Yeast-fermented cassava chip protein (YEFECAP) concentrate for lactating dairy cows fed on urea–lime treated rice straw

Livestock Science 139 (2011) 258–263

Contents lists available at ScienceDirect

Livestock Science j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / l i v s c i

Yeast-fermented cassava chip protein (YEFECAP) concentrate for lactating dairy cows fed on urea–lime treated rice straw M. Wanapat ⁎, S. Polyorach, V. Chanthakhoun, N. Sornsongnern Tropical Feed Resources Research and Development Center (TROFREC), Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand

a r t i c l e

i n f o

Article history: Received 19 October 2010 Received in revised form 24 January 2011 Accepted 26 January 2011

Keywords: Urea–lime treated rice straw Yeast Rumen fermentation YEFECAP Protein Lactating dairy cows

a b s t r a c t The objective of this study was to study the effect of YEFECAP (yeast-fermented cassava chip) in replacing soybean meal (SBM) in concentrate mixtures. Four, early lactating (30 ± 13 day-inmilk) Holstein Friesian crossbred cows (50 × 50; HF × Native Thai cattle) were randomly assigned according to a 4 × 4 Latin square design to receive 4 dietary treatments (4 replacement levels of SBM by YEFECAP at 0, 33, 67 and 100% CP in concentrates). Cows were offered concentrate mixtures according to concentrate:milk ratio at 1:2 Urea (2%)–lime (2%) treated rice straw was a roughage source and fed ad libitum. Measurements of feed intake and collection of feeds, feed refusals, feces, rumen fluid, and blood samples were taken. As a result of this experiment, it was found that, pH values in the rumen were linearly (P b 0.01) increased when increasing replacement levels of SBM by YEFECAP while ruminal NH3–N concentrations were not significantly different among treatments (P N 0.05). BUN and MUN were linearly decreased (P b 0.01) when increasing YEFECAP level. Total VFA and propionic acid (C3) were linearly increased (P b 0.05) when increasing YEFECAP level and were highest at 100% of replacement, while butyric acid (C4) and acetic acid (C2) were not significantly different among treatments (P N 0.05), hence, proportion of C2/C3 were linearly decreased. Population of bacteria and fungi were linearly increased (P b 0.01), especially the population of total viable bacteria, cellulolytic bacteria, amylolytic bacteria and proteolytic bacteria. Dry matter intake and organic matter digestibilities were linearly increased (P b 0.05) by YEFECAP levels. Moreover, increasing YEFECAP level was closely associated with linearly increased (P b 0.01) in milk yield, milk fat and milk protein. Based on this experiment, it could be concluded that YEFECAP can fully replace SBM in concentrate mixtures for milking dairy cows on enhancing rumen fermentation, dry matter intake, nutrient digestibility, milk yield and compositions. © 2011 Elsevier B.V. All rights reserved.

1. Introduction Feed resources are very important for livestock production, especially during the dry season in the tropical area. The scarcity of feed has been critically exerting in terms of quantity and quality, particularly protein sources which result in low productivity. Rice straw is the main cropresidue which farmers usually store for use as ruminant feed in tropical areas, especially in Asia. However, rice straw is low ⁎ Corresponding author. Tel./fax: +66 4320 2368. E-mail address: [email protected] (M. Wanapat). 1871-1413/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.livsci.2011.01.016

in nutritive value with low level of protein (2–5%DM), high fiber and lignin content (NDF N 50%), low DM digestibility (b65%) thus resulting in low voluntary feed intake (1.5–2.0%) (Wanapat et al., 1985). Of the chemical treatment procedures available generally for improving cereal straws, Fadel Elseed et al. (2003) show that when using urea combined with calcium hydroxide, it could improve rumen degradability. Furthermore, Wanapat et al. (2009) suggested that using 2% urea and 2% calcium hydroxide treated rice straw could improve rumen fermentation and milk production. The concentrated alkaline agents can chemically break the ester bonds between lignin and hemicellulose and cellulose, and

