Ruminal degradability and whole-tract digestibility of protein and fibre fractions in fenugreek haylage

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1 Ruminal degradability and whole-tract digestibility of protein and fibre fractions in fenugreek haylage L. Doepel 1, J. E. Montgomery 1, K. A. Beauchemin 2, J. R. King 1, and S. N. Acharya 2 1 University of Alberta, Edmonton, Alberta, Canada T6G 2P5 ( ldoepel@ucalgary.ca); and 2 Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada T1J 4B1. Received 13 September 2011, accepted 30 January Doepel, L., Montgomery, J. E., Beauchemin, K. A., King, J. R. and Acharya, S. N Ruminal degradability and wholetract digestibility of protein and fibre fractions in fenugreek haylage. Can. J. Anim. Sci. 92: The purpose of this study was to evaluate the digestibility of fenugreek forage compared with alfalfa in dairy cows. Alfalfa and two genotypes of fenugreek, Quatro and F70, were harvested and prepared as plastic-wrapped high-moisture bales. Fourteen weeks after baling, forage samples were obtained for determination of ruminal degradation and whole-tract digestibility. To determine ruminal degradation, forage samples were placed in polyester bags and incubated in the rumen for various time points (up to 168 h) in lactating Holstein cows. Digestibility in the rumen, intestine and the whole digestive tract was estimated by incubating samples in the rumen, followed by measurements of intestinal digestibility using the mobile bag technique in two non-lactating Holstein cows. Effective ruminal degradability of DM was lower for F70 than for alfalfa, while for ADF and NDF it was equivalent in all forages. Whole-tract disappearance of DM, CP, ADF and NDF was lower for F70 than Quatro. In general, Quatro and alfalfa were similar in terms of ruminal degradation and digestion in the rumen, intestine and whole-tract, while F70 tended to be of lower quality. Key words: Fenugreek haylage, ruminal degradability, intestinal digestibility, ruminant Doepel, L., Montgomery, J. E., Beauchemin, K. A., King, J. R. et Acharya, S. N Dégradation dans le rumen et digestibilite dans le tube digestif des protéines et des fibres de l ensilage préfané de fenugrec. Can. J. Anim. Sci. 92: L e tude devait servir a` e valuer la digestibilite du fourrage de fenugrec, comparativement à celui de luzerne pour les vaches laitie` res. Pour cela, les auteurs ont re colté de la luzerne et deux génotypes de fenugrec, Quatro et F70, puis les ont enveloppe s dans du plastique en balles très humides. Pour de terminer la de gradation du fourrage dans le rumen, ils ont place des e chantillons dans des sachets en polyester qu ils ont incube s dans le rumen de vaches Holstein en lactation pendant une pe riode variable (allant jusqu a` 168 heures). La digestibilite dans le rumen, dans l intestin et dans l ensemble du tube digestif a été e valuée, dans le rumen, par incubation d e chantillons de fourrage, et dans l intestin, par la technique du sac mobile chez deux vaches Holstein qui n allaitaient pas. La matie` re se` che du fenugrec F70 se de grade moins efficacement que celle de la luzerne, mais les fibres au de tergent acide et les fibres au détergent neutre des deux types de fourrages se de gradent de manie` re e quivalente. L assimilation de la matie` re sèche, des prote ines brutes, des fibres au de tergent acide et des fibres au de tergent neutre dans l ensemble du tube digestif était plus faible pour le fenugrec F70 que pour Quatro. En ge néral, le fourrage de fenugrec Quatro et celui de luzerne se de gradent de la meˆme façon dans le rumen et se dige` rent aussi bien dans le rumen, l intestin et le tube digestif, le fourrage de fenugrec F70 étant de moins grande qualité. Mots clés: Ensilage pre fane de fenugrec, de gradation dans le rumen, digestibilite intestinale, ruminant Alfalfa is the primary leguminous forage used by most dairy operations in Canada. Annual legumes have many of the same benefits as alfalfa including nitrogen fixation and high nutrient content, but they also increase crop rotation flexibility as they occupy cropping land for only one