Scielo RSS <![CDATA[South African Journal of Animal Science]]> http://www.scielo.org.za/rss.php?pid=0375-158920190003&lang= vol. 49 num. 3 lang. <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Probiotics as alternatives to antibiotics in treating post-weaning diarrhoea in pigs: Review paper</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300001&lng=&nrm=iso&tlng= The use of antibiotics to prevent post-weaning diarrhoea (PWD) in pigs has faced a setback owing to the associated antibiotic resistance in pigs and in the human populace that consumes the pork. In fact, antibiotic resistance that originates from the food chain is estimated to cause around 700,000 deaths globally each year. Consequently, scientists and researchers have suggested possible alternatives to antibiotics in pig diets. The chief of these has been the use of probiotics. The authors reviewed the literature on the use of probiotics as an alternative to antibiotics in treating PWD in pigs. It is clear that because of pathogenic Escherichia coli PWD continues to be a challenge to profitable swine production. The vast number of studies that was reviewed, point to the beneficial effects of probiotic supplementation on reducing the severity and incidence of PWD. However, some studies report inconsistencies to the general hypothesis. The majority of the microorganisms used as probiotics in the studies belong to the genera Lactobacilli, Bacillus, Bifidobacterium, Enterococcus, probiotic Escherichia coli, and Saccharomyces. The review also revealed that the bacterial strains that are used as probiotics are given individually or as combinations of multiple strains, and at various dosages, yielding varied results in each case. Interestingly, the authors observed wide disparities in the onset of probiotic supplementation and duration of the treatment to attain the results. Hence there is a need to standardize supplementation strategies, including dosage, onset and duration of treatment for probiotics. Furthermore, many of the in vivo studies that revealed positive effects of probiotics on diarrhoea and other production parameters were carried out in more controlled environments. The authors therefore suggest that more field studies in more natural and commercial farm settings should be conducted to augment the literature in relation to the use of probiotics as alternatives to antibiotics in treating PWD. <![CDATA[<b>Effect of betaine and ascorbic acid in drinking water on growth performance and blood biomarkers in meat ducks exposed to heat stress</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300002&lng=&nrm=iso&tlng= The aim of this study was to compare the effect of drinking water that contains various levels of ascorbic acid (AA) and betaine (BT) on growth performance and blood biomarkers in meat ducks exposed to heat stress. Six hundred and forty one-day-old Cherry Valley ducks were randomly assigned to one of seven treatment groups: i) control group, drinking water without ascorbic acid or betaine, ii) AA100, drinking water containing ascorbic acid at 100 milligrams per litre, iii) AA200, drinking water containing ascorbic acid at 200 milligrams per litre, iv) AA300, drinking water containing ascorbic acid at 300 milligrams per litre, v) BT400, drinking water containing betaine at 400 milligrams per litre, vi) BT800, drinking water containing betaine at 800 milligrams per litre, and vii) BT1200, drinking water containing betaine at 1200 milligrams per litre. The ducks were exposed to heat stress (11:00 to 17:00, 33 °C to 43 °C, relative humidity 70%, artificially controlled-environment houses) from the 22nd to 42nd days. Ducks from treatment groups AA300 and BT1200 displayed significantly increased bodyweight gains compared with those in the control group. Blood levels of glucose, and activities of aspartate aminotransferase and alanine aminotransferase in all treatment groups were significantly lower than those observed in the control group. Red blood cell count, platelet number, electrolytes and blood gas concentrations were significantly higher in all treatment groups compared with those in the control group. Blood pH levels in all treatment groups were lower than those in the control group. In conclusion, drinking water containing ascorbic acid or betaine improved the growth performance via biomarker homeostasis in blood of meat ducks exposed to heat stress. <![CDATA[<b>Ractopamine-induced changes in the proteome of post-mortem beef<i> longissimus lumborum </i>muscle</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300003&lng=&nrm=iso&tlng= Ractopamine is a beta-adrenergic agonist that is approved for use in beef cattle, pigs and turkeys as a repartitioning agent to increase lean muscle deposition and decrease lipogenesis. Although the effects of dietary