The productivity of small animal species in small-scale mixed farming systems in subtropical Bolivia.

The productivity of the scavenging, small animal species (chickens, ducks, pigs, hair sheep and guinea-pigs) commonly found on small-scale farms at the forest margin in subtropical Bolivia was monitored over a full year. Chickens and guinea-pigs were kept mainly for home consumption, while ducks and pigs were kept mainly for sale. Sheep served both purposes, depending upon the family requirements. In the absence of veterinary treatment, the productivity varied greatly between farms. Pigs gave the greatest gross return, but received the largest amount of supplementary feed. Under the existing system, chickens, ducks and sheep all gave similar gross returns per breeding female, although chickens produced good returns and made a large contribution to the family diet where the reproductive efficiency was high and the chick mortality was low. Mortality resulting from disease was a major problem in poultry, while internal parasites appeared to be important limiting factors in pigs and sheep. Guinea-pigs showed no major problems apart from theft, and were an important dietary component for immigrant families from the highlands of the country. Small animal species have largely been ignored by agricultural research and development activities in Bolivia and elsewhere. They currently make significant contributions to the livelihoods of poor people in terms of both income and food security, and this could be greatly increased by simple improvements in animal husbandry.

The feeding of leaf meal of Calliandra calothyrsus to laying hens.

A 67-day feeding experiment was conducted to study the effects of inclusion of 5%, 7.5% or 10% leaf meal of Calliandra calothyrsus (calliandra) in the diets of laying hens on feed intake, egg production, egg weights, yolk colour and the birds' weights. While no significant effects were seen on either egg numbers or egg size, feed intake increased and the efficiency of feed utilization decreased with increasing inclusion of the foliage. Absolute initial and final body weights did not show significant treatment differences but live weight changes over the course of the experiments were statistically significant, weight gains decreasing with increasing calliandra levels. The strength of colour of the yolks increased within 3 days of offering the calliandra, irrespective of the level of inclusion. The persistence of the colour change after withdrawal of the leaf meal ranged from 3 days at the 5% inclusion to over 10 days at the 10% level. While it may be possible to include calliandra leaf meal in poultry rations along with other, local, low-cost components, there would appear to be little advantage in using it in conjunction with commercial layers meal at levels higher than those necessary to provide the desired pigmentation level in the yolks (5% or less).

Calliandra calothyrsus as a supplement for milk production in the Kenya highlands.

Two on-farm experiments and one on-station observation were conducted between July 1994 and September 1995 to study the effect of supplementation with fresh fodder of Calliandra calothyrsus on milk production from grade Friesian and Ayrshire cows in the second trimester of their lactations. The cattle were kept under zero-grazing systems on small farms in the coffee-based land use system at altitudes of 1500 to 1800 m on the slopes of Mt Kenya. These cows form a pivotal part of the farming system since they produce both milk for sale and manure for crop production. Milk production is normally in the region of 10 kg/cow per day when the animals are fed on a diet based on Napier grass and crop residues, together with 2-4 kg day of commercial concentrate. In terms of milk production, 3 kg of fresh calliandra had the same effect on yield as 1 kg of additional dairy meal and, at normal production levels, the effects of the two supplements were strictly additive. Calliandra had a marked positive effect (about a 10% increase) on the butterfat content of the milk, a factor that was highly valued by farmers, even though institutional buyers as yet offer no premium price for milk quality. The average small farm can produce enough calliandra fodder to supplement two dairy cows and some additional small stock from relatively underutilized niches along the farm perimeter and terrace risers, without any adverse effect on current levels of crop production.

Modified Gianturco arterial stents--preliminary results in iliac arteries of sheep.

Modified Gianturco arterial stents were placed in the iliac arteries of 3 non-atherogenic sheep. At three months after placement there was no evidence of migration of the stents or of excessive intimal overgrowth in relation to the stents.