M. Wanapat et al. / Livestock Science 139 (2011) 258–263

physically make structural fibers swollen. These effects enable rumen microbes to attack the structural carbohydrates more easily, increasing digestibility, and at the same time increasing palatability of the treated straw. Moreover, Soybean meal has long been used as a prominent source of protein for ruminants especially for dairy cows but the price has been dramatically increased thus, impacting on higher cost of production (Wanapat et al., 2007). Cassava (Manihot esculenta, Crantz) is widely grown in the tropical and sub-tropical areas (Sommart et al., 2000; Wanapat, 2009). Its root is a good source of rumen fermentable carbohydrate and has been used with NPN especially urea in ruminants (Wanapat, 2009). While, dietary yeasts have been widely used as a ruminant feed especially with Saccharomyces cerevisiae since it contained useful nutrients for ruminants especially high lysine composition (8.0 g/100 g of protein) (Yamada and Sgarbieri, 2005). Yeast products are beneficial by enhancing dry matter (DM) intake and overall animal performance in ruminants (Denvev et al., 2007). Boonnop et al. (2009) and Polyorach et al. (2010) reported that yeast-fermented cassava chip (YEFECAP) was prepared and the crude protein of cassava was increased from 3.4 to 32.5% CP in the YEFECAP. Boonnop et al. (2010) further studied the effects of YEFECAP as a protein source replacement of soybean meal in concentrate and found that YEFECAP could fully replace soybean meal in terms of rumen fermentation efficiency and nutrient digestibilities in beef cattle. Nevertheless, YEFECAP has not yet been used as a protein source in lactating dairy cows especially when fed on rice straw. Therefore, the objective of this research was to study the effect of YEFECAP in concentrate mixtures in lactating dairy cows fed on rice straw. 2. Materials and methods 2.1. Preparation of yeast-fermented cassava chip (YEFECAP) YEFECAP preparation was done according to the method of Boonnop et al. (2010) and some details are as follows: ▪ Weigh 20 g of yeast into a flask and add 20 g sugar and 100 ml distilled water, mixed well and incubate at room temperature for 1 h (A). ▪ To prepare medium, weigh and mix well 24 g molasses, 100 ml distilled water, 48 g urea and then adjust pH of medium solution using H2SO4 to achieve final pH 3.5–5 (B). ▪ Mix (A) and (B) at 1:1 ratio then flush with air for 60 h. ▪ After 60 h, transfer yeast medium solution to mix with cassava chip at a ratio of 1 ml:2 g, then dry under shade for 72 h, followed by sun-drying for 48 h. Final product is stored in plastic bag for mixing in the concentrate. 2.2. Animals, diets and experimental design Four, early lactating (30 ± 13day-in-milk) Holstein Friesian (HF) crossbred cows (50 × 50 HF× Thai native cattle) were randomly assigned according to a 4 × 4 Latin square design to receive 4 dietary treatments (4 replacement levels of soybean meal (SBM) by YEFECAP in concentrate mixtures at 0, 33, 67 and 100% ; T1, T2, T3, and T4, respectively). YEFECAP contained 29.7% CP. Each treatment contained 18% CP and 80% TDN. Cows

259

were offered concentrate mixtures according to concentrate: milk yield ratio at 1:2 and urea–lime treated rice straw (ULTRS; 2% urea + 2% lime; Wanapat et al., 2009) was fed ad libitum, twice daily at 0600 and 1600 o'clock after milking. Clean fresh water and mineral blocks were available at all times. The diets were fed for 21 days during each experimental diet, 14 days dry matter feed intake, milk yield were recorded and 7 days for rumen fluid sampling (stomach tube with vacuum pump) and feces collection (rectal sampling). 2.3. Data collection, sampling procedures Feed intake was measured and refusals recorded. Body weights were measured daily during the sampling period prior to feeding. Feeds were sampled daily during the collection period and were composited by period prior to analysis. Feed and fecal samples were collected during the last seven days of each period. Composited samples were dried at 60 °C, ground (1 mm screen using Cyclotech Mill, Tecator), and then analyzed for DM, ash, and CP contents (AOAC, 1997), NDF and ADF (Van Soest et al., 1991) and acid-insoluble ash (AIA). AIA was used to estimate the digestibility of nutrients (Van Keulen and Young, 1977). Milk samples were composited daily, according to yield, for both the a.m. and p.m. milking, preserved with 2-bromo-2 nitropropane-1, 3-dial, and stored at 4 °C until analysis for fat, protein, lactose, total solids, and solids-not-fat content by infrared methods using Milko-Scan 33 (Foss Electric, Hillerod, Demark). Milk urea nitrogen (MUN) was determined using Sigma kits #640 (Sigma Diagnostics, St. Louis, MO). At the end of each period, rumen fluid and jugular blood samples were collected at 0, 3, and 6 h after feeding. Approximately 200 ml of rumen fluid was taken from the rumen by a stomach tube connected with a vacuum pump at each time at the end of each period. Rumen fluid was immediately measured for pH and temperature (Hanna Instruments HI 8424 microcomputer, Singapore) after withdrawal. Rumen fluid samples were then filtered through 4 layers of cheesecloth. Samples were divided into 3 portions; 1 portion was used for NH3–N analysis with 5 ml of 1 M H2SO4 added to 45 ml of rumen fluid. The mixture was centrifuged at 16,000 ×g for 15 min, and the supernatant was stored at −20 °C before NH3–N analysis using the Kjeltech Auto 1030 Analyzer and VFA analysis using HPLC. The HPLCsystem consisted of a Shimadzu VP SERIES with SpD10A detector and WINCHROM software. A 3.9 mm × 300 mm stainless-steel column, packed with ReproGel H and a precolumn, packed with the same material were used. The mobile phase consisted of 10 mM H2SO4 (pH 2.5) and the flow rate was 0.8 ml/min. The UV detector (at 210 nm) was employed for quantification. The UV–Visible spectra were recorded at the peak maxima and were corrected for the solvent background. The results were determined, using the standard volatile acids (Merck, India) as control. A second portion was fixed with 10% formalin solution in sterilized 0.9% saline solution. The total direct counts of bacteria, protozoa, and fungal zoospores were made by the methods of Galyean (1989) based on the use of a hemocytometer (Boeco, Hamburg, Germany). The third was cultured for groups of bacteria using a roll-tube technique (Hungate, 1969) for identifying bacteria groups (cellulolytic, proteolytic, amylolytic, and total viable count bacteria). A blood sample (about 10 ml) was collected from a jugular vein (at the same time as rumen fluid sampling) into tubes containing

