Browsing by Author "Mpairwe, Denis"

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    Behavioural response of pure Ankole and crossbred(Ankole × Holstein) cows to seasonal pasturevariations in south-western Uganda
    (Applied Animal Behaviour Science, 2016) Idibu, Joachine; Kabi, Fred; Mpairwe, Denis
    tThis study evaluated the effects of season and pasture species on variations in sward composition, pasture quantity (plant-height and biomass) and quality [crude protein (CP), neutral detergent fibre (NDF)and in vitro organic matter digestibility (IVOMD)]. Behavioural responses of a group of 10 pure Ankole and another of 10 crossbred (Ankole × Holstein) cows to the seasonal variations in pasture quantity and quality were also examined. Irrespective of season, the dominant pasture species was Brachiaria decum-bens, with scanty presence of Hyparrhenia rufa, Themeda triandra, Sporobolus pyramidalis and Cymbopogonafronardus. The sward height, biomass, CP, NDF and IVOMD were dependent on both season and species(P < 0.001). Whereas the sward-height and biomass of B. decumbens, H. rufa, and T. triandra peaked during the rainy season, that of C. afronardus and S. pyramidalis peaked in the dry season. During the grazing cycle, a minimum plant-height of 31 cm and forage biomass of 118 g/m2, an equivalent of 1180 kg/ha,was recorded for most of the pasture species. The CP content of the pasture species were below 7%,irrespective of season, except for B. decumbens which had 8.7% CP in the rainy season. Minimum NDFcontent for all the pasture species was 67% and 50% during the dry and rainy seasons, respectively. Con-sequently, IVOMD ranged between 29–61% and 51–65% during the dry and rainy seasons, respectively. Ankole and the crossbred cows increased the number of feeding stations, bites and residence time in patches of species, which were scantly grazed in the rainy season. They also increased standing (P < 0.01)at the expense of walking (P < 0.001) and social activities (P < 0.001). Irrespective of season, more than40% of grazing occurred in B. decumbens patches and both genotypes grazed for ¾ of the time on pasture.However, the crossbred cows required extended grazing duration, resulting into less lying and rumi-nation (P < 0.05) on pasture than the Ankole cows. Ankole and the crossbred cows grazed locales with high pasture ground cover and biomass. However, locales with high CP but low forage quantity were also grazed. This study revealed that at an appropriate stocking rate, sufficient forage supply was possible in both seasons. However, the low CP content and less preference for majority of the dominant species compelled the Ankole and the crossbred cows to graze for a long time. Thus, the crossbred cows were constrained by time in both the dry and rainy seasons.
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    Effects of feeding systems on rumen environment, degradability and passage kinetics in Ankole × Friesian crossbred steers
    (Livestock Science, 2018) Asizua, Denis; Mpairwe, Denis; Kabi, Fred; Mutetikka, David; Budara Bareeba, Felix; Hvelplund, Torben; Riis Weisbjerg, Martin; Madsen, Jørgen
    Natural pastures constitute a large proportion of the feed resource base for meat and milk production in Sub- Saharan Africa. However, there is increasing use of agro-industrial by-products, especially those that are cerealbased as supplementary feedstuff to grazing animals and in diets under semi-intensive and intensive production systems. This study evaluated the influence of feeding systems on rumen environment, degradability and passage kinetics. Six Ankole x Friesian F1 crossbred steers weighing 339 ± 29 kg (about two years of age), each fitted with permanent rumen cannula were used in a replicated 3×3 Latin square design (ns =2). Two steers were allocated per period to one of three feeding systems i.e. (1) sole grazing (control), (2) control plus concentrate supplement (composition g/kg DM: 375 maize bran, 559 brewer's spent grain, 62.5 molasses and 3.75 NaCl), and (3) feedlot systems where steers were fed total mixed ration (TMR) comprising g/kg DM: 200 maize stover, 300 maize bran, 447 brewers’ spent grain, 50 molasses and 3 NaCl. Data was collected on rumen pH, ammonianitrogen (NH3-N), volatile fatty acids (VFA) and degradability of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF). Rumen pH was lowest (P < 0.001) at feedlot (5.3) but highest (P < 0.001) under sole grazing (6.2). Rumen NH3-N ranged between 62.8 and 120 mg/l and was higher (P < 0.001) in sole grazing than in grazing but supplemented steers and those at the feedlot. Total VFA concentration for sole grazing steers (124 mmol/Mol) was higher (P < 0.05) than values observed under feedlot (102 mmol/Mol) while grazing but supplemented steers showed an intermediate value (108 mmol/Mol), not differing significantly from the two other systems. Molar proportion of acetate was higher (P < 0.001) in grazing steers compared to values for either grazing but supplemented or those under feedlot while the reverse was true for propionate. The degradation characteristics of DM, CP and NDF were generally higher in sole grazing steers. Although, in most cases, the influence of feeding system on degradability was dependent on the type of feedstuff, feeding systems did not influence total mean retention time. The high extent of DM, CP and fiber degradation in grazing steers compared to supplemented and feedlot steers demonstrates that forage diversity under grazing positively influences degradability. However, attention to the nature and fermentation characteristics of proteins and carbohydrate sources and how they modify rumen environment in different production systems is needed to improve utilization of supplements and TMR.