growing season. Fenugreek is a single-cut, annual legume originating in the Mediterranean and Indian subcontinent grown primarily for seed production with good potential as a forage in Canada because of the high and sustained quality of the plant (Acharya et al. 2008; Basu et al. 2008) and drought and frost tolerance (McCormick et al. 2006; Acharya et al. 2008). Fenugreek forage is thought to be comparable to alfalfa in terms of nutrient content. Mir et al. (1997) found that whole-plant fenugreek (variety Amber) harvested 9 wk post-seeding was superior [higher crude protein (CP) and lower neutral detergent fibre (NDF) concentration] to that of early-bloom alfalfa, whereas fenugreek cut at 15 or 19 wk had lower CP content and equivalent or higher NDF content compared with alfalfa. At all stages of maturity, the in vitro dry matter (DM) digestibility of fenugreek was higher than that of alfalfa. Mustafa et al. (1996) reported that the in vitro DM digestibility of fenugreek hay was equivalent to that of full-bloom alfalfa hay. Mir et al. (1993) compared mature (50% seed fill) fenugreek hay with 10% bloom and full-bloom alfalfa hay and found that fenugreek CP and fibre concentrations were intermediate between Abbreviations: ADF, acid detergent fibre; CP, crude protein; DM, dry matter; ERD, effective ruminal degradability; NDF, neutral detergent fibre Can. J. Anim. Sci. (2012) 92: doi: /cjas

2 212 CANADIAN JOURNAL OF ANIMAL SCIENCE 10% bloom alfalfa and full-bloom alfalfa, but that in vitro DM digestibility of fenugreek was higher than that of alfalfa. Two genotypes of fenugreek that have not been examined extensively are F70, developed by Agriculture and Agri-Food Canada (AAFC), and Quatro, developed by the Crop Development Centre in Saskatchewan, Canada. F70 is not commercially available, but is used as a breeding line at AAFC, Lethbridge, while Quatro is a commercially released variety. The main objective of this research was to establish whether these fenugreek genotypes would be suitable alternatives to alfalfa for use in dairy rations based on their rumen degradability and total tract digestibility. It was hypothesized that F70, a cultivar bred for its forage quality, would be digested to a greater extent in the gastro-intestinal tract than Quatro, a seed cultivar, and that the two fenugreek cultivars would be at least as digestible as alfalfa. MATERIALS AND METHODS Haylage Production Two cultivars of fenugreek, Quatro and F70, were inoculated using an alfalfa Rhizobium species, seeded and harvested as wrapped baled haylage at the University of Alberta Edmonton Research Station in Details regarding soil fertilization, seeding and harvesting have been previously published (Montgomery 2009; Alemu and Doepel 2011). The Quatro fenugreek was swathed and baled as wrapped high-moisture bales at 109 d post-seeding, while the F70 was swathed at 109 d, but was not baled until 2 d later as its moisture content at cutting was higher than that of Quatro. At baling, the DM content of Quatro was 34% and that of F70 was 50%, which indicates substantial drying occurred over the 2-d period between cutting and baling. Both fenugreek cultivars were at approximately 80% seedfill, had a leaf to stem ratio of approximately 0.6, and were beginning to senesce. Second-cut alfalfa was swathed at 1520% bloom and baled as haylage, at 57% DM, to use as a comparison to the fenugreek forage. The alfalfa was from an established stand and was the variety Beaver, the variety normally seeded on the Edmonton Research Station. Forage samples were collected at harvest, and on days 1, 5 and 28 post-harvest. Core samples were obtained from multiple bales of each forage type, samples were composited for the various bales on each sampling day for each forage, and the composited samples were sent to Cumberland Valley Analytical Services Inc. (Hagerstown, MD) for analysis of fermentation characteristics, including DM, ph, ammonia, titration acidity, lactic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid. Because pooled samples were analyzed, only descriptive data for fermentation characteristics