260

M. Wanapat et al. / Livestock Science 139 (2011) 258–263

12 mg of EDTA, and plasma was separated by centrifugation at 500 ×g for 10 min and stored at −20 °C until analysis of blood urea N. 2.4. Statistical analysis The data were analyzed in a 4 × 4 Latin square design by analysis of variance run in the GLM procedure of SAS (SAS Institute Inc., 1998). Data were analyzed using the model Yijk = μ + Mi + Aj + Pk + εijk where Yijk is the observation from animal j, receiving diet i, in period k; μ, the overall mean, Mi, replacement levels (i = 1, 2, 3, 4), Aj, the effect of animal (j = 1, 2, 3, 4), Pk, the effect of period (k = 1, 2, 3, 4), and εijk the residual effect. The results are presented as mean values and standard error of the means. Differences between treatment means were determined by Duncan's New Multiple Range Test (Steel and Torrie, 1980). Treatments trends were compared by using orthogonal polynomials. Differences among means with P b 0.05 were accepted as representing statistically significant differences. 3. Results and discussion 3.1. Chemical composition of feeds Feed ingredients and their chemical composition as well as respective concentrate mixtures are presented in Table 1. The crude protein content of YEFECAP and ULTRS were 29.7 and 5.6%, respectively. These values were similar to those earlier reported by Boonnop et al. (2009) and Wanapat et al. (2009), though slightly lower. Higher of CP contents of the products could be attributed by time and temperature of the treatments, as well as sample container during treatment period. The CP content of all four concentrates were similar

Table 1 Feed ingredients and chemical composition of dietary treatments used in the experiment. Item

Treatment a T1

Ingredient Cassava chip Rice bran YEEFECAP Soybean meal Molasses Urea Mineral premix Sulfur Salt Chemical composition (% of dry matter) DM OM CP EE NDF ADF

64.9 8.5 0.0 19.5 2.3 2.3 1.0 0.5 1.0

84.7 92.4 18.1 2.3 15.8 7.5

T2

T3

% DM 63.3 59.9 8.5 8.2 7.1 16.9 14.3 8.3 2.0 2.0 2.4 2.3 1.0 1.0 0.5 0.5 1.0 1.0

85.4 93.1 18 2.9 15.2 7.3

86.7 92.4 17.9 3.1 14.7 6.9

YEFECAP

ULTRS

– – – – – – – – –

– – – – – – – – –

T4 57 8.1 28 0.0 2.0 2.4 1.0 0.5 1.0

85.1 93.5 17.9 3.5 14.3 6.8

86.9 95.9 29.7 3.8 7.6 4.9

(18% CP) while NDF and ADF tended to be slightly decreased when level of replacement increased. It should be notable that relatively higher cassava chip was used in all concentrate mixtures. As reported by Wanapat and Khampa (2007) that cassava chip was a good source of rumen fermentable carbohydrate and was efficient when used with urea as a NPN source for efficient microbial protein synthesis. 3.2. Rumen microorganism populations Table 2 shows data on rumen microorganism population. Increasing level of YEFECAP in the concentrate mixtures linearly increased population of bacterial and fungal zoospores in the rumen while protozoa were not changed. The highest populations were found in 100% YEFECAP replacement. Furthermore, replacement level of YEFECAP clearly influenced on rumen total viable bacteria as well as cellulolytic, amylolytic and proteolytic bacteria. The increases could be attributed by the quality of YEFECAP and its ability in improving rumen environment enabling these microbes to grow favourably. These results agree with Mosoni et al. (2007) who reported that proportions of 16S ribosomal RNA of the three main cellulolytic bacterial species (F. succinogenes, R. albus, and R. flavefaciens) increased in the rumen of sheep fed with yeast. Additional S. cerevisiae leads to increased germination of zoospores from a rumen fungal strain of Neocallimastix frontalis as shown in in vitro study (Chaucheyras et al., 1995). Denvev et al. (2007) reported that yeast culture could consume oxygen in rumen fluid that enters the rumen by coating with feed particles. Yeast culture in addition could provide some of the important nutrients and co-factors (vitamins B) to ruminal microflora. 3.3. Characteristics of ruminal fermentation and blood metabolites Higher ruminal pH were found when increasing replacement level of YFFECAP (P b 0.01) while BUN and MUN concentrations were significantly reduced. These results could be reflected by effect of YEFECAP in improving higher ruminal pH, maintaining NH3–N, while reducing BUN concentrations. The high level of CP of YEFECAP and good amino acid profile especially lysine and/or other unknown factors contained in Table 2 Effect of YEFECAP as a protein source in concentrate on ruminal bacteria, protozoa, fungi population, total viable, amylolytic, proteolytic and cellulolytic bacteria in milking dairy cows. Item

