Non-fiber Carbohydrate Content Research Articles

Farm-level risk factors associated with increased milk β-hydroxybutyrate and hyperketolactia prevalence on farms with automated milking systems

The objectives of this study were to determine the farm-level hyperketolactia (HKL) prevalence, as diagnosed from milk β-hydroxybutyrate (BHB) concentration, on dairy farms milking with an automatic milking system (AMS) and to describe the farm-level housing, management, and nutritional risk factors associated with increased farm-average milk BHB and the within-herd HKL prevalence in the first 45 DIM. Canadian AMS farms (n = 162; eastern Canada n = 8, Quebec n = 23, Ontario n = 75, western Canada n = 55) were visited once between April to September 2019 to record housing and herd management practices. The first test milk data for each cow under 45 DIM were collected, along with the final test of the previous lactations for all multiparous cows, from April 1, 2019 to September 30, 2020. The first test milk BHB was then used to classify each individual cow as having HKL (milk BHB ≥ 0.15 mmol/L) at the time of testing. Milk fat and protein content, milk BHB, and HKL prevalence were summarized by farm and lactation group (all, primiparous, and multiparous). During this same time period, formulated diets for dry and lactating cows, including ingredients and nutrient composition, and AMS milking data were collected. Data from the AMS were used to determine milking behaviors and milk production of each herd during the first 45 DIM. Multivariable regression models were used to associate herd-level housing, feeding management practices, and formulated nutrient composition with first test milk BHB concentrations and within-herd HKL levels separately for primiparous and multiparous cows. The within-herd HKL prevalence for all cows was 21.8%, with primiparous cows having a lower mean prevalence (12.2 ± 9.2%) than multiparous cows (26.6 ± 11.3%). Milk BHB concentration (0.095 ± 0.018 mmol/L) and HKL prevalence for primiparous cows were positively associated with formulated prepartum DMI and forage content of the dry cow diet while being negatively associated with formulated postpartum DMI, the major ingredient in the concentrate supplemented through the AMS, and the PMR-to-AMS concentrate ratio. However, multiparous cows' milk BHB concentration (0.12 ± 0.023 mmol/L) and HKL prevalence were positively associated with the length of the previous lactation, milk BHB at dry off, prepartum diet nonfiber carbohydrate content, and the major forage fed on farm, while tending to be negatively associated with feed bunk space during lactation. This is the first study to determine the farm-level risk factors associated with herd-level prevalence of HKL in AMS dairy herds, thus helping optimize management and guide diet formulation to promote the reduction of HKL prevalence.

Metabolomic and morphologic surveillance reveals the impact of lactic acid-treated barley on in vitro ruminal fermentation.

Lactic acid (LA) treatment of cereals is known to improve ruminant performance. However, changes in cereal nutrient levels and variations in rumen fermentation remain unclear. This study was designed to compare the effects of 5% LA treatment on the trophic and morphological characteristics of barley and to discover the differences in rumen fermentation characteristics and metabolomes between LA-treated and untreated barley. Compared with those of untreated barley (BA), the dry matter (DM), crude protein (CP), ash and water-soluble carbohydrate contents of barley plants treated with 5% LA for 48 h (BALA) decreased, but the resistant starch (RS) and non-fiber carbohydrate contents increased. Moreover, the amount of proteinaceous matrix in BA decreased in response to LA treatment. During in vitro fermentation, BALA had a greater pH but lower dry matter disappearance and ammonia, methane, and short-chain fatty acid levels than BA. The differential metabolites between BA and BALA were clustered into metabolic pathways such as purine metabolism, lysine degradation, and linoleic acid metabolism. Observable differences in ultrastructure between BALA and BA were noted during fermentation. Lactic treatment altered barley nutrient content, including DM, CP, RS, ash, water-soluble carbohydrates and non-fiber carbohydrates, and affected barley ultrastructure. These variations led to significant and incubation time-dependent changes in the in vitro fermentation characteristics and metabolome.

Effects of the Incubation Period of Pleurotus ostreatus on the Chemical Composition and Nutrient Availability of Solid-State-Fermented Corn Stover.

