Silage- and forage-based diets compared to commercial diets in Ugandan pig growth

Introduction: Smallholder pig farmers in east Africa report that lack of feed, seasonal feed shortages, quality and cost of feed are key constraints to pig rearing. Commercially prepared pig diets are too expensive and there is competition for food between pigs and people. Smallholder farmers typically feed nutritionally unbalanced diets. This results in low average daily gain (ADG) and poor farmer profits. The objective was to compare the ADG of Ugandan pigs fed forage- or silage-based or commercial diets. Materials and Methods: Local and crossbred Ugandan weaner-grower pigs were randomly assigned to commercial or forage- or silage-based diets. The forage-based diet, on an as-fed basis included specific amounts (%) of the following ingredients; avocado (25.5 kg), banana leaf (1.7), cottonseed meal (1.8), jackfruit (21.9), maize bran (9.5), sun-dried fish (3.1), sweet potato vine (36.1), limestone (0.14), salt (0.14) and vitamin/mineral premix (0.07). Silage-based diet included similar amounts of cottonseed meal, jackfruit, minerals and vitamins, but more maize bran (12.4), sun-dried fish (2.7), and ensiled sweet potato vine and tubers (60.8). Pigs were individually weighed every 3 weeks from 9 to 32 weeks of age. Pen-level ADG was compared across diets controlling for breed and starting weight using multiple linear regression. Results: ADG of pigs fed commercial diet was higher than those fed forage- or silage-based diets between 9 and 24 weeks of age (p<0.03). Between 28 and 32 weeks, pigs fed forage-based diets had a lower ADG than those on other diets (P<0.001). Least squares mean ADG (g/pig/day) for pigs fed commercial, forage- and silage-based diets were 294, 36 and 52, respectively at 9–15 weeks; 329, 163, 212 at 15–19 weeks; 574, 112, 362 at 20-24 weeks and 1233, 694, and 994 at 28 to 32 weeks of age. Conclusion: Forage-and silage-based diets were unsuitable for newly-weaned pigs, which may be attributed to higher than anticipated diet ash and fiber contents. However, pigs on forage- and silage-based diets grew better than those on smallholder farms once they reached 20–24 weeks and 15–19 weeks, respectively. This was when pigs were approximately 12 kg body weight. Well-balanced cost-effective diets are needed to improve pig performance in east Africa. Fresh and ensiled locally available feedstuffs can be used in diets that meet the nutrient requirements of pigs. Low-cost forage- and silage-based diets containing some zero-cost feedstuffs are needed to improve the potential for profitability of smallholder pig farming. Efficient use of these feedstuffs is required to promote sustainable smallholder pig rearing enterprises

Feeding decisions for the newly weaned pigs in East Africa are weight dependent

Introduction: Smallholder pig farmers in east Africa typically wean pigs at 6 to 8 weeks. Farmers report that commercially prepared pig diets are too expensive and therefore typically feed forage and food waste. This results in low average daily gain (ADG), especially for the newly weaned pig. The objective was to describe the weaning weights of local and crossbred Ugandan pigs purchased from smallholder farmers and to compare the growth rate of the pigs fed forage- or silage-based or commercial diets by their starting weights. Materials and Methods: Littermate local (n = 45) and crossbred (n = 45) Ugandan pigs were purchased from 14 smallholder farmers and individually weighed at 9 weeks of age. Pigs were randomly assigned to forage- or silage-based or commercial diets, housed in pens of 3 pigs and weighed every 3 weeks. Pigs on each diet were categorized into the lightest, middle, or heaviest tertile. Pig-level ADG was compared within diet and across diet by weight tertile multiple linear regression. Results: Average (SD) and range of body weight for 9-week-old pigs was 5.7 (1.6) and 2.8–10.2 kg for local and 8.0 (1.8) and 3.9 to 11.4 kg for crossbred pigs. From 9 to 20 weeks of age, 19 pigs gained less than 5 kg. All were fed either forage- or silage-based diets. Most pigs on these diets gained less than the smallest pigs fed commercial diet. For pigs fed forage-based, silage-based or commercial diets, the ADG of the lightest tertile of pigs was 18, -8 and 154 gm/d from 9–12 weeks and 115, 142 and 268 gm/d for 18–20 week old pigs fed forage-based, silage-based and commercial diets, respectively. Similarly, for these 3 diets, the ADG for the heaviest tertile of pigs was 32, 44, and 247 gm/d from 9–12 weeks, and 221, 332, and 319 gm/d for 18- to 20-week-old pigs. The ash levels ranged from 9–12, 12–20, and 9–11 % DM for forage-based, silage-based, and commercial diets. The high ash levels may in part explain the low ADG in the study. The highest ash levels were found in the first diets fed to the 9-week-old pigs because we included animal-grade dried fish dust rather than human-grade whole dried fish. The ash levels decreased when this change was made. Conclusion: At 9 weeks of age, there was a wide range of weaning weights for local and crossbred Ugandan pigs purchased from smallholder farms. Farmers should be encouraged to feed commercial diet until the pigs reach 11 kg of body weight. Older and heavier pigs grow well on less expensive forage-based and silage-based diets. ADG will likely be further improved when the ash content of diets can be reduced from both farmer made and commercial diets

Controlling erosion and sediment loss from furrow-irrigated cropland

Irrigation-induced erosion and subsequent sediment loss is a serious agricultural and environmental problem. Recent recognition of this problem has stimulated the development and evaluation of erosion and sediment-loss-control technology. Research results indicate that the application of the technology available today can reduce sediment loss by 70-100%. Important practices include irrigation-water management, sediment-retention basins, buried-pipe tailwater-control systems, vegetative filter strips, tailwater-recovery systems, keeping crop residues on the soil surface and in furrows, and implementing conservation tillage practices

Management practices for erosion and sediment control in irrigated agriculture

Irrigation erosion and subsequent sediment losses to rivers and streams continue to be serious problems confronting irrigated agriculture. The seriousness of these problems depends upon user concerns which in turn depend upon geographic area and populations. Erosion problems are less severe in California than in Idaho, but the concern for controlling water quality can be greater in parts of California because of subsequent water uses. Basin irrigating rice can reduce suspended sediment loads in water because the basins serve as sediment retention basins. Furrow erosion causes significant suspended sediment loads in return flows in California, but the problem is much more severe in Idaho. Topsoil redistribution by furrow erosion and sedimentation has reduced potential crop yields by approximately 25%. Several sediment loss control practices have been developed and evaluated, and are effective, but costs deter their application. Research is presently directed toward controlling erosion along irrigation furrows. Methods to increase soil cohesion and utilize residues in minimum tillage and no-till systems have high potential for controlling erosion and sediment loss during the next decade

Cone Penetration Tests (CPTs) in layered soils: a Material Point approach

Cone Penetration Tests (CPTs) can be used to determine in-situ soil properties and represent a practical choice for site investigation offshore, especially for linear infrastructure, such as offshore wind export cables. Information gained from CPTs is key for predicting soil-structure interaction behaviour, for example when predicting the tow forces involved in seabed ploughing, as the CPT provides an analogue to the process. The numerical modelling of CPTs is challenging due to the significant distortion in the soil displaced by the penetrating cone. This means that solving this sort of problem using finite elements, although not impossible, is numerically tiresome in terms of remeshing and mapping of state variables. Therefore, in this paper we adopt the Material Point Method (MPM) to develop a CPT prediction tool in layered soils. This MPM is combined with a novel non-matching mesh frictional boundary to represent the penetrometer. The developed tool will be used to understand the response of layered soils commonly found offshore as a step towards predicting the interaction of ploughs and anchors with the seabed