Total direct count, cells/ml Bacteria, × 109 Protozoa, × 105 Fungal zoospores, × 105 Ruminal bacteria group, CFU/ml Total viable bacteria, × 109 Cellulolytic bacteria, × 108 Amylolytic bacteria, × 107 Proteolytic bacteria, × 107

51.2 83.7 5.6 1.3 76.3 57.9

a Level of soybean meal (SBM) replacement by YEFECAP: at 0% (T1), 33% (T2), 67% (T3), 100% (T4), DM = dry matter; OM = organic matter; CP = crude protein; NDF = neutral-detergent fiber; ADF = acid-detergent fiber, EE = ether extract, YEFECAP = yeast-fermented cassava chip protein, ULTRS = urea–lime treated rice straw.

1

Treatments1

SEM

T1

T2

T3

T4

5.8 6.0 2.6

6.8 5.3 4.0

7.7 5.1 4.8

8.7 4.7 5.8

5.1 2.5 3.7 4.4

7.3 5.1 5.1 5.8

8.5 6.5 5.8 6.4

10.2 9.0 6.4 7.4

Contrasts2 L

Q

C

0.44 0.47 0.52

** ns **

ns ns ns

ns ns ns

0.94 0.83 0.31 0.45

** ** ** **

ns ns ns ns

ns ns ns ns

Level of replacement of soybean meal (SBM) by YEFECAP: at 0% (T1), 33% (T2), 67% (T3), 100% (T4), 2L = linear, Q = quadratic, cubic, SEM = standard error of the means, **P b 0.01, ns = non-significance.

M. Wanapat et al. / Livestock Science 139 (2011) 258–263

YEFECAP may have been responsible in the improvements. Ruminal NH3–N in this study were 15.2 to 16.0 mg/100 ml and were close to those previously reported by Church and Santos (1981) and Wanapat and Pimpa (1999). However, Leng (1990) reported the values 15–30 mg/100 ml of NH3–N will support the microbial growth in the tropical conditions. Hristov et al. (2010) presented that live yeast would enhance microbial growth and decreased N loss with adequate dietary balance between soluble N and carbohydrate supply. Incorporation of ammonia into microbial protein was enhanced due to supplementation of yeast which was confirmed by greater microbial yield and microbial true protein reaching the duodenum (Erasmus, 1991). Erasmus et al. (1992) reported higher flow of non-ammonia nitrogen (NAN), microbial-N and dietary-N to the duodenum by addition of yeast culture in the diet of lactating dairy cows. Changes in the dietary factors will alter NH3 concentration in the rumen (Ørskov, 1982). Furthermore, higher rumen pH also impacted on higher nutrient digestibilities essentially on the fibrous fraction digestibilities as shown in Tables 3 and 4 and agreed with reports of Jouany (2006), and Calsamiglia et al. (2008). Fermentation endproducts especially volatile fatty acids (VFA) as well as individually VFA including those of propionate (C3) and proportion of C2/C3 were significantly enhanced as influenced by higher level of YEFECAP replacement and were highest at 100% full replacement. Total VFA and propionate production were significantly increased when YEFECAP replacement level increased and were highest in the 100% replacement group. As a consequence, acetate to propionate ratio was remarkably reduced from 2.9 to 2.4 in the non-YEFECAP and the 100% YEFECAP replacement group, respectively. As reported by Orskov (1987) and Preston and Leng (1987) that propionate was an essential glucogenic compound and synthezed via gluconeogenesis in the liver of the ruminants and is highly required during lactation. Moreover, the more rumen balanced, the higher propionate production would be produced (Wanapat, 2000). Under this study, YEFECAP was shown as a good source, Table 3 Effect of YEFECAP as a protein source in concentrate on rumen ecology, fermentation characteristics and blood urea nitrogen (BUN) in milking dairy cows. Item

Treatments a

SEM Contrasts b

T1

T2

T3

T4

Ruminal temperature (°C) Ruminal pH NH3–N, mg/100 ml BUN, mg/100 ml Molar proportion of VFA (mol/100 mol) Total VFA, mmol/l Acetate (C2),% Propionate (C3),% Butyrate (C4), % C2/C3 ratio

39.1

39.3

39.4

39.5 0.23

ns

6.4 17.0 16.3

6.5 16.7 14.2

6.6 16.2 13.7

6.7 0.01 15.9 0.86 13.3 0.6

ns ⁎

87.1 100.3 101.9 112.7 4.67 64.5 63.9 63.5 62.5 1.50 22.3 23.5 25.7 26.2 0.90 13.2 12.6 10.8 11.3 1.9 2.9 2.8 2.5 2.4 0.15