are presented. At 14 wk post-harvest, fenugreek and alfalfa haylage samples were collected for use in the study. Samples from several bales of each forage type were taken using a core sampler. Samples were composited by forage and dried at 558C for 72 h to determine DM. A portion of each sample was ground through a 1 mm screen of a Thomas Wiley Laboratory Mill (Model 4, Arthur H., Thomas Co., Philadelphia, PA) and analyzed for CP, NDF and acid detergent fibre (ADF) concentrations, with a second portion ground through a 6 mm screen (Thomas Wiley Mill Model 4, Arthur H., Thomas Co., Philadelphia, PA) and used to determine ruminal degradation and whole-tract digestion. Rumen Degradation Measurements Animals were cared for in accordance with the guidelines of the Canadian Council on Animal Care (1993). Six ruminally cannulated, lactating dairy cows at the Dairy Research and Technology Centre, University of Alberta, were used for in situ measurements of the ruminal degradation kinetics of the fenugreek and alfalfa haylages. Each forage type was incubated in two cows that were fed for ad libitum intake diets of the corresponding feed type; for example, F70 was incubated in cows fed a F70-based diet (Alemu and Doepel 2011). The diets were fed as a total mixed ration and contained on a DM basis 41% haylage, 9% barley silage, and 50% of a barley grain-based concentrate. Bags (6 14 cm) were prepared using nitrogen-free polyester with a mean pore size of 50 mm (Ankom Technology, Macedon, New York, USA). Five grams (90.1 g) of dried and ground haylage were weighed into the bags, which were then sealed. The bags were placed in weighted large mesh sacs that permitted free percolation of rumen fluid. Duplicate bags were placed in the rumen for 1, 2, 4, 6, 8, 12, 18, 24, 36, 48, 72, 96, 120 and 168 h. All bags were placed in the rumen at the same time and then removed sequentially. Zero-hour bags were washed under cold water until water ran clear. Upon removal from the rumen, bags were immediately immersed in ice water to halt microbial activity, rinsed in cold water until run-off was clear, and then frozen for 72 h to halt any further microbial activity. Following thawing in cool water, the bags were agitated in cold water to remove microbial material and then dried at 558C for 48 h. Bags and contents were weighed to determine DM disappearance, and the contents of the replicate bags for each incubation time were composited and retained for protein and fibre analysis. Whole-tract Digestibility Digestibility in the rumen, intestine and the whole digestive tract was estimated by incubating samples in the rumen, followed by measurements of intestinal digestibility. The assumption was that disappearance in the rumen and intestine was synonymous with digestion, and digestion in the whole tract was calculated as the sum of the digestion in the rumen and intestine.

3 DOEPEL ET AL. * DIGESTIBILITY OF FENUGREEK HAYLAGE IN RUMINANTS 213 The study was conducted at the Agriculture and Agri- Food Canada Lethbridge Research Centre. Two nonlactating dairy cows, previously fitted with ruminal and duodenal cannulae, were used. The cows were fed alfalfa hay for ad libitum intake for the duration of the experiment. Mobile bags (3 cm 5 cm) were constructed using PeCap monofilament polyester fabric with a 51 mm pore size (Sefar, St.-Laurent, QC). One gram (90.05 g) of feed was weighed into the bags. Six bags per forage type (Quatro, F-70 and alfalfa) were used as 0-h bags; these were not inserted in the rumen, but were soaked in warm water for 20 min, rinsed under running water until the effluent from the bags was clear, and dried at 558C. Sixteen bags for each forage type and each incubation time were placed in the rumen of each cow (192 bags). The bags were placed inside weighted mesh bags and incubated in the rumen for either 18 or 30 h; these times were chosen to represent the range in residence time in the rumen for the quality of forages being tested. Upon removal, the bags were immersed in ice water to halt microbial action. Six bags from each incubation time and forage type were washed