Feeding of sugar cane juice and "A" molasses to fattening pigs

Faculty of Animal Husbandry and Veterinary Medicine, Cantho University, Vietnam

A trial was carried out during 165 days in 1991 at the Hoa An Sulphate-Acid Soil Research Station of the University using 27 local baxuyen pigs, allotted in a randomized complete design with 3 treatments and 3 blocks and 3 pigs per experimental unit. In each of the post-weaning, growing and fattening stages, the experimental animals were fed with diets containing sugar cane juice or "A" molasses as complete replacement of cereals, in comparison with control pigs fed with a cereal-based control diet. Pigs consumed readily diets containing cane juice and molasses and showed good health, except some cases of prolonged diarrhoea, rectal protrusion and hindleg weakness. Cane juice gave the highest daily weight gain, followed by control and finally molasses, though differences were not statistically significant. Molasses gave the worst feed conversion as compared with cane juice and control diet (P<0.05). Cane-juice fed pigs seemed to have the highest feed intake, followed by molasses and basal-diet group though the differences were not significantly different. Sugar cane juice and "A" molasses can thus replace totally cereals in the diets of local Baxuyen pigs from weaning up to slaughter.

KEY WORDS: Pigs, growth, fattening, sugar cane juice, "A" molasses, cereals, Vietnam

It is a Government priority in Vietnam to reserve rice grain for human consumption and therefore to find alternatives to cereal grains for developing the pig industry. In the acid-sulphate soils in the Mekong Delta region, sugar cane grows well and is more productive than rice.

The present trial aimed at complete replacement by sugar cane juice and "A" molasses of energy feeds derived from cereals such as rice bran, rice polishings, broken rice and maize in the diets of pigs.

The trial was conducted at the Hoa An Sulphate-Acid Soil Research Station of the University from March 1 to August 15, 1991 during a 165-day experimental period.

The experimental animals were 27 local Baxuyen pigs aged 2 months and of 9 kg mean liveweight. The experimental design was a randomized complete block consisting of 3 treatments in 3 blocks with groups of 3 pigs as each experimental unit. The experimental diets are shown in Table 1. Details on the method of manufacture and the composition of "A" molasses were given in an earlier paper (Bui Hong Van and Le Thi Men 1990).

Table 1: Composition of experimental diets for post- weaning pigs (from 2 up to 4 months of age; growth period from 9 to 25 kg)

Ingredient/Analysis			Sugar cane
(% of diet DM)	Control	"A" molasses	juice

"A" molasses	-	32.7	-
Sugar cane juice	-	-	34.3
Protein supplement	-	67.3	65.7
Basal diet	100	-	-

N x 6.25 (% in DM)	19.0	18.5	18.3
N x 6.25 (g/d)	150	144	166

Table 2: Composition of experimental diets for growing pigs (from 4 up to 5.5 months of age, weighing from 26 up to 50 kg)

Ingredient/Analysis			Sugar cane
(% of diet DM)	Control	"A" molasses	juice

"A" molasses	-	57.3	-
Sugar cane juice	-	-	60.3
Protein supplement	-	42.7	39.7
Basal diet	100	-	-

N x 6.25 (% in DM)	14.3	14.5	13.8
N x 6.25 (g/day)	220	250	275

Weaned pigs for the experiment were purchased from farm households in the countryside at the age of 30-40 days, weighing 5-8 kg. During the 15 days before the experiment, the pigs were made acquainted with the new accommodation and the diets of sugar cane juice and molasses. The pigs were fed ad libitum with the experimental diets which were adjusted to similar protein contents. The feeding scheme was partitioned into 3 stages, namely post- weaning from 2-4 months, growing from 4-5.5 months of age and finishing from 5.5 months to slaughter weight of approximately 85 kg. Data on feed intake were collected every day; those on liveweights every 15 days and those on carcass value were recorded once at slaughtering of all experimental pigs

Table 3: Composition of experimental diets for finishing pigs (from 5.5 up to 7.5 months of age, weighing from 51 up to 85 kg)