L

Q

C

Table 4 Effect of YEFECAP as a protein source in concentrate on feed intake and digestibility of nutrients in milking dairy cows. Item

Treatments a T1

T2

SEM Contrasts b T3

T4

ULTRS DM intake kg/day 5.7 5.9 7.0 7.9 %BW daily 1.3 1.3 1.6 1.85 0.75 59.8 61.1 73.4 83.7 g/kg BW daily Concentrates intake kg/day 5.5 5.8 5.8 5.9 %BW daily 1.2 1.4 1.3 1.4 g/kg BW 0 . 7 5 56.9 61.6 60.6 62.3 daily Total DM intake kg/day 11.2 11.7 12.8 13.9 %BW daily 2.6 2.7 3.0 3.2 g/kg BW 0 . 7 5 116.7 122.7 134 145.9 daily Nutrient intake, kg/day DM 7.6 8.0 8.6 9.1 OM 9.9 10.4 11.2 12.2 CP 1.3 1.4 1.4 1.5 EE 0.20 0.25 0.27 0.31 NDF 5.2 5.4 6.2 6.9 ADF 3.7 3.8 4.5 5.0 Apparent digestibility (%) DM 61.9 69.1 72.1 71.1 OM 68.5 72.5 73.8 74.5 CP 64.6 68.7 71.0 70.2 EE 62.7 69.2 69.7 71.5 NDF 63.8 65.7 67.8 67.6 ADF 61.5 63.8 64.4 65.5

L

Q

C

0.26 0.14 5.28

⁎⁎ ns ns ⁎ ns ns ⁎ ns ns

0.41 0.16 5.98

ns ns ns

0.41 0.25 9.63

ns ns

0.33 0.37 0.07 0.01 0.18 0.14

⁎ ns ns ⁎⁎ ns ns ns ns ns ⁎⁎ ns ns ⁎⁎ ns ns ⁎⁎ ns ns

1.89 0.95 1.17 1.56 0.85 1.29

⁎ ⁎⁎ ⁎ ⁎⁎ ⁎

ns ns ns ns ns ns

⁎⁎ ns ns ns ns ns ns

ns

ns ns ns ns ns ns

ns ns ns ns ns ns

ns = non-significance. a Level of replacement of soybean meal (SBM) by YEFECAP: at 0% (T1), 33% (T2), 67% (T3), 100% (T4). b L = linear, Q = quadratic, C = cubic, SEM = standard error of the means. ⁎ P b 0.05. ⁎⁎ P b 0.01.

not only as a protein but also as a carbohydrate source and impacted on the such results. The enhancement in propionate concentration, along with significant increases in nutrient digestibilities (OM, CP, EE, and NDF) (Table 4) as influenced by higher level of YEFECAP replacements in the concentrate mixtures have a great impact on higher milk yield (13.7 to 17.1 4% kg/hd/d of FCM) as well as fat and protein percentages (Table 5).

ns ns

⁎⁎ ns ns ns ns ns ns

⁎⁎ ns ns ns ns ns ⁎ ns

ns ⁎

261

ns ns ns ns ns

ns = non-significance. a Level of replacement of soybean meal (SBM) by YEFECAP: at 0% (T1), 33% (T2), 67% (T3), 100% (T4), NH3–N = ammonia nitrogen, BUN = blood urea nitrogen. b L = linear, Q = quadratic, C = cubic, SEM = standard error of the means. ⁎ P b 0.05. ⁎⁎ P b 0.01.

3.4. Effect on feed intake, nutrient intake and digestibility Table 4 shows data of feed intakes and nutrient digestibility as affected by YEFECAP replacement levels. The highest DM intakes of ULTRS were found in the 100% YEFECAP replacement treatment. As shown all nutrient digestibilities except ADF were significantly improve by higher level of YEFECAP replacement particularly those of organic matter and fat digestibilities. Thus, higher intakes could be attributed by higher digestibilities. Moallem et al. (2009) showed that DMI and milk yield in yeast supplemented group were 2.5% and 4.1% greater than those in control group, respectively. Moreover, Wohlt et al. (1991) reported that supplementation of S. cerevisiae increased the digestibility of protein cellulose, fibre (Gomez-Alarcon et al., 1990), NDF (Plata et al., 1994 ), DM (Gomez-Alarcon et al.,

262

M. Wanapat et al. / Livestock Science 139 (2011) 258–263

Table 5 Effect of YEFECAP as a protein source in concentrate mixtures on milk production, milk composition and economic return. Item

Treatments a

Milk yield, kg/day 4% FCM, kg/day Milk composition, % Fat Protein Lactose Solids-not-fat Total solids Milk urea nitrogen (MUN), mg/100 ml Economic return, $US/hd/d Feed cost Milk sale Profit