and dried as described previously to determine ruminal disappearance. The remaining 10 bags were immersed for 1 h in a pepsin-hcl solution to mimic the abomasum and then inserted into the small intestine via the duodenal cannula at a rate of two bags every 20 min. The bags were then collected from the faeces for up to 24 h after the insertion of the last bag into the duodenal cannula. All bags were rinsed upon collection and dried as described above. Bags and contents were weighed to calculate DM disappearance. For each feed type, samples were pooled for each cow by time and treatment (either rumen-only or duodenum) to obtain sufficient sample volume for analysis of CP, ADF, and NDF. Chemical Analysis Acid detergent fibre and NDF were determined sequentially using the Ankom 200 Fiber Analyzer (Ankom Technology, Macedon, NY) using heat-stable a-amylase and sodium sulphite. Crude protein (N 6.25) was determined using a Leco TruSpec C/N Elemental Determinator (Leco, St. Joseph, MI). Statistical Analysis The non-linear regression procedure of SAS (SAS Institute, Inc. 2002) was used to estimate the rumen kinetic parameters using the following model (McDonald 1981): yab(1e Kd(tL) )for tl where y is the the percent DM, NDF, ADF or CP that disappeared at time point t, a is the soluble fraction (%), b is the potentially degradable fraction (%), K d is the fractional rate of disappearance (% h 1 ), t is the incubation time (h), and L is the lag time (h). The undegradable fraction c was calculated as 100 (ab). Effective ruminal degradability (ERD) was calculated as: ERDa(bK d )=(K d K p ) where K p represents the theoretical rate of passage from the rumen; 5% h 1 was used. In situ degradation parameters (a, b, c and K d ) were analyzed using the mixed procedure of SAS for each forage type using cow nested within forage type as the random term and forage type as the fixed term. For the whole-tract digestion study, DM, NDF, ADF, and CP digestion in the rumen, intestine, and total tract were analyzed using the Repeated Measures option in the MIXED procedure of SAS software, with forage type and time as the fixed factors and cow as the random factor. Time was the repeated measure. Upon comparison of Bayesian Information Criteria (lowest indicating best fit) for covariance structures that did not require equal spacing of sampling time (unstructured, compound symmetry, heterogeneous compound, and ante-dependence), the covariance structure with the best fit to the model was found to be compound symmetry. Differences between treatments are discussed when PB0.05. RESULTS AND DISCUSSION Haylage Production The DM concentration of all haylage types stayed relatively constant over the first 28 d of fermentation in the wrapped bales (Table 1). Alfalfa haylage had numerically the greatest DM concentration, between 57 and 61%. The DM concentration of Quatro was substantially lower than that of F70 (35 vs. 50%) because F70 was wilted in the field for 2 d following cutting while Quatro was baled immediately upon cutting. Table 1. Fermentation characteristics of alfalfa, F70 and Quatro haylages as affected by time after harvest Item DM ph Ammonia Fermentation parameter (% of DM) Acetic acid Isobutyric acid Lactic acid Alfalfa at harvest d d d F70 at harvest d d d Quatro at harvest d d d

4 214 CANADIAN JOURNAL OF ANIMAL SCIENCE The ph of F70 haylage showed an initial numerical decrease in the first 24 h of fermentation while the ph of Quatro and alfalfa remained constant throughout the 28-d sampling period. Haylage moisture content is usually 4555%, and ph normally ranges from 4.7 to 5.8 [Alberta Agriculture and Rural Development (AARD) 2003]. Fermentation in haylage is slower and progresses to a lesser degree than that in chopped silage because of the lower moisture content and the longer chop length of plant material. Low moisture will result in decreased fermentation and increased ph (Macaulay 2003). The haylage in this study appeared to undergo minimal fermentation as the ph changed only slightly over the ensiling period. The reasons for the lack of fermentation are not apparent. For