ractopamine on the proteome profile of post-mortem pork muscles have been examined, its influence on beef muscle proteome has not been studied. Therefore, the objective of this study was to examine the effect of ractopamine on the proteome profile of post-mortem beef longissimus lumborum (LL) muscle. LL muscle samples were obtained from the carcasses of six (n = 6) steers fed ractopamine (RAC; 400 mg ractopamine hydrochloride for 28 days) and six (n = 6) steers fed no ractopamine (CON). The muscle proteome was analysed using two-dimensional gel electrophoresis and tandem mass spectrometry. Five differentially abundant spots were identified, and all the spots were over-abundant in RAC. The identified proteins were involved in muscle structure development (F-actin-capping protein subunit beta-2; PDZ and LIM domain protein-3), chaperone activity (heat shock protein beta-1), oxygen transport (myoglobin), and glycolysis (L-lactate dehydrogenase A chain). These results suggested that dietary ractopamine could influence the abundance of enzymes associated with muscle development and muscle fibre type shift in beef LL muscle. <![CDATA[<b>Effect of alternating total mixed ration and pasture feeding on the fatty acid content and health indices of Jersey and Fleckvieh x Jersey milk</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300004&lng=&nrm=iso&tlng= Certain fatty acids (FAs), such as omega-3 and conjugated linoleic acid (CLA) are considered essential FAs with beneficial health effects for humans. Milk is considered a relatively inexpensive and readily available source of these FAs and is part of a recommended healthy daily diet. The aim of the study was to determine the effect of diet changes on the FA composition of Jersey (J) and Fleckvieh x Jersey (FxJ) milk. Cows were alternately put on kikuyu-ryegrass pasture, followed by a feedlot system, then returned to kikuyu-ryegrass pasture for four weeks each. The same concentrate mixture was fed to cows regardless of feeding system. The feedlot system consisted of a partial total mixed ration (pTMR). Milk samples were collected two and four weeks after diet changes and stored at -20 °C until laboratory analysis by gas chromatography. The FA concentration of milk was not affected by breed, although it was affected significantly by diet changes. Most notably, the total omega-3 and -6 FAs decreased when cows were fed pTMR while increasing when the diet was changed back to pasture feeding. The CLA content of milk was similarly affected. That is, concentrations decreased significantly when the cows were on the pTMR diet and increased when cows were put back on the pasture-based diet. The results suggested that the health benefits of milk fat are affected negatively when cows are fed pTMR compared with being fed in a pasture-based system. The health benefits of milk are reduced owing to decreased levels of the CLA content of milk fat. Therefore, feeding additional hay in a pasture-based production system should be reconsidered when aiming to produce milk that provides health beneficial qualities. <![CDATA[<b>Effects of hourly, daily and seasonal variation of hazardous gases and climatic factors on the welfare of sheep housed in solid-floor confinement barns</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300005&lng=&nrm=iso&tlng= Ambient air quality in livestock buildings is one of the most important factors affecting environmental pollution and global warming. Carbon dioxide (CO2), methane (CH4), ammonia (NH3) and hydrogen sulphide (H2S) are among the most hazardous gases in terms of human and animal health. The aim of this study was to determine the effect of hourly, daily and seasonal variations in the levels of hazardous gases, such as CO2, CH4, NH3 and H2S in a solid-floor confinement sheep barn; as well as the effect of climatic parameters, temperature (T), relative humidity (RH) and air flow (AF) on animal welfare. The correlation between hazardous gases and climatic factors in the barn was also determined. The study was carried out on a sheep farm between July 2012 and June 2013 in Konya (Turkey) where few data are currently available on this subject. Climatic data were measured at intervals of five minutes at different points during this study, while hazardous gases were measured at the same intervals during the experimental periods (10 days for each season). All data were analysed by one-way analysis of variance (ANOVA) and Tukey's method was used to reveal intergroup differences. Cross-bilateral correlation between all data and different time periods was examined. There were significant differences between hourly and daily mean values of CO2, NH3, T, RH and AF. CO2 and NH3 levels showed a significant correlation with T and RH. Unfortunately, H2S and CH4 were below the level of detection in