The current study aimed to optimize and improve the feeding value of Pleurotus ostreatus-fermented corn stover by evaluating the effects of five solid-state fermentation times and three in vitro fermentation periods on the chemical composition, dry matter disappearance (DMD), microbial mass and volatile fatty acid (VFA) production of treated and untreated corn stover. The study utilized a 3 × 5 factorial design, with eight replicates per treatment. Dry matter, crude protein (CP), ash and non-fiber carbohydrate (NFC) contents increased quadratically (p < 0.05) with increases in the solid-state fermentation time. Increases of 44.4-59.1%, 20.6-78.6% and 40.5-121% were noted for the CP, ash and NFC contents, respectively. Organic matter, ether extract, neutral detergent fiber and hemicellulose contents decreased quadratically (p < 0.05) across the treatments. Similar trends were noted for DM and fiber disappearance in the treatments. The total gas production and in vitro true dry matter digestibility (IVTDMD) increased quadratically, while microbial mass and in vitro apparent DMD increased in a linear manner. The total VFA, propionate and butyrate contents increased linearly. Both the acetate content and the A:P ratio decreased in a linear manner. The results show that the rumen fermentation pathway favors the production of propionate, with increases in propionate production of 7.46 and 8.30% after 2 and 4 wk, respectively. The study showed that a 2 wk period of solid-state fermentation is sufficient to provide a bio-transformed cow-calf feed resource from P. ostreatus-treated corn stover.

Nutritional Values and In Vitro Fermentation Characteristics of 29 Different Chinese Herbs

The present study evaluated the nutritional values and in vitro fermentation characteristics of 29 different Chinese herbs in order to develop effective feed additives for livestock nutrition. The Chinese herbs were analyzed for their chemical composition. The in vitro fermentation characteristics were evaluated using the gas production technique with swine cecal chyme inoculum. The results showed that the Allium tuberosum Rottl (Semen allii tuberosi, SAT) had the highest gross energy (GE), crude protein (CP), ether extract (EE), and total amino acid (TAA) contents, whereas Anemones raddeanae Rhizoma (Agstache rugosus, AR) had the highest crude fiber, neutral detergent fiber, and acid detergent fiber contents compared with the other Chinese herbs. The Rhus chinensis Mill (Chinese gall, CG), Scrophularia ningpoensis Hemsl (Radix scrophulariae, RS), Punica granatum L (Punica granatum L, PGL), Atractylodes macrocephala Koidz (White atractylodes rhizome, WAR), Sanguisorbae radix (Garden burnet, GB), Anemarrhena asphodeloides Bunge (Rhizoma anemarrhenaw, RA), and Rhei radix Et Rhizoma (Rheum officinale, RO) had a higher non-fiber carbohydrate content than the other Chinese herbs. The in vitro fermentation kinetic analysis showed that the RS, WAR, and RA had a higher gas production, a theoretical gas production, and a fractional rate of gas production than the other groups. Furthermore, the RA, WAR, RS, and Crataegi fructus (Crataegus pinnatifida Bun, CPB) had a higher total short-chain fatty acids (SCFAs) concentration, and CPB had the highest acetate concentration, whereas the WAR and RS had higher propionate and butyrate concentrations than the other groups. Moreover, the Isatis indigotica Fort (Folium isatidis, FI) and SAT had higher ammonia-N concentration than the other groups. In summary, among the 29 different Chinese herbs, the SAT had the highest nutritional value, which is reflected in the highest contents of GE, CP, EE, and TAA, whereas the RA, WAR, and RS showed better intestinal fermentation profiles, which is reflected in the higher fermentation degree and suitable SCFAs fermentation pattern. These findings provide a theoretical basis for using Chinese herbs as feed additives or microbial carbon sources in the intestines of animals.

The Effects of Non-Fiber Carbohydrate Content and Forage Type on Rumen Microbiome of Dairy Cows.