the fenugreek varieties, it may have been due to the advanced stage of maturity at harvest, which would have resulted in low water-soluble carbohydrate concentrations available to the microorganisms. Although the nutrient analysis of the fenugreek would not indicate advanced maturity, the pods were fairly well developed so the amount of seed in the total plant material would contribute to the high CP concentration and the low fibre concentration. For the alfalfa, the low moisture concentration may have been a contributing factor for the lack of fermentation. Additionally, for all forages, the long chop length, which would have minimized the ability of the microbes to access the plant material (AARD 2004), may have contributed to the lack of fermentation. For forage legumes that are preserved with 35% DM, a typical fermentation profile is % ammonia, % lactic acid, % acetic acid, % propionic acid, % butyric acid, and % isobutyric acid (Jones et al. 2004). The fermentation products of the haylages are shown in Table 1. The ammonia concentration, which increased over time, remained below the range indicated by Jones et al. (2004) for the alfalfa, but was within the range for the fenugreek. Lactic acid concentration was within a normal range for Quatro, but was below normal for F70 and alfalfa. Lactic acid content influences the ph of silage (AARD 2004); thus, the low lactic acid concentration of the haylages was consistent with the moderately high, stable ph. Acetic acid was also within the normal range for Quatro, but was below normal in F70 and alfalfa. While butyric acid was not detected in the F70 and alfalfa it was detected (0.37%) on day 28 in the Quatro haylage. The production of butyric acid indicates the presence of undesirable species of microorganisms in the forage (AARD 2004); therefore, it appears that these undesirable bacterial species were present in Quatro, possibly as a result of the low DM content of this haylage. Isobutyric acid was not detected in the alfalfa but was present in both fenugreek forages within the normally reported range. Propionic acid was not detected in any of the forage samples. Rumen Degradation Kinetics The nutrient composition of the forages used in the incubation studies are shown in Table 2, while Table 3 outlines the rumen kinetic degradation parameters. The soluble DM fraction was higher for alfalfa than Quatro, which was higher than for F70. The potentially degradable DM fraction of Quatro was higher than that of F70, while alfalfa was intermediate and not different from Quatro or F70. The undegradable DM fraction was higher for F70 than for the other two forages, with Quatro higher than alfalfa. Effective ruminal DM degradability was higher for alfalfa than for F70, while Quatro was intermediate. While the soluble DM fraction of alfalfa was the highest of the three forages, the high degradable fraction of Quatro combined with an intermediate rate of degradation of that fraction resulted in a similar ERD of DM for Quatro and alfalfa. The numerically lowest ERD of DM for F70 was the result of its low soluble fraction, high undegradable fraction, and low rate of degradation. Whether these characteristics are specific to the cultivar or were influenced by the wilting process is unknown, and warrants further research in this area. The undegradable fractions for all nutrients measured were higher for F70 than for the other two forages. The soluble and degradable DM fractions of Quatro in the current study were similar to that reported for alfalfa silage (35 and 39%, respectively) by Khorasani et al. (2001). In addition, the rate of degradation (4.7% h 1 ) and ERD of the alfalfa silage (50.6%) in that study were also similar to that of Quatro. The DM fractions of Quatro and alfalfa in the current study were also similar to those reported for alfalfa by Kennelly (1999). In that study, the soluble DM fractions of low- and high-quality alfalfa silage were 37 and 36%, respectively, while the degradable fractions were 39 and 43%. While the Quatro DM degradability in this study is similar to alfalfa degradability in other