The use of sugar cane juice and molasses in the diet of growing pigs

An experiment was carried out with 18 pigs of Yorkshire x Landrace breed divided into the following treatments: CON: 200 g/d of protein from a supplement (Soybean 71.26, fish meal 23.75, calcium phosphate 3.80, salt 0.95, vitamin-trace mineral premix 0.24%) and rice bran ad libitum; SCJL: the supplement was given in quantities ajusted to meet the total amount of protein the pigs consumed in CON plus sugar cane juice ad libitum (made by adding water to dehydrated cane juice, in ratio 3 parts water to 1 part dehydrated juice); AM: Same as SCJL but with "A" molasses instead of cane juice. There were no differences in rate of gain in weight among the three treatments. Feed conversion was poorest on the "A" molasses treatment but did not differ between the cane juice and the rice bran treatments.

This research is a continuation of the programme of work aimed at adapting for Vietnamese conditions the pig feeding system based on derivatives of sugar cane developed originally in Latinamerica (Mena 1981; Fermin et al 1984; Sarria et al 1990).

The experiment was carried out at the Experimental farm of UAF from 28/8/1991 to 1/1/1992. 18 pigs of Yorkshire x Landrace breed chosen from 3 litters were divided into 3 treatments.

CON: The pigs were fed 200 g/d of protein from a supplement (Soybean 71.26, fish meal 23.75, calcium phosphate 3.80, salt 0.95, vitamin-trace mineral premix 0.24%) and rice bran ad libitum.

SCJL: The pigs were fed the supplement in quantities ajusted to meet the total amount of protein the pigs consumed in CON, plus sugar cane juice ad libitum (made by adding water to dehydrated cane juice, in ratio 3 parts water to 1 part dehydrated juice).

There were 2 pigs per pen. The supplement was fed twice daily at 07:30 and 13:30 hours. Water was freely available. Liveweights were determined every 2 weeks, and the amount of feed was recorded daily. At the end of the experiment, three pigs per treatment were slaughtered to estimate the carcass quality.

Table 2 Mean values of growth and feed parameters (3 replicates of 2 pigs/treatment; 126 day trial)

		Dehydrated
	Control	cane juice	"A" molasses	SE/Prob

Liveweight (kg)
Initial	30.1	30.2	30.5
Final	92.7	96.7	91.6
Daily gain	0.497	0.527	0.484	0.01/0.920
Feed intake (kg/d)
Concentrate	0.57	0.92	0.93
Rice bran	1.57
Sugar cane juice		9.83
"A" molasses			2.07
Total dry matter	1.86	1.93	2.35	0.03/0.001
Conversion (DM)	3.75	3.68	4.97	0.17/0.005
Calculated intakes:
N x 6.25 (g/d)	412	383	388	2.20/0.001
Lysine (g/d)	18.2	19.2	19.3	0.11/0.002
Met+Cys (g/d)	14.0	9.9	10.0	0.05/0.000
Ratio (Met+cys/
lysine)	0.77	0.52	0.52

There were no differences in rate of gain in weight among the three treatments. Feed conversion was poorest on the "A" molasses treatment but did not differ between the cane juice and the rice bran treatments.

On the basis of the findings of Wang and Fuller (1989), all the diets were poorly balanced for the principal essential aminoacids lysine and methionione+cystine (recommended ratio is 0.63). The rice bran diet was deficient in lysine (ratio of 0.77) and the dehydrated cane juice and "A" molasses were deficient in methionine+cystine (ratio of 0.52).

Table 3: Mean values for carcass parameters adjusted by covariance for final liveweight (3 pigs/treatment)

	Control	Dehydrated	"A" molasses	SE/Prob

Live weight (kg)	95.6	94.0	91.8
Carcass (kg)	67.9	69.5	67.7	1.24/0.56
Carcass yield (%)	72.4	74.0	72.2	1.30/0.59
Carcass
Length (cm)	74.8	74.8	78.6	1.71/0.29
Back fat (mm)	27.1	28.7	28.7	1.73/0.75
Organs (g)
Pancreas	240	263	263	31.6/0.85
Liver	1482	1284	1539	103.3/0.27
Heart	330	329	326	14.3/0.97
Lung	839	862	854	33.6/0.88

There were no differences in carcass yield, back fat thickness or in the internal organ weights.

Indices of meat quality in samples of Longissimus dorsi muscle are given in Table 4.

Table 4: Mean values for meat quality parameters adjusted by covariance for carcass weight (3 pigs per treatment)

	Control	Dehydrated	'A' molasses	SE/P

Iodine index	87.1	61.6	62.4	1.27/0.001
Dry matter (%)	27.4	28.8	30.5	0.67/0.07
Protein (%)	22.1	19.9	19.6	0.77/0.12
Ether extract (%)	4.3	7.7	9.1	0.98/0.04

The intramuscular fat from pigs fed molasses and reconstituted sugar cane juice had a lower iodine index than the fat from pigs fed rice bran. The moisture in the meat was less and the ether extract higher for the pigs fed the sugar-based diets.

It is difficult to explain why there should have been more fat in the eye muscle from pigs fed cane juice or "A" molasses compared with pigs fed rice bran. Differences were significant despite the small numbers (3 per treatment). Neverthess the small size of the sample is a limitation and further observations are needed on larger numbers before any firm conclusions can be drawn.

The lower iodine index in the fat of pigs fed "A" molasses or cane juice is to be expected in view of the unsaturated oils in rice bran and the virtual absence of lipids in the molasses and cane juice diets. Similar findings for "A" molasses versus rice bran as the basis of pig diets were reported in a companion paper (Bui and Luu 1993).

Bui Huy Nhu Phuc and Luu Trong Hieu 1993 "A" Molasses in diets for growing pigs. Livestock Research for Rural Development, Volume 5, Number 2:11-15

Fermin D, Fermin R, Pina A and Mena A 1984 Sugar cane juice as a substitute for maize and molasses in diets for fattening pigs. Tropical Animal Production 9:271-274

Mena A 1981 Sugar cane juice as an energy source for fattening pigs. Tropical Animal Production 6:338-344

Sarria Patricia, Solano A y Preston T R 1990 Utilización de jugo de caña y cachaza panelera en la alimentación de cerdos. Livestock Research for Rural Development Volume 2, Number 2: 92-99

Table 1: Chemical composition of feeds (as fed basis)

	Rice bran	Soybean	Fish meal

N x 6.25	12.3-12.7	41.20	38.40
Lysine	0.41	2.24	2.03
Met+Cys	0.51	1.18	1.03

	Dehydrated juice	Molasses

Brix	71.0	75.0
Pol	54.9	34.8
Reducing sugars	6.9	14.1