Livestock Research for Rural Development 12 (3) 2000

Citation of this paper


Pig productivity: A case study for South-Eastern Botswana

R G Chabo, P Malope and B Babusi

Department of Animal Science and Production, Botswana College of Agriculture
Private Bag 0027, Gaborone, Botswana;



An evaluation of the pig enterprise at the Botswana College of Agriculture (BCA) farm using sow productivity and gross margin analysis was carried out. The data were obtained from breeding and financial records of the Landrace and Duroc breeds from 1997 to 1999. Litter size at birth influenced litter size at weaning and both traits decreased with an increase in parities. A positive correlation (0.70) was observed between litter size at birth and litter size at weaning. A negative gross margin was realised due to the high feed costs and low market price of pigs which did not cover production costs.

Keywords: pigs, gross margins, productivity, Botswana


In Botswana, the demand for pork and bacon continues to increase. According to the Ministry of Agriculture (1995), a total of 5,000 pigs were slaughtered in the local abattoirs with a mean carcass weight of 53 kg. The estimated demand for pig meat was 60 tonnes per month. The local pig producers contributed about 50% of the demand and the other 50% was imported from neighbouring South Africa. The high demand in pig meat and products is related to household income and nutritional awareness. Pork, milk and poultry are superior goods. They increase in consumption as household income rises.

Pig producers in Botswana are mainly concentrated in the cities and big villages where the market and the demand for pig products is high. The major markets for pig farmers are local meat processors and butcheries. There is also a shortage of the local supply of weaner pigs and replacement breeding stock. For instance, the government multiplier unit supplied only 234 of the 903 weaner pigs demanded in 1995.

In Botswana, beef production has been the dominant agricultural activity since independence in 1966, contributing annually about 80% of the livestock sector's Gross Domestic Product (GDP). The government has instituted a number of programmes such as the financial assistance policy (FAP) with the primary objective of promoting other livestock production activities such as pig production.

The viability of a pig enterprise is influenced by many factors: the most important being feeding cost, management and market prices. In order to operate an efficient pig enterprise, the producer needs to maintain proper production and financial records. Studies on the economic performance of pig production in Botswana has never been carried out. Therefore, the objective of this study was to evaluate pig productivity using the College farm as a model. 

Materials and methods

Data collection

The Botswana College of Agriculture (BCA) pig unit, located in Sebele Content Farm was used as the experimental site. The data were collected from January 1997 to December 1999 from production records of Duroc and Landrace breeds. An interview was carried out with the farm management staff to document pig management practices and to verify the records kept.

Gross margin analysis

In order to evaluate the financial performance of the pig enterprise the gross margin analysis was used. The gross margin is the difference between the total income and the total variable costs of an enterprise and it measures what the enterprise is adding to the overall farm profit (Rasmussen 1982). The gross margin of a particular farm enterprise can then be compared with the previous years, similar farms in the area; or may be compared with that of other enterprise units within the same farm. In order to enable the gross margins to be computed, the following information is required:

(a) simple financial records of outputs from each enterprise and input expenses

(b) physical records of crop and livestock enterprise units

(c) changes in number of livestock during the year, i.e, opening and closing inventories, and

(d) total yield figures for each kind of crop and livestock enterprise

Statistical analysis

A correlation coefficient was computed for litter size at birth and at weaning. The student's t-test procedure in SAS (1991) was used to compare means for birth and weaning weight for the first and fifth parities, respectively.

Results and discussion

Herd management

From the interview with the Farm Management staff, it was established that sows and boars are housed in individual pens with concrete floors with a slope of about 4% to allow for drainage. Sows and boars are allowed into a single boar pen for mating purposes. The piglets are allowed to suckle for four weeks and then weaned. They are then reared in group pens until they reach market liveweight of about 60 kg.

The piglets are creep fed at two weeks of age up to weaning age. A pig grower ration was introduced at four weeks of age; after six weeks of age, pigs are fed a finisher ration. Sows and boars are fed sow and boar meal each at 2 kg per pig given in two parts; one in the morning and the other in the late afternoon. At farrowing a sow is given 3.5 kg of feed plus half a kilogram for each piglet in the litter depending on the appetite of the pig. Thomton (1999) reported that feed intake should be related to the stage of production of the pig and further recommended up to 3.5 kg feed during gestation and ad libitum feeding during lactation. Many authors recommend ad libitum feeding of the sow during lactation. Neil (1996) reported that a high plane nutrition fed ad libitum during lactation improves the ability of sows to come into oestrus after weaning.

Water to all the pigs was given ad libitum in drinking nipples in all pens. The pigs are also sprayed with water twice a day to clean and cool them off reducing heat stress which normally affects feed intake and productivity (Ayo et al 1998).

The boar is introduced to the sow whenever she showed signs of heat. The gestation period of a pig is 3 months 3 weeks and 3 days. Selection of replacement breeding gilts was done at six months of age. Gilts were put to the boar at seven to nine months of age.