Ingredient/Analysis			Sugar cane
(% of diet DM)	Control	"A" molasses	juice

"A" molasses	-	63.5	-
Sugar cane juice	-	-	64.8
Protein supplement	-	36.5	35.2
Basal diet	100	-	-

N x 6.25 (% in DM)	13.0	13.2	12.6
N x 6.25 (g/d)	310	340	350

The pigs consumed readily the sugar cane juice and the "A" molasses. Several of the molasses-fed pigs suffered from prolonged diarrhoea; the two fastest growing had rectal protrusion and three others were weak in their hind legs and had to sit like a dog when eating. Cane-juice fed pigs were also very contented to consume the feed and had good health compatible with the control group fed the cereal-based diet.

Table 4: Liveweight gain, feed conversion, feed intake and feed cost per kg weight gain of experimental pigs

Item	Control	"A" molasses	Cane juice	Prob

Number of pigs	9	9	9
Liveweight (kg)
Initial	9.0	9.3	9.4
Final	87.1	80.2	91.2
Daily gain	0.473	0.430	0.495	NS
Feed intake (kg/d)
Molasses, 77 brix	-	1.24	-
Cane juice, 18 brix	-	-	6.36
Protein supplement	-	0.865	0.880
Basal diet	1.813	-	-
Total dry matter	1.578	1.730	1.923	NS
Feed conversion
(feed DM/LWt gain)	3.33a	4.02b	3.88bc	P<0.01
Feed cost per kg
gain (VN dong)	4316	5614	4794

NS not significant
a,b,c Values followed by at least one common letter are not significantly different

Liveweight gain appeared to be highest on the cane juice diet, the cereal diet was next and molasses was the poorest, though the differences were not statistically significant (Table 4). The dry matter intake was highest on the cane juice diet, followed by the molasses and the cereal diet lowest (P>0.05). The feed conversion was poorest on the molasses treatment, followed in order by the cane juice and the cereal diet (P<0.01).

The feed cost per kg weight gain of pigs fed "A" molasses or sugar cane juice was higher than that of cereal-fed pigs because of the high price of molasses and cane stalk during the experiment period. The data indicate that molasses and sugar cane juice can only replace economically cereals when the price of 1 kg molasses or 9 kg sugar cane stalk is lower than that of 1 kg rice polishings.

Table 5: Carcass and viscera characteristics of experimented pigs

		"A"	Cane
Item	Control	molasses	juice	Prob

Slaughter weight (kg)	87	80	91
Dressing percentage	84.6	84.0	85.1	NS
Whole-sale meat (%)	78.2	76.9	79.2	NS
Loin eye area (cm²)	32.9	29.1	34.4	NS
Backfat depth (cm)	4.02	3.74	4.20	NS
Liver (kg)	1.43	1.42	1.52	NS
Heart (kg)	0.233	0.211	0.244	NS

All experimental pigs were slaughtered at the end of the experiment, at the Haugiang provincial meat processing plant for exported meat. Carcass and viscera characteristics are presented in Table 5. It is apparent that the carcasses of pigs fed sugar cane juice and molasses are as good as those from pigs fed cereals in terms of carcass and viscera yields.

The results for weight gain, feed intake and conversion and carcass value prove that sugar cane juice and molasses can substitute totally for cereals in the diets of local Baxuyen pigs from weaning up to slaughter. The only notable disadvantage was the poorer feed conversion rate on cane juice, and especially on molasses, relative to cereals despite liveweight gain being slightly higher on the cane juice. This is in agreement with reports from Cuba (Figueroa 1990) and from Colombia (Sarria et al 1990).

Figueroa Vilda 1990 Sugar cane as the main crop for animal production. IN: Integration of livestock with crops in response to increasing population pressure on available resources (Editors: T R Preston and M Rosales). CTA: Wageningen

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

Van B H and Men L T 1990 "A" molasses in diets for growing pigs. Livestock Research for Rural Development Volume 2, Number 3:76-80