Simple SummaryFor sustainable development in the dairy industry, crop by-products play an important role, especially in areas that lack pasture and are not suitable for intensive cereal-adapted production (i.e., diets containing high amounts of cereal grains). However, feeding crop by-products usually lowers milk production in dairy cows due to their poor nutrient quality. In a previous study, we have demonstrated that non-fiber carbohydrate content (NFC) is a major limiting factor for the utilization of diets based on corn stover (CS). Although the higher abundance of easily fermentable energy in NFC and forage type can influence the synthesis of VFAs and MCP in the rumen and higher NFC content or high quality forages normally have a positive influence on the lactation performance of dairy cows, the underlying microbial mechanisms and potential effects on milk production are under-investigated to date. Here, we examined microbial composition and predicted the metabolism from cows fed CS-based diets with either high levels of NFC (H-NFC), or low levels of NFC (L-NFC). Control cows were fed an alfalfa-based diet (AH). Our results show that, supplementation of the CS-based diet with additional NFC increased amino acid biosynthesis in rumen microbiota in dairy cattle, and thus resulted in better nitrogen conversion. However, lower levels of fibrolytic capacity may limit dry matter intake of cows fed H-NFC and may prevent increased milk yield.The main objective of our current study was evaluating the effects of NFC supplementation and forage type on rumen microbiota and metabolism, by comparing microbial structures and composition among samples collected from cows fed AH (alfalfa-based diet), H-NFC (CS-based diet with high NFC) and L-NFC (CS-based diet with low NFC) diets. Our results show that microbial communities were structurally different but functionally similar among groups. When compared with L-HFC, NFC increased the population of Treponema, Ruminobacter, Selenomonas and Succinimonas that were negatively correlated with ruminal NH3-N, and urea nitrogen in blood, milk and urine, as well as significantly increasing the number of genes involved in amino acid biosynthesis. However, when compared to the AH group, H-NFC showed a higher abundance of bacteria relating to starch degradation and lactate production, but a lower abundance of bacteria utilizing pectin and other soluble fibers. This may lead to a slower proliferation of lignocellulose bacteria, such as Ruminococcus, Marvinbryantia and Syntrophococcus. Lower fibrolytic capacity in the rumen may reduce rumen rotation rate and may limit dry matter intake and milk yield in cows fed H-NFC. The enzyme activity assays further confirmed that cellulase and xylanase activity in AH were significantly higher than H-NFC. In addition, the lower cobalt content in Gramineae plants compared to legumes, might have led to the significantly down-regulated microbial genes involved in vitamin B12 biosynthesis in H-NFC compared to AH. A lower dietary supply with vitamin B12 may restrict the synthesis of milk lactose, one of the key factors influencing milk yield. In conclusion, supplementation of a CS-based diet with additional NFC was beneficial for nitrogen conversion by increasing the activity of amino acid biosynthesis in rumen microbiota in dairy cattle. However, lower levels of fibrolytic capacity may limit dry matter intake of cows fed H-NFC and may prevent increased milk yield.

Maximizing Land Use Efficiency and Productivity of Soybean and Fodder Maize Intercrops through Manipulating Sowing Schedule and Maize Harvest Regime

The incorporation of both food and forage crops in an intercropping system is receiving increasing attention, especially in developing countries with increasing populations and limited resources. In a two-year (2019–2020) field trial, conducted in Northern Egypt, productivity of soybean and fodder maize, as well as the quality of maize herbage, were investigated under three sowing schedules; soybean and maize sown together, and maize sown 15 and 30 days after soybean, in addition to soybean and fodder maize sown in pure stands, with maize harvested at green fodder maturity (GFM), and silage maturity (SM). Harvesting fodder maize at SM resulted in higher herbage yield than harvesting it at GFM, yet it negatively affected the soybean productivity. However, this negative impact was offset when fodder maize sowing was delayed 30 days after soybean sowing. Maize harvested at GFM was characterized by a higher leaf component, which was reflected in its higher crude protein content, yet the decline in quality with advanced maturity was to a great extent, counterbalanced by the presence of high-quality ears in maize harvested at SM. This was clear in its lower fiber and higher non-fiber carbohydrate contents. Land equivalent ratio (LER) demonstrated yield advantage with the delayed sowing of fodder maize (LER &gt; 1), while the dry matter equivalent ratio (DMER) associated the yield advantage with the late harvesting of fodder maize at SM (DMER &gt; 1), across all sowing schedules, which was more realistic for an additive intercropping model where the dry matter is the economic component. In a soybean-fodder maize intercropping system, whether fodder maize will be cultivated for green feeding or for silage production, it is recommended that sowing is delayed until 30 days after the soybean, in order to maximize yield advantage and land use efficiency.

Aerobic semi-solid fermentation of Opuntia megacantha as feed supplement and its effect on dairy cows (Holstein)

Fermented prickly pear (Opuntia megacantha) has been used as forage in goats and sheep. Thus, the objectives of this study were to assess bimonthly production of cladodes var. Narro, compare the quality of those fermented versus non-fermented, and assess the effect of fermented cladodes in milk production of Holstein cows in stables (La Partida, Matamoros, Coahuila, México). Central pivot irrigation was used to water prickly pear plantation with a density of 17,500 plants ha-1. To assess cladode quality (proximal analysis) before and after fermentation, a completely randomized bifactorial design was used -non-fermented (N-0) and fermented (N-F) cladodes- with three replicates each. To assess the fermented cladode effect in milk production, a completely randomized design was established with first-calving Holstein cows where each one represented one replicate. The treatments were two diets, Dnor (normal) and Dnop (fermented cladodes). The results showed sufficient bimonthly production (14,380.8±1,676 kg t ha-1) of fresh prickly pear leaves for daily bio-digestor functioning (200 kg). Crude protein content and metabolizable energy showed significantly greater and contrasting values compared with non-fiber carbohydrate content (sugars and starch), showing a significant decrease in fermented cladodes with respect to non-fermented. Other proximal components did not show significant differences between both N-F vs N-0 cladodes. Average milk production increased when cows changed from Dnor (26.08 ± 4.8 L Day-1) to Dnop (30.07 ± 5.3 L Day-1) diets, recording three groups with less, medium, and greater significant increase in milk production. No correlation was found between production and increase.