studies, the fact that there were differences between the two forages in the current study demonstrates the wide variation that exists within forage type. As such, overarching conclusions regarding degradability of forage type cannot be made. Alfalfa had a higher soluble CP fraction than Quatro, but neither was different from F70. Quatro had the highest degradable CP fraction while alfalfa had the lowest; F70 was intermediate and not different from the other forages. The undegradable CP fraction of F70 Table 2. Nutrient composition (% of DM) of alfalfa, F70, and Quatro haylages sampled 14 weeks post-harvest and used in the degradation study Haylage Item Alfalfa F70 Quatro CP NDF ADF

5 DOEPEL ET AL. * DIGESTIBILITY OF FENUGREEK HAYLAGE IN RUMINANTS 215 Table 3. In situ ruminal degradability of alfalfa, F70, and Quatro haylage Haylage Parameter (n2) Alfalfa F70 Quatro SEM DM Soluble (% of DM) 41.7a 26.6c 33.0b 0.4 Degradable (% of DM) 36.0ab 32.2b 39.7a 0.9 Undegradable (% of DM) 22.3c 41.2a 27.3b 0.8 Rate of degradation (% h 1 ) Lag (h) ERD (%) z 63.5a 41.2b 53.8ab 3.0 CP Soluble (% of CP) 52.3a 38.9ab 33.7b 4.1 Degradable (% of CP) 40.2a 45.2ab 58.9b 2.8 Undegradable (% of CP) 7.5b 15.9a 7.4b 1.4 Rate of degradation (% h 1 ) Lag (h) 0b 10.8a 5.2ab 1.5 ERD (%) z 79.6a 74.9ab 71.2b 1.9 NDF Soluble (% of NDF) 0.0c 7.6b 12.8a 0.8 Degradable (% of NDF) Undegradable (% of NDF) 58.9a 61.6a 50.4b 1.9 Rate of degradation (% h 1 ) Lag (h) 3.1a 1.9ab 0.0b 0.5 ERD (%) z ADF Soluble (% of ADF) 0.0c 6.4b 12.5a 1.3 Degradable (% of ADF) 44.0a 35.1b 36.7b 0.5 Undegradable (% of ADF) 56.2a 58.5a 50.7b 1.0 Rate of degradation (% h 1 ) Lag (h) ERD (%) z z ERD, effective ruminal degradability determined from digestion kinetics assuming a rate of passage of 5% h 1. ac lsmeans within a row with different superscripts differ (PB0.05). was higher than that of alfalfa and Quatro. The rate of CP degradation was not different among the forages but the ERD of CP in alfalfa was higher than that of Quatro, with F70 being intermediate and not different from the others. The lower ERD of the CP in Quatro was the result of a relatively small soluble fraction in combination with a low rate of degradation. In contrast, alfalfa had a large soluble CP fraction, a relatively low degradable CP fraction that was degraded more quickly than the other two forages, and a small undegradable CP fraction, allowing the ERD of CP to be highest in alfalfa. The soluble CP fraction was lower for all forages in the current study than reported by Khorasani et al. (2001) and Kennelly (1999) for alfalfa silage, which may have been due to the use of wetter material in those studies. Silages typically have a larger soluble CP component than do hays due to the high non-protein N content of silages (Hedqvist and Ude n 2006). Considering the minimal fermentation changes that occurred during the first 28 d post-baling in the current study it is not surprising that the soluble CP fractions are more similar to that of hay than of silage. In the study of Mir et al. (1993), CP ERD of fenugreek was 80%, higher than that for fenugreek haylage in the current study. This difference may be related to the stage of maturity at harvest, as the forage in the Mir study was harvested at about 12 wk of age and 50% seed fill whereas the haylage in the current study was harvested at 15 wk and approximately 80% seed fill. The degradable NDF fraction was not different among the three haylages, whereas the degradable ADF fraction was higher for alfalfa than for the fenugreek forages. For both NDF and ADF, the soluble fraction was highest for Quatro, lowest for alfalfa, and intermediate for F70. The rates of NDF and ADF degradation were similar among the three forages as was the ERD. Mustafa et al. (1996) reported soluble and degradable ADF fractions of fenugreek hay that were comparable with those of Quatro haylage and greater than those of F70 haylage. The ERD of the NDF and ADF fractions of the fenugreek hay in that study were comparable with the fractions observed for Quatro, but higher than the ERD of F70. Unlike in the Mustafa (1996) study, the