16 research outputs found
Validity of Weight Estimation Models in Pigs Reared under Different Management Conditions
A study was carried out to determine the relationship between linear body measurements and live weight in Landrace and Large White pigs reared under different management conditions in Zimbabwe. Data was collected for body length, heart girth, and live weight in 358 pigs reared under intensive commercial conditions. The stepwise multiple linear regression method was done to develop a model using a random selection of 202 records of pigs. The model showed that age, body length, and heart girth were useful predictors of live weight in these pigs with significantly high positive correlations observed. The model was internally validated using records of the remaining 156 pigs and there was a significantly high positive correlation between the actual and predicted weights. The model was then externally validated using 40 market age pigs reared under communal conditions and there was a significantly low positive correlation between the actual and predicted weights. The results of the study show that while linear measurements can be useful in predicting pig weights the appropriateness of the model is also influenced by the management of the pigs. Models can only be applicable to pigs reared under similar conditions of management
Recommended from our members
Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Growth performance of Brangus steers fed graded levels of sun-dried broiler litter as a substitute for cottonseed cake
An experiment was conducted to determine the optimum inclusion levels of dried broiler litter (DBL) as a substitute for cottonseed cake (CSC) in fattening diets for Brangus steers. Thirty Brangus steers were randomly allocated to five groups of six animals each. Each group was fed one of the experimental diets which had CSC substituted for DBL at levels of 0 (DBL0), 50 (DBL50), 100 (DBL100), 150 (DBL150) and 200 g/kg (DBL200). Average daily gain (ADG), dry matter intake and live weight gain (LWG) were measured over a period of 90 days, and the results were analysed using the MIXED procedures of SAS. Linear and quadratic effects of DBL inclusion on dry matter intake, LWG and ADG were also determined. Results showed interactions between diet and time that significantly affected ADG and LWG (p < 0.05). Both ADG and LWG decreased with increases in DBL inclusion with the depressed performance becoming more pronounced with time. Linear and non-linear decreases in LWG and ADG, respectively, were observed with increasing levels of DBL. The DBL50 diet resulted in performance that was similar to DBL50 and was 4 % cheaper. Broiler litter can be used as a supplement for conventional protein sources, but at higher inclusion levels, it needs to be augmented by increased fermentable energy
Sow removal in a commercial pig herd in Zimbabwe
A study was carried out at a 2,200 sow farrow-finisher facility in Zimbabwe to determine the main reasons for sow removal and the season when removal was most common. Data on the number of sows culled and the reasons for culling as well as mortalities was recorded weekly for a 12-month period. The culling frequency was 52.8 % (n = 1 162). Descriptive statistics indicated that reproductive problems accounted for 70.8 % (n = 823) of sow removals, death (15.6 %, n = 181), lameness (4.6 %, n = 53), miscellaneous (2.5 %, n = 29), production (2.2 %, n = 26), peripartum (2.2 %, n = 25) and age (2.2 %, n = 25). The results also showed that culling was highest in gilts and primiparous sows (41.3 %, n = 480) with the least culling being observed in sows in parity 7 (5.3 %, n = 61). The hot wet season was observed to be the one when culling was most common (33.5 %, n = 389) with the least being in the cold dry season (17 %, n = 198). It was concluded that most of the sow removal was unplanned. There is a need to improve replacement gilt selection, reproductive efficiency, health and nutrition management to increase productivity in a sow unit
Sow removal in a commercial pig herd in Zimbabwe
A study was carried out at a 2,200 sow farrow-finisher facility in Zimbabwe to determine the main reasons for sow removal and the season when removal was most common. Data on the number of sows culled and the reasons for culling as well as mortalities was recorded weekly for a 12-month period. The culling frequency was 52.8 % (n = 1 162). Descriptive statistics indicated that reproductive problems accounted for 70.8 % (n = 823) of sow removals, death (15.6 %, n = 181), lameness (4.6 %, n = 53), miscellaneous (2.5 %, n = 29), production (2.2 %, n = 26), peripartum (2.2 %, n = 25) and age (2.2 %, n = 25). The results also showed that culling was highest in gilts and primiparous sows (41.3 %, n = 480) with the least culling being observed in sows in parity 7 (5.3 %, n = 61). The hot wet season was observed to be the one when culling was most common (33.5 %, n = 389) with the least being in the cold dry season (17 %, n = 198). It was concluded that most of the sow removal was unplanned. There is a need to improve replacement gilt selection, reproductive efficiency, health and nutrition management to increase productivity in a sow unit
Effect of Cow Urine on the Growth Characteristics of Fusarium lateritium, an Important Coffee Fungus in Zimbabwe