Chitosan level effects on fermentation profile and chemical composition of sugarcane silage

This study aimed to evaluate the effects of increasing levels of chitosan (CHI) on sugarcane fermentation profile and losses, chemical composition, and in situ degradation. Treatments were: 0, 1, 2, 4, and 8 g of CHI/kg of dry matter (DM). Twenty experimental silos (PVC tubing with diameter 28 cm and height 25 cm) were used. Sand (2 kg) was placed at the bottom of each silo to evaluate effluent losses, and silos were weighed 60 d after ensiling to calculate gas losses. Samples were collected from the center of the silo mass to evaluate silage chemical composition, in situ degradation, fermentation profile, and mold and yeast count. Data were analyzed as a completely randomized design, and the treatment effect was decomposed using polynomial regression. Chitosan linearly increased acetic acid and NH3-N concentration, while yeast and mold count, and ethanol concentration decreased. Intermediary levels of CHI (from 4.47 to 6.34 g/kg DM) showed the lower values of effluent, gas, and total losses. There was a quadratic effect of CHI on the content of non-fiber carbohydrates, neutral and acid detergent, and in situ DM degradation. The lowest fiber content was observed with levels between 7.01 and 7.47 g/kg DM, whereas the highest non-fiber carbohydrate content and in situ DM degradation were found with 6.30 and 7.17 g/kg DM of CHI, respectively. Chitosan linearly increased acetic acid and NH3-N concentration, whereas it linearly reduced ethanol concentration and count of yeast and mold. Thus, intermediary levels of CHI, between 4.47 and 7.47 g/kg of DM, decrease fermentation losses and improve the nutritional value of sugarcane silage.

In Vitro Ruminal VFA Concentrations from Rice Straw and Sugarcane Bagase Based Diets with Different NFC Sources

Information concerning with ruminal nutrient availability of feed could help in balancing ruminant ration. Rice straw and sugarcane bagase are known as fiber sources, and molasses is known as non fiber carbohydrate (NFC) source for ruminant. The banana plant root meal (BPRM) is postulated to replace the portion of molasses in a ruminant diet because of its NFC content. This study determined the in vitro ruminal concentrations of volatile fatty acids (VFA) from ammoniated rice straw and sugarcane based diets supplemented with molasses and BPRM, respectively, as NFC sources. In the experiment, two diets of rice straw based diets suppelemented with molasses (RSM) and BPRM (RSB) respectively, and two diets of ammoniated sugarcane bagase based diets supplemented with molasses (SGM) and BPRM (SGB) were tested their in vitro ruminal VFA concentrations using a technique of batch culture. Result of the in vitro test showed that there was no significant different in ruminal concentrations of total VFA, acetic, propionic, butyric, isobutyric, isovaleric, and n-valeric among experimental diets. The portions of molasses and BPRM could be replaced each other in the diet, and likewise for rice straw and sugarcane bagase. This is valuable indicative in attempt for sustaining ruminant feed availability.

Milk production, methane emissions, nitrogen, and energy balance of cows fed diets based on different forage systems

Eight lactating Italian Friesian cows were housed in individual respiration chambers in a repeated Latin square design to determine their dry matter intake (DMI) and their milk and methane production, as well as to collect the total feces and urine to determine the N and energy balances. Four diets, based on the following forages (% of dry matter, DM), were tested: corn silage (CS, 49.3), alfalfa silage (AS, 26.8), wheat silage (WS, 20.0), and a typical hay-based Parmigiano Reggiano cheese production diet (PR, 25.3 of both alfalfa and Italian ryegrass hay). The greatest DMI was observed for cows fed PR (23.4 vs. 20.7 kg/d, the average of the other 3 diets). The DM digestibility was lower for PR (64.5 vs. 71.7%, the average of the other diets). The highest ash-free neutral detergent fiber digestibility values were obtained for CS (50.7%) and AS (47.4%). In the present study, no differences in milk production were observed between diets, although PR showed a higher milk yield trend. The highest milk urea N concentration (mg/dL) was found for the cows fed the WS diet (13.8), and the lowest was observed for the cows fed AS (9.24). The highest milk urea N concentration for the cows fed WS was also correlated with the highest urinary N excretion (g/d), which was found for the cows fed that same diet (189 vs. 147 on average for the other diets). The protein digestibility was higher for the cows fed the CS and WS diets (on average 68.5%) than for the cows fed AS and PR (on average 57.0%); dietary soybean inclusion was higher for CS and WS than for AS and PR. The rumen fermentation pattern was affected by the diet; the cows fed the PR diet showed a higher rumen pH and decreased propionate production than those fed CS, due to the lower nonfiber carbohydrate content and higher ash-free neutral detergent fiber content of the PR diet than the CS diet. Feeding cows with PR diet increased the acetate:propionate ratio in comparison with the CS diet (3.30 vs. 2.44 for PR and CS, respectively). Cows fed the PR diet produced a greater daily amount of methane and had a greater methane energy loss (% of digestible energy intake) than those fed the CS diet (413 vs. 378 g/d and 8.67 vs. 7.70%), but no differences were observed when methane was expressed as grams per kilogram of DMI or grams per kilogram of milk. The PR diet resulted in a smaller net energy for lactation content than the CS diet (1.36 vs. 1.70 Mcal/kg of DM for the PR and CS diets, respectively). Overall, our research suggests that a satisfactory milk production can be attained by including different high-quality forages in balanced diets without any negative effect on milk production or on the methane emissions per kilogram of milk.

