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

In the search for low-cost year-round feeds: Pen-level growth performance of local and crossbred Ugandan pigs fed forage- or silage-based diets versus commercial diet

Smallholder pig farmers in East Africa report that lack of feed, seasonal feed shortages, quality and cost are key constraints to pig rearing. Commercially prepared pig diets are too expensive and people and pigs compete for food. Smallholder farmers typically feed nutritionally unbalanced diets, resulting in low average daily gain (ADG) and poor farmer profits. Our objective was to compare the ADG of Ugandan pigs fed forage- or silage-based or commercial diets. Ugandan weaner-grower pigs were randomly assigned to forage- or silage-based diets or commercial diet. Pigs were weighed every 3 weeks from 9 to 32 weeks of age. Pen-level ADG and feed conversion were compared across diets using multiple linear regression. The ADG of pigs fed forage- or silage-based diets was lower than those fed commercial diets between 9 and 24 weeks of age (p  0.05). Between 28 and 32 weeks, pigs fed forage-based diets had lower ADG than those on other diets (p  0.05). Least squares mean ADG (g/pig/day) for pigs fed forage- or silage-based diets or commercial diet were 36, and 52, and 294 respectively at 9–15 weeks; 163, 212, 329 at 15–19 weeks; 112, 362, 574 at 20–24 weeks and 694, 994, and 1233 at 28 to 32 weeks of age. It was concluded that forage- and silage-based diets are unsuitable for small, newly weaned pigs. Feeding forage- or silage-based diets to finishing pigs is more suitable. Forage- and silage based diets are year-round low-cost pig-feeding strategies that will improve the growth performance of East African pigs, thereby increasing pig farmer income and food security

Sea-level change: Living with uncertainty

Sea level change is a naturally occurring process. Since the last glacial maximum, some 18,000 years ago, de-glaciation has taken place and this natural global warming has led to sea-level rise of on average 120 m or so. At some times, pulses of melt water coming from large peri-glacial lakes led to rates of sea-level rise as high as 3 m per century. The rate slowed down some 7000 years ago and since then has been naturally fluctuating by only a few meters. The remaining global sea-level rise has been about 20 cm in the 20th century. Has this led to global disasters? The answer is no. If the projected rise over the 21st century is double what was seen in the 20th, is it likely that it will result in global disasters? Again, the answer is most likely no; human ingenuity, innovation and engineering, and the proper material and financial resources should solve local problems if and when they arrive, as they have in the 20th century (see the Dutch example). In this short and accessible monograph, Willem de Lange and Robert Carter describe and explain sea-level change, including the many remaining uncertainties in our full understanding of what exactly drives this change, and discuss the implications, mainly regarding coastal management. The monograph is intended for policy makers, but it should be informative for any educated reader. De Lange and Carter analyse the causes of sea-level change, and describe how it has been measured – with tide gauges over the past 100 to 150 years and from satellites over the past 30 years. Their key message is to recall that sea-level change is a local phenomenon, with high variability and multiple causes. In the 20th century, for a global average rise of 20 cm, there has been sea-level rise of up to twice that value in some places, but in others a drop of the same amount! Because of the melting of a large former ice cap over the Baltic area, the Earth’s viscous mantle is slowly deforming and as a result sea-level is decreasing in the North of the British Isles at the same time as it is rising on the south coast. Moreover, we have known since Darwin and understood since the plate tectonics revolution that atolls in the Pacific form over slowly subsiding volcanoes and will eventually drown (but at a slower ‘geological’ rate, due to thermal subsidence of the lithosphere on which they stand). In any case, the global average has no practical value in local or regional coastal management

Semiparametric Bayesian inference in smooth coefficient models

We describe procedures for Bayesian estimation and testing in cross-sectional, panel data and nonlinear smooth coefficient models. The smooth coefficient model is a generalization of the partially linear or additive model wherein coefficients on linear explanatory variables are treated as unknown functions of an observable covariate. In the approach we describe, points on the regression lines are regarded as unknown parameters and priors are placed on differences between adjacent points to introduce the potential for smoothing the curves. The algorithms we describe are quite simple to implement - for example, estimation, testing and smoothing parameter selection can be carried out analytically in the cross-sectional smooth coefficient model. We apply our methods using data from the National Longitudinal Survey of Youth (NLSY). Using the NLSY data we first explore the relationship between ability and log wages and flexibly model how returns to schooling vary with measured cognitive ability. We also examine a model of female labor supply and use this example to illustrate how the described techniques can been applied in nonlinear settings