In vitro gas production and in vivo nutrient digestibility and growth performance of Thai indigenous cattle fed fresh and conserved pangola grass

Figures & data

Table 1. The chemical composition of the forages and the concentrate and protein block fed for supplementation.

Item	Ruzi grass	Fresh pangola	Pangola hay	Pangola silage	SEM	Concentrate	Protein block
Dry matter, g/kg	236	229	836	231	10.0	890	706
Nutrient composition, g/kg DM
Organic matter	899	897	933	872	0.8	916	841
Crude protein	81.9	93.5	94.5	97.7	0.20	119	406
Crude fat	25.9	26.8	21.4	27.6	0.09	31.9	18.6
Ash	102	104	67.3	128	0.82	84.3	159
NDF	688	695	723	695	0.52	337	–
ADFom	363	379	394	374	0.42	–	–
ADL	41.2	45.4	50.0	43.6	0.12	–	–

SEM: standard error of the means; DM: dry matter; NDF: neutral detergent fibre; ADFom: acid detergent fibre expressed exclusive residual ash; ADL: acid detergent lignin.

Table 2. Cumulative gas produced at different times of incubation for forages and parameters of gas production estimated with the exponential model, in vitro organic matter digestibility and metabolisable energy.

Item	Ruzi grass	Fresh pangola	Pangola hay	Pangola silage	SEM	p
Parameters of exponential model
B, mL/200 mg dry matter	51.3^d	56.4^b	54.2^c	60.6^a	1.03	.001
c, 1/h	0.059^b	0.073^a	0.061^b	0.067^ab	0.001	.011
Lag, h	0.116^a	−0.253^b	−0.263^b	−1.323^c	0.16	.001
In vitro organic matter digestibility, %
IVOMD24	59.2	64.3	59.9	70.5	2.41
IVOMD48	67.5	73.4	68.2	78.3	2.36
ME, MJ/kg dry matter	8.55	9.15	8.85	9.63	0.16

SEM: standard error of the means; B: the asymptotic gas volume; c: the rate constant; Lag: the time between inoculation and commencement of gas production; IVOMD: in vitro organic matter digestibility; ME: metabolisable energy.

^a–dMeans with different letters within rows differ (p < .05).

Figure 1. In vitro gas production profiles of the forages. Gas production profiles have been fitted to curves using the equation y = B (1 − e^{–c(t – lag)}); B, the asymptotic gas volume; c, the rate constant, lag, the time between inoculation and commencement of gas production.

Table 3. The in vivo nutrient digestibility (%) and concentration of metabolisable energy (ME) of the different diets (forages supplemented with concentrate and protein block).

	Diet
Item	Ruzi grass	Fresh pangola	Pangola hay	Pangola silage	SEM	p
Dry matter	59.5^d	60.9^c	63.1^b	65.0^a	0.242	.001
Organic matter	61.3^c	65.7^b	61.2^c	69.2^a	0.152	.001
Crude protein	50.5^d	55.8^c	56.3^b	58.0^a	0.102	.001
Crude fat	43.3^b	44.0^b	41.4^c	48.9^a	0.665	.001
Crude fibre	65.2^c	67.0^b	69.1^a	67.1^b	0.193	.001
NDF	70.7^c	73.2^b	74.9^a	73.7^b	0.149	.001
ADFom	56.8^c	58.6^b	60.6^a	58.7^b	0.350	.001
ME, MJ/kg dry matter	8.25^c	8.85^b	8.40^c	9.22^a	0.067	.001

SEM: standard error of the means; NDF: neutral detergent fibre; ADFom: acid detergent fibre expressed exclusive residual ash; ME: metabolisable energy.

^a–dMeans with different letters within rows differ (p < .05).

Table 4. Dry matter intake, body weight gain and average daily gain of native White Lamphun bulls fed on diets with different forages supplemented with concentrate and protein block (values represent least squares means and standard error of the means (SEM)).

	Diet
Item	Ruzi grass	Fresh pangola	Pangola hay	Pangola silage	SEM	p
Dry matter intake, kg/day	2.90	2.95	3.05	3.13	0.232	.665
-Forage	2.21	2.25	2.27	2.24	0.065	.906
-Concentrate	0.56	0.51	0.51	0.54	0.058	.874
-Protein block	0.10	0.11	0.12	0.15	0.003	.053
Initial body weight, kg	112	123	124	124	7.87	.746
Final body weight, kg	145	167	160	172	8.58	.172
Body weight gain, kg	30.6^c	51.0^a,b	48.0^b,c	64.4^a		.0197
Average daily gain, kg/day	0.36^c	0.48^a,b	0.40^b,c	0.53^a		.0029

SEM: standard error of the means.

^a–dMeans with different letters within rows differ (p < .05).