Estimating black soldier fly larvae biowaste conversion performance by simulation of midgut digestion

Black soldier fly larvae treatment is an emerging technology for the conversion of biowaste into potentially more sustainable and marketable high-value products, according to circular economy principles. Unknown or variable performance for different biowastes is currently one challenge that prohibits the global technology up-scaling. This study describes simulated midgut digestion for black soldier fly larvae to estimate biowaste conversion performance. Before simulation, the unknown biowaste residence time in the three midgut regions was determined on three diets varying in protein and non-fiber carbohydrate content. For the static in vitro model, diet residence times of 15 min, 45 min, and 90 min were used for the anterior, middle, and posterior midgut region, respectively. The model was validated by comparing the ranking of diets based on in vitro digestion products to the ranking found in in vivo feeding experiments. Four artificial diets and five biowastes were digested using the model, and diet digestibility and supernatant nutrient contents were determined. This approach was able to distinguish broadly the worst and best performing rearing diets. However, for some of the diets, the performance estimated based on in vitro results did not match with the results of the feeding experiments. Future studies should try to establish a stronger correlation by considering fly larvae nutrient requirements, hemicellulose digestion, and the diet/gut microbiota. In vitro digestion models could be a powerful tool for academia and industry to increase conversion performance of biowastes with black soldier fly larvae.

Estimation and validation of total digestible nutrient values of forage and concentrate feedstuffs

Total digestible nutrient (TDN) values represent utilisable energy contents of feedstuffs, and these are extremely important values in order to provide adequate energy supply for livestock. This study aimed to estimate and validate TDN values of forage and concentrate feedstuffs from their nutrient contents. Nutrient composition data were obtained from BR CORTE database, comprised of 86 forage and 36 concentrate feedstuffs. The data included contents of dry matter (DM), organic matter (OM), ash, neutral detergent fiber (NDF), lignin, non-fiber carbohydrate (NFC), ether extract (EE), crude protein (CP) and TDN. A correlation analysis was conducted among the nutrient composition parameters for forage and concentrate. Data were then randomly divided into two parts, the first part (two-third of data) was used to estimate TDN whereas the second part (one-third) was used to validate the estimated TDN. Estimation of TDN was performed by employing a multiple linear regression method and it was validated by plotting between observed and estimated TDN. Results revealed that TDN in forage was negatively correlated with NDF (P<0.001) and lignin (P<0.05), but positively correlated with NFC and EE contents (both at P<0.001). Such pattern was similarly obtained with that in concentrate. Prediction equations of TDN in forage and concentrate were TDN = 0.479 NDF + 0.704 NFC + 1.594 EE + 0.714 CP and TDN = 0.323 NDF + 0.883 NFC + 1.829 EE + 0.885 CP, respectively. Values of estimated and observed TDN both in forage and concentrate were closely similar. It is concluded that TDN can be accurately estimated from nutrient composition data.