13.5 14.0 14.5 15.0 0.27 13.7 14.7 15.9 17.1 0.49

T1

T2

SEM Contrasts b T3

T4

4.0 4.1 4.5 4.7 3.2 3.3 3.4 3.5 4.5 4.6 4.6 4.7 8.2 8.4 8.4 8.5 12.3 12.7 12.8 13 14.8 12.5 12.3 12.0

2.5 9.5 7.0

L

Q

C

⁎⁎ ns ns ⁎⁎ ns ns

0.17 ⁎⁎ 0.06 ⁎⁎ 0.07 ns 0.29 ns 0.78 ns 0.58 ⁎

ns ns ns ns ns ns

ns ns ns ns ns ns

2.6 2.6 2.7 0.14 ns ns ns 9.8 10.2 10.5 0.19 ⁎⁎ ns ns 7.2 7.6 7.8 0.16 ⁎⁎ ns ns

ns = non-significance. a Level of replacement of soybean meal (SBM) by YEFECAP: at 0% (T1), 33% (T2), 67% (T3), 100% (T4), Feed cost: concentrate T1 = 0.38 $US/kg, T2 = 0.37 $US/kg, T3 = 0.37 $US/kg, T4 = 0.35 $US/kg, ULRS = 0.07 $US/kg, Milk price = 0.7 $US/kg. b L = linear, Q = quadratic, C = cubic, SEM = standard error of the means. ⁎ P b 0.05. ⁎⁎ P b 0.01.

1987) and ADF (Kim et al., 1992). Similarly, Weidmeier et al. (1987) found that supplementation of yeast culture increased hemicellulose and CP digestibility in ruminants. 3.5. Milk production and milk composition Milk yield and milk compositions are presented in Table 5. Increased milk yield were obtained in these dairy crossbreds ranging from 13.5 to 15.0 kg/hd/d. Milk yield were remarkably enhanced when YEFECAP level increased in the concentrates, and were highest in 100% replacement level (15.0 kg/hd/d). In addition, milk fat and milk protein percentages also increased, thus 4% fat-corrected milk were greatly enhanced from 13.7 to 17.1 kg/hd/d for 0 and 100% YEFECAP replacement levels, respectively. Milk urea nitrogen (MUN) were 14.8 mg/100 ml in 0% and 12.0 mg/100 ml in 100% YEFECAP replacement level, respectively. This could be interpreted that YEFECAP as a protein source in the concentrate mixtures could provide good level of protein and a better balance with energy source as compared with soybean meal (0% replacement of YEFECAP, T1). Fully replacement of soybean meal with YEFECAP resulted in significantly higher milk yield and milk compositions. This result is in agreement with Formigoni et al. (2005) who reported that Yea-Sacc®1026 improved DMI significantly and milk yield of dairy cows. Yea-Sacc ®1026 also improved significantly the composition of cow's milk, including fat (Pb 0.01) and protein (Pb 0.05) content. Alshaikh et al. (2002) also showed that feeding yeast culture in lactating Holstein cows at 50 g/hd/d increased milk yield, fat, protein, lactose, total solids and solids-not-fat percentages than those in control. Moreover, Abd El-Ghani (2004) reported that lactating Zaraibi goats supplemented with yeast culture had higher (Pb 0.05) milk yield, and milk composition in Zaraibi goats. Higher flow of amino acids especially methionine and lysine to lower-gut were found by yeast supplementation as reported by Putnam et al.

