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Effect of dietary Yucca schidigera extract on rumen and blood profiles of steers fed concentrate- or roughage-based diets
ANIMAL FEED SCIENCE AND TECHNOLOGY
ELSEVIER
Animal Feed Science and Technology 5 1 ( 1995) 23 I-242
Effect of dietary Yucca schidigera extract on rumen and blood profiles of steers fed concentrate- or roughage-based diets I. Hussain’, P.R. Cheeke* Department ofAnimal Sciences, Oregon State University, Corvailis OR 97331, USA Received 10 February 1994; accepted 15 June 1994
Abstract In two experiments, four rumen-fistulated steers were used in a Latin square design arrangement with each rotation period of 15 days. Yucca schidigera extract (YE) was added at the rate of 250 mg kg-’ of mixed feed. In the first experiment, four isonitrogenous highroughage (HR) feeds were tested: HR+ soybean meal (R 1); R 1+ YE (R2 ); HR + urea (R3); R3+YE (R4). Feed intakes (FI) (kg day-‘) were 11.4, 11.2, 11.3, and 11.0 for R 1, R2, R3 and R4, respectively. Ruminal pH and rumen ammonia-N (RAN, mg dl- ’) for Rl, R2, R3 and R4 (pooled values for 0, 3, 6, 9 h postfeeding, HPF) were: 6.5, 11.5; 6.6, 10.2; 6.6, 15.1; 6.6, 12.9. Plasma ammonia-N (pg ml-‘) and plasma urea-N (mg dl-‘) for R 1, R2, R3 and R4, respectively, were: 1.13, 13.64; 1.24, 14.79; 1.19, 16.11; and 1.04, 14.7 In Trial 2, the four isonitrogenous, high-concentrate (HC) diets were: HC (barley)+soybean meal (Cl); Cl +YE (C2); HC+urea (C3); C3+YE (C4). Average daily FI (kg) were: 14.2, 13.5, 14.2 and 13.7 for Cl, C2, C3 and C4, respectively. Ruminal pH and RAN for Cl, C2, C3 and C4, respectively, were: 5.81, 7.92; 5.82, 6.88; 6.09, 10.85; 6.00, 10.50 The plasma ammonia-N (PAN) and plasma urea-N (PUN) for Cl, C2, C3 and C4 were: 1.17, 14.00; 0.89, 11.52; 1.15, 13.87; 1.15, 13.76. In the HR trial, rumen fluid concentrations of different volatile fatty acids (VFA) (averaged across time) were not different among treatments, except that isovalerate concentration in Rl was higher (PC 0.05 ) than R2. Numerically, acetate concentration was lower in R2 vs. R 1, and propionate, isobutyrate and valerate concentrations were higher in R4 vs. R3. There was less fluctuation in VFA concentrations at different HPF in R4 vs. R3. Total VFA concentration was higher in Rl vs. R2 and R4 vs. R3. The acetate:propionate ratio was lower in RI vs. R2 and R4 vs. R3. In the HC trial, acetate, propionate, isobutyrate and valerate concentrations were lower in the YE diets. Total VFA concentrations and acetate:propionate ratios were generally lower in the YE diets. The results showed a tendency for YE to reduce RAN, * Corresponding author. ’Present address: SSO(AN)ASI,
NARC, Park Road, Islamabad, Pakistan.
0377-8401/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDIO377-8401(94)00694-5
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PAN and PUN, which could lead to more efficient utilization ularly when HR diets supplemented with urea are fed.
of dietary nitrogen, partic-
Keywords: Cattle, beet Supplement feeding; Yucca schidigera
1.Introduction
Deodorase (an extract of the Yucca schidigeru plant (Alltech Biotechnology, Nicholasville, KY ), comprising 30% active yucca extract and remaining materials Bacillus subtilis fermentation extract and calcium silicate) contains glycosylated components which can bind ammonia (Headon, 199 1) . The yucca plant contains several steroid saponins known collectively as sarsaponins (SAR). Goodall and Matsushima ( 1980) found that SAR (40 ppm) can improve nutrient digestibility (6%) and reduce feed intake (7%) in yearling steers. Goodall et al. ( 1982) reported that with 66 ppm SAR in the diet, the gains of cattle receiving high concentrate diets containing 10% crude protein (CP) were increased, but performance did not respond to SAR with a 17% CP diet. Goetsch and Owens ( 1985) fed dairy cows on sorghum silage (67% of diet dry matter, DM) with 44 ppm SAR and noted increased digestion coefficients for organic matter, starch and nitrogen (N) for the SAR diet. In their second study, diets contained 50% concentrate (corn grain) either with or without SAR added at 44 ppm; ruminal pH for animals given SAR tended to be lower at 4, 8 and 12 h postfeeding (HPF). Grobner et al. ( 1982) suggested that SAR at 30 and 60 ppm of diet DM increased microbial synthesis of protein in continuous fermentation cultures. Our objective was to investigate the effect of Deodorase as a source of yucca extract (YE) on feed intake (FI), rumen fermentation and blood N parameters when cattle are fed high-roughage (HR) such as fescue grass hay and high-concentrate (HC) such as rolled barley diets with or without urea. We hypothesized that YE can bind ammonia in the rumen and act as a slow-release N source. With HR diets, a slow-release N source might enhance fermentation by maintaining adequate rumen N for microbial growth throughout the postfeeding period. With urea-containing diets, rumen ammonia-N (RAN) levels peak rapidly postfeeding, with the excess RAN being absorbed and excreted as urea. This results in inefficient use of dietary-N and increases energy requirements for hepatic urea synthesis. Binding of excess RAN to YE when RAN levels are high, and slow N release as RAN levels decline postfeeding might enhance fermentation of HR and HC diets, with and without urea as a source of rapidly fermentable N. Rumen and blood samples were collected at 3 h intervals postfeeding to determine if RAN was modulated by feeding YE. 2. Materials and methods Two trials were conducted, using either HR or HC diets, each with either soybean meal (SBM) or urea as the source of supplementary N. Each of these com-
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233
binations was compared with and without Deodorase at 250 mg kg-’ diet. For the HR trial, four rumen-fistulated Hereford steers (mean weight 574 kg) were used; in the HC experiment, the mean weight of four rumen-fistulated Hereford steers was 658 kg. In both experiments, the arrangement of treatments was a 4x 4 Latin square design, with each rotation period of 15 days. Ingredient composition of the experimental diets is given in Table 1. Feed samples of each treatment were collected twice a week, and dried at 50°C for 48 h in a forced-air oven for DM determination. All the dry samples were ground to pass through a 1 mm screen and analysed for DM and ash by standard procedures (Association of Official Analytical Chemists ( AOAC), 1990). Feed samples were analysed for CP by the Kjeldahl method ( AOAC, 1990). Neutral detergent libre (NDF) and acid detergent libre (ADF) were analysed by the method of Goering and van Soest ( 1970) as modified by a micromethod described by Waldem ( 197 1). Hemicellulose (HC ) was calculated as NDF-ADF, and organic matter (OM ) was calculated as 1OO- Wash. Chemical composition of the diets is given in Table 2. The steers were kept in individual pens with free choice access to water. All animals were fed once daily at 0830 h and feed was offered ad libitum. Orts were removed and weighed twice a week to calculate individual feed intake. At the start of each experiment, a 1 week adjustment period was given. Steers were weighed at the start of the experiment and then on the morning of Day 15 of each rotation period before feeding. After weighing, rumen liquor and jugular blood samples were collected in heparinized vacutainers at 0, 3,6 and 9 HPF. Rumen fluid and blood samples were transported to the laboratory immediately after collection, where the pH of the rumen fluid was determined using a pH meter. Blood samples were centrifuged at 3000 rpm for 15 min, and plasma was separated and stored at - 20 ’C for further analysis of plasma urea-N (PUN ) . Plasma ammonia-N (PAN) was measured immediately using a Sigma kit (Sigma, St. Louis, MO). For determination of rumen ammonia-N (RAN), 5 ml of rumen liquor were mixed with 5 ml of 0.1 N HCl, and 2 ml of this mixture were added to 28 ml distilled water and 0.6 ml of 32% NaOH. The RAN concentration was measured using an ammonia ion electrode (Orion 95 12) on an Orion 720A pH/ ISE meter. The PAN and PUN were analysed using Sigma kits, using a narrowband width UV spectrophotometer (Model UV 160, Shimadzu, Kyoto, Japan ) . Rumen fluid was strained through four layers of cheese cloth and frozen at - 20’C following mixing with 25% metaphosphoric acid in a 1:1 dilution for volatile fatty acid (VFA) analysis. Ruminal VFA concentrations were determined using a fused silica capillary column ( 15 m, 0.53 nm internal diameter, helium gas phase) in a gas chromatograph (Hewlett Packard, HP 5890, Series II) with automatic injection of 1~1 sample. Rumen fluid and plasma profiles were analysed as a Latin square design, split plot in time with respect to sampling time, using the GLM procedure of Statistical Analysis Systems Institute Inc. ( 1987). Differences among treatments were noted by least significant difference (LSD) using 95% level of probability.