Effects of ensiling treatment for tuber crop forages and grain source on carbohydrate digestion, nitrogen utilization, and urea metabolism in sheep

This study investigated the effects of formic acid (FA) treatment for ensiling cassava foliage (CF) and sweet potato vine (SPV) with corn or barley grains on ruminal and total tract nutrient digestion, nitrogen (N) utilization, and urea metabolism in sheep. Four wethers fitted with ruminal and duodenal cannulae were assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement with ensiling treatment and grain source as the main effects. Sheep were fed four mixed diets containing the untreated CF and SPV silages with rolled barley or steam- flaked corn, or the FA-treated silages with rolled barley or steam-flaked corn. All experimental diets were formulated to contain 600 g forage (CF silage:SPV silage:oat hay, 150:150:300) and 400 g concentrate per kg dry matter (DM). The diets (120 g crude protein/kg DM; 10.6 and 11.2 MJ metabolizable energy/kg DM for the barley- and corn-based diets, respectively) were provided at 22 g/kg of body weight on a DM basis. The dietary treatments did not affect DM intake, but the total tract DM digestibility was higher for the corn-based diets than for the barley-based diets. The ruminal digestion of non-fiber carbohydrate (NFC) was higher (P < 0.01) for the corn-based diets than for the barley-based diets, and tended to be higher (P = 0.08) for the FA-treated silage diets than for the untreated silage diets, which reflected higher NFC content in the FA-treated CF silage than in the untreated silage. The ruminal digestion of neutral detergent fiber was lower (P < 0.05) for the corn-based diets than for the barley-based diets, but was not affected by the ensiling treatment. Ruminal pH and total volatile fatty acid concentration did not differ among the diets, but the ruminal ammonia-N concentration was lower (P < 0.01) for the FA-treated silage diets than for the untreated silage diets. The intake and total digestion of N were higher (P < 0.01) for the corn-based diets than for the barley-based diets, but net ruminal N loss and ruminal microbial N synthesis were similar among the treatments. The urea-N production, determined by constant intravenous infusion of [15N2]urea, was lower (P < 0.05) for the barley-based diets than for the corn-based diets. In conclusion, the use of FA-treated tuber crop silages may increase ruminal NFC digestion and reduce the ruminal ammonia-N concentration. However, the changes in carbohydrate digestion from the FA-treated silages and grain sources had little effect on ruminal microbial N synthesis or ruminal N digestion in sheep.

Soybean whole-plant ensiled with chitosan and lactic acid bacteria: Microorganism counts, fermentative profile, and total losses

Chitosan is a biopolymer derived from chitin deacetylation, present in the exoskeleton of crustaceans and insects. Chitosan has been evaluated as rumen modulator and silage additive due to its antimicrobial properties. The objective of this study was to determine the effects of both chitosan and a bacterial additive on microbiological quality, chemical composition, nutrient in vitro degradation, fermentative profile, and total losses of whole-soybean plant silage (SS) harvested at R6 stage. Four treatments in a factorial arrangement were randomly assigned to 40 experimental minisilos as no additives (CON), 8 g/t fresh forage of microbial inoculant (INO; Kera SIL, Kera Nutrição Animal, Bento Gonçalves, Brazil); 5 g/kg of fresh forage chitosan (CHI); and CHI + INO. Microbial inoculant was composed of Lactobacillus plantarum (4.0 × 1010 cfu/g) and Propionibacterium acidipropionici (2.6 × 1010 cfu/g). The CHI and INO alone increased counts of lactic bacteria and anaerobic bacteria and decreased counts of mold and yeast in SS. The CHI or INO alone increased in vitro degradation of dry matter, crude protein, and neutral detergent fiber, and decreased nonfiber carbohydrate content of SS. Chitosan increased NH3-N and lactate concentrations and decreased ethanol concentration in SS. The CHI increased dry matter recovery from SS; INO increased silage aerobic stability. The combination of CHI+INO showed the lowest value of gas losses. In general, the combination of CHI and INO had small positive effects on gas losses of SS; however, both CHI or INO alone improved nutrient in vitro degradation and decreased mold and yeast in SS. Chitosan or INO utilization improves SS quality.

English

This study was conducted to evaluate the effect of urea and molasses addition on physical properties, pH, temperature, dry matter loss and chemical composition of sugarcane top (SCT) silage. Treatments were arranged as 2*4 factorial, with two SCT types (green and burnt) and four silage treatment types (without additive, 4% molasses, 1% urea and 1% urea + 4% molasses) in a completely randomized design. Forages were chopped into 2 to 3 cm, treated with the additives and ensiled in 1.09 L mini silos for 45 days. The best average score values for smell, color, texture, mold appearance and pH was noted in silages made without additive or with molasses. The desirable pH (3.7 to 5.0) was obtained in all silages, except in green SCT ensiled with urea-based additives, while lower (P 0.05) with molasses alone. Fiber fractions (NDF, ADF and ADL) of burnt SCT were not affected (P>0.05) by additives, while NDF increased with urea based additives and ADF decreased with molasses based additives in green SCT silage. The highest (P<0.0001) in vitro dry matter digestibility (53.68%), organic matter digestibility (48.34%) and metabolizable energy (7.74 MJ/kg DM) content were observed contained in burnt SCT silage treated with urea-molasses mix, whereas a significant reduction (P<0.0001) in non-fiber carbohydrate content was observed in green SCT ensiled with urea (8.4%) and urea + molasses (1.65%). In conclusion, both burnt and green SCT can be adequately fermented and preserved as silage without additive; however silage nutritive value, particularly of burnt SCT can be further enhanced by ensiling with urea and molasses. Key words: Sugarcane top, molasses, urea, silage.