(1997). Furthermore, based on simple economic determination of concentrate supplements and milk sales, it was clearly demonstrated that the highest profitable return was obtained when YEFECAP fully replaced SBM (T4) (Table 5). 4. Conclusions and recommendations Based on this study it could be concluded that YEFECAP can fully replace SBM in concentrate for dairy cows and improve rumen fermentation, dry matter intake, nutrient digestibility, milk production and composition and economical return in early lactating dairy crossbreds. However, further research is required to elucidate the possible mechanisms in the rumen of feeding YEFECAP in the diets of lactating dairy cows especially fed on low-quality roughages such as rice straw. Acknowledgements The authors would like to express their most sincere thanks to all who have assisted and supported the research in this study, particularly the Tropical Feed Resources Research and Development Center (TROFREC), Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand, the Royal Golden Jubilee Ph. D. Scholarship Program, and Dairy Farming Promotion Organization of Thailand (DPO), Northeast Region, for their active collaborations and support. References Abd El-Ghani, A.A., 2004. Influence of diet supplementation with yeast culture (Saccharomyces cerevisiae) on performance of Zaraibi goats. Small Rumin. Res. 52, 223–229. Alshaikh, M.A., Alsiadi, M.Y., Zahran, S.M., Mograwer, H.H., Aalshowime, T.A., 2002. Effect of feeding yeast culture from different sources on the performance of lactating Holstein cows in Saudi Arabia. Asian-Aust. J. Anim. Sci. 15, 352–356. AOAC, 1997. Official Methods of Analysis, 16th ed. Association of Official Analytical Chemists, Gaithersburg, MD. Boonnop, K., Wanapat, M., Nontaso, N., Wanapat, S., 2009. Enriching nutritive value of cassava root by yeast fermentation. Sci. Agric. 66, 616–620. Boonnop, K., Wanapat, M., Navanukraw, C., 2010. Replacement of soybean meal by yeast fermented-cassava chip protein (YEFECAP) in concentrate diets fed on rumen fermentation, microbial population and nutrient digestibilities in ruminants. J. Anim. Vet. Adv. 9, 1727–1734. Calsamiglia, S., Cardozo, P.W., Ferret, A., Bach, A., 2008. Changes in rumen microbial fermentation are due to a combined effect of type of diet and pH. J. Anim. Sci. 86, 702–711. Chaucheyras, F., Fonty, G., Bertin, G., Salmon, J.M., Gouet, P., 1995. Effects of a strain of Saccharomyces cerevisiae (Levu-cell SC), a microbial additive for ruminants, on lactate metabolism in vitro. Can. J. Microbiol. 42, 927–933. Church, D.C., Santos, A., 1981. Effect of graded levels of soybean meal and of a nonprotein nitrogen–molasses supplement on consumption and digestibility of wheat straw. J. Anim. Sci. 53, 1609–1615. Denvev, S.A., Peeva, T., Redulova, P., Stancheva, N., Staykova, G., Beev, G., Todorova, P., Tchobanova, S., 2007. Yeast cultures in ruminant nutrition. Bulg. J. Agric. Sci. 13, 357–374. Erasmus, L.J., 1991. The importance of the duodenal amino acid profile for dairy cows and the impact of changes in these profiles following the use of Yea-Sacc®1026. Feed Compounder 11, 24–29. Erasmus, L.J., Botha, P.M., Kistner, A., 1992. Effect of yeast culture supplement on production, rumen fermentation and duodenal nitrogen flow in dairy cows. J. Dairy Sci. 75, 3056. Fadel Elseed, A.M.A., Sekine, J., Hishinuma, M., Hamana, K., 2003. Effects of ammonia, urea plus calcium hydroxide and animal urine treatments on chemical composition and in sacco degradability of rice straw. Asian-Aus. J. Anim. Sci. 16, 368–373. Formigoni, A., Pezzil, P., Tassinari, M., Bertin, G., Andrieu, S., 2005. Effect of yeast culture (Yea-Sacc®1026) supplementation on Italian dairy cow performance. Proceedings of the 21st Annual Symposium Nutritional Biotechnology in the Feed and Food Industries. May 23–25, 2005. Lexington, KY, USA, p. 125.

M. Wanapat et al. / Livestock Science 139 (2011) 258–263 Galyean, M., 1989. Laboratory Procedure in Animal Nutrition Research. Department of Animal and Range Sciences, New Mexico State University, USA, pp. 107–122. Gomez-Alarcon, R., Dubas, C., Huber, J.T., 1987. Effect of Aspergillus oryzae (Amaferm) and yeast on feed utilization by Holstein cows. J. Dairy Sci. 70 (Suppl. I), 218. Gomez-Alarcon, R.A., Dudas, C., Huber, J.T., 1990. Influence of cultures of Aspergillus oryazae on rumen and total tract digestibility of dietary components. J. Dairy Sci. 73, 703–709. Hristov, A.N., Varga, G., Cassidy, T., Long, M., Heyler, K., Karnati, S.K.R., Corl, B., Hovde, C.J., Yoon, I., 2010. Effect of Saccharomyces cerevisiae fermentation product on ruminal fermentation and nutrient utilization in dairy cows. J. Dairy Sci. 93, 682–692. Hungate, R.E., 1969. A roll tube method for cultivation of strict anaerobes. In: Norris, J.R., Ribbons, D.W. (Eds.), Method in Microbiology. Academic Press, New York, pp. 117–131. Jouany, J.P., 2006. Optimizing rumen functions in the close-up transition period and early lactation to drive dry matter intake and energy balance in cows. Anim. Reprod. Sci. 96, 250–264. Kim, D.Y., Figueroa, M.R., Dawson, D.P., Batallas, C.E., Arambel, M.J., Walters, J.L., 1992. Efficacy of supplemental viable yeast culture with or without Aspergillus oryzae on nutrient digestibility and milk production in early to midlactating dairy cows. J. Dairy Sci. 75 (Suppl. I), 206. Leng, R.A., 1990. Factors affecting the utilization of “poor-quality” forages by ruminants particularly under tropical conditions. Nutr. Res. Rev. 3, 277–303. Moallem, U., Lehrer, H., Livshitz, L., Zachut, M., Yakoby, S., 2009. The effects of live yeast supplementation to dairy cows during the hot season on production, feed efficiency, and digestibility. J. Dairy Sci. 92, 343–351. Mosoni, P., Chaucheyras-Durand, F., Béra-Maillet, C., Forano, E., 2007. Quantification by real-time PCR of cellulolytic bacteria in the rumen of sheep after supplementation of a forage diet with readily fermentable carbohydrates: effect of a yeast additive. Appl. Microbiol. 103, 2676–2685. Orskov, E.R., 1987. Feeding of Ruminant Livestock, Principle and Practice. Chalcombe Publications, Marlow, England. 90 pp. Ørskov, E.R., 1982. Protein Nutrition in Ruminants. Academic Press, New York, USA. 160 pp. Plata, P.F., Nendoza, M.G.D., Barcena-Gama, J.R., Gonzalez, M.S., 1994. Effect of yeast culture (Saccharomyces cerevisiae) on neutral detergent fibre digestion in steers fed oat straw based diets. Anim. Feed Sci. Technol. 49, 203–210. Polyorach, S., Wanapat, M., Sornsongnern, N., 2010. Effect of yeastfermented cassava chip protein (YEFECAP) in concentrate of lactating dairy cows. In: Proceedings of the 14th Animal Science Congress of the Asian-Australasian Association of Animal Production Societies (AAAP), vol. 3, August 23–26, 2010. National Pingtung University of Science and Technology, Pingtung, Taiwan, Republic of China, pp. 304–307. Preston, T.R., Leng, R.A., 1987. Matching Ruminant Production Systems with Available Resources in the Tropics and Subtropics. Penambul Books, Armidale, N.S.W., Australia. 245 pp.