undegradable NDF and ADF fractions in Quatro and F70 comprised more than 50% of the fibre due to their more advanced stage of maturity and increased lignification [refer to Alemu and Doepel (2011) for lignin concentration]. In the Mustafa et al. (1996) study, the hay was harvested between late bloom and early pod formation. Overall, F70 was the poorest quality feed due its low rate of degradation and small soluble fractions and large undegradable fractions for all nutrients measured. Alfalfa and Quatro were comparable in quality. Degradation of Quatro DM occurred more slowly than the degradation of alfalfa DM, which was also observed by Mir et al. (1993), who found that fenugreek has a sustained release of nutrients, especially N, in the rumen. Whole-tract Digestion Alfalfa and Quatro DM were digested in the rumen and in the whole-tract to a similar extent, which was higher than for F70 (Table 4). These data are consistent with the in situ ruminal degradability (Table 3). The DM and CP total-tract disappearance of all three forage types was similar to that reported by Trˇina cty et al. (2003) for alfalfa hay. Likewise, DM and CP digestion of the haylages was similar to that reported by Kennelly et al. (1991) in which DM digestion of alfalfa in the rumen, intestine, and whole tract was 68.2 and 71%, respectively, while for CP it was 87.8 and 96%. Digestion of NDF and ADF in the rumen was highest for Quatro, while alfalfa and F70 were not different. When calculated for the whole tract, Quatro NDF and ADF digestion was greater than for F70, which in turn was higher than alfalfa. There were no differences in intestinal digestion of any of the nutrients among the three haylages measured either as a percentage of nutrient placed in the rumen or as a percentage of nutrient entering the intestine. With the exception of whole-tract DM and CP digestibility

6 216 CANADIAN JOURNAL OF ANIMAL SCIENCE Table 4. Digestibility (%) of alfalfa, F70, and Quatro haylage in the rumen, intestine and whole tract Digestibility (%) n2 Forage Time (h) Alfalfa F70 Quatro SEM SEM DM Rumen 74.8a 60.4b 73.7a Intestine z Intestine y Whole tract 76.7a 65.4b 77.5a d 75.0e 0.29 CP Rumen Intestine z Intestine y Whole tract 94.0a 91.9b 93.8a d 94.4e 0.23 NDF Rumen 45.6b 48.4b 62.0a d 56.5e 0.75 Intestine z Intestine y Whole tract 46.0c 52.5b 63.2a ADF Rumen 48.3b 50.7b 61.6a d 57.9e 0.69 Intestine z Intestine y Whole tract 47.7c 53.9b 62.5a d 57.6e 0.45 z Disappearance in the intestine as a percentage of nutrient placed in the rumen. y Disappearance in the intestine as a percentage of nutrient entering the intestine. ac lsmeans within a row for forage type with different superscripts differ (PB0.05). d, e lsmeans within a row for time with different superscripts differ (0.05P50.10). and rumen NDF and ADF digestibility, incubation length in the rumen (18 or 30 h), did not affect digestion of DM, NDF, or ADF in the rumen, intestine, or the whole tract, or digestion of CP in the rumen or intestine (Table 4). However, for whole-tract digestion of CP there was a timeforage interaction. At 18 h incubation there was no difference in the whole-tract digestion of CP of the three haylages (Quatro: 91.6%, alfalfa: 93.5%, F70: 91.4%; SEM 0.40), whereas at 30 h incubation, whole-tract digestion was greatest for Quatro (96.0%), followed by alfalfa (94.6%) and then F70 (92.5%; SEM 0.22). In addition, whole-tract CP digestion of Quatro incubated for 18 h was significantly lower than Quatro incubated for 30 h. The increase in digestibility of Quatro with extended rumen incubation time may indicate a protein structure (e.g., presence of disulphide bonds, number of accessible hydrolysable sites) that is somewhat resistant to microbial action and requires more time for microbial attachment and subsequent degradation. CONCLUSION Fenugreek haylage produced in the 2006 growing season and harvested 15 wk after planting showed little evidence of fermentation during ensiling. For the particular forages tested, Quatro haylage was comparable with alfalfa haylage in terms of ruminal degradation and digestion in the