Effects of the dietary nonfiber carbohydrate content on lactation performance, rumen fermentation, and nitrogen utilization in mid-lactation dairy cows receiving corn stover

BackgroundCorn stover (CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate (NFC) might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments: (1) low-NFC diet (NFC = 35.6%, L-NFC), (2) high-NFC diet (NFC = 40.1%, H-NFC), and (3) alfalfa hay diet (NFC = 38.9%, AH).ResultsIntake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC (P < 0.01). The feed efficiency (milk yield/DM intake, 1.15 vs. 1.08, P < 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups (P > 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH (P < 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC (P < 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups (P < 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups (P = 0.06).ConclusionsFrom the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion.

The nutritional composition and digestion of plants foraged by red deer (Cervus elaphus xanthopygus) in northeast China

We studied species of plants foraged by red deer in the Muling forest region of northeastern China during January 2014 and 2015. We focused on nutritional composition, energy content, and the digestibility of these plants. Crude protein content varied by plant species. Average crude protein content was 7.5 ± 1.7% of dry matter, ranging from 4.5 to 10.3%. Crude lipid content did not vary by species and averaged 7 ± 1.5% (range 5.4–9.8%). Non-fiber carbohydrate (NFC) and neutral detergent fiber (NDF) content varied broadly with average values being 20.1 ± 4.8% (range 13.5–28.8%) and 64.7 ± 5.9% (range 53.5–71.8%), respectively. Energy content ranged from 16.7 to 19.7 kJ/g. Average dry matter digestibility (DMD) was 46.1 ± 4.8%, with a range from 38.7 to 54.6%. Only three plants, Saussurea manshurica, Aralia elata and Equisetum hyemale exhibited DMD > 50%. NFC content explained most of the variation in energy content (r = 0.451). In contrast, energy content was inversely related to NDF (r = −0.443). There was no correlation between crude protein, crude lipid, and energy content (r protein = 0.004, r lipid = −0.190). S. manshurica, A. elata and E. hyemale had higher NFC and lower NDF content. Thus, these species offered the greatest nutritional value for wintering red deer in the study area. Along with high CP and NFC content, Taxus cuspidate also had high lignin content, and was thus, considered a good forage species for red deer.

Nutritional value of sorghum silage of different purposes

ABSTRACT Sorghum is a crop that stands out as an alternative to corn due to lower soil fertility demand and increased tolerance to drought. Lack of information about the qualitative behaviour of sorghum hinders the recommendation of different purpose sorghum cultivars. The goal was to evaluate the chemical composition and in vitro digestibility of different purpose sorghum cultivar silages, at two cropping seasons. The trial was conducted at the Plant Production Department, Federal Institute of Education, Science and Technology of Rondônia, Colorado do Oeste campus, and chemical analyses and in vitro incubation were performed at the Laboratory of Animal Nutrition, Federal University of Mato Grosso, Cuiabá campus. The experimental design was a randomized block with a split-plot arrangement and four replications. Plot treatments consisted of six different purpose sorghum cultivars (BRS 308 and BRS 310, grain sorghum; BR 655 and BRS 610, forage sorghum; and BRS 506 and CMSXS 647, sweet sorghum). Split-plot treatments consisted of two cropping periods (first crop and second crop). Forage sorghum cultivar BRS 655 demonstrated higher non-fiber carbohydrate content and lower potentially digestible fibre content than the other cultivars did. Sweet sorghum cultivars had higher levels of water soluble carbohydrates and non-protein nitrogen based on protein, lower indigestible neutral detergent fibre content at second crop, and higher in vitro dry matter digestibility than the other cultivars. The silages of sweet sorghum cultivars BRS 506 and CMSXS 647, and forage sorghum cultivar BRS 655 presented higher nutritional values.