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3. Results 3. I. Trial I (high-roughage diets)
The ingredient and chemical composition of feeds is given in Tables 1 and 2, respectively. Data (averaged across times) for FI, rumen pH (pH) , RAN, PAN and PUN are presented in Table 3. Because of the short experimental period and variable effects of gut fill, weight gain data were quite variable and are not presented. FI was numerically slightly lower in the YE diets. The pH and RAN were not different between treatments, although RAN was 11% lower in R2 (YE-SBM diet) vs. Rl and 15% lower in R4 (YE-urea diet) vs. R3. The RAN in R2 was Table 1 Ingredient composition
of diets (%) fed to steers (as fed basis)
Ingredient
High-roughage diets
Grass hay (fescue) Alfalfa hay Soybean meal Molasses TMS” Dical Urea DeodoraseY Rolled barley
High-concentrate
diets
Rl
R2
R3
R4
Cl
c2
c3
c4
62.00 30.00 5.00 2.00 0.50 0.50
62.00 30.00 5.00 2.00 0.50 0.50
66.25 30.00 2.00 0.50 0.50 0.75 -
66.25 30.00 2.00 0.50 0.50 0.75 +
25.00 20.00 4.00 0.50 0.50 50.00
25.00 20.00 4.00 0.50 0.50 + 50.00
28.35 20.00 0.50 0.50 0.65
28.35 20.00 0.50 0.50 0.65 + 50.00
+
50.00
’ TMS composition (%): Common salt, 95-97; zinc, > 0.35; Mn, > 0.3; Fe, > 0.23; Cu, > 0.023; I, > 0.012; Co, > 0.006; Se, > 0.009. y Deodorase was added at 250 mg kg-’ diet. Deodorase contains 30% Yucca schidigera plant extract; therefore, actual yucca extract was added at 75 mg kg-’ mixed diet. Table 2 Chemical composition
(96) of feeds fed to steers (DM basis)
Feed type
DM
OM
CP
ADF
NDF
HC
Ash
Rl R2 R3 R4
95.99 96.04 95.90 95.95
90.59 90.82 90.68 90.74
13.37 13.32 13.44 13.02
30.89 31.51 32.61 33.19
53.31 53.90 55.69 57.35
22.42 22.39 23.08 24.16
9.41 9.18 9.32 9.26
Cl c2 c3 c4
96.44 96.79 96.59 96.64
92.29 93.23 92.72 92.98
13.59 12.79 13.37 13.25
22.06 21.49 20.93 21.40
44.78 44.21 44.07 44.22
22.72 22.72 23.14 22.82
7.71 6.77 7.28 7.02
For abbreviations,
see text.
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Table 3 Feed intakes (DM basis) and rumen and blood profiles of steers fed high-roughage diets ParameterY
Feed intake (kg day-’ ) Rumen pH Rumen ammonia-N (mg dl-’ ) Plasma NH,-N (,~g ml-‘) Plasma urea-N (mg dl - ’)
Diets”
SE
RI
R2
R3
R4
11.40 6.48 11SO”b 1.13 13.64a
11.22 6.58 10.16b 1.24 14.79ab
11.34 6.59 15.11” 1.19 16.11b
10.96 6.59 12.88ab 1.04 14.66ab
0.38 0.17 2.53 0.25 1.62
‘RI, soybean meal (SBM); R2, SBM+deodorase (YE); R3, urea; R4, urea+YE. y Date were averaged across time periods. ab Values in the same row with different superscripts differ (PC 0.05 ) SE, pooled standard error.
significantly lower than for the R3 treatment. Numerically pH was higher in R2 vs. RI and in R3 vs. R4. The diets with urea (R3, R4) had slightly higher pH than the diets with SBM (Rl, R2). PAN (pg ml- ’) was not different among the four treatments. PUN concentrations were numerically lower in R4 vs. R3 and Rl vs. R2 and significantly lower in Rl vs. R3. Data on pH, RAN, PAN and PUN at different HPF are given in Table 4. The pH did not differ within each treatment at different time periods (0, 3, 6, 9 HPF). There was a linear decrease in pH postfeeding from 0 to 9 h in all treatments. RAN in all treatments peaked at 3 HPF, with the peak higher in R3 and R4 vs. R 1 and R2. However, the peak was less high in R4 compared to R3 and values remained low in R2 and R4 compared to Rl and R3 during all sampling times. In Rl, RAN was lower (P~0.05) at 9 HPF compared to 0 and 3 HPF. In R2, R3 and R4, RAN was significantly higher at 3 HPF compared to 0,6 and 9 HPF. PAN concentrations in each treatment at different times postfeeding did not differ. In Rl , PUN at 9 HPF was significantly lower than at 0, 3 and 6 HPF. In R2, PUN was higher (P~0.05) at 3 HPF compared to 9 HPF. In R4, PUN at 6 HPF was higher (P~0.05) than 0 HPF, while in R3 no differences among times were found. In the urea diets (R3, R4), PUN levels were lower in R4 vs. R3. When the treatments were compared within each time, no differences were observed among treatments at any HPF. Data on VFA concentrations (averaged across times) by animals on the HR diets are presented in Table 5. No differences occurred in average VFA production among treatments for all VFAs except isovalerate, which was higher (P< 0.05 ) in RI compared to R2, R3 and R4. Total VFA concentration on Rl was numerically higher than R2, while it was similar in R3 and R4. The acetate:propionate ratio was lower in the Rl and R2 and slightly higher in the R3 and R4 treatments. There was lack of consistency in VFA concentrations at different times postfeeding. There were no differences (P> 0.05 ) in most VFA levels at different HPF except for isobutyrate and isovalerate, where isobutyrate in RI at 0 h was higher (P-C 0.05 ) than 6 and 9 HPF. A similar pattern was observed in R2. Isovalerate concentration in RI at 0 HPF was higher (PC 0.05) compared
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Table 4 Rumen and blood profiles at different time period postfeeding of steers fed high-roughage diets Item
Rl
Plasma ammonia-N
( mg dl- ’)
R3
R4
6.87 6.59 6.46 6.39
6.72 6.66 6.54 6.45
6.71 6.62 6.51 6.52
0.17 0.17 0.17 0.17
10.88” 15.9” 10.14ab 9.03s
9.85” 14.68b 8.85” 7.27”
10.9oa 23.23b 14.538 1 1.808
10.87” 18.98b 11.93” 9.74”
2.37 2.37 2.37 2.37
0.92 1.21 1.27 1.09
0.86 1.57 1.32 1.22
1.14 1.34 1.22 1.05
0.83 1.17 1.04 1.12
0.24 0.24 0.24 0.24
14.70” 14.28” 15.00” 10.59s
14.548b 17.28a 14.98ab 12.35b
12.57” 14.60ab 17.48b 14.008s
1.56 1.56 1.56 1.56
(pg ml-’ )
Plasma urea-N (mg dl- ’)
R2
6.68 6.60 6.36 6.30
Ruminal pH
Ruminal ammonia-N
SE
Diets”
Time after feeding (h)
14.35 16.31 17.67 16.10
’ Rl, SBM, R2, SBM+YE, R3, urea; R4, urea+YE. ab Values in columns for each item with different superscripts differ (PC 0.05). SE, pooled standard error.
Table 5 Rumen fluid volatile fatty acid (VFA) concentrations diets (averaged across times) VFA
Acetate Propionate Isobutyrate Butyrate Isovalerate Valerate Total Acetate:propionate
(mmol 1-l) for animals fed high-roughage
Diets”
ratio
SE
Rl
R2
R3
R4
78.44 21.42 1.03 10.61 1.05” 1.03 113.58 3.66
68.76 17.97 0.83 9.04 0.79s 0.87 98.26 3.83
72.56 18.11 0.81 9.87 0.80b 0.86 103.01 4.01
73.20 19.02 0.86 9.81 0.72b 0.88 104.49 3.85
’ Rl, SBM; R2, SBM+YE; R3, urea; R4, urea+YE. y Data were averaged across time periods. ‘b Values in the same row with different superscripts differ (PC 0.05 ) . SE, pooled standard error.
3.68 1.21 0.08 0.69 0.08 0.09 -
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237
to 6 and 9 HPF. Its concentration at 3 HPF was higher (P~0.05) from 9 HPF. In R2, isovalerate concentration at 0 and 3 HPF was higher than at 6 and 9 HPF. A similar trend was observed in R4, while in R3 at 0 HPF it was higher (PcO.05) than at 6 and 9 HPF. However, in the R4 diet, there was less fluctuation in VFA concentrations compared to the R3 diet. There were differences (PcO.05) in propionate, isovalerate and valerate concentrations at 0 HPF and in isovalerate at 3 HPF among the four treatments. At 0 HPF, propionate in RI was higher (Pt0.05 ) than in R2, isovalerate was higher in RI vs. R2 and R4, and valerate concentration was higher in Rl than in R2. At 3 HPF, isovalerate was higher (PcO.05) in Rl vs. R3 and R4. At 6 and 9 HPF, there were no differences among the four treatments. 3.2. Trial 2 (high-concentrate diets) Data (averaged across times) regarding FI, pH, RAN, PAN and PUN are presented in Table 6. Average FI among the four treatments was not different (P> 0.05 ). FI was numerically lower in animals on feeds having YE (C2, C4) vs. animals on diets without YE (C 1, C3 ) . Ruminal pH of animals on the urea diet without YE (C3) was significantly higher than for animals on both SBM diets (Cl, C2), while pH with C4 was higher (PxO.05) than with Cl. RAN in animals on the SBM diet with YE (C2) was significantly lower than for animals on both types of urea diets (C3, C4). Although the two SBM diets did not differ significantly, RAN concentration was 13% lower on the SBM diet with YE (C2) vs. C 1. Similarly, it was 3% lower in animals on the diet with urea and YE (C4) vs. the diet with simple urea (C3). PAN concentration was significantly lower in animals on C2 compared with Cl, C3 and C4. PUN was significantly lower in animals on the C2 diet compared with Cl, C3 and C4. However, in the two urea diets, the difference in concentration of PUN was not significant. At different HPF (Table 7), there was a linear decrease in the pH from 0 to 9 HPF in all Table 6 Feed intake (DM basis), weight gain, rumen and blood profiles of steers fed high-concentrate ParameterY
Feed intake (kg day-‘) Weight gain (kg day-’ ) Rumen pH Rumen ammonia-N (mg dl- ’) Plasma ammonia-N (pg ml - ’) Plasma urea-N (mg dl- ’)
diets
Diets’ Cl
c2
c3
c4
SE
14.19 1.29 5.81” J.92”b l.lJ= 14.01=
13.46 1.10 5.82” 6.88s 0.89b 1 1.52b
14.16 1.47 6.09b 10.85” 1.15” 13.8Ja
13.74 0.79 6.00k 10.50” 1.15” 13.76”
0.30 0.31 0.07 1.24 0.07 0.72
’ Cl, soybean meal (SBM); C2, SBM+deodorase (YE); C3, urea; C4, urea+YE. y Data were averaged across time periods. ab Values in the same row with different superscripts differ (PC 0.05 ) . SE, pooled standard error.
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Table 7 Rumen and blood profiles at different hours postfeeding for steers fed high-concentrate diets Item
Time after feeding (h )
SE
Diets” Cl
c2 6.18” 5.80ab 5.65b 5.64b
c3
c4 6.25 6.17 5.83 5.77
0.13 0.13 0.13 0.13
9.42”
17.02b 9.39” 6.17a
2.48 2.48 2.48 2.48
0.91 1.17 1.11 1.34
0.74 1.12 1.01 1.51
0.24 0.24 0.24 0.24
12.68 15.31 15.12 11.92
12.70”” 16.09’ 15.10” 11.69”
1.44 1.44 1.44 1.44
6.45” 6.23ab 5.89b 5.81b
Ruminal pH
0 3 6 9
6.24b 5.86ab 5.60” 5.53”
Ruminal NHp-H (mg dl-’ )
0 3 6 9
1o.34a 1 1.38a 6.5Sab 3.39b
8.35 10.73 4.40 4.05
9.84” 17.47b 7.16” 8.95”
Plasma NHJ-N (pg ml-‘)
0 3 6 9
1.11 1.20 1.16 1.24
0.86 0.64 1.02 0.91
Plasma urea-N (mg dl- ’)
0 3 6 9
14.67ab 17.35” 13.69ab 10.31b
10.82 14.13 11.41 9.71
’ Cl, SBM, C2, SBM+YE; C3, urea; C4, urea+YE. ‘beValues in columns for each item with different superscripts differ (PC 0.05). SE, pooled standard error.
treatments. In Cl, pH at 0 HPF was higher (PqO.05) than at 6 and 9 HPF. A similar trend was observed in C2 and C3, but in C4 no differences were observed at different HPF. BAN decreased linearly from 3 to 9 HPF in all treatments. The BAN peak occurred at 3 HPF and was higher in the urea diets (C3, C4) compared to the SBM diets (C 1, C2). However, BAN was lower in diets having YE (C2, C4) vs. without YE (Cl, C3). In the Cl treatment, BAN at 9 HPF was lower (P-z 0.05) than at 0 and 3 HPF, but in C2 no differences were seen among different HPF. In C3, BAN was significantly higher at 3 HPF compared to 0, 6 and 9 HPF and a similar trend was observed in C4. Concentrations of PAN at different HPF did not differ. PAN was numerically lower in diets with YE (C2, C4) compared to Cl and C3, and its peak occurred mostly at 9 HPF. PUN peaked at 3 HPF in all treatments, and its concentration was lower in diets with YE. In Cl, PUN concentration at 3 HPF was significantly higher compared to 9 HPF. In C4, PUN was higher at 3 and 6 HPF compared to 9 HPF. In C2 and C3, no differences were observed at different HPF. When treatments were compared within each time, pH at 3 HPF was higher (PcO.05) in C3 vs. C2. The BAN at 6 HPF was lower (PxO.05) in C2 compared to C4. The pH, BAN, PAN and PUN did not differ at other times among treatments. The VFA concentrations (averaged across times) for animals on the HC diets
I. Hussain, P.R. Cheeke /Animal Feed Science and Technology 51(1995) 231-242 Table 8 Rumen fluid volatile fatty acid (VFA) concentrations diets (averaged across times) VFA
Acetate Propionate Isobutyrate Butyrate Isovalerate Valerate Total Acetate:propionate
(mmol 1-l) for steers fed high-concentrate
Diets” Cl
ratio
85.94 25.34” 1.15 14.86” 1.23” 1.40” 129.92 3.39
239
SE c2 78.65 22.47”b 1.00 12.59b
1.07ab 1.15b 116.93 3.50
c3
c4
80.01 22.56ab 1.00 10.65b 0.94b 1.13b 116.29 3.55
14.46 20.75b 0.92 11.62b 0.94b 1.08b 109.77 3.59
4.16 1.48 0.08 0.76 0.07 0.08 -
Data presented were averaged across time periods. ’ Cl, soybean meal (SBM); C2, SBM+YE; C3, urea; C4, urea+YE. ab Values in the same row with different superscripts differ (PcO.05). SE, pooled standard error.
are shown in Table 8. Total VFA concentrations were numerically higher with diets without YE. The acetate:propionate ratio was higher in urea diets (C3, C4) vs. SBM diets (Cl, C2), and it was slightly higher in diets with YE (C2, C4) compared to C 1 and C3. Propionate was higher (PC 0.05 ) in C I vs. C4. Butyrate was higher in Cl vs. C2, C3 and C4. A similar trend was seen for valerate. Isovalerate was higher in the Cl vs. C3 and C4 treatments. In Cl and C2, peak VFA concentrations occurred at 3 HPF, but in C3 and C4 in most cases VFA levels peaked at 6 HPF. Acetate concentration in C2 was higher (P~0.05) at 3 HPF compared to at 0, 6 and 9 HPF. A similar trend was observed for isobutyrate. Valerate concentrations at 3 HPF were higher (PcO.05) than at 0 and 9 HPF while butyrate concentration at 3 HPF was higher than at 0,6 and 9 HPF. In C3, acetate and propionate concentrations at 6 HPF were higher than at 0 and 3 HPF, while butyrate at 3 HPF was lower (PC 0.05 ) than at 6 and 9 HPF. In C4, valerate at 6 HPF was higher (PxO.05) than 0 and 3 HPF. At 0, 6 and 9 HPF, no differences among treatments were observed, while at 3 HPF, acetate concentration in C2 was higher (PC 0.05) than in C3 and C4. Propionate and butyrate in C3 were lower (P-z 0.05) than in C 1 and C2. Isovalerate concentration was higher (PcO.05) in the Cl diet than in the C3 diet. Valerate in C3 waslower (PeO.05) than in Cl and C2.
4. Discussion
In both trials, FI was 2-3% lower in the two feeds with YE vs. the feeds without YE. Goodall and Matsushima ( 1980) found that 40 ppm SAR improved nutrient digestibility and reduced feed intake in young steers. Johnston et al. ( 198 1) re-
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ported that feeding YE (63 ppm) improved gain and FE in broilers, and Al-Bar et al. (1993) found similar results in rabbits and replacement pullet chicks. Cromwell et al. ( 1985) reported improved gains after feeding YE to pigs. Mader and Brumm ( 1987) during the first 28 days of their four trials found that daily gains (0.74 kg) of steers fed urea plus YE were significantly higher than those fed the diet without YE (0.66 kg). Goodall and Matsushima ( 1980) reported lower intakes but better digestibility and lower passage rates by feeding YE in both corn grain and corn silage diets. However, Goetsch and Owens ( 1985) did not observe a consistent intake or passage rate response to feeding YE and suggested that an interaction between YE and diet energy density or diet composition may exist. They reported that the lag time of digestion tended to be longer with the SAR diets for corn, sorghum, SBM and corn gluten meal but shorter for alfalfa and prairie hay. They also reported improvements (PcO.05) in ruminal DM digestibilities by supplementing silage diets with YE. Headon ( 199 1) reported that YE contains glycosylated components which bind ammonia. In non-ruminant studies, levels of ammonia in poultry houses (Rowland et al., 1976; Al-Bar et al., 1993) and rabbit houses (Al-Bar et al., 1993) were reduced by feeding YE. Lowered environmental ammonia may result in improved performance. Foster ( 1983 ) found an interaction between YE and pig density, and concluded that the performance response from YE appears to be greater as floor space and feeder space per pig are reduced. In our study, rumen pH with the different YE treatments was similar, The pH was lower in the HC trial compared to the HR trial; this was as expected because of the higher content of fermentable carbohydrate. Ryan et al. ( 1993) reported that YE did not affect rumen pH. Numerically, rumen pH in the HR trial was higher in R2 vs. Rl, but it was the same in R3 vs. R4. In the HC trial, pH was numerically slightly higher in C2 vs. Cl (5.82 vs. 5.81), while it was lower in C4 vs. C3 (6.00 vs. 6.09). In a study with dairy cows (Goetsch and Owens, 1985), when diets contained 50% concentrate either with or without YE added at 44 ppm, ruminal pH for animals given YE tended to be lower at 4,8 and 12 HPF. Grobner et al. ( 1982) reported that 30 ppm YE increased pH and 60 ppm decreased pH in a continuous flow fermentor. In our HR trial, there was an 11% reduction in RAN in the R2 diet vs. RI, and a 15% reduction in the R4 vs. R3 diets. In the HC trial, the reduction was 13% and 3% for C2 vs. Cl and C4 vs. C3, respectively. A reduction in RAN levels would be beneficial by allowing greater quantities of urea to be utilized in HR ruminant diets (Glimp and Tillman, 1965 ). Grobner et al. ( 1982) found lower RAN concentrations with YE supplementation. Gibson et al. ( 1985) found that RAN level was reduced by 27% when YE was fed to cattle in diets containing 0.87% urea, although DM digestibility was not influenced by YE supplementation. Ellenberger et al. ( 1985) noted decreased in vitro ruminal urease activity with YE supplement. Ryan et al. (1993) and Wu et al. (1994) found that addition of YE had no effect on RAN. In the HC trial, concentration of RAN was lower than in the HR trial. Haaland et al. ( 1982) reported that higher OM intakes result in better utilization of ammonia by rumen microbes, which would
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lower RAN levels. Wu et al. ( 1994) reported that addition of YE via the ruminal cannulae (0,2,4,6,8 g day-’ ) had no effect on VFA and rumen pH. Ryan et al. ( 1993) reported that addition of YE decreased (P> 0.05) total VFA production compared to the control. In our study, there was also some reduction (I?=- 0.05 ) in total VFA concentration in feeds having YE compared to the control. Willms et al. ( 199 1) reported that lambs fed SBM had higher (PC 0.05) total VFA ( 106 mM) than those fed 33% supplemental CP from urea (95 mM). Increases in OM digestion increased total VFA concentration and lowered pH. We also observed similar trends in our study where total VFA concentrations were higher in C 1 and C2 vs. C3 and C4, and RI vs. R2, but concentration was higher in R4 vs. R2. Another mechanism by which YE could affect rumen fermentation is through effects on the rumen microbes. For example, Lu and Jorgensen ( 1987) reported that alfalfa saponins reduced rumen protozoa numbers. Defaunation often improves ruminant performance. Thus an effect of the SAR fraction of YE on rumen microbes and fermentation efficiency should not be overlooked. In conclusion, in the HR trial, RAN was lower in YE diets vs. control diets, and the RAN peak was less high in R4 vs. R3. The trend for PUN concentration was lower in R4 vs. R3, there was less fluctuation in VFA production at different times postfeeding in R4 vs. R3, and the acetate:propionate ratio was lower in R4 vs. R3. In the HC trial, RAN, PAN and PUN were numerically lower in the YE diets, and rumen pH was lower in C4 vs. C3. These results indicate that YE supplementation favoured rumen N metabolism, especially in the HR trials and diets with urea.
References Al-Bar, A., Ismail, A., Cheeke, P.R. and Nakaue, H.S., 1993. Effect of dietary Yucca schidigera extract (deodorase) on environmental ammonia and growth performance of chickens and rabbits. Proc. West. Sec. Am. Sot. Anim. Sci., 44: 106- 108. Association of Official Analytical Chemists, 1990. Offtcial Methods of Analysis, 15th edn. .40.4C, Arlington, VA. Cromwell, G.L., Stably, T.S. and Monegue, J.J., 1985. Efficacy of sarsaponin for weanling and growing finishing swine housed at two animal densities. J. Anim. Sci., 6 1 (Suppl. 1): 111. Ellenberger, M.A., Rumpler, W.V., Johnson, D.E. and Goodall, S.R., 1985. Evaluation of the extent of ruminal urease inhibition by sarsaponin and its fractions. J. Anim. Sci., 6 1 (Suppl. 1): 49 1. Foster, J.R., 1983. Sarsaponin for growing finishing swine alone or in combination with an antibiotic at different pig densities. J. Anim. Sci., 7 (Suppl 1): 245. Gibson, M.L., Preston, R.L., Pritchard, R.H. and Goodall, S.R., 1985. Effect of sarsaponin and monensin on ruminal ammonia levels and in vitro dry matter digestibilities. J. Anim. Sci., 6 1 (Suppl. 1): 492. Glimp, H.A. and Tillman, A.D., 1965. Effect of jackbean urease injections on performance, antiurease production and plasma ammonia and urea levels in sheep. J. Anim. Sci., 24: 105- 108. Goering, H.K. and van Soest, P.J., 1970. Forage Fiber Analysis (Apparatus, Reagents, Procedures and Some Applications). USDA-ARS Agriculture Handbook No. 379. USDA, Washington, DC. Goetsch, A.L. and Owens, F.N., 1985. Effects of sarsaponin on digestion and passage rates in cattle fed medium to low concentrates. J. Dairy Sci., 68: 2377-2384.
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Goodall, S.R. and Matsushima, J.K., 1980. The effects of sarsaponin on ruminant digestion and rate of passage. J. Anim. Sci., 51 (Suppl. 1): 363. Goodall, S.R., Brady, P., Horton, D. and Beckner, B., 1982. Steam flaked versus high moisture corn rations with and without sarsaponin for finishing steers. Proc. West. Sec. Am. Sot. Anim. Sci., 33: 45-48. Grobner, M.A., Johnson, D.E., Goodall, S.R. and Benz, D.A., 1982. Sarsaponin effects on in vitro continuous flow fermentation of a high grain diet. J. Anim. Sci., 55 (Suppl. 1): 49 1. Haaland, G.L., Tyrell, H.F., Moe, P.W. and Wheeler, W.E., 1982. Effect of crude protein level and limestone buffer in diets fed at two levels of intake on rumen pH, ammonia-nitrogen, buffering capacity and volatile fatty acid concentration of cattle. J. Anim. Sci., 55: 943-950. Headon, D.R., 1991. Glycofractions of the yucca plant and their role in ammonia control. In: Biotechnology in the Feed Industry. Proc. 7th Alltech Symposium. Alltech Technical Publications, Nicholasville, KY, pp. 95-108. Johnston, N.L., Quarles, C.L., Fagerberg, D.J. and Caveny, D.D., 198 1. Evaluation of yucca saponin on broiler performance and ammonia suppression. Poult. Sci., 60: 2289-2292. Lu, C.D. and Jorgensen, N.A., 1987. Alfalfa saponins affect site and extent of nutrient digestion in ruminants. J. Nutr., 117: 919-927. Mader, T.L. and Brumm, M.C., 1987. Effect of feeding sarsaponin in cattle and swine diets. J. Anim. Sci., 65: 9-15. Rowland, Jr., L.O., Plyler, J.E. and Bradley, J.W., 1976. Yucca schidigera extract effects on egg production and house ammonia levels. Poult. Sci., 55: 2086, abstract. Ryan, J.P., Leek, B.F. and Jacques, K., 1993. The complementary effects of Saccharomyces cerevisiae yeast culture (Yea-Sacc 1026) and yucca schidigera extract (solid deodorase) on ruminal metabolism in sheep. J. Anim. Sci., 71 (Suppl. 1): 287. Statistical Analysis Systems Institute Inc., 1987. User’s Guide: Statistics. Statistical Analysis Systems Institute Inc., Cary, NC. Waldem, D.E., 197 1. A rapid micro-digestion procedure for neutral and acid detergent fiber. Can. J. Anim. Sci., 5 1: 67-69. Willms, C.L., Berger, L.L., Merchen, N.R. and Fahey, Jr., G.C., 199 1. Effects of supplemental protein source and level of urea on intestinal amino acid supply and feedlot performance of lambs fed diets based on alkaline hydrogen peroxide-treated wheat straw. J. Anim. Sci., 69: 4925-4938. Wu, Z., Sadii, M., Huber, J.T., Sleiman, F.T., Simas, J., Pessarakli, M. and Huber, J.T., 1994. Influence of yucca extract on ruminal metabolism in cows. J. Anim. Sci., 72: 1038-1042.
ELSEVIER
Animal Feed Science and Technology 5 1 ( 1995) 23 I-242
Effect of dietary Yucca schidigera extract on rumen and blood profiles of steers fed concentrate- or roughage-based diets I. Hussain’, P.R. Cheeke* Department ofAnimal Sciences, Oregon State University, Corvailis OR 97331, USA Received 10 February 1994; accepted 15 June 1994
Abstract In two experiments, four rumen-fistulated steers were used in a Latin square design arrangement with each rotation period of 15 days. Yucca schidigera extract (YE) was added at the rate of 250 mg kg-’ of mixed feed. In the first experiment, four isonitrogenous highroughage (HR) feeds were tested: HR+ soybean meal (R 1); R 1+ YE (R2 ); HR + urea (R3); R3+YE (R4). Feed intakes (FI) (kg day-‘) were 11.4, 11.2, 11.3, and 11.0 for R 1, R2, R3 and R4, respectively. Ruminal pH and rumen ammonia-N (RAN, mg dl- ’) for Rl, R2, R3 and R4 (pooled values for 0, 3, 6, 9 h postfeeding, HPF) were: 6.5, 11.5; 6.6, 10.2; 6.6, 15.1; 6.6, 12.9. Plasma ammonia-N (pg ml-‘) and plasma urea-N (mg dl-‘) for R 1, R2, R3 and R4, respectively, were: 1.13, 13.64; 1.24, 14.79; 1.19, 16.11; and 1.04, 14.7 In Trial 2, the four isonitrogenous, high-concentrate (HC) diets were: HC (barley)+soybean meal (Cl); Cl +YE (C2); HC+urea (C3); C3+YE (C4). Average daily FI (kg) were: 14.2, 13.5, 14.2 and 13.7 for Cl, C2, C3 and C4, respectively. Ruminal pH and RAN for Cl, C2, C3 and C4, respectively, were: 5.81, 7.92; 5.82, 6.88; 6.09, 10.85; 6.00, 10.50 The plasma ammonia-N (PAN) and plasma urea-N (PUN) for Cl, C2, C3 and C4 were: 1.17, 14.00; 0.89, 11.52; 1.15, 13.87; 1.15, 13.76. In the HR trial, rumen fluid concentrations of different volatile fatty acids (VFA) (averaged across time) were not different among treatments, except that isovalerate concentration in Rl was higher (PC 0.05 ) than R2. Numerically, acetate concentration was lower in R2 vs. R 1, and propionate, isobutyrate and valerate concentrations were higher in R4 vs. R3. There was less fluctuation in VFA concentrations at different HPF in R4 vs. R3. Total VFA concentration was higher in Rl vs. R2 and R4 vs. R3. The acetate:propionate ratio was lower in RI vs. R2 and R4 vs. R3. In the HC trial, acetate, propionate, isobutyrate and valerate concentrations were lower in the YE diets. Total VFA concentrations and acetate:propionate ratios were generally lower in the YE diets. The results showed a tendency for YE to reduce RAN, * Corresponding author. ’Present address: SSO(AN)ASI,
NARC, Park Road, Islamabad, Pakistan.
0377-8401/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDIO377-8401(94)00694-5
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PAN and PUN, which could lead to more efficient utilization ularly when HR diets supplemented with urea are fed.
of dietary nitrogen, partic-
Keywords: Cattle, beet Supplement feeding; Yucca schidigera
1.Introduction
Deodorase (an extract of the Yucca schidigeru plant (Alltech Biotechnology, Nicholasville, KY ), comprising 30% active yucca extract and remaining materials Bacillus subtilis fermentation extract and calcium silicate) contains glycosylated components which can bind ammonia (Headon, 199 1) . The yucca plant contains several steroid saponins known collectively as sarsaponins (SAR). Goodall and Matsushima ( 1980) found that SAR (40 ppm) can improve nutrient digestibility (6%) and reduce feed intake (7%) in yearling steers. Goodall et al. ( 1982) reported that with 66 ppm SAR in the diet, the gains of cattle receiving high concentrate diets containing 10% crude protein (CP) were increased, but performance did not respond to SAR with a 17% CP diet. Goetsch and Owens ( 1985) fed dairy cows on sorghum silage (67% of diet dry matter, DM) with 44 ppm SAR and noted increased digestion coefficients for organic matter, starch and nitrogen (N) for the SAR diet. In their second study, diets contained 50% concentrate (corn grain) either with or without SAR added at 44 ppm; ruminal pH for animals given SAR tended to be lower at 4, 8 and 12 h postfeeding (HPF). Grobner et al. ( 1982) suggested that SAR at 30 and 60 ppm of diet DM increased microbial synthesis of protein in continuous fermentation cultures. Our objective was to investigate the effect of Deodorase as a source of yucca extract (YE) on feed intake (FI), rumen fermentation and blood N parameters when cattle are fed high-roughage (HR) such as fescue grass hay and high-concentrate (HC) such as rolled barley diets with or without urea. We hypothesized that YE can bind ammonia in the rumen and act as a slow-release N source. With HR diets, a slow-release N source might enhance fermentation by maintaining adequate rumen N for microbial growth throughout the postfeeding period. With urea-containing diets, rumen ammonia-N (RAN) levels peak rapidly postfeeding, with the excess RAN being absorbed and excreted as urea. This results in inefficient use of dietary-N and increases energy requirements for hepatic urea synthesis. Binding of excess RAN to YE when RAN levels are high, and slow N release as RAN levels decline postfeeding might enhance fermentation of HR and HC diets, with and without urea as a source of rapidly fermentable N. Rumen and blood samples were collected at 3 h intervals postfeeding to determine if RAN was modulated by feeding YE. 2. Materials and methods Two trials were conducted, using either HR or HC diets, each with either soybean meal (SBM) or urea as the source of supplementary N. Each of these com-
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binations was compared with and without Deodorase at 250 mg kg-’ diet. For the HR trial, four rumen-fistulated Hereford steers (mean weight 574 kg) were used; in the HC experiment, the mean weight of four rumen-fistulated Hereford steers was 658 kg. In both experiments, the arrangement of treatments was a 4x 4 Latin square design, with each rotation period of 15 days. Ingredient composition of the experimental diets is given in Table 1. Feed samples of each treatment were collected twice a week, and dried at 50°C for 48 h in a forced-air oven for DM determination. All the dry samples were ground to pass through a 1 mm screen and analysed for DM and ash by standard procedures (Association of Official Analytical Chemists ( AOAC), 1990). Feed samples were analysed for CP by the Kjeldahl method ( AOAC, 1990). Neutral detergent libre (NDF) and acid detergent libre (ADF) were analysed by the method of Goering and van Soest ( 1970) as modified by a micromethod described by Waldem ( 197 1). Hemicellulose (HC ) was calculated as NDF-ADF, and organic matter (OM ) was calculated as 1OO- Wash. Chemical composition of the diets is given in Table 2. The steers were kept in individual pens with free choice access to water. All animals were fed once daily at 0830 h and feed was offered ad libitum. Orts were removed and weighed twice a week to calculate individual feed intake. At the start of each experiment, a 1 week adjustment period was given. Steers were weighed at the start of the experiment and then on the morning of Day 15 of each rotation period before feeding. After weighing, rumen liquor and jugular blood samples were collected in heparinized vacutainers at 0, 3,6 and 9 HPF. Rumen fluid and blood samples were transported to the laboratory immediately after collection, where the pH of the rumen fluid was determined using a pH meter. Blood samples were centrifuged at 3000 rpm for 15 min, and plasma was separated and stored at - 20 ’C for further analysis of plasma urea-N (PUN ) . Plasma ammonia-N (PAN) was measured immediately using a Sigma kit (Sigma, St. Louis, MO). For determination of rumen ammonia-N (RAN), 5 ml of rumen liquor were mixed with 5 ml of 0.1 N HCl, and 2 ml of this mixture were added to 28 ml distilled water and 0.6 ml of 32% NaOH. The RAN concentration was measured using an ammonia ion electrode (Orion 95 12) on an Orion 720A pH/ ISE meter. The PAN and PUN were analysed using Sigma kits, using a narrowband width UV spectrophotometer (Model UV 160, Shimadzu, Kyoto, Japan ) . Rumen fluid was strained through four layers of cheese cloth and frozen at - 20’C following mixing with 25% metaphosphoric acid in a 1:1 dilution for volatile fatty acid (VFA) analysis. Ruminal VFA concentrations were determined using a fused silica capillary column ( 15 m, 0.53 nm internal diameter, helium gas phase) in a gas chromatograph (Hewlett Packard, HP 5890, Series II) with automatic injection of 1~1 sample. Rumen fluid and plasma profiles were analysed as a Latin square design, split plot in time with respect to sampling time, using the GLM procedure of Statistical Analysis Systems Institute Inc. ( 1987). Differences among treatments were noted by least significant difference (LSD) using 95% level of probability.
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3. Results 3. I. Trial I (high-roughage diets)
The ingredient and chemical composition of feeds is given in Tables 1 and 2, respectively. Data (averaged across times) for FI, rumen pH (pH) , RAN, PAN and PUN are presented in Table 3. Because of the short experimental period and variable effects of gut fill, weight gain data were quite variable and are not presented. FI was numerically slightly lower in the YE diets. The pH and RAN were not different between treatments, although RAN was 11% lower in R2 (YE-SBM diet) vs. Rl and 15% lower in R4 (YE-urea diet) vs. R3. The RAN in R2 was Table 1 Ingredient composition
of diets (%) fed to steers (as fed basis)
Ingredient
High-roughage diets
Grass hay (fescue) Alfalfa hay Soybean meal Molasses TMS” Dical Urea DeodoraseY Rolled barley
High-concentrate
diets
Rl
R2
R3
R4
Cl
c2
c3
c4
62.00 30.00 5.00 2.00 0.50 0.50
62.00 30.00 5.00 2.00 0.50 0.50
66.25 30.00 2.00 0.50 0.50 0.75 -
66.25 30.00 2.00 0.50 0.50 0.75 +
25.00 20.00 4.00 0.50 0.50 50.00
25.00 20.00 4.00 0.50 0.50 + 50.00
28.35 20.00 0.50 0.50 0.65
28.35 20.00 0.50 0.50 0.65 + 50.00
+
50.00
’ TMS composition (%): Common salt, 95-97; zinc, > 0.35; Mn, > 0.3; Fe, > 0.23; Cu, > 0.023; I, > 0.012; Co, > 0.006; Se, > 0.009. y Deodorase was added at 250 mg kg-’ diet. Deodorase contains 30% Yucca schidigera plant extract; therefore, actual yucca extract was added at 75 mg kg-’ mixed diet. Table 2 Chemical composition
(96) of feeds fed to steers (DM basis)
Feed type
DM
OM
CP
ADF
NDF
HC
Ash
Rl R2 R3 R4
95.99 96.04 95.90 95.95
90.59 90.82 90.68 90.74
13.37 13.32 13.44 13.02
30.89 31.51 32.61 33.19
53.31 53.90 55.69 57.35
22.42 22.39 23.08 24.16
9.41 9.18 9.32 9.26
Cl c2 c3 c4
96.44 96.79 96.59 96.64
92.29 93.23 92.72 92.98
13.59 12.79 13.37 13.25
22.06 21.49 20.93 21.40
44.78 44.21 44.07 44.22
22.72 22.72 23.14 22.82
7.71 6.77 7.28 7.02
For abbreviations,
see text.
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Table 3 Feed intakes (DM basis) and rumen and blood profiles of steers fed high-roughage diets ParameterY
Feed intake (kg day-’ ) Rumen pH Rumen ammonia-N (mg dl-’ ) Plasma NH,-N (,~g ml-‘) Plasma urea-N (mg dl - ’)
Diets”
SE
RI
R2
R3
R4
11.40 6.48 11SO”b 1.13 13.64a
11.22 6.58 10.16b 1.24 14.79ab
11.34 6.59 15.11” 1.19 16.11b
10.96 6.59 12.88ab 1.04 14.66ab
0.38 0.17 2.53 0.25 1.62
‘RI, soybean meal (SBM); R2, SBM+deodorase (YE); R3, urea; R4, urea+YE. y Date were averaged across time periods. ab Values in the same row with different superscripts differ (PC 0.05 ) SE, pooled standard error.
significantly lower than for the R3 treatment. Numerically pH was higher in R2 vs. RI and in R3 vs. R4. The diets with urea (R3, R4) had slightly higher pH than the diets with SBM (Rl, R2). PAN (pg ml- ’) was not different among the four treatments. PUN concentrations were numerically lower in R4 vs. R3 and Rl vs. R2 and significantly lower in Rl vs. R3. Data on pH, RAN, PAN and PUN at different HPF are given in Table 4. The pH did not differ within each treatment at different time periods (0, 3, 6, 9 HPF). There was a linear decrease in pH postfeeding from 0 to 9 h in all treatments. RAN in all treatments peaked at 3 HPF, with the peak higher in R3 and R4 vs. R 1 and R2. However, the peak was less high in R4 compared to R3 and values remained low in R2 and R4 compared to Rl and R3 during all sampling times. In Rl, RAN was lower (P~0.05) at 9 HPF compared to 0 and 3 HPF. In R2, R3 and R4, RAN was significantly higher at 3 HPF compared to 0,6 and 9 HPF. PAN concentrations in each treatment at different times postfeeding did not differ. In Rl , PUN at 9 HPF was significantly lower than at 0, 3 and 6 HPF. In R2, PUN was higher (P~0.05) at 3 HPF compared to 9 HPF. In R4, PUN at 6 HPF was higher (P~0.05) than 0 HPF, while in R3 no differences among times were found. In the urea diets (R3, R4), PUN levels were lower in R4 vs. R3. When the treatments were compared within each time, no differences were observed among treatments at any HPF. Data on VFA concentrations (averaged across times) by animals on the HR diets are presented in Table 5. No differences occurred in average VFA production among treatments for all VFAs except isovalerate, which was higher (P< 0.05 ) in RI compared to R2, R3 and R4. Total VFA concentration on Rl was numerically higher than R2, while it was similar in R3 and R4. The acetate:propionate ratio was lower in the Rl and R2 and slightly higher in the R3 and R4 treatments. There was lack of consistency in VFA concentrations at different times postfeeding. There were no differences (P> 0.05 ) in most VFA levels at different HPF except for isobutyrate and isovalerate, where isobutyrate in RI at 0 h was higher (P-C 0.05 ) than 6 and 9 HPF. A similar pattern was observed in R2. Isovalerate concentration in RI at 0 HPF was higher (PC 0.05) compared
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Table 4 Rumen and blood profiles at different time period postfeeding of steers fed high-roughage diets Item
Rl
Plasma ammonia-N
( mg dl- ’)
R3
R4
6.87 6.59 6.46 6.39
6.72 6.66 6.54 6.45
6.71 6.62 6.51 6.52
0.17 0.17 0.17 0.17
10.88” 15.9” 10.14ab 9.03s
9.85” 14.68b 8.85” 7.27”
10.9oa 23.23b 14.538 1 1.808
10.87” 18.98b 11.93” 9.74”
2.37 2.37 2.37 2.37
0.92 1.21 1.27 1.09
0.86 1.57 1.32 1.22
1.14 1.34 1.22 1.05
0.83 1.17 1.04 1.12
0.24 0.24 0.24 0.24
14.70” 14.28” 15.00” 10.59s
14.548b 17.28a 14.98ab 12.35b
12.57” 14.60ab 17.48b 14.008s
1.56 1.56 1.56 1.56
(pg ml-’ )
Plasma urea-N (mg dl- ’)
R2
6.68 6.60 6.36 6.30
Ruminal pH
Ruminal ammonia-N
SE
Diets”
Time after feeding (h)
14.35 16.31 17.67 16.10
’ Rl, SBM, R2, SBM+YE, R3, urea; R4, urea+YE. ab Values in columns for each item with different superscripts differ (PC 0.05). SE, pooled standard error.
Table 5 Rumen fluid volatile fatty acid (VFA) concentrations diets (averaged across times) VFA
Acetate Propionate Isobutyrate Butyrate Isovalerate Valerate Total Acetate:propionate
(mmol 1-l) for animals fed high-roughage
Diets”
ratio
SE
Rl
R2
R3
R4
78.44 21.42 1.03 10.61 1.05” 1.03 113.58 3.66
68.76 17.97 0.83 9.04 0.79s 0.87 98.26 3.83
72.56 18.11 0.81 9.87 0.80b 0.86 103.01 4.01
73.20 19.02 0.86 9.81 0.72b 0.88 104.49 3.85
’ Rl, SBM; R2, SBM+YE; R3, urea; R4, urea+YE. y Data were averaged across time periods. ‘b Values in the same row with different superscripts differ (PC 0.05 ) . SE, pooled standard error.
3.68 1.21 0.08 0.69 0.08 0.09 -
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to 6 and 9 HPF. Its concentration at 3 HPF was higher (P~0.05) from 9 HPF. In R2, isovalerate concentration at 0 and 3 HPF was higher than at 6 and 9 HPF. A similar trend was observed in R4, while in R3 at 0 HPF it was higher (PcO.05) than at 6 and 9 HPF. However, in the R4 diet, there was less fluctuation in VFA concentrations compared to the R3 diet. There were differences (PcO.05) in propionate, isovalerate and valerate concentrations at 0 HPF and in isovalerate at 3 HPF among the four treatments. At 0 HPF, propionate in RI was higher (Pt0.05 ) than in R2, isovalerate was higher in RI vs. R2 and R4, and valerate concentration was higher in Rl than in R2. At 3 HPF, isovalerate was higher (PcO.05) in Rl vs. R3 and R4. At 6 and 9 HPF, there were no differences among the four treatments. 3.2. Trial 2 (high-concentrate diets) Data (averaged across times) regarding FI, pH, RAN, PAN and PUN are presented in Table 6. Average FI among the four treatments was not different (P> 0.05 ). FI was numerically lower in animals on feeds having YE (C2, C4) vs. animals on diets without YE (C 1, C3 ) . Ruminal pH of animals on the urea diet without YE (C3) was significantly higher than for animals on both SBM diets (Cl, C2), while pH with C4 was higher (PxO.05) than with Cl. RAN in animals on the SBM diet with YE (C2) was significantly lower than for animals on both types of urea diets (C3, C4). Although the two SBM diets did not differ significantly, RAN concentration was 13% lower on the SBM diet with YE (C2) vs. C 1. Similarly, it was 3% lower in animals on the diet with urea and YE (C4) vs. the diet with simple urea (C3). PAN concentration was significantly lower in animals on C2 compared with Cl, C3 and C4. PUN was significantly lower in animals on the C2 diet compared with Cl, C3 and C4. However, in the two urea diets, the difference in concentration of PUN was not significant. At different HPF (Table 7), there was a linear decrease in the pH from 0 to 9 HPF in all Table 6 Feed intake (DM basis), weight gain, rumen and blood profiles of steers fed high-concentrate ParameterY
Feed intake (kg day-‘) Weight gain (kg day-’ ) Rumen pH Rumen ammonia-N (mg dl- ’) Plasma ammonia-N (pg ml - ’) Plasma urea-N (mg dl- ’)
diets
Diets’ Cl
c2
c3
c4
SE
14.19 1.29 5.81” J.92”b l.lJ= 14.01=
13.46 1.10 5.82” 6.88s 0.89b 1 1.52b
14.16 1.47 6.09b 10.85” 1.15” 13.8Ja
13.74 0.79 6.00k 10.50” 1.15” 13.76”
0.30 0.31 0.07 1.24 0.07 0.72
’ Cl, soybean meal (SBM); C2, SBM+deodorase (YE); C3, urea; C4, urea+YE. y Data were averaged across time periods. ab Values in the same row with different superscripts differ (PC 0.05 ) . SE, pooled standard error.
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Table 7 Rumen and blood profiles at different hours postfeeding for steers fed high-concentrate diets Item
Time after feeding (h )
SE
Diets” Cl
c2 6.18” 5.80ab 5.65b 5.64b
c3
c4 6.25 6.17 5.83 5.77
0.13 0.13 0.13 0.13
9.42”
17.02b 9.39” 6.17a
2.48 2.48 2.48 2.48
0.91 1.17 1.11 1.34
0.74 1.12 1.01 1.51
0.24 0.24 0.24 0.24
12.68 15.31 15.12 11.92
12.70”” 16.09’ 15.10” 11.69”
1.44 1.44 1.44 1.44
6.45” 6.23ab 5.89b 5.81b
Ruminal pH
0 3 6 9
6.24b 5.86ab 5.60” 5.53”
Ruminal NHp-H (mg dl-’ )
0 3 6 9
1o.34a 1 1.38a 6.5Sab 3.39b
8.35 10.73 4.40 4.05
9.84” 17.47b 7.16” 8.95”
Plasma NHJ-N (pg ml-‘)
0 3 6 9
1.11 1.20 1.16 1.24
0.86 0.64 1.02 0.91
Plasma urea-N (mg dl- ’)
0 3 6 9
14.67ab 17.35” 13.69ab 10.31b
10.82 14.13 11.41 9.71
’ Cl, SBM, C2, SBM+YE; C3, urea; C4, urea+YE. ‘beValues in columns for each item with different superscripts differ (PC 0.05). SE, pooled standard error.
treatments. In Cl, pH at 0 HPF was higher (PqO.05) than at 6 and 9 HPF. A similar trend was observed in C2 and C3, but in C4 no differences were observed at different HPF. BAN decreased linearly from 3 to 9 HPF in all treatments. The BAN peak occurred at 3 HPF and was higher in the urea diets (C3, C4) compared to the SBM diets (C 1, C2). However, BAN was lower in diets having YE (C2, C4) vs. without YE (Cl, C3). In the Cl treatment, BAN at 9 HPF was lower (P-z 0.05) than at 0 and 3 HPF, but in C2 no differences were seen among different HPF. In C3, BAN was significantly higher at 3 HPF compared to 0, 6 and 9 HPF and a similar trend was observed in C4. Concentrations of PAN at different HPF did not differ. PAN was numerically lower in diets with YE (C2, C4) compared to Cl and C3, and its peak occurred mostly at 9 HPF. PUN peaked at 3 HPF in all treatments, and its concentration was lower in diets with YE. In Cl, PUN concentration at 3 HPF was significantly higher compared to 9 HPF. In C4, PUN was higher at 3 and 6 HPF compared to 9 HPF. In C2 and C3, no differences were observed at different HPF. When treatments were compared within each time, pH at 3 HPF was higher (PcO.05) in C3 vs. C2. The BAN at 6 HPF was lower (PxO.05) in C2 compared to C4. The pH, BAN, PAN and PUN did not differ at other times among treatments. The VFA concentrations (averaged across times) for animals on the HC diets
I. Hussain, P.R. Cheeke /Animal Feed Science and Technology 51(1995) 231-242 Table 8 Rumen fluid volatile fatty acid (VFA) concentrations diets (averaged across times) VFA
Acetate Propionate Isobutyrate Butyrate Isovalerate Valerate Total Acetate:propionate
(mmol 1-l) for steers fed high-concentrate
Diets” Cl
ratio
85.94 25.34” 1.15 14.86” 1.23” 1.40” 129.92 3.39
239
SE c2 78.65 22.47”b 1.00 12.59b
1.07ab 1.15b 116.93 3.50
c3
c4
80.01 22.56ab 1.00 10.65b 0.94b 1.13b 116.29 3.55
14.46 20.75b 0.92 11.62b 0.94b 1.08b 109.77 3.59
4.16 1.48 0.08 0.76 0.07 0.08 -
Data presented were averaged across time periods. ’ Cl, soybean meal (SBM); C2, SBM+YE; C3, urea; C4, urea+YE. ab Values in the same row with different superscripts differ (PcO.05). SE, pooled standard error.
are shown in Table 8. Total VFA concentrations were numerically higher with diets without YE. The acetate:propionate ratio was higher in urea diets (C3, C4) vs. SBM diets (Cl, C2), and it was slightly higher in diets with YE (C2, C4) compared to C 1 and C3. Propionate was higher (PC 0.05 ) in C I vs. C4. Butyrate was higher in Cl vs. C2, C3 and C4. A similar trend was seen for valerate. Isovalerate was higher in the Cl vs. C3 and C4 treatments. In Cl and C2, peak VFA concentrations occurred at 3 HPF, but in C3 and C4 in most cases VFA levels peaked at 6 HPF. Acetate concentration in C2 was higher (P~0.05) at 3 HPF compared to at 0, 6 and 9 HPF. A similar trend was observed for isobutyrate. Valerate concentrations at 3 HPF were higher (PcO.05) than at 0 and 9 HPF while butyrate concentration at 3 HPF was higher than at 0,6 and 9 HPF. In C3, acetate and propionate concentrations at 6 HPF were higher than at 0 and 3 HPF, while butyrate at 3 HPF was lower (PC 0.05 ) than at 6 and 9 HPF. In C4, valerate at 6 HPF was higher (PxO.05) than 0 and 3 HPF. At 0, 6 and 9 HPF, no differences among treatments were observed, while at 3 HPF, acetate concentration in C2 was higher (PC 0.05) than in C3 and C4. Propionate and butyrate in C3 were lower (P-z 0.05) than in C 1 and C2. Isovalerate concentration was higher (PcO.05) in the Cl diet than in the C3 diet. Valerate in C3 waslower (PeO.05) than in Cl and C2.
4. Discussion
In both trials, FI was 2-3% lower in the two feeds with YE vs. the feeds without YE. Goodall and Matsushima ( 1980) found that 40 ppm SAR improved nutrient digestibility and reduced feed intake in young steers. Johnston et al. ( 198 1) re-
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ported that feeding YE (63 ppm) improved gain and FE in broilers, and Al-Bar et al. (1993) found similar results in rabbits and replacement pullet chicks. Cromwell et al. ( 1985) reported improved gains after feeding YE to pigs. Mader and Brumm ( 1987) during the first 28 days of their four trials found that daily gains (0.74 kg) of steers fed urea plus YE were significantly higher than those fed the diet without YE (0.66 kg). Goodall and Matsushima ( 1980) reported lower intakes but better digestibility and lower passage rates by feeding YE in both corn grain and corn silage diets. However, Goetsch and Owens ( 1985) did not observe a consistent intake or passage rate response to feeding YE and suggested that an interaction between YE and diet energy density or diet composition may exist. They reported that the lag time of digestion tended to be longer with the SAR diets for corn, sorghum, SBM and corn gluten meal but shorter for alfalfa and prairie hay. They also reported improvements (PcO.05) in ruminal DM digestibilities by supplementing silage diets with YE. Headon ( 199 1) reported that YE contains glycosylated components which bind ammonia. In non-ruminant studies, levels of ammonia in poultry houses (Rowland et al., 1976; Al-Bar et al., 1993) and rabbit houses (Al-Bar et al., 1993) were reduced by feeding YE. Lowered environmental ammonia may result in improved performance. Foster ( 1983 ) found an interaction between YE and pig density, and concluded that the performance response from YE appears to be greater as floor space and feeder space per pig are reduced. In our study, rumen pH with the different YE treatments was similar, The pH was lower in the HC trial compared to the HR trial; this was as expected because of the higher content of fermentable carbohydrate. Ryan et al. ( 1993) reported that YE did not affect rumen pH. Numerically, rumen pH in the HR trial was higher in R2 vs. Rl, but it was the same in R3 vs. R4. In the HC trial, pH was numerically slightly higher in C2 vs. Cl (5.82 vs. 5.81), while it was lower in C4 vs. C3 (6.00 vs. 6.09). In a study with dairy cows (Goetsch and Owens, 1985), when diets contained 50% concentrate either with or without YE added at 44 ppm, ruminal pH for animals given YE tended to be lower at 4,8 and 12 HPF. Grobner et al. ( 1982) reported that 30 ppm YE increased pH and 60 ppm decreased pH in a continuous flow fermentor. In our HR trial, there was an 11% reduction in RAN in the R2 diet vs. RI, and a 15% reduction in the R4 vs. R3 diets. In the HC trial, the reduction was 13% and 3% for C2 vs. Cl and C4 vs. C3, respectively. A reduction in RAN levels would be beneficial by allowing greater quantities of urea to be utilized in HR ruminant diets (Glimp and Tillman, 1965 ). Grobner et al. ( 1982) found lower RAN concentrations with YE supplementation. Gibson et al. ( 1985) found that RAN level was reduced by 27% when YE was fed to cattle in diets containing 0.87% urea, although DM digestibility was not influenced by YE supplementation. Ellenberger et al. ( 1985) noted decreased in vitro ruminal urease activity with YE supplement. Ryan et al. (1993) and Wu et al. (1994) found that addition of YE had no effect on RAN. In the HC trial, concentration of RAN was lower than in the HR trial. Haaland et al. ( 1982) reported that higher OM intakes result in better utilization of ammonia by rumen microbes, which would
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lower RAN levels. Wu et al. ( 1994) reported that addition of YE via the ruminal cannulae (0,2,4,6,8 g day-’ ) had no effect on VFA and rumen pH. Ryan et al. ( 1993) reported that addition of YE decreased (P> 0.05) total VFA production compared to the control. In our study, there was also some reduction (I?=- 0.05 ) in total VFA concentration in feeds having YE compared to the control. Willms et al. ( 199 1) reported that lambs fed SBM had higher (PC 0.05) total VFA ( 106 mM) than those fed 33% supplemental CP from urea (95 mM). Increases in OM digestion increased total VFA concentration and lowered pH. We also observed similar trends in our study where total VFA concentrations were higher in C 1 and C2 vs. C3 and C4, and RI vs. R2, but concentration was higher in R4 vs. R2. Another mechanism by which YE could affect rumen fermentation is through effects on the rumen microbes. For example, Lu and Jorgensen ( 1987) reported that alfalfa saponins reduced rumen protozoa numbers. Defaunation often improves ruminant performance. Thus an effect of the SAR fraction of YE on rumen microbes and fermentation efficiency should not be overlooked. In conclusion, in the HR trial, RAN was lower in YE diets vs. control diets, and the RAN peak was less high in R4 vs. R3. The trend for PUN concentration was lower in R4 vs. R3, there was less fluctuation in VFA production at different times postfeeding in R4 vs. R3, and the acetate:propionate ratio was lower in R4 vs. R3. In the HC trial, RAN, PAN and PUN were numerically lower in the YE diets, and rumen pH was lower in C4 vs. C3. These results indicate that YE supplementation favoured rumen N metabolism, especially in the HR trials and diets with urea.
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Goodall, S.R. and Matsushima, J.K., 1980. The effects of sarsaponin on ruminant digestion and rate of passage. J. Anim. Sci., 51 (Suppl. 1): 363. Goodall, S.R., Brady, P., Horton, D. and Beckner, B., 1982. Steam flaked versus high moisture corn rations with and without sarsaponin for finishing steers. Proc. West. Sec. Am. Sot. Anim. Sci., 33: 45-48. Grobner, M.A., Johnson, D.E., Goodall, S.R. and Benz, D.A., 1982. Sarsaponin effects on in vitro continuous flow fermentation of a high grain diet. J. Anim. Sci., 55 (Suppl. 1): 49 1. Haaland, G.L., Tyrell, H.F., Moe, P.W. and Wheeler, W.E., 1982. Effect of crude protein level and limestone buffer in diets fed at two levels of intake on rumen pH, ammonia-nitrogen, buffering capacity and volatile fatty acid concentration of cattle. J. Anim. Sci., 55: 943-950. Headon, D.R., 1991. Glycofractions of the yucca plant and their role in ammonia control. In: Biotechnology in the Feed Industry. Proc. 7th Alltech Symposium. Alltech Technical Publications, Nicholasville, KY, pp. 95-108. Johnston, N.L., Quarles, C.L., Fagerberg, D.J. and Caveny, D.D., 198 1. Evaluation of yucca saponin on broiler performance and ammonia suppression. Poult. Sci., 60: 2289-2292. Lu, C.D. and Jorgensen, N.A., 1987. Alfalfa saponins affect site and extent of nutrient digestion in ruminants. J. Nutr., 117: 919-927. Mader, T.L. and Brumm, M.C., 1987. Effect of feeding sarsaponin in cattle and swine diets. J. Anim. Sci., 65: 9-15. Rowland, Jr., L.O., Plyler, J.E. and Bradley, J.W., 1976. Yucca schidigera extract effects on egg production and house ammonia levels. Poult. Sci., 55: 2086, abstract. Ryan, J.P., Leek, B.F. and Jacques, K., 1993. The complementary effects of Saccharomyces cerevisiae yeast culture (Yea-Sacc 1026) and yucca schidigera extract (solid deodorase) on ruminal metabolism in sheep. J. Anim. Sci., 71 (Suppl. 1): 287. Statistical Analysis Systems Institute Inc., 1987. User’s Guide: Statistics. Statistical Analysis Systems Institute Inc., Cary, NC. Waldem, D.E., 197 1. A rapid micro-digestion procedure for neutral and acid detergent fiber. Can. J. Anim. Sci., 5 1: 67-69. Willms, C.L., Berger, L.L., Merchen, N.R. and Fahey, Jr., G.C., 199 1. Effects of supplemental protein source and level of urea on intestinal amino acid supply and feedlot performance of lambs fed diets based on alkaline hydrogen peroxide-treated wheat straw. J. Anim. Sci., 69: 4925-4938. Wu, Z., Sadii, M., Huber, J.T., Sleiman, F.T., Simas, J., Pessarakli, M. and Huber, J.T., 1994. Influence of yucca extract on ruminal metabolism in cows. J. Anim. Sci., 72: 1038-1042.