An in vitro assay was carried out to establish if cow urine at different concentrations (500 µL/mL, 300 µL/mL, 200 µL/mL, and 100 µL/mL) can be used to control the growth of F. lateritium, the fungal agent causing Fusarium bark disease in coffee. The growth characteristics selected were conidial germination, germ tube length, mycelial growth rate, and sporulation. Copper oxychloride 50% W.P. was the standard, distilled water was the negative control, and undiluted cow urine was the positive control. The undiluted cow urine was most effective in inhibiting fungal growth with the rest of the cow urine concentrations showing dose dependent efficacy compared to the negative control (P < 0.01). Copper oxychloride had the highest efficacy of all treatments with the exception of the inhibition of mycelial growth where undiluted cow urine had higher efficacy and sporulation where efficacy was comparable to undiluted cow urine. There is potential for the use of cow urine as a means of controlling Fusarium bark disease with other advantages being availability, low cost, and limited environmental damage
Efficacy of different concentrations of aloe chabaudii leaf gel as a substitute for a sulfonamide for the control of avian coccidiosis
The objectives of this study were to investigate the effectiveness of Aloe chabaudiiSconland juice as a potential substitute of sulphonamide drugs and to measure its effects when administered at different concentrations in the control of avian coccidiosis. Thirty Cobb 500 broiler chickens were used for the
experiment. The broilers were randomised into six groups of five birds each and the groups were assigned
to six treatments in a Complete Randomised Design (CRD). Four of the groups were given any one of the
following treatments, different concentrations of Aloe (weight/volume: 10%, 20% and 30%) and a sulphonamide. There was a control group which was not given a treatment and one cohort group which
was neither infected nor treated (Control). At two weeks of age, 25 of the birds were infected with coccidia
via drinking water using infected chicken feacal matter, while the remaining five birds were left uninfected.
Infection proceeded for 1 week and after the infection period, feacaloocysts were counted from each individual bird using the McMaster technique. Treatments started one day post infection and continued for one week where after 20 gram samples of feacal matter were taken from each bird per treatment and oocysts were counted. After oocyst counting, all birds were slaughtered and lesion scoring was done on the intestines using the Johnson and Reid technique. Data was analysed for oocysts count in different treatments, feacal egg count reduction, relative risk of coccidiosis and the effectiveness of aloe concentrations as a substitute for a commercial sulphonamide. The results showed that the concentrations of aloe used in the experiment were not effective as compared to the sulphonamide in controlling coccidiosis as the feacal egg reduction was below 90% for all concentrations. The relative risk of coccidiosis infection in the farm was found to be 100% meaning coccidiosis is a disease of economic importance at the farm. However there was a reduction in the feacaloocyst count with increase in aloe juice concentration to control coccidiosis, though this could be not be compared to the sulphonamide used (ESB3) which was more effective (p<0.05). This study has shown that there is potential for use of Aloe chabaudii leaf gel as a chemotherapeutic though much research is needed to determine absolute concentrations which will make it comparable to commercially available drugs in terms of efficacy
Effect of Cow Urine on the Growth Characteristics of Fusarium lateritium, an Important Coffee Fungus in Zimbabwe
Validity of weight estimation models in pigs reared under different management conditions
A study was carried out to determine the relationship between linear body measurements and live weight in Landrace and Large White pigs reared under different management conditions in Zimbabwe. Data was collected for body length, heart girth, and live weight in 358 pigs reared under intensive commercial conditions. The stepwise multiple linear regression method was done to develop a model using a random selection of 202 records of pigs.The model showed that age, body length, and heart girth were useful
predictors of live weight in these pigs with significantly high positive correlations observed.The model was internally validated using records of the remaining 156 pigs and there was a significantly high positive correlation between the actual and predicted weights. The model was then externally validated using 40 market age pigs reared under communal conditions and there was a significantly low positive correlation between the actual and predicted weights. The results of the study show that while linear measurements
can be useful in predicting pig weights the appropriateness of the model is also influenced by the management of the pigs. Models can only be applicable to pigs reared under similar conditions of management
Effect of cow urine on the growth characteristics of fusarium lateritium, an important coffee fungus in Zimbabwe
An in vitro assay was carried out to establish if cow urine at different concentrations (500 uL/mL, 300 uL/mL, 200 uL/mL, and 100 uL/mL) can be used to control the growth of F. lateritium, the fungal agent causing Fusarium bark disease in coffee. The growth characteristics selected were conidial germination, germ tube length, mycelial growth rate, and sporulation. Copper oxychloride 50% W.P. was the standard, distilled water was the negative control, and undiluted cow urine was the positive control. The undiluted
cow urine was most effective in inhibiting fungal growth with the rest of the cow urine concentrations showing dose dependent efficacy compared to the negative control (P < 0.01). Copper oxychloride had the highest efficacy of all treatments with the exception
of the inhibition of mycelial growth where undiluted cow urine had higher efficacy and sporulation where efficacy was comparable to undiluted cow urine. There is potential for the use of cow urine as a means of controlling Fusarium bark disease with other advantages being availability, low cost, and limited environmental damage