Sow productivity

Litter size at birth between the two breeds (Landrace and Duroc) decreased with the number of parities. The decline is evident in the 5th farrowing which suggests that sows need to be culled at this age. Smith (1993) reported that at the fourth lactation the sow is ready to be culled because it is no longer economical to keep her. Litter size at birth and at weaning were greater in the Landrace than in the Duroc sows as shown in Table 1 below.

Table 1: Average production by breed

Selected pig breeds

Duroc Landrace
Litter size at birth
Litter weight at birth (kg)
Litter size at weaning
Litter weight at weaning (kg)
Survival rate (Birth-Weaning) (%)
Mortality (%)
Weaning age (weeks)
Litters per year



Blasco et al (1996) reported a high positive correlation between prenatal survival and litter size. There was also a positive correlation (0.70) between piglets born alive and those weaned. Daniel et al (1993) reported that the large litter size of the Landrace is attributed to her good mothering traits. Due to this outstanding mothering ability and docility the Landrace pigs are raised extensively worldwide although they are susceptible to stress. Durocs on the other hand cannot be regarded as good mothers although in general, they give birth to large litters.

There was no significant difference between breeds in litter birth weight, however, weaning weight was different (P<0.01). Landrace sows weaned heavier litters than Duroc sows as shown in Table 1. Weaning age, lactation, food intake, parity, season and litter size are the possible factors affecting average pig weight at weaning. Table 2 shows a comparison across breeds of birth and weaning weights at the first and fifth parities, respectively. In general, the fifth parity weights were smaller that the weights in the first parity. Yen et al (1987) reported that mid-parity sows produced heavier litter weights and greater litter size than parity 1 and older (>6) parity sows.

Table 2: Comparison of birth and weaning weights between farrowings 1 and 5

Piglet birth weight (kg)

Piglet weaning weight (kg)

Farrowing 1 Farrowing 5 Farrowing 1 Farrowing 5
n 4 4 4 4
mean 1.28 1.19 6.8 6.2
SD 0.096 0.13 0.33 1.23
Calculated t



Tabulated t




n1 + n2 - 2 = 6

n1 + n2 - 2 = 6

Piglet mortality from birth to weaning

The high piglet mortality at the BCA farm (35%) was associated with crushing of piglets by the sow due to the poor design of the pen. At the BCA pig farm, the slope of the floor in the farrowing pens is less than 5%, thus contributing to the higher than normal piglet crushing by the sow. McGlone and Morrow-Tesch (1990) conducted a study to determine the cause of mortality in piglets farrowed in pens with varying slopes. The researchers reported that floor slopes of at least 8% altered sow and piglet behaviour and reduced the rate of piglet crushing. They concluded that sloping of conventional farrowing pens is ideal to reduce these mortalities. Other causes of piglet mortality reported at the BCA farm were starvation due to agalactia in the sow and stress related factors.

Manure handling

The manure or slurry is flushed in a closed sewage system. This is an anomaly since the slurry in other farms is used as crop fertilizer and hence saves on input costs. Peters (1991) reported that the use of pig manure as a source of crop fertilizer reduces the cost of commercial fertilizers.

Gross margin analysis

Table 3 shows the gross margin analysis of the pig enterprise. The cost of feeding alone accounted for about 88% of the variable costs. The low revenue was due to low market price for porkers. These results show that the enterprise contributes negatively to the farm. According to the BCA Farm management, the gross income received from selling pigs was not sufficient to cover the feed costs.

According to Viljoen (1993), the contributing factor to negative net farm income per sow is the feed costs which account for about 80 % of the production costs. He suggested that in order to reduce feed costs without affecting production, one should reduce feed wastage and utilize cheap feed materials and to emphasize on efficiency and productivity and utilization of movable assets in the piggery enterprise to supplement other enterprises. The pig slurry could be used to save costs of fertilizers by crediting its cost to the pig enterprise. This could increase the gross income of the pig enterprise and hence the gross margin.

Table 3: Gross Margin Analysis for a 10-Sow unit with 2 litters per year and 8 piglets per sow
Item Number Total Value
Sausage pigs
Total income

less sows purchased
less boar purchased
Total gross income



7 680
17 280
6 776
1 155
33 191
3 000
1 500
28 691

1 728
3 319
2 869

Variable costs
Margin above feed cost
Animal health
Total variable costs

26 117
2 573
1 920
29 437

2 611
2 943

Gross margin -746 -74
# The average currency exchange rate during the study : US$1.00 ~ 4.30 BWP (Botswana Pula)


Sow productivity is affected by litter size at birth and at weaning as well as the corresponding weights. The Landrace breed appears to have better mothering ability than the Duroc breed. The negative gross margin at BCA farm was mainly due to low market price of pigs and high feed costs.


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Received 5 June 2000


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