the study. Reducing the formation of these harmful gases, which have negative effects on animal production and cause environmental pollution, will be carried out with new sheep barn designs that take into account ambient air quality appropriate for animal welfare. <![CDATA[<b>Protease and phytase supplementation of broiler diets in which soybean meal is partially or completely replaced by raw full-fat soybean</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300006&lng=&nrm=iso&tlng= The nutrient composition and enzymatic in vitro nutrient digestibility of raw full-fat soybean (RFSB) were assessed prior to evaluating the influences of enzyme supplementation in diets in which commercial soybean meal (SBM) was partially (phase 1) or completely (phase 2) replaced by RFSB. A 2 x 2 + 1 arrangement was used in a two-phase feeding trial. In phase 1 (0 - 25 days) a positive control, commercial-type diet (PC), without RFSB or enzymes, and a negative control diet (NC), with 75 g RFSB/kg were used. The NC diet was supplemented with or without protease (0 or 15000 PRPOT/kg) and phytase (0 or 2000 FYT/kg). In phase 2 (26 - 31 days), RFSB (NC) or SBM (PC) was used as the sole source of crude protein (CP) for birds. Each treatment was replicated six times. Phases 1 and 2 had the same enzyme supplementation and treatment arrangements. The results showed that the concentration of trypsin inhibitors in RFSB as an ingredient was 16 564 TIU/g, and its CP in vitro digestibility was improved significantly by protease and protease plus phytase. Birds fed on PC and on NC plus protease and phytase finally consumed higher quantities of feed and had the highest bodyweight gain (BWG). Protease improved feed intake (FI), BWG and feed conversion ratio (FCR) by approximately 5.3%, 22.5% and 11.4%, respectively, in phase 2. Birds on the diet with protease plus phytase were 11.7% and 24.8% superior in BWG and FCR, respectively, to NC between 26 and 31 days. Supplementation with both enzymes reduced the weight of the pancreas. Supplementing NC with protease and phytase marginally improved the apparent ileal digestibility (AID) of protein and some amino acids (AA) at 25 and 31 days. Overall, BWG and feed efficiency of birds were improved by supplementation of both enzymes and, to a lesser extent, by protease on its own. <![CDATA[<b>Physical and mechanical characteristics of Hisex Brown hen eggs from three different housing systems</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300007&lng=&nrm=iso&tlng= The aim of this study was to compare physical and mechanical characteristics of Hisex hen eggs collected from three different housing systems: enriched cage housing, aviary housing, and free-range systems. The following physical and mechanical characteristics if eggs were compared: dimensions, surface area, volume, sphericity, shape index, shell thickness, weight, composition, yolk to albumen ratio, rupture force, specific deformation, absorbed energy, and firmness. The largest and heaviest eggs were collected from cage housing, followed by eggs from free-range systems and aviary housing. According to shape index, eggs from aviary housing can be described as round, while eggs from cage housing and free-range systems can be characterised as normal or standard. Eggs from free-range laying hens had the highest yolk percentage and yolk to albumen ratio (26.2% and 0.427). In comparison to eggs from aviary housing and free-range systems, eggs from enriched cage housing had the thickest shells and the highest shell strength, and required the highest force to rupture those eggs. The average force required to rupture Hisex Brown hen eggs from cage housing in all three axes was 44.14 N, which was 12.1% higher than the average force required to rupture eggs from a free-range system (39.37 N) and 17.1% higher than the average force required to rupture eggs from aviary housing (37.68 n). The highest forces required to rupture eggs from all three housing systems were determined on loading along the X-front axis and the lowest forces were determined along the Z-axis. The results obtained in this study can be useful to producers when selecting hen housing systems in order to reduce egg damage during storage and transport. <![CDATA[<b>Influence of low-tannin sorghum on performance and bone morphometries of male Ross 308 broilers aged 1 - 42 days</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300008&lng=&nrm=iso&tlng= The objective of this study was to determine the effects of low tannin sorghum as a maize replacement on the performance and bone morphometrics of Ross 308 broiler chickens. A total of 250 one-day-old broiler chickens were allotted to a complete randomized design with five treatments replicated five times. Birds were offered varying sorghum levels as maize replacement