Short communication: Using diurnal patterns of 13C enrichment of CO2 to evaluate the effects of nitrate and docosahexaenoic acid on fiber degradation in the rumen of lactating dairy cows

Nitrate decreases enteric CH4 production in ruminants, but may also negatively affect fiber degradation. In this experiment, 28 lactating Holstein dairy cows were grouped into 7 blocks. Within blocks, cows were randomly assigned to 1 of 4 isonitrogenous treatments in a 2×2 factorial arrangement: control (CON); NO3 [21g of nitrate/kg of dry matter (DM)]; DHA [3g of docosahexaenoic acid (DHA)/kg of DM]; or NO3+DHA (21g of nitrate/kg of DM and 3g of DHA/kg of DM). Cows were fed a total mixed ration consisting of 21% grass silage, 49% corn silage, and 30% concentrates on a DM basis. Based on the difference in natural 13C enrichment and neutral detergent fiber and starch content between grass silage and corn silage, we investigated whether a negative effect on rumen fiber degradation could be detected by evaluating diurnal patterns of 13C enrichment of exhaled carbon dioxide. A significant nitrate × DHA interaction was found for neutral detergent fiber digestibility, which was reduced on the NO3 treatment to an average of 55%, as compared with 61, 64, and 65% on treatments CON, DHA, and NO3+DHA, respectively. Feeding nitrate, but not DHA, resulted in a pronounced increase in 13C enrichment of CO2 in the first 3 to 4 h after feeding only. Results support the hypothesis that effects of a feed additive on the rate of fiber degradation in the rumen can be detected by evaluating diurnal patterns of 13C enrichment of CO2. To be able to detect this, the main ration components have to differ considerably in fiber and nonfiber carbohydrate content as well as in natural 13C enrichment.

출수형태와 BMR이 수수×수단그라스 교잡종의 생육특성, 생산성 및 품질에 미치는 영향

본 시험은 수수<TEX>${\times}$</TEX>수단그라스 교잡종 품종의 생육특성, 사초수량 및 품질을 비교하기 위하여 2009년 경북 성주와 충남 천안에서 수행하였다. 시험구 배치는 8처리 3반복의 난괴법 배치로 하였다. 시험구의 처리는 품종으로 하였으며, 공시한 품종은 'Sordan79', 'SX17', 'Honey chew', 'Honey grazer', 'G7', 'Jumbo', 'Green star' 및 'GT56'를 공시하였다. 2지역 모두에서 출수형 4품종은 출수를 하였다. 그 외 생육특성에서는 품종 간에 차이가 없었으나 출수형과 BMR 품종이 다른 품종보다 당도가 높았다. 건물률 및 초장은 출수형이 비출수형 보다 높았다. 생초수량, 건물수량 및 TDN 수량도 출수형이 비출수형 보다 높았고 BMR 품종은 다른 품종보다 적었다. 조단백질과 조회분 함량은 출수형 품종이 비출수형 품종보다 많았으나 비섬유성탄수화물(NFC)은 상반된 결과를 보였다. BMR 품종의 ADF 및 NFC 함량은 다른 폼종 보다 작았다. 이상의 결과를 종합해 볼 때 출수형이 비출수형에 비하여 사초 생산성이 우수하고, 품질은 비출수형과 BMR 품종이 우수한 경향을 보였다. 그리고 BMR 품종은 당도가 높고 ADF 함량이 낮아 사초 품질 이 우수한 것으로 판단되었다. This experiment was carried out to compare the agronomic characteristics, forage yield and quality of sorghum <TEX>${\times}$</TEX> sudangrass hybrid at two locations (Sungju and Cheonan) in 2009. The experiment was a randomized complete block design with three replications. The eight recommended hybrids used in this experiment were 'Sordan 79', 'SX17', 'Honey chew', 'Honey grazer', 'G7', 'Jumbo', 'Green star' and 'GT56' hybrids. The heading of four hybrids were headed at both region, Sungju and Cheonan. There are no big differences in general agronomic characteristics among hybrids, but brix scale of heading and BMR (brown mid rib) types were higher than those of other hybrids. Dry matter (DM) and plant height of heading type hybrids were higher than those of headless types. The fresh, DM and TDN (total digestible nutrients) yields of heading type hybrids were also higher than those of headless types, and BMR types were lower than others. The crude protein and crude ash contents of headless hybrids were higher than those of heading hybrids, while its non-fiber carbohydrate (NFC) content showed the opposite results. The acid detergent fiber (ADF) and NFC contents of BMR types were lower than others. The results of this experiment indicates that heading hybrids were more higher than headless hybrids in the agronomics and forage yield of sorghum <TEX>${\times}$</TEX> sudangrass. However heading types were lower headless types in quality of sorghum <TEX>${\times}$</TEX> sudangrass. And BMR hybrids were also high quality of sorghum <TEX>${\times}$</TEX> sudangrass hybrid because of higher brix content and lower ADF content among tested hybrids.