, 71, 3, 60, 4, 59, 6 and 60,8, to the passage ratio of 5% an hour, and of the crude protein, 8,5; 56,1; 57,4; 67,9; 30,1; and 85,2 fot the same passage ratio. The citrus pulp presented high value for the effective degradability of DM (76,6%), the corn a slow degradation ruminal of PB, with the value of the degradation ratio for the fraction “b” of 2,9%, the corn gluten presented a fraction "a", of 11,9% for to DM; where a source of protein of high ruminal escape, it presented ED of 8,5%; the peanut meal presented value, for the fraction "b", of 67,3%, the nutritional value of this food is similar to the soy meal, but had the largest ED of CP 48% highest than the soy meal. The corn gluten presented low ruminal degradation, while the citrus pulp and the corn had slow ruminal degradation, specially when compared to the peanut meal.

O objetivo deste trabalho foi o de avaliar o efeito das silagens de três híbridos de sorgo: granífero (Conti-Silo, de porte baixo), duplo propósito (Conti-Silo-03, de porte médio) e forrageiro (547-F, de porte alto) e de três épocas distintas (aos 105, 112 e 119 dias após a semeadura) sobre a degradabilidade in situ da matéria seca (MS) e da fibra em detergente neutro (FDN). Foram utilizados três bovinos adultos mestiços fistulados no rúmem, distribuídos em um delineamento experimental em parcelas subdivididas, com três tempos de incubação (6, 24, 96 horas). Houve diferença (PA three point (6, 24 and 96 hours of incubation) split-plot design was carried out with three rumen-fistulated steers to evaluate the effect of three sorghum silages (C-silo, C-silo-03 and 547-F) and three harversting times (105, 112 and 119 days of age) on "in situ" degradability of dry matter (DM), and neutral detergent fiber (NDF). Fractions of DM and of NDF were different (P0,05) among silages and incubation times.

The aim of this study was to assess the chemical composition and rumen degradability of ensiled soybean forage harvested at three plant vegetative stages ( i.e. , R4, R5, R6) and wilted for 20 or 28 h. The wilted forages were chopped from 1 to 2 cm and then manually pressed into 6 kg bags of fresh material (two bags for each combination of maturity stage and wilting duration) prior to storage under anaerobic condition for 90 days. The soybean silages were analysed for fermentative parameters and manually separated into leaves, stalks and pods. Whole forage and separated plant components were chemically analysed and the in vitro neutral detergent fibre (NDF) ruminal degradation (NDFD) was determined. Only whole plant silages were assessed for in vitro gas production (GP) and in vitro crude protein degradability (CPD). The dry matter (DM) content of the ensiled whole plants increased (P=0.005) from 454 to 485 and 518 g/kg from the R4 to R5 and R6 vegetative stages and was higher for forages wilted at 28 h than those at 20 h (528 vs 444 g/kg, P<0.001). Advancing plant maturity increased (P<0.001) the crude protein (CP) and ether extract (EE) content from 164 to 199 and from 18 to 53 g/kg DM, respectively, but reduced ash (P=0.011) from 71 to 63 g/kg DM. The NDFD increased with plant maturity from 0.319 to 0.465 (P<0.001). The GP did not differ among maturity stages of forages or wilting lengths, while CPD increased from 0.391 to 0.548 (P<0.001) with advancing maturity and slightly decreased with the longer wilting duration (P<0.008). The DM content of the pods and stalks increased (P<0.01) with the vegetative stage and CP content increased in pods and decreased in leaves. Results indicate that harvesting soybean forage at an advanced maturity stage ( e.g. , from R4 to R6) greatly increases the protein, the fat and the degradable NDF contents. Moreover, the wilting soybean forage has to be targeted to achieve a DM content of ensiled forage of about 440 g/kg (between about 410 and 480 g/kg, according to the maturity stage), and a further wilting determines no fermentative improvements at ensiling or relevant modification of silage nutritional contents. [ABSTRACT FROM AUTHOR]

High-production ruminants are commonly fed maize silage, which makes accurate evaluation of its nutritive value a key economic issue. However, evaluations of the rate and extent of ruminal degradation of starch and cell wall fractions from maize silage carry uncertainty due to the lack of a standardized method. Here, we investigated the effects of ensiling and sample conditioning on in situ -measured degradation of maize forage. Eight series of maize samples (two hybrids × two maturity stages × two methods of conservation [non-ensiled or fresh and ensiled]) were nylon-bagged in three conditionings: dried and ground to 1 mm (D1), dried and ground to 4 mm (D4), frozen and coarse-ground (FG). Disappearance of dry matter (DM), starch and fibre (aNDF) was measured in situ in cow rumen after different incubation times (2, 4, 8, 16, 24, 48 and 96 h). Effects of ensiling, sample conditioning, genotype, maturity and their interactions on DM, starch and aNDF degradation were analyzed using the SAS MIXED procedure. Effective dry matter degradability (ED4 DM ) was significantly higher (P<0.001) in silage than in fresh maize due to a significantly higher rapidly degradable fraction ( a ) (P<0.001). Effective starch degradability (ED6 Starch ) followed the same trend due to a higher silage degradation rate (P<0.01). Conversely, effective aNDF degradability (ED2 aNDF ) was lower in silage (P<0.001) than fresh maize due to the longer lag-time to degradation (P<0.001) and lower hemicellulose ((aNDF − ADF)/aNDF) fraction in silage. Effective DM degradability was higher (P<0.001) for D1 samples than D4 and FG samples, mainly due to the higher rapidly degradable fraction ( a ) (P<0.001) in D1 than D4 or FG samples. In relation to high degradation rate, starch degradability was significantly higher (P<0.001) in FG than D1 and D4 samples, whereas aNDF degradation was lowest in the FG samples. This study shows that ensiling maize increases starch degradability and decreases aNDF degradability compared to fresh plant. Alongside conservation method, fine-grinding samples (as D1) led to high losses through the pores of the nylon bags, and these losses were correlated with high starch degradability, whereas coarse grinding (as FG) led to low aNDF degradability, probably due to insufficiently reduced particle sizes. In conclusion, using ensiled samples dried and ground to 4 mm (D4) emerges as the appropriate method for in situ studies of starch-rich forages used as silages. [ABSTRACT FROM AUTHOR]

For determining the potential of tannins extracted from two tropical shrub-like legumes (Albizia lebbekoides and Acacia cornigera) in the protection of soybean meal proteins and to establish their effects on fermentation indicators, the in vitro gas production technique was applied. A random block design was used. Untreated soybean meal (800 mg) were incubated and treated with aqueous extract of A. lebbekoides and heat, A. cornigera extract and heat, water and heat and only with heat. Treatments were incubated alone and with two levels of soluble starch (150 and 300 mg) for estimating N solubility of the substrate. Gas production was measured until 8 h and short chain fatty acid production and ammonia were determined. There was no effect of the treatments on the production of total SCFA, only the treatment with heat increased gas production (P < 0.05). Neither were there differences in the productions of individual SCFA nor in the acetic/propionic relationship. Albizia and acacia tannins decreased the NH3 levels regarding the untreated substrate (P < 0.05), although the treatment with acacia tannins did not differ from the treated soybean meal with water and heat. Also the decrease of the amounts of solubilized N was established, on treating soybean meal with both tannin sources (P < 0.01). It is concluded that tannins extracted from A. lebbekoides and A. cornigera could be used for protecting of ruminal degradation to proteins of high biological value, as those of soybean meal. [ABSTRACT FROM AUTHOR]