at 0% (control), 25%, 50%, 75% and 100%, formulated to be isonutritive and isoenergetic. The condensed tannin and total phenolic contents of the sorghum were analysed. Bodyweight and feed intake were measured weekly to calculate feed conversion ratio (FCR), and mortality was recorded as it occurred. Digestibility measurements were done when the chickens were between 15 and 21 days and between 35 and 42 days old. At ages 21 and 42 days, two chickens per pen were slaughtered to determine bone characteristics. A digital calliper was used to measure the length and diameter of the bones, and an electronic scale was used to determine the weight of the bones. Ash, calcium and phosphorus concentrations of the bones were determined. The Seedor and robusticity indices of the tibia were also calculated. The general linear model procedure of Statistical Analysis Software was used to analyse the data. At 1 - 21 days old bodyweight was higher for birds fed a level of 50% sorghum than those that were offered the control diet. Replacing maize with sorghum improved the metabolizable energy (ME) of broiler chickens aged 42 days. Bodyweight and FCR of birds fed diets with 50%, 75% and 100% sorghum were higher and better, respectively, than those on diets with 25% and 0% sorghum at 22 - 42 days old. Bone morphometries of chickens aged 1 - 21 days and 22 - 42 days were not affected by replacing maize with sorghum. Thus, maize can be replaced by a low tannin white sorghum without causing adverse effects on chickens. <![CDATA[<b>Responses of chemical composition, amino acid and fatty acid profiles of breast muscle to dietary crude fibre levels in China Micro-Ducks</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300009&lng=&nrm=iso&tlng= The effects of dietary crude fibre (CF) levels on the chemical composition, amino acid (AA) and fatty acid (FA) profiles of breast muscle in male China Micro-ducks (21 - 56 d) were investigated in this study. The birds were randomly allocated to four treatments, of which dietary CF levels were 16.7, 42.6, 77.9 and 101.6 g/kg of dry matter (DM), respectively. No influences on the proportions of crude ash, crude protein, lysine, methionine, threonine, phenylalanine, histidine, arginine, aspartic acid, glutamic acid, glycine, alanine, serine, cysteine, tyrosine, proline, C12:0, C18:0, C18:1n9, C20:0 and C22:1n9 in muscle were observed across the treatments. Consequently, the concentrations of semi-essential AA, non-essential AA, total AA, aromatic AA and delicious AA in muscle, along with the Δ-9-desaturase (18) index, were not affected by the treatments. Significant lower concentrations of valine, leucine, isoleucine, essential AA, branched-chain AA, C16:1n7 and monounsaturated FA in muscle, along with a lower ratio of branched-chain to aromatic AA, were noted in a dietary treatment with a CF level of 16.7 g/kg DM compared to other dietary treatments. The rise of the dietary CF level significantly increased the proportions of DM, ether extract, gross energy, C18:2n6, C18:3n3, C20:4n6, unsaturated FA, total FA, polyunsaturated FA, n-3 polyunsaturated FA, n-6 polyunsaturated FA, essential FA, and the Δ-9-desaturase (16) index. Furthermore, the rise of the dietary CF level increased the ratios of unsaturated to saturated FA, polyunsaturated to saturated FA, and n-6 to n-3 polyunsaturated FA in muscle. However, it decreased the atherogenic index and the proportions of C14:0, C16:0, and saturated FA significantly. In conclusion, depending largely on dietary levels, CF profoundly and positively influenced the nutritional quality of breast muscle, especially the FA profile. <![CDATA[<b>Effects of different probiotics on the gut microbiome and metabolites in the serum and caecum of weaning piglets</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300010&lng=&nrm=iso&tlng= The objective of the study was to determine the effects of antibiotics, yeast culture (YC), and Lactobacillus culture (LC) on the gut microbiome and metabolites in the serum and caecum of weaning piglets. Twenty-four weaning piglets were divided into four treatment groups: control, antibiotic (1% chlortetracycline), 1.8% yeast culture (YC), and 1.6% Lactobacillus culture groups (LC). Each group had six replicated pens with one pig per pen. Feed and water were available ad libitum. Dietary supplementation with antibiotics, YC and LC increased the abundance of phylum, Firmicutes, and decreased the abundance of phylum, Proteobacteria. Beneficial bacteria such as Lactobacillus and Megasphaera in YC and LC groups increased, whereas the proportion of Shigella was decreased. Genera Alloprevotella and Lachnospira were biomarkers in the control and antibiotic groups, respectively. Phylum, Bacteroidetes, and genus, Collinsella, were biomarkers in the YC group, and