Broilers perform better on short or step-up photoperiods

Rearing broilers on 6-h photoperiods and transferring them to 23 h at 21 d has been shown to reduce mortality and the incidence of leg disorders without adversely affecting final body weight or feed conversion efficiency. However, in many countries, welfare codes for meat chickens currently stipulate a minimum photoperiod of 8 h, and are likely to specify a minimum uninterrupted dark period of 8 h in the future. This paper reports a study of the response of two genotypes of broiler females to a lighting regimen that complies with these requirements: an initial 8-h photoperiod followed by a 16-h photoperiod from 21 to 42 d. Constant 8- and 16-h photoperiods were provided as controls. The two breeds responded similarly to all lighting treatments. Constant 8-h and photostimulated birds had significantly heavier body weights, and strong tendencies towards larger feed intakes and superior feed conversion, than the 16-h controls. Lighting treatment had no significant effect on mortality or the incidence of leg problems. Ross birds had a significantly slower growth to 21 d, higher feed intake after 21 d, and inferior feed conversion efficiency throughout than Cobb birds. Ross birds had significantly lower mortality and fewer leg disorders than Cobb, due possibly to their slower initial growth. South African Journal of Animal Science Vol. 37 (2) 2007: pp. 90-9

Growth and development of the reproductive organs of female breeding ostriches

CITATION: Olivier, T. R., Olivier, T. R. & Gous, R. M. 2009. Growth and development of the reproductive organs of female breeding ostriches. South African Journal of Animal Science, 39(5):260-262.The original publication is available at https://www.sasas.co.za/A study was conducted to determine the growth rate of the reproductive organs of breeding female ostriches, which may be used in a prediction model for estimating nutrient requirements of breeders. Forty breeding female ostriches were sampled over an eight week period (five per week) starting at the onset of the breeding season. The ovary and oviducts were collected and weighed at each slaughter interval. No significant trend in the weight of the oviduct of the ostriches could be observed over the 49 d period, this weight being highly correlated with the body weight of the ostrich, whereas the ovary weight tended to be correlated with the time after the onset of the breeding period, although the variation in weights both within and between weights was very high. The variation in the weight of the ovary probably reflects differences in the laying pattern of individuals, and this lends itself to simulating the ovulatory cycle and consequently gaining a better understanding of the process, which would in turn aid in determining the requirement for the nutrients responsible for the growth of the ova.https://www.sasas.co.za/journals/growth-and-development-of-the-reproductive-organs-of-female-breeding-ostriches/Publisher's versio

Predicted optimum ambient temperatures for broiler chickens to dissipate metabolic heat do not affect performance or improve breast muscle quality

<p></p><p>An experiment was conducted to test the hypothesis that muscle damage in fast-growing broiler chickens is associated with an ambient temperature that does not permit the birds to lose metabolic heat resulting in physiological heat stress and a reduction in meat quality.</p><p>The experiment was performed in 4 climate chambers and was repeated in 2 trials using a total of 200 male broiler chickens. Two treatments compared the recommended temperature profile and a cool regimen. The cool regimen was defined by a theoretical model that determined the environmental temperature that would enable heat generated by the bird to be lost to the environment.</p><p>There were no differences in growth rate or feed intake between the two treatments. Breast muscles from birds on the recommended temperature regimen were lighter, less red and more yellow than those from the cool temperature regimen. There were no differences in moisture loss or shear strength but stiffness was greater in breast muscle from birds housed in the cool compared to the recommended regimen.</p><p>Histopathological changes in the breast muscle were similar in both treatments and were characterised by mild to severe myofibre degeneration and necrosis with regeneration, fibrosis and adipocyte infiltration. There was no difference in plasma creatine kinase activity, a measure of muscle cell damage, between the two treatments consistent with the absence of differences in muscle pathology.</p><p>It was concluded that breast muscle damage in fast-growing broiler chickens was not the result of an inability to lose metabolic heat at recommended ambient temperatures. The results suggest that muscle cell damage and breast meat quality concerns in modern broiler chickens are related to genetic selection for muscle yields and that genetic selection to address breast muscle integrity in a balanced breeding programme is imperative.</p><p></p> <p>An experiment was conducted to test the hypothesis that muscle damage in fast-growing broiler chickens is associated with an ambient temperature that does not permit the birds to lose metabolic heat resulting in physiological heat stress and a reduction in meat quality.</p> <p>The experiment was performed in 4 climate chambers and was repeated in 2 trials using a total of 200 male broiler chickens. Two treatments compared the recommended temperature profile and a cool regimen. The cool regimen was defined by a theoretical model that determined the environmental temperature that would enable heat generated by the bird to be lost to the environment.</p> <p>There were no differences in growth rate or feed intake between the two treatments. Breast muscles from birds on the recommended temperature regimen were lighter, less red and more yellow than those from the cool temperature regimen. There were no differences in moisture loss or shear strength but stiffness was greater in breast muscle from birds housed in the cool compared to the recommended regimen.</p> <p>Histopathological changes in the breast muscle were similar in both treatments and were characterised by mild to severe myofibre degeneration and necrosis with regeneration, fibrosis and adipocyte infiltration. There was no difference in plasma creatine kinase activity, a measure of muscle cell damage, between the two treatments consistent with the absence of differences in muscle pathology.</p> <p>It was concluded that breast muscle damage in fast-growing broiler chickens was not the result of an inability to lose metabolic heat at recommended ambient temperatures. The results suggest that muscle cell damage and breast meat quality concerns in modern broiler chickens are related to genetic selection for muscle yields and that genetic selection to address breast muscle integrity in a balanced breeding programme is imperative.</p

