Oil-rich fibrous residue from african oil palm as basal diet of pigs; effects of supplementation with methionine

Oil-rich fibrous residue from african oil palm as basal diet of pigs; effects of supplementation with methionine

Universidad Tecnológica de los Llanos Orientales, Villavicencio, Meta, AA 2621, Colombia

This research was carried out by the IFS-UNILLANOS project in its experimental farm, located in the city of Villavicencio, Colombia. 64 crossbred pigs (Yorkshire x Landrace) of average weight 20 kg were allocated to 8 pens, each one with 8 animals. The four treatments were: C: 0.5 kg/d of soya bean meal (FSM) fortified with vitamins and minerals, M: 0.5 kg/d of FSM plus 8 --> 9 g/d of methionine, MB: 0.5 kg/d of FSM plus methionine and 0.93 --> 1.05 g/d B complex vitamins, and B: 0.5 kg/d of FSM plus B complex vitamins. The basal diet was the oil-rich fibrous residue from factory processing of african oil palm which was fed ad libitum. There were no significant effects of treatments (C, M, MB, B) on time to reach 90 kg (143, 138, 133 and 148 days), daily liveweight gain (480, 485, 504 and 466 g/d) and intake of the oil-rich residue (2.77, 2.75, 2.74 and 2.80 kg/d).

KEY WORDS: African oil palm residue, pigs, growth, methionine, B- complex vitamins.

Colombia is the fourth producer of palm oil in the world and the first in South America, with an actual planted area of 106,000 hectares. The average production of the fruit is 15 tonnes/ha/year and of the oil 3.06 tonnes.

The feed resource used in this experiment was the oil-rich fibrous residue which remains when the crude oil is filtered after leaving the press. It accounts for approximately 5% of the weight of fresh fruit that enters the factory. It has a yellow colour, a fibrous consistency, a sweetish smell and is greasy to the touch. The dry matter content is 95%, crude protein (N x 6.25) 5.25%, fat 23.1%, crude fibre 15.1% and ash 1.94%. The fatty acids in the oil are: myristic 1.6%, palmitic 45.3% stearic 5.1%, oleic 38.7% and linolenic acid 9.2%.

In previous trials it has been shown that this feed resource can be fed to growing-fattening pigs as the basal diet replacing completely the sorghum grain (Ocampo et al 1990a); and that there are no apparent advantages from giving more than 200 g/d of supplementary protein derived from soya bean meal (Ocampo et al 1990b).

The research was carried out as part of the IFS-UNILLANOS project located in the experimental farm of the Universidad Tecnológica de los Llanos Orientales, Villavicencio. The region is 300 m above sea level with a relative humidity of 80%, average temperature 28 °C and average rainfall 3500 mm/year.

64 crossbred pigs (Yorkshire x Landrace) of initial weight 20.0 kg were allocated in uniform groups to 8 pens. The males were castrated and all were treated for intestinal parasites.

Four treatments were applied in two blocks (replicates) as follows: C: 0.5 kg/d of soya bean meal (FSM) fortified with vitamins and minerals, M: 0.5 kg/d of FSM plus methionine, MB: 0.5 kg/d of FSM plus methionine and B complex vitamins, and B: 0.5 kg/d of FSM plus B complex vitamins. The basal diet was the oil-rich fibrous residue from factory processing of african oil palm which was fed ad libitum. The amounts of vitamins of the B complex were 0.93 and 1.05 g/d per pig in the growing (20 - 55 kg) and finishing stages respectively; supplementary methionine was given at 8 and 9 g/d per pig. The pigs were slaughtered when they reached 90 kg bodyweight (average of the pen).

The FSM supplement (contains 986 kg soya bean meal [46% protein], 10 kg dicalcium phosphate, 2 kg NaCl and 2 kg pre-mixture of vitamins and trace minerals) was given as the first feed in the early morning and after it was consumed the oil-rich residue was offered ad libitum. Records were kept of daily feed intake, body weight (every 14 days), fat content of the oil-rich residue, analysis of the fat content of the "cachaza", and the characteristics of the back fat at slaughter. faecal substance of the pigs, its degradation and a sampling of the dorsal fat in the canals were carried out.

The results will be analyzed considering 3 phases: growing, fattening up and consolidated, which is the summary of the behaviour of all the trial. It was necessary to discard some animals for specific individual problems, and negative behaviour of some pigs after castration and initial management.

The results obtained during this phase are reported in Table 2. The treatment that gave the best results was MB, which needed the shortest time to reach the weight limit in this phase with the best increase in weight and feed conversion. However, there were not significative differences in the increase of weight, nor in the consumption of "cachaza" which was practically the same for all the treatments.

Table 1: Growth performance of the pigs during the growing phase

		Treatement
	C	M	MB	B

No of animals	15	15	14	13
No of days	70	70	63	77
Live weight, kg
Initial 20.7	20.7	21.0	22.1	20.2
Final 56.0	56.0	55.7	55.3	56.1
Daily gain	0.503	0.495	0.527	0.466
Feed intake, kg/day
FSM	0.5	0.5	0.5	0.5
Oil-rich residue	2.45	2.44	2.40	2.45
Total DM	2.77	2.77	2.73	2.77
Conversion (DM)	5.5	5.6	5.2	6.0

Table 2: Growth performance of the pigs during the finishing phase

	Treatment
	C	M	MB	B

No of animals	15	15	14	13
No of days	73	68	70	71
Live weight, kg
Initial	56.0	55.7	55.3	56.1
Final	89.4	89.4	89.6	89
Daily gain	0.459	0.496	0.489	0.462
Feed intake, kg/day
FSM	0.5	0.5	0.5	0.5
Oil-rich residue	3.1	3.0	3.0	3.2
Total DM	3.4	3.3	3.3	3.5
Conversion (DM)	7.4	6.6	6.7	7.5

There were no significant effects on growth, intake or feed conversion attributable to supplementation with methionine or vitamins of the B-complex (Tables 1-3).

A comparison of the profile of essential amino acids (expressed as a proportion of the amount of lysine), in soya bean compared with the optimum for pig growth (Wang et al 1990), reveals that there is only a marginal imbalance (deficiency) of the sulphur amino acids methionine and cysteine. Apparently, either this difference was insufficient to have facilitated a positive response to supplementary methionine, or that animal performance was limited by availability of energy. The latter explanation is the most logical since the observed growth rates (range of 460 to 507 g/d) were less than was observed in previous experiments (range from 505 to 639 g/d) with the oil palm residue (Ocampo et al 1990a,b). There were problems with the supply of material during the last weeks of the trial as many factories had closed for the Xmas vacation and it was not always possible to maintain the intended ad libitum system of feeding.

Table 3: Growth performance of the pigs during the overall growing-finishing period

	Treatment
	C	M	MB	B	SE(Prob)

No of animals	15	15	14	13
No of days	143	138	133	148	"5.9
Live weight, kg
Initial	20.7	21.0	22.1	20.2
Final	89.4	89.4	89.6	89
Daily gain	0.480	0.495	0.507	0.466
Feed intake, kg/day
FSM	0.5	0.5	0.5	0.5
Oil-rich residue	2.77	2.75	2.74	2.8
Total DM	3.0	3.0	3.0	3.1
Conversion (DM)	6.2	6.0	5.9	6.6

Table 4:Degradability of faecal samples in nylon bags placed in the rumen of cattle

	Treatment
	C	M	MB	B

N x 6.25 (% in DM)	15.3	17.8	17.5	16.2
Neutral detergent
fibre (% in DM)	49.4	50.0	50.0	42.4
Rumen degradability
(% DM basis)
24hr incubation	27	30	37	35
48hr incubation	37	29	47	48

It was noted also that there were inconsistencies in animal performance, from one weighing date to the next. Part of this variation it is believed stems from variation in the composition of the oil-rich residue, due perhaps to changes in the composition of the fruit being processed, or to management factors in the factory. Analysis of the oil content of 6 samples from two different factories at different times showed a range in values of 20.7 to 33.7 (mean and SD = 25.7"5.8).

Samples of faeces were taken throughout the trial to determine the presence or not of internal parasites. All results were negative. Faecal samples were also incubated in nylon bags in the rumen (Orskov et al 1980) during 24 and 48hr (Table 4). The results showed that this material could have potential in the feeding of ruminants.

The results of this experiment, although slightly inferior to those reported previously, confirm the potential of the oil-rich fibrous residue from processing African oil palm as a basal diet for pig growth and fattening. There were no benefits from feeding supplementary methionine which indicates that the strategy of giving minimal levels of protein derived from soya bean (200 g/animal/d) is appropriate when the basal diets are low in protein, and irrespective of whether the energy is derived from sugar cane (Sarria et al 1990), cassava (Solano et al 1992) or oil palm (Ocampo et al 1990a,b).

Further studies are required on the feeding value of the faeces for ruminant animals. The moderate rates of rumen degradability and the relatively high content of protein indicate that using the faeces as ruminant feed could be an interesting option.

Ocampo A, Lozano E y Reyes E 1990a Utilización de la cachaza de palma africana como fuente de energía en el levante, desarrollo y ceba de cerdos. Livestock Research for Rural Development Volume 2, Number 1:43-50

Ocampo A, Castro C y Alfonso L 1990b Determinación del nivel óptimo de proteína al utilizar cachaza de palma africana como fuente de energía en raciones para cerdos de engorde. Livestock Research for Rural Development Volume 2, Number 2:67-76

Orskov E R, Hovell F D DeB and Mould F 1980 The use of the nylon bag technique for the evaluation of feedstuffs. Tropical Animal Production 5:195-213

Pardo S y Moreno E 1971 Caracterización de los ácidos grasos en el aceite de la palma africana. Departamento de química. Facultad de ciencias. Universidad Nacional. Bogotá, Colombia

Sarria P, 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:pp92-99

Wang T C and Fuller M F 1989 The optimum dietary amino acid pattern for growing pigs. 1. Experiments by amino acid deletion. British Journal of Nutrition 62:77-89