263

Putnam, D.E., Schwab, C.G., Socha, M.T., Whitehouse, N.L., Kierstead, N.A., Garthwaite, B.D., 1997. Effect of yeast culture in the diets of early lactation dairy cows on ruminal fermentation and passage of nitrogen fractions and amino acids to the small intestine. J. Dairy Sci. 80, 374–384. SAS, 1998. User's Guide: Statistic, Version 6, 12th ed. SAS Inst. Inc., Cary, NC. Sommart, K., Wanapat, M., Rowlinson, P., Parker, D.S., Climee, P., Panishying, S., 2000. The Use of Cassava Chips as an Energy Source for Lactating Dairy Cows Fed with Rice Straw. Asian-Aust. J. Anim. Sci. 13, 1094–1101. Steel, R.G.D., Torrie, J.H., 1980. Principles and Procedures of Statistics. McGraw Hill Book Co, New York, USA. Van Keulen, J., Young, B.A., 1977. Evaluation of acid insoluble ash as a neutral marker in ruminant digestibility studies. J. Anim. Sci. 44, 282–287. Van Soest, P.J., Robertson, J.B., Lewis, B.A., 1991. Methods for dietary fiber neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74, 3583–3597. Wanapat, M., 2000. Rumen manipulation to increase the efficient use of local feed resources and productivity of ruminants in the tropics. Asian-Aust. J. Anim. Sci. 13, 59–67. Wanapat, M., 2009. Potential uses of local feed resources for ruminants. Trop. Anim. Health Prod. 41, 1035–1049. Wanapat, M., Khampa, S., 2007. Effect of levels of supplementation of concentrate containing high levels of cassava chip on rumen ecology, microbial N supply and digestibility of nutrients in beef cattle. Asian-Aust. J. Anim. Sci. 20, 75–82. Wanapat, M., Pimpa, O., 1999. Effect of ruminal NH3–N levels on ruminal fermentation, purine derivatives, digestibility and rice straw intake in swamp buffaloes. Asian-Aust. J. Anim. Sci. 12, 904–907. Wanapat, M., Sundstol, F., Garmo, T.H., 1985. A comparison of alkali treatment methods to improve the nutritive value of straw. I. Digestibility and metabolizability. Anim. Feed Sci. Technol. 12, 295–309. Wanapat, M., Promkot, C., Khumpa, S., 2007. Supplementation of cassava hay as a protein replacement for soybean meal in concentrate supplement for dairy cows. Pak. J. Nutr. 6, 68–71. Wanapat, M., Polyorach, S., Boonnop, K., Mapato, C., Cherdthong, A., 2009. Effects of treating rice straw with urea or urea and calcium hydroxide upon intake, digestibility, rumen fermentation and milk yield of dairy cows. Livest. Sci. 25, 238–243. Weidmeier, R.D., Arambel, M.J., Walters, J.L., 1987. Effect of yeast culture and Aspergillus oryzae fermentation extract on ruminal characteristics and nutrient digestibility. J. Dairy Sci. 70, 2063–2071. Wohlt, J.E., Finkelstein, A.D., Ghung, C.H., 1991. Yeast culture to improve intake, nutrient digestibility and performance by dairy cattle during early lactation. J. Dairy Sci. 74, 1395–1400. Yamada, A.E., Sgarbieri, V.C., 2005. Yeast (Saccharomyces cerevisiae) protein concentrate: preparation, chemical composition, and nutritional and functional properties. J. Agric. Food Chem. 53, 3931–3936.