Defining International Critical Care Pharmacist Contributions to Sepsis and Exploring Variability

Purpose of Review To define international clinical pharmacist contributions to managing sepsis in critically unwell patients and explore variation. Recent Findings Clinical pharmacists improve clinical outcomes and cost efficiencies. They provide pharmaceutical advice on selection, administration, plus monitoring of antimicrobials and supportive therapies. Logistical activities reduce drug administration times. Guideline production, patient/clinician education, prescribing error identification, plus therapeutic optimisation activities are also reported. Summary A survey incorporating semi-structured interviews identified further antimicrobial stewardship, prescribing and digital contributions to optimise sepsis management. However, disparities associated with multidisciplinary team integration and intensive care unit service provision were found. Variability was attributed to multifaceted physical, social, financial, training and education themes. Findings empower collaborations between pharmacists and stakeholders to identify and overcome contribution barriers. Strategies to mitigate barriers and enhance sepsis contributions were envisaged by reported aspirations. These emphasised the importance of professional advocacy, interprofessional education and impactful implementation research

Comparison of Xpert MTB/RIF with Other Nucleic Acid Technologies for Diagnosing Pulmonary Tuberculosis in a High HIV Prevalence Setting: A Prospective Study

In this prospective, real-world cohort study nested within a national screening program for tuberculosis, Lesley Scott and colleagues compare the performance of Xpert MTB/RIF on a single sputum sample with different TB sputum detection technologies

Ash agglomeration and deposition during combustion of poultry litter in a bubbling fluidized-bed combustor

peer-reviewedn this study, we have characterized the ash resulting from fluidized bed combustion of poultry litter as being dominated by a coarse fraction of crystalline ash composed of alkali-Ca-phosphates and a fine fraction of particulate K2SO4 and KCl. Bed agglomeration was found to be coating-induced with two distinct layers present. The inner layer (0.05–0.09 mm thick) was formed due to the reaction of gaseous potassium with the sand (SiO2) surface forming K-silicates with low melting points. Further chemical reaction on the surface of the bed material strengthened the coating forming a molten glassy phase. The outer layer was composed of loosely bound, fine particulate ash originating from the char. Thermodynamic equilibrium calculations showed slag formation in the combustion zone is highly temperature-dependent, with slag formation predicted to increase from 1.8 kg at 600 °C to 7.35 kg at 1000 °C per hour of operation (5.21 kg of ash). Of this slag phase, SiO2 and K2O were the dominant phases, accounting for almost 95%, highlighting the role of K-silicates in initiating bed agglomeration. The remaining 5% was predicted to consist mainly of Al2O3, K2SO4, and Na2O. Deposition downstream in the low-temperature regions was found to occur mostly through the vaporization–condensation mechanism, with equilibrium decreasing significantly with decreasing temperatures. The dominant alkali chloride-containing gas predicted to form in the combustion zone was KCl, which corresponds with the high KCl content in the fine baghouse ash

Brucellosis in Sub-Saharan Africa:Current challenges for management, diagnosis and control

Brucellosis is a highly contagious zoonosis caused by bacteria of the genus Brucella and affecting domestic and wild mammals. In this paper, the bacteriological and serological evidence of brucellosis in Sub-Saharan Africa (SSA) and its epidemiological characteristics are discussed. The tools available for the diagnosis and treatment of human brucellosis and for the diagnosis and control of animal brucellosis and their applicability in the context of SSA are presented and gaps identified. These gaps concern mostly the need for simpler and more affordable antimicrobial treatments against human brucellosis, the development of a B. melitensis vaccine that could circumvent the drawbacks of the currently available Rev 1 vaccine, and the investigation of serological diagnostic tests for camel brucellosis and wildlife. Strategies for the implementation of animal vaccination are also discussed.Publishe