Evaluation of Sorghum Stover Based Complete Rations with Different Roughage

Table 2. Effect of sorghum stover to concentrate ratio on in vitro gas production parameters in Deccani sheep

Roughage : Gas volume IVOMD ME (MJ/

TDOM

MBP

EMBP

Ammonia N

PF

TVFA (meq/l)

concentrate (ml/200mg)

(mg)

kg)

(mg)

(mg)

(%)

(mg/100ml)

100:0

44.33 f

97.53 f

8.45 h

2.97 cd

131.81 h

34.27 d

26.00 cd

19.20 h

25.67 d

90:10

45.67 e

100.47 e

8.73 g

2.94 d

134.07 g

33.60 d

25.06 d

24.00 g

27.00 cd

80:20

46.50 e

102.30 e

8.93 f

3.02 bc

140.43 f

38.13 c

27.15 bc

32.00 f

31.00 c

70:30

48.33 d

106.33 d

9.28 e

3.08 ab

148.99 e

42.66 ab

28.63 ab

36.53 e

35.67 b

60:40

49.17 d

108.17 d

9.50 d

3.12 a

153.36 d

45.19 a

29.47 a

43.20 d

37.67 b

50:50

50.50 c

111.10 c

9.79 c

3.06 ab

154.69 c

43.59 ab

28.18 ab

54.13 c

42.33 a

40:60

52.17 b

114.77 b

10.10 b

3.03 bc

157.81 b

43.05 ab

27.28 bc

59.73 b

42.00 a

30:70

54.50 a

119.90 a

10.51 a

2.97 cd

161.75 a

41.85

25.87 cd

67.20 a

42.33 a

SEM

0.68

1.50

0.14

0.01

2.18

0.90

0.35

3.37

1.40

abcdefgh value bearing different superscripts in a column differ significantly (P<0.01); IVOMD: In vitro organic matte digestibility; ME:

Metabolizable energy; PF: Partitioning factor; TDOM: Total digestible organic matter; MBP: Microbial protein; EMBP: Effective

microbial protein; TVFA: Total volatile fatty acids

RESULTS AND DISCUSSION

proportion, indicating a better nutrient availability for

Gas volume production (ml/200mg) was increased

rumen microorganisms (Mahala and Elseed, 2007). The

(P<0.01) linearly as increasing the concentrate proportion

findings of the present study were in agreement with the

in the sorghum stover based complete diet from 0 to 70

observations that, the gas production was higher (P<0.05)

and these values were ranged from 44.33 to 54.50 (Table

on high energy levels (Chattarjee et al. , 2007). On

2). The higher gas production of rations containing higher

increasing the sugarcane bagasse level in complete feed,

proportion of concentrates might have resulted from the

gas production per unit digestible dry matter (DM) or

increased production of propionate as carbon dioxide is

organic matter (OM) was reduced (Hozhabri and Singhal,

produced when propionate is made by ruminal bacteria via

2006). Further, there was a positive correlation between

the succinate: propionate pathway. In vitro gas production

CP and the rate of gas production and negative correlations

reflects ruminal apparent substrate degradability (Blummel

between neutral detergent fibre (NDF) and acid detergent

and Orskov, 1993) which is defined as the amount of feed

fibre (ADF), and the rate and extent of gas production

fermented to short chain fatty acids and gases (AFRC,

(Nsahlai et al. , 1994 and Larbi et al. , 1998).

1993). A decrease in gas volume was observed as the

Similar trend as that of gas production was also observed

red gram straw level increased in the complete ration

in in vitro organic matter digestibility (IVOMD) and true

by replacing the concentrate proportion (Dutta et al. ,

digestible organic matter (TDOM) (Table 2). Highest

2002 and Baswa Reddy, 2003). The differences in gas

(119.90 mg) and lowest (97.53 mg) IVOMD was noticed

production for different rations was due to the suppressing

withadditionofconcentrateatthelevelof70and0percent,

effect of high cell wall and lignin present in these feeds

respectively. IVOMD was comparable between 70R:30C

resulting in decreased attachment of ruminal microbes

and 60R:40C. The decrease in IVOMD with reducing the

to feed particles (Paya et al. , 2007). This might be the

concentrate level (30R:70C to 100R:0C) might be due to

reason for lowest gas production with sole sorghum

decrease in readily available energy, protein contents and

stover incubation. Gas production is basically the result of

increase in structural carbohydrates content of complete

fermentation of carbohydrates to acetate, propionate and

rations which might have impaired fermentation. An

butyrate and gas production from protein fermentation is

increase in the in-vitro organic matter degradability on

relatively small as compared to carbohydrate fermentation

high-energy rations was observed (Chatterjee et al. , 2006).

(Makkar et al. , 1995). Higher gas values obtained for the

A decrease in the IVOMD in rations containing sunflower

experimental rations by gradual increase in concentrate

heads and maize cobs as the roughage portion increased

Journal of Animal Research: v.5 n.1. April 2015

49