Browsing by Author "Mutetikka, David"

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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.