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    Effects of grazing and feedlot finishing duration on the performance of three beef cattle genotypes in Uganda
    (Livestock Science, 2017) Asizua, Denis; Mpairwe, Denis; Kabi, Fred; Mutetikka, David; Hvelplund, Torben; Weisbjerg, Martin Riis; Madsend, Jørgen
    Beef production in Uganda is progressing from the traditional pastoral practices to sedentary semi-intensive systems. Consequently, farmers are continuously crossbreeding the indigenous cattle with exotic genotypes to improve meat yield. This study was conducted on-farm to evaluate the effects of feeding systems and feeding durations on performance of three locally available genotypes. A 2×3×3 factorial experiment was used to randomly allot 108 young bulls (9–15 months old), 36 for each of the three genotypes; Ankole x Holstein Friesian (AXF) (175±22 kg), pure Boran (208±34 kg) and a composite genotype (212±35 kg). The bulls were allotted to two feeding systems and three finishing durations. The feeding systems comprised sole grazing as the control where animals only grazed natural pastures and feedlot finishing where animals were fed a locally formulated total mixed ration containing 200 maize stover, 300 maize bran, 447 brewers’ spent grain, 50 molasses and 3 salt (NaCl) as g/kg on dry matter (DM) basis. The three durations were 60, 90 and 120 days excluding 14 days of adaptation period. Data was collected on feed intake, growth, slaughter and carcass characteristics. The Boran consumed less DM per kg of body weight gain than the AXF and composite. Feed conversion ratio (kg DM/kg body weight gain) ranged between 6.3±0.6 to 8.2±1.5 at the feedlot and 11.1± 4.1 to 17±4.0 for all genotypes and all durations. Growth and slaughter characteristics did not vary (P>0.05) between genotypes. However, carcass quality grade scores were higher (P<0.05) in the pure Boran and the composite genotypes than in the AXF crossbreds at 120 days of finishing. Average daily live weight gain (ADG) for all genotypes was approximately twice under feedlot finishing compared to sole grazing while hot carcass weight under feedlot was only higher than that of sole grazing by 30 kg in AXF, 37 kg in Boran and 45 kg in composite genotype at 120 days of finishing. Hot carcass weight and dressing percentages were similar (P> 0.05) between genotypes irrespective of the feeding system for all durations but hot carcass weight was higher (P<0.05) at the feedlot for all durations. Therefore, intensification through feedlotting is a viable option for improving beef production. However, understanding the appropriate levels of crossing between genotypes is needed to achieve the desired improvement in productivity from crossbreds.
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    Greenhouse gas emissions from Uganda's cattle corridor farming systems
    (Agricultural systems, 2019) Kiggundu, Nicholas; Ddungu, Stanley Peter; Wanyama, Joshua; Cherotich, Sam; Mpairwe, Denis; Zziwa, Emmanuel; Mutebi, Faizal; Falcucci, Alessandra
    The objective of this study was to estimate the greenhouse gas (GHG) emissions from practised cattle farming systems (Stall, Semi-Intensive, Grazing, Tethering and Scavenging) and identify potential areas for GHG mitigation. Using the Global Livestock Environmental Assessment Model (GLEAM-i), GHG emissions in 2016 were 2009 Gg CO2-eq/yr of which the Grazing system contributed 88.5%. Enteric fermentation produced about 75.8% of the total GHG emissions. At an annual growth rate of 3%, the projected GHG for 2020 and 2025 would increase by 12.6% and 30.7% respectively. The milk and meat emission intensities were far higher than the global averages. A reduction in grazing by 10% and a 10% increase in use of anaerobic digesters to handle manure resulted in a 4.4% reduction in annual GHG emission.