rumen, intestine and whole-tract, although alfalfa had greater CP degradation in the rumen, and the fibre fraction of Quatro was more highly degradable in the rumen and more digestible through the whole-tract. In contrast, F70 was generally lower in quality than the other forages. Whether these differences are truly reflective of the cultivars or are due to external factors such as wilting is unknown; however, it is reasonable to think that these are cultivar specific considering that the two fenugreek cultivars were grown on the same soil type, with identical fertilization, and sown and mowed at identical times. Based on these results, Quatro fenugreek has the potential to provide high-quality forage that could partially replace alfalfa in rations for high producing dairy cows. Acharya, S. N., Thomas, J. E. and Basu, S. K Fenugreek, an alternative crop for semiarid regions of North America. Crop Sci. 48: Alberta Agriculture and Rural Development Agdex 120/ 52-2, silage manual. Print Media Branch, Alberta Agriculture, Edmonton, AB. Alberta Agriculture and Rural Development Bale silage. [Online] Available: deptdocs.nsf/all/agdex6134 [2009 Jul. 06]. Alemu, A. W. and Doepel, L Fenugreek (Trigonella foenum-graecum L.) as an alternative forage for dairy cows. Animal 5: Basu, S. K., Acharya, S. N. and Thomas, J. E Genetic improvement of fenugreek (Trigonella foenum-graecum L.) through EMS induced mutation breeding for higher seed yield under western Canada prairie conditions. Euphytica 160: Canadian Council on Animal Care Guide to the care and use of experimental animals, CCAC, Ottawa, ON. Hedqvist, H. and Udén, P Measurement of soluble protein degredation in the rumen. Anim. Feed Sci. Technol. 126: 121. Jones, C. M., Heinrichs, A. J., Roth, G. W. and Ishler, V. A From harvest to feed: Understanding silage management. Pennsylvania State University, University Park, PA. Kennelly, J. J Alberta Agricultural Research Institute Matching Grant Program, Project 95M712. High quality whole crop cereal grain silage as a forage for cattle. Alberta Agriculture, Edmonton, AB. Kennelly, J. J., deboer, G., Robinson, P. H., Song, M. K., Murphy, J. J. and Khorasani, G. R Farming for the future: Final Report, Project Factors influencing the efficiency of protein (amino acids) and energy utilization by dairy cows. Alberta Agriculture, Edmonton, AB. Khorasani, G. R., Okine, E. K. and Kennelly, J. J Effects of forage source and amount of concentrate on rumen and intestinal digestion of nutrients in late-lactation cows. J. Dairy. Sci. 84: Macaulay, A Bale silage. [Online] Available: www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex6134. [2008 Oct. 16].

7 DOEPEL ET AL. * DIGESTIBILITY OF FENUGREEK HAYLAGE IN RUMINANTS 217 McCormick, K., Norton, R. and Eagles, H. A Fenugreek has a role in south-eastern Australian farming systems. Proceedings of Groundbreaking stuff, 13th Annual Agronomy Conference, Perth, Australia. McDonald, I A revised model for the estimation of protein degradability in the rumen. J. Agric. Sci. 96: Mir, P. S., Mir, Z. and Townley-Smith, L Comparison of the nutrient content and in situ degradability of fenugreek (Trigonella foenum-graecum) and alfalfa hays. Can. J. Anim. Sci. 73: Mir, Z., Acharya, S. N., Mir, P. S., Taylor, W. G., Zaman, M. S., Mears, G. J. and Goonewardene, L. A Nutrient composition, in vitro gas production and digestibility of fenugreek (Trigonella foenum-graecum) and alfalfa forages. Can. J. Anim. Sci. 77: Montgomery, J The potential of fenugreek (Trigonella foenum graecum) as a forage for dairy herds in central Alberta. M.Sc. dissertation. University of Alberta, Edmonton, AB. Mustafa, A. F., Christensen, D. A. and McKinnon, J. J In vitro and in situ evaluation of fenugreek (Trigonella foenum-graecum) hay and straw. Can. J. Anim. Sci. 76: SAS Institute, Inc SAS user s guide. Version 9.1. SAS Institute, Inc., Cary, NC. Trˇináctý, J., Homolka, P., Zeman, L. and Richter, M Whole tract and post ruminal digestibility determined by in situ ruminal, intestinal mobile nylon bag and whole tract nylon capsule methods. Anim. Feed Sci. Technol. 106: 5967.