Mitsuokella, Anaerotruncus, Syntrophococcus and Sharpea were biomarkers in the LC group. Dietary supplementation with different probiotics changed the serum and caecum metabolite profiles too. Antibiotic supplementation increased the levels of D-mannose, D-glucose, and hexadecanoic acid in the serum, and the levels of myo-inositol, D-mannose and benzenepropanoic acid in the caecum. LC increased the concentrations of D-mannose, cis-9-hexadecenoic acid and heptadecanoic acid in caecum compared with the control group. YC and LC supplementation in the weaning diet could improve the abundance of beneficial bacteria by changing the concentrations of some metabolites in the serum and caecum. Therefore, dietary supplementation with YC or LC could be used as additives instead of antibiotics in weaning piglets. <![CDATA[<b>Influence of various dietary fat sources on freezing capacity of Moghani ram semen</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300011&lng=&nrm=iso&tlng= The aim of this study was to investigate the effects of dietary supplementation of protected fish oil (FO) and Persia fat® (PF) on the quality of Moghani ram semen. For this purpose, a total of 96 ejaculates were collected from 12 healthy mature Moghani rams, which were divided into three distinct groups (n = 4) and were assigned to one of three experimental diets. The first group (control) received a diet supplemented with palm oil (PO), while the second and third groups received encapsulated FO and PF, respectively. After primary evaluation, semen samples of each group were pooled to eliminate individual differences, and then evaluated for semen concentration and volume. Afterwards, the samples were diluted with a Tris-based extender and frozen with a standard protocol. After thawing, motion kinetics, viability, membrane functionality and abnormality were assessed. The results showed that the group that received FO had significanty higher viability (quadratic), progressive motility (PM) (%), average path velocity (VAP) (μm/s), curvilinear velocity (VCL) (μmΐ/s) (linear), amplitude of lateral head displacement (ALH) (μm) (quadratic) and sperm concentration (linear) than the others. Additionally, total motility (TM) (%) and straight-line velocity (VSL) (μmΐ/s) were significantly higher in the groups that received FO and PF compared with the control (quadratic) The results indicated that sperm abnormalities in the control group were significantly higher than the other groups. In conclusion, enrichment of the diet with FO or Persia fat could enhance ram sperm quality after freeze-thawing process. <![CDATA[<b>Performance and egg quality of laying hens fed different dietary levels of cashew nut shell liquid</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300012&lng=&nrm=iso&tlng= Organic acids have stood out as alternatives to antibiotic growth promoters, especially those extracted from plants, such as anacardic acid, which is present in cashew nut shell liquid (CNSL). This study evaluates the effects of CNSL as a source of anacardic acid in diets of laying hens on performance, egg quality, lipid stability of yolk and microbiological analysis of excreta. A total of 216 commercial Hisex White laying hens were housed in cages and distributed in a completely randomized design with six treatments and six replicates of six birds per treatment. Treatments consisted of a diet without antibiotic growth promoter (AGP); diet with AGP (Halquinol 60% at 0.1 g/kg and Enramycin 8% at 0.1 g/kg); and four diets without AGP and with the inclusion of 2.5, 5.0, 7.5 and 10.0 g/kg CNSL. No effects of dietary addition of AGP and CNSL were observed in bird performance and external quality of eggs. A quadratic effect was observed for lipid oxidation in egg yolk, the minimum value of which was found at 5.8 g/kg CNSL. There were no significant effects of treatments on total mesophilic, total coliform and thermotolerant coliform counts on excreta. In conclusion, adding up to 10.0 g/kg of CNSL as source of anacardic acid in laying hen diet did not influence performance or egg quality, but the addition from 7.5 g/kg of CNSL upwards reduced lipid oxidation and improved the yolk colour. <![CDATA[<b>Fermentation characteristics and chemical composition of elephant grass silage with ground maize and fermented juice of epiphytic lactic acid bacteria</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300013&lng=&nrm=iso&tlng= This study aimed to evaluate the microbial populations, fermentation profile, dry matter recovery and chemical composition of elephant grass silage with ground maize (GM) and the fermented juice of epiphytic lactic acid bacteria (FJLB). A factorial design was used with four levels of GM (0 g/kg, 50 g/kg, 100 g/kg and 200 g/kg), untreated or treated with FJLB, in a completely randomized design with