EJC Search Results: authorExact:"Yang, W.Z."

1. Fluoride Electrode-Coupled Minicomputer for Determination of Fluoride in Human Hair. Wang, C.Y.; Zhou, Y.M.; Yang, W.Z. Microchemical Journal vol. 51 issue 3 June, 1995. p. 374-378

► This article presents a method of measuring the degree of fluorosis in people… (more)

DOI: 10.1006/mchj.1995.1043. ISSN: 0026-265X.

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2. Surface modification of biphasic calcium phosphate bioceramic powders. Yang, W.Z.; Zhou, D.L.; Yin, G.F.; Li, G.D. Applied Surface Science vol. 255 issue 2 November 15, 2008. p. 477-479

► Biphasic calcium phosphate (BCP)/poly l-lactide (PLLA) biocomposite is proven to be a promising… (more)

Keywords: 82.65.+r; 81.20.−n; 87.68.+z; Surface modification; Grafted; Biphasic calcium phosphate

DOI: 10.1016/j.apsusc.2008.06.182. ISSN: 0169-4332.

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3. Effects of Physically Effective Fiber on Chewing Activity and Ruminal pH of Dairy Cows Fed Diets Based on Barley Silage. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 89 issue 1 January, 2006. p. 217-228

► The objective of this study was to investigate the effects of physically effective… (more)

▼ The objective of this study was to investigate the effects of physically effective neutral detergent fiber (peNDF) content of dairy cow diets containing barley silage as the sole forage source on feed intake, chewing activity, and ruminal pH. The experiment was designed as a replicated 3x3 Latin square using 6 lactating dairy cows with ruminal cannulas. Cows were offered 1 of 3 diets (high, medium, and low peNDF) obtained using barley silage that varied in particle length: long (theoretical cut length of 9.5mm), medium (equal proportions of long and fine silages), and fine (theoretical cut length of 4.8mm). The peNDF contents were determined using the Penn State Particle Separator and were 13.8, 11.8, and 10.5%, for the high, medium, and low diets, respectively. The physical effectiveness factors (defined as proportion retained on 19- and 8-mm screens) for the long and fine silages were 0.84 and 0.68, respectively. Increased forage particle size increased intake of peNDF but did not affect intake of DM and NDF. Ruminating and total chewing time were linearly increased with increasing dietary peNDF. Mean ruminal pH, area between the curve and a horizontal line drawn at pH 5.8 or 5.5, and time that pH was below 5.8 or 5.5 were not affected by peNDF content. Intake of peNDF was not correlated to any chewing activity but proportion of long particles on the 19-mm sieve tended to be correlated to ruminating chews (r = 0.36) and ruminating time (r = 0.36). These results indicate that increasing the peNDF content of diets increases chewing time. However, increased chewing time does not always improve ruminal pH status. Increasing chewing time and thus increasing salivary secretion may not fully overcome the effects of feed digestion and the production of fermentation acids that lower rumen pH. The results suggest that dietary peNDF and fermentable OM intake are critical in regulating rumen pH. Dietary particle size, expressed as peNDF, was a reliable indication of chewing activity.

Keywords: physically effective neutral detergent fiber; chewing; rumen pH; dairy cow

DOI: 10.3168/jds.S0022-0302(06)72086-0. ISSN: 0022-0302.

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4. Increasing physically effective fiber content of dairy cow diets through forage proportion versus forage chop length: Chewing and ruminal pH. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 92 issue 4 April, 2009. p. 1603-1615

► A study was conducted to evaluate whether the risk of acidosis in dairy… (more)

▼ A study was conducted to evaluate whether the risk of acidosis in dairy cows can be lowered by increasing the physically effective fiber (peNDF) concentration of the diet, either through increased theoretical chop length of alfalfa silage or higher proportion of forage in the diet. The experiment was designed as a replicated 4x4 Latin square using 8 ruminally cannulated lactating dairy cows. Treatments were arranged in a 2x2 factorial design; 2 forage particle lengths (FPL) of alfalfa silage (short and long) were combined with low (35:65) and high (60:40) forage:concentrate (F:C) ratios [dry matter (DM) basis]. Dietary peNDF concentration (DM basis) was determined from the sum of the proportion of dietary DM retained either on the 2 sieves (8 and 19mm) or on the 3 sieves (1.18, 8, and 19mm) of the Penn State Particle Separator multiplied by the neutral detergent fiber concentration of the diet. The dietary peNDF concentrations were altered by changing the F:C or the FPL, and ranged from 10.7 to 17.5% using 2 sieves, or from 23.1 to 28.2% using 3 sieves. Intake of peNDF was increased by increasing FPL but not by increasing F:C ratio because of the reduction of DM intake at the higher F:C ratio. Chewing activity, including number of chews and chewing time, increased with increasing F:C ratio or FPL. Mean ruminal pH was elevated by 0.4 and 0.2 units with increasing F:C ratio and FPL, respectively. Lowering the F:C ratio decreased the duration that ruminal pH was below 5.8 (1.2 vs. 8 h/d). Increased F:C ratio or FPL reduced ruminal volatile fatty acids concentration from 137 to 122 or from 133 to 126mM, respectively, whereas acetate:propionate ratio was increased from 2.55 to 3.46 with increasing F:C ratio. Dietary peNDF concentration measured using 2 sieves was correlated to chewing time (r=0.57) and mean ruminal pH (r=0.75), whereas dietary peNDF concentration measured using 3 sieves was correlated to mean ruminal pH (r=0.83) and negatively correlated to the time that pH was below 5.8 (r=-0.78). This study shows that the risk of ruminal acidosis is high for cows fed a low F:C diet. Increasing the proportion of forage in the diet helps prevent ruminal acidosis through increased chewing time, a change in meal patterns, and decreased ruminal acid production. Increasing FPL elevates ruminal pH, but in low forage diets, increased FPL does not alleviate subacute acidosis because the fermentability of the diet is high and changes in chewing activity are marginal.

Keywords: physically effective fiber; chewing; ruminal pH; acidosis

DOI: 10.3168/jds.2008-1379. ISSN: 0022-0302.

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5. Physically Effective Fiber: Method of Determination and Effects on Chewing, Ruminal Acidosis, and Digestion by Dairy Cows. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 89 issue 7 July, 2006. p. 2618-2633

► A study was conducted to investigate the effects of physically effective neutral detergent… (more)

▼ A study was conducted to investigate the effects of physically effective neutral detergent fiber (peNDF) content of dairy cow diets containing corn silage as the sole forage on intake, chewing, ruminal pH, microbial protein synthesis, digestibility, and milk production. A second objective was to compare current methods of measuring peNDF to determine the most suitable approach for use in ration formulation. The experiment was designed as a replicated 3x3 Latin square using 6 lactating dairy cows with ruminal cannulas. Diets varied in peNDF content (high, medium, and low) by altering the particle length of corn silage. The physical effectiveness factors (pef) and peNDF contents of the corn silage and diets were determined based on the original (19- and 8-mm sieves) and new Penn State Particle Separator (PSPS; 19-, 8-, and 1.18-mm sieves). A dry-sieving technique that measures the proportion of particles retained on a 1.18-mm sieve was also used. The new PSPS and the 1.18-mm sieve produced similar estimates of pef and peNDF of diets but gave higher values than the original PSPS. There was a much smaller range in pef of corn silage when 3 sieves, rather than 2, were used with the PSPS (range of 0.93 to 0.96 vs. 0.41 to 0.72, respectively). Consequently, increased forage particle length in the diets increased dietary peNDF content and its intake when using the original PSPS; however, the new PSPS and the 1.18-mm sieve failed to detect changes in dietary peNDF and peNDF intake. The peNDF values estimated based on fractional NDF rather than the total NDF content were higher, but the ranking of diets was not changed. Increased intake of peNDF linearly increased digestibility of CP and tended to linearly increase digestibility of fiber in the total tract. As a result, milk yield tended to linearly increase with no effect on milk composition. Ruminal microbial protein synthesis and microbial efficiency were higher with the medium peNDF than with the high or low peNDF diets. Total chewing time and ruminating time were linearly increased with increasing dietary peNDF, whereas influence of dietary peNDF on ruminal pH and fermentation was minimal. This study showed that increasing peNDF content of diets improved fiber digestion. Of the systems used to measure peNDF, the original PSPS provided a good description of dietary particle length and its effects on chewing time and rumen pH, whereas the new PSPS provided a more consistent chewing index, the ratio of total chewing activity to peNDF, across diets varying in chop length of corn silage.

Keywords: physically effective neutral detergent fiber; chewing; digestion; dairy cow

DOI: 10.3168/jds.S0022-0302(06)72339-6. ISSN: 0022-0302.

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6. Increasing the Physically Effective Fiber Content of Dairy Cow Diets May Lower Efficiency of Feed Use. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 89 issue 7 July, 2006. p. 2694-2704

► Barley silages varying in theoretical chop length were used to evaluate the effects… (more)

▼ Barley silages varying in theoretical chop length were used to evaluate the effects of physically effective (pe) neutral detergent fiber (NDF) content of dairy cow diets on nutrient intakes, site and extent of digestion, microbial protein synthesis, and milk production. The experiment was designed as a replicated 3x3 Latin square using 6 lactating dairy cows with ruminal and duodenal cannulas. During each of 3 periods, cows were offered 1 of 3 diets (low, medium, and high peNDF) obtained using barley silage that varied in particle length: fine (theoretical chop length of 4.8mm), medium (equal proportions of long and fine silages), and long (theoretical chop length of 9.5mm). The peNDF contents were determined by multiplying the proportion (dry matter basis) of feed retained on the 2 screens (8 and 19mm) of the Penn State Particle Separator by the NDF content of the diet, and were 10.5, 11.8, and 13.8% for the low, medium, and high diets, respectively. Increased forage particle length linearly increased intake of peNDF but intakes of dry matter, organic matter, starch, and N were highest for cows fed the medium peNDF diet. Digestibilities of organic matter, NDF, and acid detergent fiber in the total tract were linearly decreased with increasing dietary peNDF, although total digestibility of starch and N was not affected by the treatments. Nevertheless, decreased digestibility due to increased dietary peNDF did not reduce milk production or milk composition because the cows were in mid to late lactation. Ruminal microbial protein synthesis and microbial efficiency were numerically higher with the low peNDF than with the medium or high peNDF diets. These results indicate that increasing the peNDF content of a diet containing barley silage decreases fiber digestibility in the total tract and lowers microbial efficiency. Therefore, the benefits of increasing dietary particle size, expressed as peNDF, on reducing the risk of ruminal acidosis should be weighed against potentially negative effects on efficiency of feed use.

Keywords: physically effective neutral detergent fi-ber; digestion; microbial protein synthesis; site of digestion

DOI: 10.3168/jds.S0022-0302(06)72345-1. ISSN: 0022-0302.

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7. Feeding barley grain steeped in lactic acid modulates rumen fermentation patterns and increases milk fat content in dairy cows. Iqbal, S.; Zebeli, Q.; Mazzolari, A.; Bertoni, G.; Dunn, S.M.; Yang, W.Z.; Ametaj, B.N. Journal of Dairy Science vol. 92 issue 12 December, 2009. p. 6023-6032

► The objectives of the present in vivo and in situ trials were to… (more)

▼ The objectives of the present in vivo and in situ trials were to evaluate whether feeding barley grain steeped in lactic acid (LA) would affect rumen fermentation patterns, in situ dry matter (DM) degradation kinetics, and milk production and composition in lactating dairy cows. The in vivo trial involved 8 rumen-fistulated Holstein cows fed once daily a total mixed ration containing rolled barley grain (27% in DM) steeped for 48h in an equal quantity of tap water (CTR) or in 0.5% LA (TRT) in a 2x2 crossover design. The in situ trials consisted of incubation of untreated rolled barley grain in cows fed CTR or TRT diets and of incubation of 3 different substrates including CTR or barley grain steeped in 0.5% or 1.0% LA (TRT1 and TRT2, respectively) up to 72h in the rumen. Results of the in vivo trial indicated that cows fed the TRT diet had greater rumen pH during most intensive fermentation phases at 10 and 12h post-feeding. The latter effect was associated with a shorter duration in which rumen pH was below 5.8 for cows fed the TRT diet (2.4h) compared with CTR diet (3.9h). Furthermore, cows fed the TRT diet had lower concentrations of volatile fatty acids at 2 and 4h post-feeding. In addition, concentrations of preprandial volatile fatty acids were lower in the rumen fluid of cows fed the TRT diet. Results also showed that molar proportion of acetate was lower, whereas propionate tended to increase by feeding cows the TRT diet. Cows fed the TRT diet demonstrated greater rumen in situ lag time of substrate DM degradation and a tendency to lower the fractional degradation rate. Other in situ results indicated a quadratic effect of LA on the effective rumen degradability of substrates whereby the latter variable was decreased from CTR to TRT1 but increased for TRT2 substrate. Although the diet did not affect actual milk yield, fat-corrected milk, percentages of milk protein, and lactose and concentration of milk urea nitrogen, cows fed the TRT diet increased milk fat content and tended to increase fat:protein ratio in the milk. In conclusion, results demonstrated that treatment of barley grain with LA lowered the risk of subacute rumen acidosis and maintained high milk fat content in late-lactating Holstein cows fed diets based on barley grain.

Keywords: lactic acid; dairy cow; rumen fermentation; barley grain

DOI: 10.3168/jds.2009-2380. ISSN: 0022-0302.

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8. Altering Physically Effective Fiber Intake Through Forage Proportion and Particle Length: Chewing and Ruminal pH. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 90 issue 6 June, 2007. p. 2826-2838

► Alfalfa silages varying in theoretical chop length and diets high and low in… (more)

▼ Alfalfa silages varying in theoretical chop length and diets high and low in forage proportion were used to evaluate whether increasing the physically effective (pe) neutral detergent fiber (NDF) content of dairy cow diets reduces the risk of acidosis. The experiment was designed as a replicated 4x4 Latin square using 8 ruminally cannulated lactating dairy cows. Treatments were arranged in a 2x2 factorial design; 2 forage particle lengths (FPL) of alfalfa silage (short and long) were combined with low (35:65) and high (60:40) forage:concentrate (F:C) ratios [dry matter (DM) basis]. Dietary peNDF content (DM basis) was determined from the sum of the proportion of dietary DM retained on either the 2 sieves (8 and 19mm) or the 3 sieves (1.18, 8, and 19mm) of the Penn State Particle Separator multiplied by the NDF content of the diet. The dietary peNDF contents ranged from 9.6 to 19.8% using 2 sieves, or from 28.6 to 34.0% using 3 sieves. Intake of peNDF was increased by increasing both the F:C ratio and the FPL of the diets. However, F:C ratio and FPL affected chewing activity differently; increasing F:C ratio increased chewing time but increasing FPL only increased chewing when a high-forage diet was fed. Mean ruminal pH was increased by 0.5 and 0.2 units with increasing F:C ratio and FPL, respectively. Cows fed the low F:C diet had>10 or 7h daily in which ruminal pH was below 5.8 or 5.5, respectively, compared with 1.2 and 0.1h for cows fed the high F:C ratio diet. Increased F:C ratio reduced ruminal VFA concentration from 135 to 121mM but increased the acetate:propionate ratio from 1.82 to 3.13. Dietary peNDF content when measured using 2 sieves was positively correlated to chewing time (r = 0.61) and mean ruminal pH (r = 0.73), and negatively correlated to the time that pH was below 5.8 or 5.5 (r = -0.46). This study shows that the risk of ruminal acidosis is high for cows fed a low F:C diet, particularly when finely chopped silage is used. Intake of dietary peNDF is a good indicator of ruminal pH status of dairy cows. Increasing the proportion of forage in the diet helps prevent ruminal acidosis through increased chewing time, a change in meal patterns, and decreased ruminal acid production. Increasing FPL elevates ruminal pH, but in low-forage diets increased FPL does not completely alleviate subacute acidosis because the fermentability of the diet is high and changes in chewing activity are marginal.

Keywords: physically effective fiber; chewing; ruminal pH; acidosis

DOI: 10.3168/jds.2007-0032. ISSN: 0022-0302.

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9. Selection of Barley Grain Affects Ruminal Fermentation, Starch Digestibility, and Productivity of Lactating Dairy Cows. Silveira, C.; Oba, M.; Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 90 issue 6 June, 2007. p. 2860-2869

► The objective of this study was to evaluate the effects of 2 lots… (more)

▼ The objective of this study was to evaluate the effects of 2 lots of barley grain cultivars differing in expected ruminal starch degradation on dry matter (DM) intake, ruminal fermentation, ruminal and total tract digestibility, and milk production of dairy cows when provided at 2 concentrations in the diet. Four primiparous ruminally cannulated (123+/-69 d in milk; mean+/-SD) and 4 multiparous ruminally and duodenally cannulated (46+/-14 d in milk) cows were used in a 4x4 Latin Square design with a 2x2 factorial arrangement of treatments with 16-d periods. Primiparous and multiparous cows were assigned to different squares. Treatments were 2 dietary starch concentrations (30 vs. 23% of dietary DM) and 2 lots of barley grain cultivars (Xena vs. Dillon) differing in expected ruminal starch degradation. Xena had higher starch concentration (58.7 vs. 50.0%) and greater in vitro 6-h starch digestibility (78.0 vs. 73.5%) compared with Dillon. All experimental diets were formulated to supply 18.3% crude protein and 20.0% forage neutral detergent fiber. Dry matter intake and milk yield were not affected by treatment. Milk fat concentration (3.55 vs. 3.29%) was greater for cows fed Dillon compared with Xena, but was not affected by dietary starch concentration. Ruminal starch digestion was greater for cows fed high-starch diets compared with those fed low-starch diets (4.55 vs. 2.49kg/d), and tended to be greater for cows fed Xena compared with those fed Dillon (3.85 vs. 3.19kg/d). Ruminal acetate concentration was lower, and propionate concentration was greater, for cows fed Xena or high-starch diets compared with cows fed Dillon or low-starch diets, respectively. Furthermore, cows fed Xena or high-starch diets had longer duration that ruminal pH was below 5.8 (6.6 vs. 4.0 and 6.4 vs. 4.2 h/d) and greater total tract starch digestibility (94.3 vs. 93.0 and 94.3 vs. 93.0%) compared with cows fed Dillon or low-starch diets, respectively. These results demonstrate that selection of barley grain can affect milk fat production and rumen fermentation to an extent at least as great as changes in dietary starch concentration.

Keywords: lactating dairy cow; barley grain; starch digestibility; ruminal fermentation

DOI: 10.3168/jds.2006-771. ISSN: 0022-0302.

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10. Altering Physically Effective Fiber Intake Through Forage Proportion and Particle Length: Digestion and Milk Production. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 90 issue 7 July, 2007. p. 3410-3421

► Intake of physically effective neutral detergent fiber (peNDF) of dairy cows was altered… (more)

▼ Intake of physically effective neutral detergent fiber (peNDF) of dairy cows was altered by adjusting the proportion of forage in the diet and forage particle length, and effects on nutrient intake, site and extent of digestion, microbial N synthesis, and milk production were measured. The experiment was designed as a triplicated 4x4 Latin square using 12 lactating dairy cows, with 4 that were ruminally and duodenally cannulated, 4 that were ruminally cannulated, and 4 that were intact. Thus, the site and extent of digestion, and microbial N synthesis were measured in a single 4x4 Latin square. Treatments were arranged in a 2x2 factorial design; 2 forage particle lengths (FPL) of alfalfa silage (short and long) were combined with low (35:65) and high (60:40) forage:concentrate (F:C) ratios (dry matter basis). Dietary peNDF content was determined from the sum of the proportion (dry matter basis) of dietary dry matter retained either on the 2 screens (8- and 19-mm) or on the 3 screens (1.18-, 8-, and 19-mm) of the Penn State Particle Separator multiplied by the neutral detergent fiber content of the diet. An increased F:C ratio reduced intakes of dry matter and starch by 9 and 46%, respectively, but increased intake of fiber from forage sources by 53%. Digestibility of dry matter in the total tract was not affected, whereas total digestion of fiber and N was improved by increasing the F:C ratio. Improved total fiber digestion resulted from higher ruminal digestion, which was partially due to a shift in starch digestion from the rumen to the intestine with the increased F:C ratio. Actual milk yield was decreased but production of 4% fat-corrected milk was similar between the low and high F:C diets because of increased milk fat content. Increased FPL increased intake of peNDF, especially when the high F:C diet was fed. However, nutrient intakes, N metabolism in the digestive tract, and milk production were not affected. Digestibility of neutral detergent fiber in the total tract was increased because of improved fiber digestion in the rumen with increased FPL. These results indicate that feeding dairy cows a low F:C diet is beneficial in terms of increasing feed intake, microbial N synthesis, and milk production. However, low F:C diets do not maximize feed digestion and production efficiency because of the effects of subacute ruminal acidosis. Increased FPL improves fiber utilization with minimal effects on the digestion of other nutrients and milk production. Increasing dietary peNDF, through an increased proportion of forage or increased FPL, improves fiber digestion because of improved rumen function.

Keywords: physically effective neutral detergent fiber; digestion; microbial nitrogen synthesis; dairy cow

DOI: 10.3168/jds.2006-818. ISSN: 0022-0302.

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11. Effects of Physically Effective Fiber on Intake, Chewing Activity, and Ruminal Acidosis for Dairy Cows Fed Diets Based on Corn Silage. Beauchemin, K.A.; Yang, W.Z. Journal of Dairy Science vol. 88 issue 6 June, 2005. p. 2117-2129

► A study was conducted to investigate the effects of physically effective (pe) neutral… (more)

Keywords: physically effective NDF; chewing; rumen pH; dairy cows; [abr] CS; corn silage; [abr] FPL; forage particle length; [abr] pef; physically effectiveness factor; [abr] peNDF; physically effective NDF; [abr] PSPS; Penn State Particle Separator containing 2 sieves (19 and 8 mm) and a pan; [abr] TCL; theoretical cut length

DOI: 10.3168/jds.S0022-0302(05)72888-5. ISSN: 0022-0302.

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12. Effects of Physically Effective Fiber on Digestion and Milk Production by Dairy Cows Fed Diets Based on Corn Silage. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 88 issue 3 March, 2005. p. 1090-1098

► Effects of physically effective (pe) neutral detergent fiber (NDF) content of dairy cow… (more)

Keywords: [abr] CS; corn silage; [abr] FPL; forage particle length; [abr] pef; physical effectiveness factor; [abr] peNDF; physically effective NDF; [abr] PSPS; Penn State Particle Separator consisting of 2 sieves (19 and 8mm) and a pan; physically effective neutral detergent fiber; digestion; milk production; dairy cow

DOI: 10.3168/jds.S0022-0302(05)72776-4. ISSN: 0022-0302.

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13. Grain Processing, Forage-to-Concentrate Ratio, and Forage Length Effects on Ruminal Nitrogen Degradation and Flows of Amino Acids to the Duodenum. Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 87 issue 8 August, 2004. p. 2578-2590

► The objectives of this study were to evaluate effects of dietary factors that… (more)

▼ The objectives of this study were to evaluate effects of dietary factors that alter ruminal fermentability on rumen N degradation, microbial protein synthesis, duodenal flows, and digestibility of amino acids (AA) in the intestines and the total tract. The experiment was a double 4x4 quasi-Latin square with a 2^3 factorial arrangement of treatments. The dietary factors were extent of barley grain processing, coarse (processing index; PI = 75.5%) or flat (PI = 60.2%); forage-to-concentrate (F:C) ratio, low (35:65) or high (55:45) on a DM basis; and forage particle length (FPL), long (7.59mm) or short (6.08mm). Eight lactating cows with ruminal and duodenal cannulas were offered ad libitum access to a total mixed diet. There were no significant interactions between dietary treatments for ruminal N degradation or its duodenal flow and digestibility in the intestines. Passage of microbial protein to the duodenum was improved with increased F:C ratio of the diet but was not affected by grain processing or FPL. Ruminal digestibility of N was increased with increased F:C ratio (49 vs. 60%) and with reduced FPL (59 vs. 50%). Increased grain processing improved N digestibility both in the intestine (15%) and in the total tract (8%). Reduction in the FPL of the diets reduced intestinal N digestion by 14% without affecting the N digestion in the total tract. Increased extent of grain processing tended to enhance duodenal flows of AA. In contrast, reducing FPL lowered flows of dietary AA to the duodenum because of lowered flows of feed plus endogenous N. Increased F:C ratio of the diet did not change the flow of total AA, but there was a reduced flow of dietary AA and increased flow of microbial AA. Flows of several individual AA were increased by feeding flatly rolled barley with limited effects of F:C ratio or FPL. An interaction between grain processing and FPL was detected for flows of some AA. Diets formulated with flatly rolled barley plus long FPL increased Arg, Thr, Asp, Glu, Ser, Tyr, and nonessential AA (NEAA) by more than 24%, compared with other combinations of grain processing and FPL. Digestibility of essential AA (EAA) in the intestine (68%) was higher than that of NEAA (63%), but digestion of total AA (65%) was similar to that of total N (66%). Digestibilities of individual AA in the intestine ranged from 46 to 77% and were generally improved with increased grain processing. However, effects of F:C ratio or FPL on digestion of AA were limited. These results indicate that manipulation of dairy cow diets can improve ruminal N degradation, microbial protein synthesis, flows of AA to the duodenum, and intestinal digestibility of AA. Combining dietary factors can be more beneficial than changing individual dietary factors for improving the delivery of AA to the small intestine.

Keywords: grain processing; forage particle length; amino acid flow; dairy cow; [abr] EAA; essential AA; [abr] F:C; forage to concentrate; [abr] FPL; forage particle length; [abr] NEAA; nonessential AA; [abr] PI; processing index

DOI: 10.3168/jds.S0022-0302(04)73383-4. ISSN: 0022-0302.

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14. Effects of Particle Size of Alfalfa-Based Dairy Cow Diets on Chewing Activity, Ruminal Fermentation, and Milk Production. Beauchemin, K.A.; Yang, W.Z.; Rode, L.M. Journal of Dairy Science vol. 86 issue 2 February, 2003. p. 630-643

► Effects of forage particle size measured as physically effective NDF and ratio of… (more)

▼ Effects of forage particle size measured as physically effective NDF and ratio of alfalfa silage to alfalfa hay of diets on feed intake, chewing activity, particle size reduction, salivary secretion, ruminal fermentation, and milk production of dairy cows were evaluated using a 4x4 Latin square design with a 2x2 factorial arrangement of treatments. The diets consisted of 60% barley-based concentrate and 40% forage, comprised either of 50:50 or 25:75 of alfalfa silage:alfalfa hay, and alfalfa hay was either chopped or ground. Various methods were used to determine physically effective NDF content of the diets. Cows surgically fitted with ruminal and duodenal cannulas were offered ad libitum access to these total mixed diets. The physically effective NDF content of the diets was significantly lower when measured using the Penn State Particle Separator than when measured based on particles retained on 1.18-mm screen. Intake of DM was increased by increasing the ratio of silage to hay but was not affected by physically effective NDF content of diets. Eating time (hours per day) was not affected by the physically effective NDF content of diets, although cows spent more time eating per unit of DM or NDF when consuming high versus low alfalfa hay diets. Ruminating time (hours per day) was increased with increased physically effective NDF content of the diets. Rumen pH was affected more by changing dietary particle size than altering the ratio of silage to hay. Feeding chopped hay instead of ground hay improved ruminal pH status: time during which ruminal pH was above 6.2 increased and time during which ruminal pH was below 5.8 decreased. Milk production was increased by feeding higher concentrations of alfalfa silage due to increased DM intake, but was not affected by dietary particle size. Feed particle size, expressed as mean particle length or physically effective NDF was moderately correlated with ruminating time but not with eating time. Although physically effective NDF and chewing time were not correlated to mean rumen pH, they were negatively correlated to the area between the curve and pH 5.8, indicating a positive effect on reducing the risk of acidosis. Milk fat content was correlated to rumen pH but not to physically effective NDF or chewing activity. These results indicate that increasing physically effective NDF content of the diets increased chewing activity and improved rumen pH status but had limited effect on milk production and milk fat content.

Keywords: physically effective NDF; chewing behavior; rumen pH; dairy cow; [abr] AH; alfalfa hay; [abr] AS; alfalfa silage; [abr] AS:AH; ratio of alfalfa silage to alfalfa hay; [abr] FPS; forage particle size; [abr] MPL; mean particle length; [abr] pe; physically effective; [abr]…

DOI: 10.3168/jds.S0022-0302(03)73641-8. ISSN: 0022-0302.

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15. Effects of Particle Size of Alfalfa-Based Dairy Cow Diets on Site and Extent of Digestion. Yang, W.Z.; Beauchemin, K.A.; Rode, L.M. Journal of Dairy Science vol. 85 issue 8 August, 2002. p. 1958-1968

► Effects of ratio of alfalfa silage to alfalfa hay and forage particle size… (more)

▼ Effects of ratio of alfalfa silage to alfalfa hay and forage particle size on nutrient intakes, site of digestion, rumen pools, and passage rate of ruminal contents were evaluated in a 4x4 Latin square design with a 2x2 factorial arrangement of treatments. The diets consisted of 60% barley-based concentrate and 40% forage made up either of 50:50 or 25:75 of alfalfa silage:alfalfa hay and alfalfa hay was either chopped or ground. Lactating dairy cows surgically fitted with ruminal and duodenal cannulas were used and offered ad libitum access to a total mixed ration. Intakes of nutrients were increased by increasing ratio of silage to hay but were not affected by particle size of forage. Change in ratio of silage to hay of diets did not affect site and extent of digestion. However, increased forage particle size of the diets improved digestibility of fiber and N in the total tract, and as well as digestibility of organic matter, starch, and acid detergent fiber in the intestine. There was a shift of starch digestion from the rumen to the intestine when forage particle size was increased, although total digestion of starch was not changed. Ruminal microbial protein synthesis and microbial efficiency also improved with increasing forage particle size. Cows fed ground hay versus chopped hay had significantly lower rumen wet mass regardless of the ratio of silage to hay. Reduced forage particle size also lowered ruminal nutrient pool size for cows fed the high silage diet. Ruminal passage rates of liquid and solid were decreased by reducing the ratio of silage to hay, and retention time of solids in the total tract was shortened by reducing forage particle size. These results indicate that manipulating ratio of silage to hay in the diets of dairy cows changed feed intake but had little effect on digestion. In contrast, increased forage particle size in dairy cow diets improved fiber digestion and microbial protein synthesis in the rumen, and shifted starch digestion from the rumen to the intestine. Dietary particle size, expressed as physically effective neutral detergent fiber, was a reliable indication of ruminal microbial protein synthesis and nutrient digestion.

Keywords: ratio of alfalfa silage to hay; physically effective neutral detergent fiber; site of digestion; dairy cow; [abr] AH; alfalfa hay; [abr] AS; alfalfa silage; [abr] AS:AH; ratio of alfalfa silage to alfalfa hay; [abr] FPS; forage particle size; [abr] peNDF; physically effective NDF; [abr] PSPS; Penn State Particle Separator

DOI: 10.3168/jds.S0022-0302(02)74272-0. ISSN: 0022-0302.

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16. Effects of Barley Grain Processing on Extent of Digestion and Milk Production of Lactating Cows. Yang, W.Z.; Beauchemin, K.A.; Rode, L.M. Journal of Dairy Science vol. 83 issue 3 March, 2000. p. 554-568

► Effects of barley processing on site and extent of digestion and milk production… (more)

Keywords: barley; grain processing; digestibility; dairy cows; [abr] ERD; effective ruminal degradability; [abr] PI; processing index measured as volume weight of barley after processing, expressed as a percentage of its volume weight before processing

DOI: 10.3168/jds.S0022-0302(00)74915-0. ISSN: 0022-0302.

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17. Fibrolytic Enzyme Supplements for Dairy Cows in Early Lactation. Rode, L.M.; Yang, W.Z.; Beauchemin, K.A. Journal of Dairy Science vol. 82 issue 10 October, 1999. p. 2121-2126

► Twenty multiparous lactating Holstein cows in early lactation were used to investigate effects… (more)

Keywords: fibrolytic enzyme supplement; digestibility; milk production; dairy cow; [abr] BCS; body condition score

DOI: 10.3168/jds.S0022-0302(99)75455-X. ISSN: 0022-0302.

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18. A Comparison of Methods of Adding Fibrolytic Enzymes to Lactating Cow Diets. Yang, W.Z.; Beauchemin, K.A.; Rode, L.M. Journal of Dairy Science vol. 83 issue 11 November, 2000. p. 2512-2520

► Holstein cows (n=43) in early lactation were used to investigate effects of method… (more)

▼ Holstein cows (n=43) in early lactation were used to investigate effects of method of adding fibrolytic enzymes to diets on feed intake, milk production, and digestibility. Cows were blocked according to parity and calving date and randomly assigned to three treatments: control, enzymes applied to the total mixed ration (E-TMR), or enzymes added to the barley-based concentrate (E-Conc). The enzyme product used was a proprietary blend that contained relatively high xylanase and low cellulase activities (Biovance Technol. Inc., Omaha, NE). An enzyme solution (50mg of enzyme powder dissolved into 20ml of water) was sprayed onto each kilogram of total mixed ration (dry matter basis) before feeding. Alternatively, 73g of enzyme powder, dissolved in 20L of water, was added per tonne of concentrate (50mg of enzyme/kg of diet dry matter). The total mixed rations contained 24% corn silage, 14% alfalfa hay, and 62% concentrate (dry matter basis) and were offered ad libitum. In vitro gas production assays and two experiments using sheep were conducted to measure the effects of enzyme treatment on digestibility. Dry matter intake (mean: 19.8 kg/d) was not affected by enzyme supplementation. Milk yield (kg/d) was higher for cows fed E-Conc (37.4) than for cows fed control (35.3) or E-TMR (35.2) with no effects on milk composition. Total tract digestibility (%) of dry matter was higher for E-Conc (66.6%) than for the control diet (63.9%) and intermediate for E-TMR (65.7%) when measured in dairy cows. However, the digestibility of the diets was substantially higher when measured in sheep than in dairy cows, with no effects of enzyme supplementation. The results indicate that fibrolytic enzymes have the potential to increase digestibility and milk production in dairy cows because digestion is low relative to potential digestibility. When digestion is higher, as was observed in lambs or in vitro, no improvement in digestibility occurs. Method of enzyme delivery must also be considered to maximize the benefits of using fibrolytic enzymes in dairy cow diets.

Keywords: dairy cow; enzymes; fiber digestion; digestibility; [abr] E-Conc; fibrolytic enzymes applied onto the concentrate during manufacturing; [abr] ETMR; fibrolytic enzymes sprayed daily onto the total mixed ration

DOI: 10.3168/jds.S0022-0302(00)75143-5. ISSN: 0022-0302.

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19. Synergy Between Ruminal Fibrolytic Enzymes and Enzymes from Trichoderma Longibrachiatum. Morgavi, D.P.; Beauchemin, K.A.; Nsereko, V.L.; Rode, L.M.; Iwaasa, A.D.; Yang, W.Z.; McAllister, T.A.; Wang, Y. Journal of Dairy Science vol. 83 issue 6 June, 2000. p. 1310-1321

► The mechanism by which enzyme additives improve feed digestion in ruminants is not… (more)

Keywords: fiber digestion; enzymes; microbial digestion; [abr] C; ellulase-rich preparation from Trichoderma longibrachiatum; [abr] CMC; carboxymethyl cellulose; [abr] HF; ruminal enzyme preparation extracted from rumen contents of steers receiving a high fiber diet; [abr] LF; ruminal enzyme preparation extracted from rumen contents…

DOI: 10.3168/jds.S0022-0302(00)74997-6. ISSN: 0022-0302.

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20. Effects of Grain Processing, Forage to Concentrate Ratio, and Forage Particle Size on Rumen pH and Digestion by Dairy Cows. Yang, W.Z.; Beauchemin, K.A.; Rode, L.M. Journal of Dairy Science vol. 84 issue 10 October, 2001. p. 2203-2216

► Dietary factors that alter the intake of effective fiber were evaluated for their… (more)

Keywords: [abr] peNDFM; physically effective NDF measured as the NDF content of the TMR multiplied by pefM; [abr] peNDFP>1.18; physically effective NDF measured as the NDF content of the TMR multiplied by pefP>1.18; [abr] peNDFPS; physically effective NDF measured as the NDF…

DOI: 10.3168/jds.S0022-0302(01)74667-X. ISSN: 0022-0302.

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21. Comparison of Hull-less Barley, Barley, or Corn for Lactating Cows: Effects on Extent of Digestion and Milk Production. Yang, W.Z.; Beauchemin, K.A.; Koenig, K.M.; Rode, L.M. Journal of Dairy Science vol. 80 issue 10 October, 1997. p. 2475-2486

► Six lactating, cannulated Holstein cows were used in a double 3 x 3… (more)

Keywords: cereal grain; ruminal fermentation; duodenal flow; hull-less barley; [abr] BCFA; branched-chain fatty acids; [abr] HB; hull-less barley

DOI: 10.3168/jds.S0022-0302(97)76200-3. ISSN: 0022-0302.

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22. Metabolite and Hormonal Responses to Glucose or Propionate Infusions in Periparturient Dairy Cows Supplemented with Chromium. Subiyatno, A.; Mowat, D.N.; Yang, W.Z. Journal of Dairy Science vol. 79 issue 8 August, 1996. p. 1436-1445

► Two studies were conducted to evaluate the effects of Cr supplementation on blood… (more)

Keywords: chromium; glucose; insulin; dairy cows; [abr] AUC; area under the response curve; [abr] GTT; glucose tolerance test; [abr] MP; multiparous; [abr] PP; primiparous

DOI: 10.3168/jds.S0022-0302(96)76502-5. ISSN: 0022-0302.

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23. Comparison of Barley, Hull-less Barley, and Corn in the Concentrate of Dairy Cows. Yang, W.Z.; Beauchemin, K.A.; Farr, B.I.; Rode, L.M. Journal of Dairy Science vol. 80 issue 11 November, 1997. p. 2885-2895

► Twelve multiparous and 12 primiparous lactating Holstein cows were used to compare the… (more)

Keywords: hull-less barley; barley; corn; digestibility; [abr] BCS; body condition score; [abr] HB; hull-less barley; [abr] MP; multiparous; [abr] PP; primiparous

DOI: 10.3168/jds.S0022-0302(97)76253-2. ISSN: 0022-0302.

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24. Barley Processing, Forage:Concentrate, and Forage Length Effects on Chewing and Digesta Passage in Lactating Cows. Yang, W.Z.; Beauchemin, K.A.; Rode, L.M. Journal of Dairy Science vol. 84 issue 12 December, 2001. p. 2709-2720

► Dietary factors that alter fermentability, NDF content, or particle size of the diet… (more)

▼ Dietary factors that alter fermentability, NDF content, or particle size of the diet were evaluated for their effects on chewing behavior and distribution and passage of feed particles in the digestive tract of dairy cows. A double 4 x 4 quasi-Latin square design with a 2^3 factorial arrangement of treatments was used. The dietary factors were: extent of barley grain processing, coarse (1.60mm) or flat (1.36mm); forage-to-concentrate ratio (F:C), low (35:65) or high (55:45) (dry matter basis); and forage particle length, long (7.59mm) or short (6.08mm). Eight lactating cows with ruminal and duodenal cannulas were offered ad libitum access to total mixed diets. Chewing time, expressed as minutes per day or per kilogram of dry matter or neutral detergent fiber (NDF), was increased with high F:C diets due to increased eating and ruminating times but was decreased when expressed per kilogram of NDF intake from forage. The influence of forage particle length or grain processing on chewing activity was less pronounced than F:C ratio. Chewing activity was positively correlated to proportion of long forage particles in the diet but not to particle length of the diets. Influence of feed particle size on particle size distribution in different sites of the digestive tract was minimal. Particle size distributions of duodenal digesta and feces differed; the proportion of particles retained on the 3.35- or 1.18-mm screens was higher, but proportion of particles that passed through the 1.18-mm screen was lower in duodenal digesta than in feces. Relationships between chewing activities and ruminal pH or fractional passage rate of rumen contents were not significant. These results indicate that particle size of barley-based diets was not a reliable indicator of chewing activity. Forage particle size and NDF content of the diets were more reliable indicators of chewing activity than was the NDF content of forage. Fecal particle size was not an appropriate means of estimating the size of particles exiting the reticulorumen, at least for barley-based diets. Breakdown of coarse particles was necessary, but not a rate-limiting step for particles exiting the rumen. Passage rate of the rumen contents was affected by numerous factors including chewing activity.

Keywords: feed particle size; chewing activity; particle size distribution; dairy cows; [abr] F:C; forage-to-concentrate ratio; [abr] MPL; mean particle length; [abr] NDFF; NDFfrom forage

DOI: 10.3168/jds.S0022-0302(01)74725-X. ISSN: 0022-0302.

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25. Effects of Grain Source and Enzyme Additive on Site and Extent of Nutrient Digestion in Dairy Cows. Beauchemin, K.A.; Yang, W.Z.; Rode, L.M. Journal of Dairy Science vol. 82 issue 2 February, 1999. p. 378-390

► Four lactating, cannulated Holstein cows were used in a 4x4 Latin square design… (more)

Keywords: grain source; enzymes; digestibility; milk production; [abr] HB; hull-less barley

DOI: 10.3168/jds.S0022-0302(99)75244-6. ISSN: 0022-0302.

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26. Effects of an Enzyme Feed Additive on Extent of Digestion and Milk Production of Lactating Dairy Cows. Yang, W.Z.; Beauchemin, K.A.; Rode, L.M. Journal of Dairy Science vol. 82 issue 2 February, 1999. p. 391-403

► A study was conducted using lactating Holstein cows with ruminal and duodenal cannulas… (more)

Keywords: [abr] HT; diet that contained both alfalfa hay cubes and concentrate treated with 1g of enzyme mixture/kg of DM; [abr] LAB; liquid-associated bacteria; [abr] LH; diet that contained alfalfa hay cubes treated with 1g of enzyme mixture/kg of hay; [abr] SAB;…

DOI: 10.3168/jds.S0022-0302(99)75245-8. ISSN: 0022-0302.

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27. Effects of partially replacing barley silage or barley grain with dried distillers grains with solubles on rumen fermentation and milk production of lactating dairy cows. Zhang, S.Z.; Penner, G.B.; Yang, W.Z.; Oba, M. Journal of Dairy Science vol. 93 issue 7 July, 2010. p. 3231-3242

► Dried distillers grains with solubles (DDGS) has been commonly used as a dietary… (more)

Keywords: barley silage; barley grain; dried distillers grains with solubles

DOI: 10.3168/jds.2009-3005. ISSN: 0022-0302.

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28. Hollow microspheres of V₂O₅ and Cu-doped V₂O₅ as cathode materials for lithium-ion batteries. Zhu, D.; Liu, H.; Lv, L.; Yao, Y.D.; Yang, W.Z. Scripta Materialia vol. 59 issue 6 September, 2008. p. 642-645

► Highly crystallized V2O5 hollow microspheres were prepared by a self-assembly method and successfully… (more)

Keywords: V₂O₅ hollow microspheres; Nanocrystalline materials; Copper; Lithium battery; Electrode

DOI: 10.1016/j.scriptamat.2008.05.020. ISSN: 1359-6462.

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29. Effects of glycerol on rumen fermentation, urinary excretion of purine derivatives and feed digestibility in steers. Wang, C.; Liu, Q.; Huo, W.J.; Yang, W.Z.; Dong, K.H.; Huang, Y.X.; Guo, G. Livestock Science vol. 121 issue 1 March, 2009. p. 15-20

► The objective of this study was to evaluate the effects of glycerol supplementation… (more)

Keywords: Glycerol; Rumen fermentation; Purine derivatives; Digestibility; Beef cattle; ADF; acid detergent fibre; BW; body weight; CP; crude protein; DM; dry matter; ED; effective degradability; NDF; neutral detergent fibre; OM; organic matter; PD; purine derivative; VFA; volatile fatty acid

DOI: 10.1016/j.livsci.2008.05.010. ISSN: 1871-1413.

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30. Effects of malic acid on feed intake, milk yield, milk components and metabolites in early lactation Holstein dairy cows. Wang, C.; Liu, Q.; Yang, W.Z.; Dong, Q.; Yang, X.M.; He, D.C.; Dong, K.H.; Huang, Y.X. Livestock Science vol. 124 issue 1-3 September, 2009. p. 182-188

► The objective of this study was to evaluate the effects of malic acid… (more)

Keywords: ADF; acid detergent fibre; BHBA; beta-hydroxybutyrate; BW; body weight; CP; crude protein; DIM; day in milk; DM; dry matter; DMI; dry matter intake; NDF; neutral detergent fibre; NEFA; non-esterified fatty acids; NEI; net energy intake; NEM; net energy required for body…

DOI: 10.1016/j.livsci.2009.01.016. ISSN: 1871-1413.

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