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to the addition of 30% lucerne fodder (II cut) in TMR–2. Thus, the saponins .... mustard cake 12%, wheat bran 20%, deoiled rice bran 11%, urea 0.8%, mineral ...

Indian Journal of Animal Sciences 79 (4): 416–421, April 2009

Effect of lucerne (Medicago sativa) fodder supplementation on nutrient utilization and enteric methane emission in male buffalo calves fed on wheat straw based total mixed ration P K MALIK1 and K K SINGHAL2

National Dairy Research Institute, Karnal, Haryana 132 001 India Received: 5 May 2008; Accepted: 30 October 2008

ABSTRACT Saponin content of lucerne (Medicago sativa) fodder was estimated at 3, viz. I, II and III cuts. Saponin content at II cut (flowering stage) was highest which decreased in the subsequent cut almost to the level of first cut. Male Murrah buffalo calves (6) were initially fed on wheat straw based total mixed ration (TMR–1) consisting R: C as 60:40 and data were recorded thereafter, these animals were shifted on isonitrogenous TMR–2 having 30 % incorporation of lucerne fodder (II cut) as source of saponins (2% on DM basis) in TMR–2 replaced wheat straw partially maintained the R: C ratio similar to TMR–1 (60:40). DM intake, nutrient utilization and enteric methane emission were studied on both feeding regimes. DM intake (kg/d) in buffalo calves was higher on TMR–2 than on TMR–1, similarly on uniform basis (kg/100 kg bw) it was also higher on feeding TMR–2. Nutrient digestibility and nitrogen intake on feeding TMR–2 was higher than that on feeding TMR–1, which resulted in higher nitrogen excretion through faeces and urine. Methane emission on feeding TMR–1 and TMR–2 was 18.11 and 12.45 g/kg DMI, respectively, showed a reduction of 32% due to the addition of 30% lucerne fodder (II cut) in TMR–2. Thus, the saponins supplied through lucerne fodder (total intake 29.58 g/d) decreased methane emission in buffalo calves. GE loss in the form of methane was more on feeding TMR–1 (5.73%) than that on TMR–2 (3.93%). The lower loss of GE in form of methane on feeding TMR–2 showed that incorporation of lucerne fodder to straw based ration can increase DMI, nutrient utilization in one hand and mitigate methane emission on another. As production of lucerne fodder is a common and a traditional practice in India, therefore, incorporation of lucerne fodder as a source of protein in total mixed ration seems more practical and promising for the mitigation of methane than the other strategies. Thus, there is urgent need to explore natural feeds and herbs having saponins and safe level of their incorporation in the ration. Key words: Buffalo calves, Lucerne, Methane, Nutrient digestibility, Saponins

India is the harbour of large livestock population (about 1/5th of total), which is quite often fed on the fibrous ration resulting in to large enteric methane emission from ruminants. In India various agencies reported 4.25 Tg (Garg and Shukla 2002) to 10.78 Tg (Singhal and Mohini 2002) emission of methane from livestock annually and among the different contributor cattle stands on the top followed by buffalo, sheep and goat. Concentration wise CO2 in the environment stands on top among the green house gases but its potential to trap the heat is around 40–60 times less than the Methane (Khan et al. 2001). Due to the better and well suited environmental conditions, buffaloes are mainly concentrated in Asia including India 95 million, which seems to be responsible for the large contribution of methane around 2.80 Tg/y to

the pool emited by ruminants. Emission of methane from ruminants due the enteric fermentation represents 6–12% loss (Johnson and Johnson 1995) of dietary energy and this loss is significant particularly in India where feed cost account around 70 % of the total cost of production. Rumen protozoa, which is indirectly involved in methanogenesis by transferring hydrogen to the attached methanogens (Hess et al. 2003) might be targeted for the mitigation of methane emission in ruminants. As the reports, showed that saponins from various sources including plant species like Sapindus saponaria (Thalib et al. 1995) and Yucca schidigera (Wang et al. 2000) decreased methane emission through the reduction in rumen protozoa numbers. Lucerne (Medicago sativa) fodder a fair source of saponins (Klita et al. 1996) and grown traditionally on wide scale in India, might be used for mitigation of methane in ruminants fed without any additional input. Therefore, the study was planned to measure the saponin

Present address: 1 Assistant Professor (Animal Nutrition), Navasari Agricultural University, Navsari , Gujarat 396 450. 2Principal Scientist and Head, Dairy Cattle Nutrition Division. 74

April 2009]

LUCERNE EFFECT ON NUTRIENT UTILIZATION AND METHANE EMISSION IN CALVES

content of lucerne fodder (Mediacgo sativa) at 3 different cuts and also to investigate the effect of lucerne fodder supplementation on nutrient utilization and enteric methane emission in male buffalo calves fed on wheat straw based total mixed ration.

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consisted of maize grain 33%, groundnut cake 20.2%, mustard cake 12%, wheat bran 20%, deoiled rice bran 11%, urea 0.8%, mineral mixture 2% and common salt 1% however, experimental ration (TMR–2) was prepared by mixing wheat straw (30%), lucerne fodder (IInd cut, 30%) and concentrate mixture (40%), which consisted of maize grain 24%, groundnut cake 15%, mustard cake 8%, wheat bran 42%, deoiled rice bran 8%, mineral mixture 2% and common salt 1%. Variation in the composition of concentrate mixture between TMR–1 and TMR–2 was to maintain the isonitrogenity in both rations. Feed, ort and faeces samples of 7 days were pooled for individual animal and then analysed for their proximate principles (AOAC 1995) as well as for fibre fractions (Goering and Van Soest 1970). Urine samples were analysed for N content as per AOAC (1995). Analysis of methane and SF6 in the gas in samples was done in the Environmental Laboratory of Dairy Cattle Nutrition Division by using separate gas chromatograph fitted with flame ionization detector (FID) and electron capture detector (ECD). Methane emission rate (QCH 4 ) was calculated by estimating the ratio of CH4 to SF6 (Johnson et al. 1994) in the samples and known release rate of SF 6 (QSF6). Background methane ((CH4) b) was subtracted from methane concentration in the PVC canister ((CH4) y). The concentration of methane was then calculated by using the formula (Johnson et al. 1994) given below.

MATERIALS AND METHODS Saponin content of lucerne (Mediago sativa) fodder at first, second and third cuts, was estimated (Yosioka et al. 1974). The samples of fodder collected directly from the farm of the institute were chopped into small pieces, and dried in hot air oven at 60±2°C until complete drying and DM in the samples was estimated. Samples were than ground by using appropriate sieve to estimate saponins. For nutrient utilization and enteric methane study, 6 male buffalo calves (b.w. 156.50±1.35 kg), selected from the institute herd, were initially fed on wheat straw and concentrate based total mixed ration (TMR–1) to acclimatize the rumen micro flora to the diet. After 21 days of preliminary feeding, metabolism trial of 7 days duration was conducted thereafter, 4 successful collections of gas sample were done from each animal. The gas samples were than analysed for methane using sulphur hexa fluoride gas technique (Johnson et al. 1994). The availability of buffalo calves in the institute herd at the time of experiment was limited that’s why the same buffalo calves after completing the study on TMR–1 were switched over to the feeding of TMR–2 (composed of wheat straw 30%, lucerne fodder II cut 30% and concentrate mixture 40%) and this was the only reason for the difference in body weight of calves among two groups. The roughage to concentrate ratio in both the TMRs was maintained as 60:40. The feeding of animals was done as per NRC (2001). Animals were kept in well ventilated shed having arrangements for individual feeding. To avoid the external and internal parasites infestation, butox 0.5% (V/V) and albandazole (0.5 mg/kg bw) were used. Chemical composition of different dietary ingredients used for the formulation of total mixed rations are given in Table 1. Concentrate mixture used for the formulation of TMR–1

QCH4=QSE6(CH4) y-(CH4) b)/(SF6)

where, QCH4 , methane release g/d; QSF6, sulphur hexafluoride release rate; (CH4) b, background methane; (CH4) y, methane in sample. The data thus obtained were analysed statistically as per the procedure of Snedecor and Cocharan (1986). RESULTS AND DISCUSSION Saponin Saponin content of lucerne (Medicago sativa) fodder measured at 3 different cuts, viz. I, II and III is given in Table 2. Saponin of lucerne fodder varied between 0.92 to

Table 1. Composition of dietary ingredients used for total mixed ration preparation Ingredients

Wheat straw Lucerne fodder (II cut) Concentrate (TMR–1) Concentrate (TMR–2) Total mixed ration–1 Total mixed ration–2

Composition (% DM basis) DM

OM

CP

EE

NDF

ADF

Ash

90.04 23.18 94.90 95.16 91.40 74.26

93.18 89.42 92.30 93.29 93.42 93.27

3.00 16.20 25.70 15.75 12.08 14.68

1.12 3.20 3.92 3.68 2.04 2.67

76.20 43.64 39.59 34.68 57.64 52.56

58.10 35.83 14.23 13.97 43.26 38.74

6.19 10.58 7.70 6.21 6.58 6.73

TMR–1 consisted of wheat straw 60 parts and concentrate mixture 38 parts, urea 0.80 parts, mineral mixture 0.80 parts and common salt 0.40 parts, R: C ratio of the diet was 60:40. TMR–2 consisted of wheat straw 30 parts, lucerne fodder (II cut) 30 parts and concentrate mixture 28 parts, wheat bran 10.8 parts, mineral mixture 0.80 parts and common salt 0.40 parts, R: C ratio of the diet was 60:40 75

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MALIK AND SINGHAL

Table 3. Effect of lucerne (Medicago sativa) fodder supplementation on dry matter intake and nutrient digestibility in buffalo calves

Table 2. Saponin content (% on DM basis) of lucerne (Medicago sativa) fodder at different cuts Cuts First Second Third Mean

*Saponins (% DM basis)

Range

1.11a±0.04 2.0b±0.05 0.92a±0.05 1.36±0.43

1.16–1.19 1.89–2.18 0.87–1.08

[Indian Journal of Animal Sciences 79 (4)

Attributes

B.W. (kg) DM intake (kg/d) DM intake (kg/100 kg B.w.) Digestibility DM OM EE CP NDF ADF

Values bearing a, b superscripts in a column differ significantly (P