five replicates. A pre-experiment was undertaken to determine the optimum level of sucrose to be added to fermented juice for the development of epiphytic microflora. In this pre-experiment, a completely randomized design with three replications was used. The treatments were represented by the levels of sucrose (0 g/kg, 5 g/kg, 10 g/kg, 20 g/kg, 40 g/kg, 60 g/kg and 80 g/kg, fresh matter basis). The microbial populations, dry matter recovery, and effluent losses were affected by the interaction between GM and FJLB. Dry matter (DM) and crude protein (CP) contents increased linearly with the inclusion of GM. The addition of GM enhanced the fermentation process via a reduction in losses, and improvements were identified in the nutritional value of elephant grass silages. The use of fermented juice increased dry matter recovery, and its effect was more pronounced when ground maize was added. <![CDATA[<b>Intensification of production, low emission pathways and sustainable strategies for backyard, layer and broiler chickens</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300014&lng=&nrm=iso&tlng= Meat and eggs produced by chickens represent an important economic resource in many economies. In future, global greenhouse gas (GHG) emissions produced by chickens will increase due to greater food demand. This study analyses the GHG emissions of chickens and identifies sustainable policy strategies for production intensification and GHG reduction. It advances beyond previous studies by combining GHG reduction and improving meat and egg production rather than reporting mitigation options only, and can thus provide low-emission pathways. The contemporaneous intensification of chicken production and GHG emission reduction are feasible for broiler, layer and backyard chickens in Moldova. For farmers, this important goal can be achieved by using feeds of good quality and high digestibility. An efficient utilization of feeds for backyard chickens (by a dietary replacement of 10% dry matter (DM) intake of fresh grass with 10% DM intake of barley) had the effect of reducing the total emissions to 78179, 79682 and 81238 tons of carbon dioxide-equivalent/year (t CO2-eq/year), increasing meat production to 2376, 2422 and 2469 t carcass weight/year and increasing egg production (in shell) to 47846, 48793, and 49741 t eggs/year with an increase of chickens of 2%, 6% and 10% per year, respectively. Policymakers can do a great deal to support the abatement of chicken emissions by developing long-term strategies, and regulations that are aimed towards mitigation targets and technologies. To effectively maximize emission reduction and increase production, however, policymakers must overcome the existing national barriers. <![CDATA[<b>Effect of litter type and perches on footpad dermatitis and hock burn in broilers housed at different stocking densities</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300015&lng=&nrm=iso&tlng= The aim of the study was to assess the effect of litter type and environmental enrichment on the occurrence of footpad dermatitis and hock burns in broilers housed at low and high stocking densities. Chopped straw and sand were used as litter, and perches as environmental enrichment. Low and high stocking density implied 12 chickens/m² and 20 chickens/m², respectively. The study sample was divided into four groups of 50 birds, which were observed during a six-week fattening period. A significantly higher rate of severe footpad dermatitis was recorded in the group of chickens raised on sand at high stocking density, compared with low stocking density, whereas no significant difference was found between the groups of chickens raised on straw at different stocking densities. The rate of footpad dermatitis was also significantly higher in the group of chickens raised on sand at high stocking density, compared with chickens raised on straw at the same stocking density. There were no group differences in the occurrences of hock burns and perching. However, a significant negative correlation was recorded between perching and the occurrence of footpad dermatitis and hock burns. According to the occurrence of footpad dermatitis and hock burns, the study results suggested that chopped straw and sand were equally acceptable as litter for broilers, yet sand should be avoided at high stocking densities. There was no effect of stocking density and litter type on perching, but perches as a form of environmental enrichment proved efficient in reducing the rate of footpad dermatitis and hock burns. <![CDATA[<b>Metabolic profile and histopathology of kidneys and liver of lambs fed silages of forages adapted to a semi-arid environment</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300016&lng=&nrm=iso&tlng= Thirty-two mixed-breed ram lambs (average age, 5.6 ± 0.4 months, and average live weight, 17.61 ± 2.63 kg) were used to evaluate the effect of diets containing silages of forages adapted to a semi-arid environment on the metabolic profile in serum and the histopathological assessment of liver and kidney tissues of the lambs. Lambs were allocated, in a completely randomised design, to four treatments (silage of old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), gliricidia (Gliricidia sepium) and 'pornunça' (Manihot sp.). The feedlot period was 49 days, and animals were slaughtered at an average weight of 27 ± 4.6 kg. On the last day of the experiment, blood was collected from the jugular vein of all animals to measure the protein, metabolic and energy profiles of the lambs. At slaughter, kidney and liver samples were collected for histopathological examination. The consuming of the diet containing buffelgrass silage resulted in a significantly higher activity of alanine-aminotransferase (30.14 IU/L) and the concentrations of urea (44.25 mg/dL), creatinine (0.94 mg/dL) and albumin (4.48 g/dL) in serum. Diets containing gliricidia silage resulted in significantly higher gamma-glutamyl transferase activity (92.0 IU/L), while the diets with pornunça silage resulted in higher serum levels of triglycerides (37.85 mg/dL). The diets had no effect on aspartate-aminotransferase enzyme activity and total protein, cholesterol and globulin concentrations, or the albumin : globulin ratio in serum. Mild congestion, necrosis and foci of mineralisation were observed in the kidneys of animals fed diets containing old man saltbush (50%) and pornunça (25%) silages, and mild fatty degeneration and mild mononuclear inflammatory infiltrate in their livers. In conclusion, diets containing silages of forages that are adapted to semi-arid environments may be used for feeding lambs, given the absence of dysfunctioning plasmatic levels of liver enzymes and energy and protein profiles. Additionally, kidney failure was not observed in lambs fed these diets during the feedlot period. <![CDATA[<b>Impacts of supplementing broiler diets with a powder mixture of black cumin, Moringa and chicory seeds</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300017&lng=&nrm=iso&tlng= The present study aimed at evaluating the effect of a phytogenic mixture in the diet on broiler production. A total of 400 day-old unsexed Cobb broiler chicks were randomly allotted to four treatment groups of 10 replications in a randomised design experiment. The phytogenic feed mixture (BMC) contained equal ratios of black cumin, Moringa oleifera and chicory seeds. The treatment groups were as follows: T1 was fed the basal diet, while T2, T3 and T4 were fed the basal diet supplemented with 0.2%, 0.4% or 0.6% of three BMC mixture, respectively. Results showed that increasing the dietary BMC level could be associated with a gradual but significant increase in body weight and improvement in the feed conversion ratio when compared with the control group. Broiler diets enriched with 0.4% to 0.6% of the BMC mixture reduced gut microbial count of coliforms, E. coli and C. perfringens as well as gut pH, compared to the control group. Increasing the dietary BMC mixture level was associated with gradual but significant decrease in serum total cholesterol, low density lipoprotein concentrations and liver enzymes concentrations. However, there was an increase in the high density lipoprotein concentration, and glutathione peroxidase and superoxide dismutase activity in serum. In conclusion, the BMC mixture could be deemed an effective growth promoter, but further research is needed to evaluate it as a viable alternative to antibiotics. <![CDATA[<b>Impacts of dietary inclusion of dried brewers' grains on growth, carcass traits, meat quality, nutrient digestibility and blood biochemical indices of broilers</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300018&lng=&nrm=iso&tlng= The current investigation aimed to evaluate the effect of dietary inclusion of dried brewers' grains (DBG) on growth performance, carcass traits, meat quality, nutrient digestibility, blood biochemical constituents and antioxidant indices of broiler chickens. A total of 300 unsexed one-week-old Hubbard chicks were randomly allotted to five treatment groups. The dietary treatments consisted of a basal diet as the control and DBG groups (3%, 6%, 9% and 12%, respectively). The best feed conversion ratio (FCR) was found in the group of birds fed a diet containing 9% DBG, compared the other groups. Dressing and abdominal fat percentages decreased significantly but gradually with the elevated DBG level in the diets from 6% to 12%. The inclusion of DBG in broiler diets resulted in significant positive effects on all of the sensory evaluation indicators except appearance and tenderness. