The effect of cutting time of grass silage in primary growth and regrowth and the interactions between silage quality and concentrate level on milk production of dairy cows

Two silages were prepared from the primary growth (PG) of timothy-meadow fescue sward at early (E) and late (L) stage of growth. The subsequent regrowth (RG) areas were further harvested at early (EE and LE) and late (EL and LL) stages of growth resulting in six silages in total. The silages were fed ad libitum to 24 lactating Finnish Ayrshire cows and supplemented with 8 or 12 kg concentrate per day in a cyclic change-over experiment with four 21-day periods and 6 × 2 factorial arrangement of treatments. The quality of silages varied markedly within and between the harvests although variation was greater within PG than RG. Postponing the harvest in PG decreased silage dry matter (DM) intake by 0.48 kg and energy corrected milk yield (ECM) by 0.61 per 10 g decrease in silage D-value (concentration of digestible organic matter in DM), while responses and the range between the diets were clearly smaller when RG silages were fed. On average, ECM yield was higher when PG rather than RG silages were fed. The mean response to increased concentrate DM intake was 0.62 kg ECM using diets based on PG. The response increased with increasing growth stage of grass being 0.34 and 1.01 kg ECM / kg additional concentrate DM for E and L, respectively. The difference was mainly mediated by the differences in substitution rates (reduction in silage DM intake per increase in concentrate DM intake, kg/kg), which were 0.71 and 0.22 for E and L, respectively. The ECM response to increased concentrate allowance was on average greater when RG rather than PG silages (0.92 vs. 0.62 kg/kg concentrate) were fed. Milk production of dairy cows reflected the intake of metabolizable energy and no differences in the utilization of it were found between diets based on silages harvested from PG and RG. However, intake of RG silages was slightly lower than that of comparable PG silage, but definite reasons for that could not be identified.     

Effects of inoculants on the fermentation characteristics and in vitro digestibility of reed canary grass (Phalaris arundinacea L.) silage on the Qinghai‐Tibetan Plateau

To effectively use local available grass resources to cover the winter feed shortage on the Qinghai‐Tibetan Plateau, direct‐cut and wilted reed canary grass (RCG) silages were prepared by using a rolled‐bale system, and their ensiling characteristics and in vitro digestibility were studied. Silages were treated without (control) or with inoculants including LP (Lactobacillus plantarum), LPLB (L. plantarum, L. buchneri), and LPLBc (L. plantarum, L. buchneri, and cellulase), and were stored at ambient temperature (5.7–14.6°C) for 90 days. Compared with control, the inoculated silages increased (p < .05) lactic acid and acetic acid contents, and reduced (p < .05) final pH value and ammonia‐N ratio of total N. The highest WSC content (41.2 g/kg DM) occurred for LPLB‐inoculated silage, whereas LPLBc‐treated silage displayed the lowest contents of NDF (522.9 g/kg DM) and ADF (275.5 g/kg DM). In addition, LPLBc‐inoculated silage had the highest in vitro gas production (51.0 ml/g DM), in vitro DM digestibility (619.3 g/kg DM), and metabolic energy (9.6 kJ/kg DM). These results confirmed that treatments with inoculants at ensiling could improve silage fermentation and in vitro digestibility of RCG, and this could be a potential winter feed for animals on the Qinghai‐Tibetan Plateau.     

Silage preparation and fermentation quality of kudzu,sugarcane top and their mixture treated with lactic acid bacteria,molasses and cellulase

We studied silage fermentation of kudzu (KZ), sugarcane top (ST) and their mixtures treated with additives to be able to effectively use available local feed resources. The silages were prepared using KZ, ST, KZ 90% + ST 10%, KZ 80% + ST 20%, KZ 70% + ST 30% and KZ 60% + ST 40%, based on fresh matter (FM). These silages were treated with 10⁸ colony‐forming units/g epiphytic lactic acid bacteria (LAB), 5% molasses and 0.02% cellulase of FM. The KZ contained higher crude protein (CP; 14.52%) content and lower levels of neutral detergent fiber (NDF; 62.15%) than those of ST (6.84% CP and 64.93% NDF) based on dry matter (DM). The KZ 60% + ST 40% silage fermented well with a higher (P < 0.05) lactic acid content and lower (P < 0.05) pH than those of the other mixed silages. Silages treated with molasses had lower (P < 0.05) ammonia‐N, NDF, acid detergent fiber, and hemi‐cellulose contents as well as pH, but higher (P < 0.05) DM, water‐soluble carbohydrate, and lactic acid contents, than those of the control, LAB and cellulase treatments. The results confirmed that KZ 60% + ST 40% was the best mixing ratio to prepare silage, and molasses improved silage fermentation and fiber degradation.     

Effect of ensiling whole crop oat with lucerne in different ratios on fermentation quality,aerobic stability and in vitro digestibility on the Tibetan plateau

The objective of this study was to determine the effect of ensiling different ratios of whole crop oat to lucerne on fermentation quality, aerobic stability and in vitro digestibility of silage on the Tibetan plateau. Four experimental treatments were produced varying in the ratio of forages on a fresh matter (FM) basis: 1) 100% oat (control, dry matter (DM) content: 317 g/kg), 2) 90% oat + 10% lucerne (OL10, DM content: 316 g/kg), 3) 80% oat+ 20% lucerne (OL20, DM content: 317 g/kg) and 4) 70% oat+ 30% lucerne (OL30, DM content: 318 g/kg). All treatments were packed into laboratory‐scale silos and ensiled for 60 days and then subjected to an aerobic stability test for 15 days. Further, the four experimental treatments were incubated in vitro with buffered rumen fluid to study the nutrient digestibility. All silages were well preserved with low pH and NH₃‐N contents, and high lactic acid contents and V‐scores (evaluation of silage quality). Increasing the lucerne proportion increased (p < 0.05) crude protein (CP) content of silage, whereas neutral (NDF) and acid (ADF) detergent fibre contents were not affected. Under aerobic conditions, the control silage showed higher (p < 0.05) yeast counts (>10⁵ cfu/g FM) followed by OL10 silage, and OL10 silage improved aerobic stability for 74 h. OL20 and OL30 silages showed fewer (p < 0.05) yeasts (<10⁵ cfu/g FM) and markedly (p < 0.05) improved the aerobic stability (>360 h). After 48‐h incubation, OL30 silage increased (p < 0.05) in vitro dry matter digestibility (IVDMD) and neutral detergent fibre digestibility (IVNDFD) compared with the control silage. These results suggest that replacing oat with lucerne had no unfavourable effects on fermentation quality of silage, but improved CP content, aerobic stability IVDMD and IVNDFD. OL30 silage was the best among the three mixed silages.     

Effect of grape pomace on fermentation quality and aerobic stability of sweet sorghum silage

The objective of this study was to evaluate the effect of grape pomace (GP) with different adding levels (0%, 5%, 10% and 15%, fresh matter basis), alone (GP‐LAB) or in combine with an inoculant LAB (GP+LAB), on the fermentation quality and aerobic stability of sweet sorghum silage. After 90 days of ensiling in vacuumized mini‐silos, silages were subject to a 7‐day aerobic stability test, in which chemical, microbial and polyphenol composition were measured. In the GP‐LAB group, adding GP decreased (P < 0.05) concentrations of water‐soluble carbohydrate (WSC) and butyric acid in silage. In the GP+LAB group, adding GP increased (P < 0.05) concentrations of lactic acid, WSC and crude protein, decreased (P < 0.05) final pH value, NH₃‐N ratio and butyric acid concentration in silage. Polyphenol level was reduced (P < 0.05) after silage fermentation. During aerobic exposure, the fungi count, pH value and silage temperature increased (P < 0.05), the levels of lactic acid, acetic acid and polyphenols (quercetin 3‐O‐glucoside and quercetin 3‐O‐glucuronid) decreased (P < 0.05) in silage. GP+LAB treated silage had a lag phase for aerobic spoilage. When the fermentation products, microbial counts, chemical and polyphenol composition were considered, the use of 10% GP+LAB at ensiling could provide a valuable source for improved fermentation quality and aerobic stability of sweet sorghum silage.     

Effects of maturity stage and feeding strategy of whole crop barley silage on intake, digestibility and milk production in dairy cows

Five diets containing concentrate, grass silage and whole crop barley silage (WCBS) harvested at different maturity stages were fed to 15 multiparous dairy cows in an incomplete change-over design over three periods. Three diets contained 10.7 kg dry matter (DM) concentrate, 4 kg DM grass silage, and ad libitum access to WCBS harvested at either the heading stage (B1), the early milk stage (B2) or the early dough stage (B3) of maturity. The other two diets contained 10.7 kg DM concentrate, whereas grass silage and WCBS at heading were mixed at two different ratios with a DM content of WCBS of either 0.30 (M1) or 0.70 (M2), and the mixtures were fed ad libitum. Intakes of DM (kg day^− 1: B1 = 21.0, B2 = 20.6 and B3 = 20.0) and neutral detergent fibre (NDF; kg day^− 1: B1 = 7.0, B2 = 6.4 and B3 = 6.3) decreased, whereas starch intake increased (kg day^− 1: B1 = 3.1, B2 = 3.5 and B3 = 4.0) with increasing maturity at harvest. The apparent organic matter (OM) digestibility (g kg^− 1: B1 = 800, B2 = 774 and B3 = 729) decreased with increasing maturity stage, and consequently so did the digestible OM intake. Milk (kg day^− 1: B1 = 27.2, B2 = 26.1 and B3 = 25.9) and energy corrected milk (ECM; kg day^− 1: B1 = 31.0, B2 = 29.4 and B3 = 28.2) yields, and protein concentration (g kg^− 1: B1 = 37.1, B2 = 36.4 and B3 = 36.0) decreased with increasing maturity stage of the WCBS. When cows were fed diet B3 the milk fat concentration decreased (46.4 g kg^− 1) compared to diets B1 (49.3 g kg^− 1) and B2 (49.4 g kg^− 1). The difference in ECM yield between diets B1 and B3 was due to a combined effect of lower milk yield, and lower protein and fat concentrations. This was caused by the higher starch and lower NDF intakes with diet B3, which decreased the milk fat concentration. Moreover, a lower energy intake of diet B3 due to lower OM digestibility decreased milk protein concentration and milk yield. Mixing WCBS at the heading stage with grass silage (M2) decreased digestibility, compared to feeding the forages separately (B1). However, the differences were small and may be a result of soil contamination at harvest of some of the silages, which made the method with using incomplete faecal collection and internal marker acid insoluble ash less reliable. Including WCBS at the heading stage at 0.30 or 0.70 of forage DM did not affect DM intake or diet digestibility, probably because the grass silage in the study was very similar in energy content to the WCBS harvested at heading.     

Feeding value of ensiling fresh cattle manure with molasses or bakery by-products in lambs

Ensiling fresh dairy cattle manure (CM), corn stover, molasses (MO) or bakery by-products (BBP), as a viable method to produce good quality silage was evaluated. Silages composition was as follows: 1) molasses silage: CM, corn stover and molasses; and 2) BBP silages: CM, corn stover, and BBP. A low (250 g/kg dry matter) and a high (500 g/kg dry matter) level of CM with MO or BBP silages were incorporated in diets, and compared with a control diet (without CM silage) in lambs. There was a linear increase (P < 0.01) of dry matter (DM) intake and a quadratic increase of fiber digestion. Linear decrease (P < 0.05) in acetate to propionate ratio was observed with increased concentrations of MO or BBP in silages. Increasing MO silage caused a linear reduction of N intake and retained N, as well as a linear increase of fecal N. There were quadratic effects of BBP silage level on N intake, urine and retained, being the lowest values observed with the low level of BBP silage. Addition of BBP silages (250 or 500 g/kg DM) bring higher DM intake and total tract digestion of fiber, as compared to those diets without CM silage.     

A survey of fermentation products and bacterial communities in corn silage produced in a bunker silo in China

To evaluate the current practice of corn silage management in China, samples of bunker‐made silage were collected from 14 farms within a 500‐km radius of Beijing for the analysis of fermentation products and bacterial communities. Mean values for dry matter (DM) content were as low as 250 g/kg in both corn stover (St) and whole crop corn (Wc) silages, and pH values averaged 4.48 and 3.73, respectively. Only three of the 14 silages exhibited a lactic‐to‐acetic acid ratio > 1.0, indicating that the presence of acetic acid was predominant in fermentation. Although 1,2‐propanediol content was marginal in most cases (< 5.0 g/kg dry matter (DM)), two Wc silages had 1,2‐propanediol levels > 25 g/kg DM. In contrast, 3 St silages had large amounts (> 10 g/kg DM) of butyric acid, and two of the three butyrate silages also had high concentrations of 1‐propanol. Denaturing gradient gel electrophoresis analysis demonstrated that the bacterial community appeared similar in 10 out of the 14 silage samples. Bands indicating Lactobacillus buchneri, L. acetotolerans and Acetobacter pasteurianus were found in both the St and Wc silages, accounting for the high acetic acid content found across silage samples.     

Nutrients intake,digestibility, nitrogen balance and growth performance of sheep fed different silages with or without concentrate

The experiment was conducted to investigate the influence of maize (Zea mays), sorghum (Sorghum bicolor) and millet (Pennisetum americannum) silages with or without concentrate on nutrients intake, digestibility, nitrogen balance and weight gain in Sipli sheep. Six experimental diets were formulated having 100% maize silage (MS), maize silage and concentrate as 50:50 (MSC), 100% sorghum silage (SS), sorghum silage and concentrate as 50:50 (SSC), 100% millet silage (MiS) and millet silage and concentrate as 50:50 (MiSC), respectively. For this purpose, 24 Sipli lambs were randomly allotted to six experimental diets in a completely randomized design for 90 days, four lambs per diet. The results indicated that among various silage diets, lambs fed MS diet consumed higher dry matter (DM) than those fed SS and MiS diets. Likewise, lambs offered MSC had higher dry matter intake than those fed SSC and MiSC diets. Crude protein (CP) and neutral detergent fibre (NDF) consumed by the lambs also followed the similar trend. Higher DM, CP and NDF digestibilities were also observed in lambs fed MS and MSC diets than those fed SS, SSC, MiS and MiSC diets. Overall digestibilities of DM, CP and NDF were higher in experimental diets containing silage with concentrate. Lambs fed MS diet had 2.79 g/day and 4.45 g/day higher N retention than those fed SS and MiS, respectively. Similarly, lambs fed MSC diet had 2.24 g/day and 5.12 g/day higher N retention than those fed SSC and MiSC diets, respectively. The results showed that lambs fed MSC gained more daily weight gain had better feed conversion ratio than those fed MS, SS, SSC, MiS and MiSC diets. The findings of the present study indicated that lambs fed MSC diet had higher nutrients intake, digestibility, nitrogen balance and weight gain.     

Prediction of Forage Energy Content by Near Infrared Reflectance Spectroscopy and Summative Equations

In livestock nutrition, summative models (SM) are displacing empirical models as a preferred method to predict energy content of forages. The objective of this study was to determine the effect of using near infrared reflectance spectroscopy (NIRS) to determine nutrient subcomponents required of SM on overall ability to predict energy content of corn and legume-grass silages. Corn (n = 90) and legume-grass (n = 70) silages were collected and analyzed for CP, ADF CP, NDF, NDF CP, in vitro (IV) digestible (d) NDF, ash, and fat by standard laboratory techniques. Samples were scanned on a Model 6500 NIRS, and calibration equations were developed for each nutrient. The TDN contents of corn and legume-grass silages were then estimated using a SM, where the model nutrients were determined by laboratory or NIRS methods. The predicted TDN content of corn and legume-grass silages was compared to IV d OM to assess overall utility. The NIRS calibrations were adequate (R² > 0.90) for CP and NDF for both corn and legume-grass silages with standard errors of calibration (SEC) < 0.55 for CP and < 1.09 for NDF. Near infrared calibrations for ADF CP, NDF CP, fat, and ash were less accurate in both corn and legume-grass silages with R² < 0.75. Calibrations for IV d NDF in corn and legume-grass silages had R² = 0.87 and 0.79, respectively, but possible co-dependency with NDF is speculated. The relationship between corn and legume-grass silage SM TDN and IV d OM was excellent when model nutrients were determined by laboratory procedures. The TDN estimates when NIRS was used to determine all SM nutrients were superior to older empirical models, but SM TDN estimates using NIRS-determined nutrients were less accurate as compared with SM TDN prediction when model nutrients were determined by laboratory procedures. In particular, using NIRS to predict IV d NDF and ash for use in SM lead to the greatest challenge in TDN prediction in both corn and legume-grass silages.     

Concentrate levels and Saccharomyces cerevisiae affect rumen fluid-associated bacteria numbers in dairy heifers

Total viable rumen bacteria counts through the use of colony-unit forming assays lack accuracy because they only include culturable bacteria capable of initiating cell division. Thus, bacterial counts can be underestimated. The use of fluorescent characteristics of cell membranes allows flow cytometry to enumerate and distinguish dead from live bacteria cells. The objective of this experiment was to investigate the viable and total ruminal bacteria counts when 3 levels of forage:concentrate in diets were fed at restricted levels with the addition of Saccharomyces cerevisiae (YC). Three cannulated post-pubertal Holstein heifers (age 18 ± 1.0 months) were fed corn silage (CS)-based diets in a 3-period (35 d) Latin square design. Heifers were fed the diets for 21 d with no yeast addition, followed by 14 d where yeast culture (YC) was added (1 g/kg as-fed basis); (Yea-Sacc¹⁰²⁶, Alltech, Inc., Nicholasville, KY). A low concentrate (LC) TMR (80% CS, 20% concentrate; 12.4% CP, 35% NDF), a medium concentrate (MC) TMR (60% CS, 40% concentrate; 12.3% CP. 28% NDF), and a high concentrate (HC) TMR (40% CS, 60% concentrate; 12.6% CP, 25% NDF), were fed once per day. Rumen fluid was sampled − 2, 0, 2, 4, 6, 8, 10, 12 h after feeding. Samples were immediately stained with fluorescent dyes using the BacLight kit (Molecular Probes Inc., Eugene, OR) and analyzed with a Coulter XL-MCL single laser flow cytometer. Mean rumen viable bacteria counts linearly increased among treatments (4.96, 4.78, 6.73 × 10¹¹ ± 0.53 × 10¹¹ cells/ml; P = 0.02) for LC, MC and HC respectively, and YC addition increased number of viable bacteria cells (P < 0.01). Total and viable bacteria counts decreased for the first 2 h after feeding then increased 4 h post-feeding. Dietary concentrate level and YC can alter rumen bacteria counts as measured by this method.     

The effect of maize silage type on the performances and methane emission of dairy cattle

To examine whether type of maize silage is important for milk production performances, maize silage LG30224 (LG) was compared with Falkone (FA), the latter having a 4.0% points lower rumen NDF digestibility and 19 g/kg dry matter (DM) more starch. To bridge the lower energy content of FA, a third treatment was involved by adding maize meal (MM) in a ratio of 92/8 on DM (FA+MM). Maize and grass silage were fed ad libitum in a ratio of 65/35 on DM basis. Concentrates were supplemented individually to meet energy and protein requirements. The experiment was set up as a Latin square with three groups of nine Holstein cows during three periods of 3 weeks. In the last 2 weeks of each period, DM intake (DMI) and milk performances were measured. Each group included one cannulated cow to study effects on rumen fermentation. During the last 4 days of each period, two cows from each group were placed in gas exchange chambers to measure nutrient digestibility and methane production. Total DMI was higher (p < 0.05) for FA+MM (20.8 kg/day) than for FA (20.3 kg/day), while DMI for LG was intermediate (20.6 kg/day). Treatment did not affect milk production nor composition, whereas fat–protein‐corrected milk was higher for LG (30.5 kg/day) and FA+MM (30.3 kg/day) than for FA (29.9 kg/day). The ration did not affect pH nor volatile fatty acid composition in the rumen. Further, total tract digestibility of OM, crude protein, NDF and starch did not differ among treatments. The ration with LG gave higher methane production per day and per kg NDF intake than both rations with FA, but the difference was not significant when expressed per kg DMI or FPCM. Thus, maize silage type is of little importance for milk production if energy and physical structure requirements are met.     

Fermentation quality and nutritive value of a total mixed ration silage containing coffee grounds at ten or twenty percent of dry matter

Six wethers were used in a replicated 3 x 3 Latin square to study the fermentation quality and nutritive value of total mixed ration (TMR) silages that included wet coffee grounds (WCG). The TMR were prepared using a commercial compound feed, timothy hay, alfalfa hay, dried beet pulp, and a vitamin-mineral supplement in a ratio of 36.5:30:20:12:1.5, respectively, on a DM basis, with timothy hay and alfalfa hay being replaced by WCG at 0, 10, or 20%. All TMR silages, irrespective of WCG addition, were well preserved, with a low pH and ammonia-N content and a high lactic acid content. Intakes by wethers of TMR silages containing 0 and 10% WCG were 96.6 and 94.8 g/kg of BW(0.75), and did not differ (P > 0.05). Intake of TMR silage containing 20% WCG was 76.8 g/kg of BW(0.75), which was equal to 80% of that of the TMR silage with no WCG (quadratic: P < 0.01). Increasing concentrations of WCG in the rations decreased the digestibility of DM, CP, ADF, NDF, and energy, and increased that of ether extract (P < 0.05). The TDN and DE contents of the TMR silages with 0 and 10% WCG were similar, but the TMR silage with 20% WCG was lower (P < 0.05). With progressive increases in WCG concentrations, N intake did not differ, but fecal and urinary N increased linearly (P < 0.001), and retained N decreased linearly (P < 0.001). This study demonstrated that the proportion of WCG to be incorporated into TMR silages should not exceed 10% of the DM.     

In vitro gas and methane production in rumen fluid from dairy cows fed grass silages differing in plant maturity,compared to in vivo data

The relationship between in vitro rumen CH₄ production of grass silages, using the gas production technique, and in vivo data obtained with the same cows and rations in respiration chambers was investigated. Silages were made from grass harvested in 2013 on May 6th, May 25th, July 1st and July 8th. The grass silages were used to formulate four different rations which were fed to 24 cows in early and late lactation, resulting in a slightly different dry matter intake (DMI; 16.5 kg/day vs. 15.4 kg/day). The experimental rations consisted of 70% grass silage, 10% maize silage, and 20% concentrates on a dry matter basis. Cows were adapted to the rations for 17 days before rumen fluid was collected via oesophageal tubing, and in vitro gas and CH₄ production were analysed. In vitro total gas and CH₄ production of the (ensiled) grass expressed as ml/g OM decreased with advancing maturity of the grass. The in vitro CH₄ production after 48 hr of incubation expressed in ml/g OM did not correlate with the in vivo CH₄ production expressed in g/kg organic matter intake or g/kg DMI (R² = .00–.18, p ≥ .287). The differences in CH₄ emission per unit of intake observed in vivo were rather small between the different rations, which also contributed to the observed poor relationship. Utilizing stepwise multiple regression improved the correlation only slightly. In vitro gas and CH₄ production varied based on whether donor cows were previously adapted to the respective ration or not, suggesting that careful adaption to the experimental diet should be envisaged in in vitro gas and CH₄ production experiments.     

Ensiling of total mixed ration containing persimmon peel: Evaluation of chemical composition and in vitro rumen fermentation profiles

The effects of inclusion of persimmon peel (PP) in total mixed ration (TMR) silage on its nutrient composition, tannin content, and in vitro ruminal fermentation were studied. Four types of TMR silages containing 0, 50, 100, and 150 g/kg of PP on a dry matter basis were prepared. The dietary contents of non‐fiber carbohydrate (NFC) decreased, while soluble protein fraction increased after ensiling of the TMR. In the TMR silages, the content of insoluble tannin increased (p < .05) with increasing PP level. The fraction of soluble protein decreased linearly (p < .01), while that of neutral detergent insoluble protein increased linearly (p < .01) with increasing the PP level in the TMR silages. The total gas and methane yields from the in vitro rumen fermentation of the TMR silages were lower (p < .01) than those of pre‐ensiled TMR and declined linearly (p < .01) with increasing PP level. These results indicate that adding PP to TMR silage may resist the breakdown of dietary protein during the ensiling process, although the ruminal fermentability of TMR possibly decreased after ensiling due to the loss of NFC.     

The effect of incremental replacement of wheat with soya hulls in diets for Jersey cows on lactational performance, diet digestibility and feeding behaviour

Eight Jersey cows were used in two balanced 4 × 4 Latin Squares to investigate the effects of replacement of dietary starch with non-forage fibre on productivity, diet digestibility and feeding behaviour. Total-mixed rations consisted of maize silage, grass silage and a soyabean meal-based concentrate mixture, each at 250 g/kg DM, with the remaining 250 g consisting of cracked wheat/soya hulls (SH) in the ratios of 250 : 0, 167 : 83; 83 : 167 and 0 : 250 g, respectively, for treatments SH0, SH83, SH167 and SH250. Starch concentrations were 302, 248, 193 and 140 g/kg DM, and NDF concentrations were 316, 355, 394 and 434 g/kg DM, for treatments SH0, SH83, SH167 and SH250, respectively.Total eating time increased (p < 0.05) as SH inclusion increased, but total rumination time was unaffected. Digestibility of DM, organic matter and starch declined (p < 0.01) as SH inclusion increased, whilst digestibility of NDF and ADF increased (p < 0.01). Dry-matter intake tended to decline with increasing SH, whilst bodyweight, milk yield and fat and lactose concentrations were unaffected by treatment. Milk protein concentration decreased (p < 0.01) as SH level increased. Feed conversion efficiency improved (p < 0.05) as SH inclusion rose, but it was not possible to determine whether this was due to the increased fibre levels alone, or the favourable effect on rumen fermentation of decreasing starch levels.     

Effect of using banana by-products and other agricultural residues for beef cattle in southern China

Banana (Musa acuminata) by-products and other agricultural residues such as rice straw and sugarcane top are abundant in the southern part of China, but most of them are wasted and discarded. Under this experiment, several silages containing banana by-products with other crop residues were investigated for their fermentation characteristics and feeding values to beef cattle. There were three treatments (T) as follows: T₁ = fresh banana by-products (FBBP) + 4% corn meal (CM), T₂ = FBBP + rice straw (RS) at 70:30 (fresh weight), T₃ = FBBP + sugarcane top (SCT) at 70:30 (fresh weight). Twenty-one beef cattle bulls (220?±?15 kg body weight) were randomly assigned to 3 groups and assigned to one of three silage treatments in a total feeding period of 237 days. Results revealed that all of the three silage mixtures had a good fermentative profile with lower pH and higher organic acids. The FBBP + CM group significantly increased DM, CP, EE, and Ca content (P?< 0.05), while decreased ash, NDF, ADF, ADL, and condensed tannins (CT) content (P?<?0.01). Significant effects on weight gain, feed intake, and feed efficiency were observed at the end of the experiment (P?<?0.05). The FBBP + CM group also had the greatest total weight gain at 109 kg/head, twice of the FBBP + RS group (P?=?0.001), as well as the greatest average daily weight gain at 0.48 kg/head/day, followed by the FBBP + SCT group at 0.30 kg/head/day and the FBBP + RS group at 0.27 kg/head/day, respectively. Cattle fed FBBP + CM silage mixture diet had better feed efficiency than the cattle fed with the other mixtures (P?<?0.001). Results of body measurements showed that cattle consumed FBBP + CM silage mixture tended to have a greater body diagonal length, height at the hip, hip width, and rump length than those either consumed FBBP + RS or FBBP + SCT (P?<?0.05). The findings showed promising results of banana by-products silage with other agricultural crop residues to be used for increasing beef cattle production in southern China.

     

Effect of temperature and duration of ensiling on in vitro degradation of maize silages in rumen fluid

The effects of ensiling temperature and duration of ensiling on the feeding quality of whole‐crop maize (Zea mays L.) silages were investigated. Samples of one cultivar of maize plants were collected from two different fields, grown in different years on sandy soils. Samples were collected when the whole‐plant dry matter content was approximately 330 g/kg. Maize plants were chopped and ensiled in mini silos at three different ambient temperatures (5, 12 and 18 °C). The ensiling temperature affected the ensiling fermentation processes, causing different rates of pH decline and different final pH values. Samples from the silos were taken after 0 (not ensiled, i.e. control), 4, 8 and 16 weeks of ensiling. The silage samples were not dried, but ground‐frozen under liquid nitrogen to pass a 1‐mm sieve. The gas production technique was used to evaluate the influence of the ensiling temperature and the duration of ensiling on the degradation of the silage samples in rumen fluid. The gas production was highest when the maize was ensiled at 12 °C (p < 0.0001). An increase in ensiling duration caused a decrease in silage pH, accompanied by a decrease in gas production (p < 0.0001). The decrease in gas production was linearly related to the decrease in pH at the three temperatures. The present study shows that both ensiling temperature and ensiling duration play a significant role in the rumen degradability of maize silage.     

Effect of NDF/undegradable crude protein ratio on in vivo digestibility, particle passage rate in riverine buffaloes compared with sheep

In vivo digestibility (eight animals) and solid particles passage rate measured by faecal Cr (four animals fistulated at the rumen) were determined on riverine buffalo bulls and Delle Langhe rams, given four diets at maintenance level (50 g/kg M^0.75 per day of dry matter), according to a Latin square design, composed of a factorial combination of high and low NDF and of high and low protein undegradability. The diets were: L-30 = low NDF (530.0 g/kg DM), low undegradability of protein (29.6%, CP = 138.0 g/kg DM); L-40 = low NDF (537.0 g/kg DM), high undegradability of protein (41.0%, CP = 139.0 g/kg DM); H-30 = high NDF (583.0 g/kg DM), low undegradability of protein (28.3%, CP = 128.0 g/kg DM); H-40 = high NDF (NDF = 580.0 g/kg DM), high undegradability of protein (40.0%, CP = 128.0 g/kg DM). The digestibility of organic matter (66.68% vs. 64.32%, P < 0.05) and of the other analytical fractions (NSC, NDF, cellulose and hemicelluloses) was significantly higher in buffaloes with the exception of that of crude protein which was similar for the two species. Considering the diets within the species, the increased undegradable protein in the small intestine produces different effects: in the buffalo, it does not positively influence the digestibility of NSC but does increase that of cellulose, on the other hand in sheep it influences the digestibility of NSC. The post-ruminal digestibility of the undegraded protein, both in buffalo and sheep, is higher than that from protein of microbial origin. The passage rate of the marker of the solid particles, through the first compartment, k₁ (2.86% h^− 1 and 2.54% h^− 1 for the buffalo and the sheep) and through the entire intestinal tract, MRT (57.50 and 58.88 h for the buffalo and the sheep) does not show significant differences in the two species. The passage rate of the marker of the solid particles in buffalo rumen, at variance with the structural carbohydrates of the diet, is more variable compared with that of the sheep.     

紫花苜蓿和裸燕麦混贮发酵品质和营养成分分析

以新鲜及晾晒后的紫花苜蓿和裸燕麦为原料,分别设计紫花苜蓿单贮、裸燕麦单贮、裸燕麦∶紫花苜蓿=1∶1、裸燕麦∶紫花苜蓿=2∶1及裸燕麦∶紫花苜蓿=1∶2混贮等5个处理,青贮60 d后,对其感官评分、发酵品质和营养成分等进行分析。结果表明,鲜贮苜蓿在感官评定、V-Score及Kaiser评价体系中表现一般,而晾晒及混合青贮各处理组均能不同程度提高青贮评分。晾晒和混合青贮对发酵品质产生影响,两者显著或极显著降低pH值、 PA(丙酸)、AA(乙酸)、BA(丁酸)和AN/TN(氨态氮/总氮)含量(P＜0.01或P＜0.05),显著或极显著升高LA(乳酸)含量(P＜0.01或P＜0.05),其中以裸燕麦∶紫花苜蓿=2∶1降低或升高最明显。晾晒对青贮饲料的干物质、可溶性碳水化合物及粗灰分含量具有显著或极显著影响(P＜0.05或P＜0.01),对其他养分含量影响不大(P>0.05)。混合比例对青贮饲料的所有发酵项目均有极显著影响(P＜0.01),对粗蛋白质、可溶性碳水化合物及中性洗涤纤维含量具有显著或极显著影响(P＜0.05或P＜0.01),对其他养分指标影响不显著(P>0.05)。晾晒和混合青贮的交互作用可显著提高青贮饲料的发酵品质,但对养分含量影响不明显。因此,从青贮后感官评价、发酵品质及养分含量来看,紫花苜蓿和裸燕麦混合青贮品质优于单独青贮,且晾晒相对于鲜贮更易于青贮,而无论晾晒和鲜贮,当裸燕麦∶紫花苜蓿=2∶1时,青贮品质均优于其他各组。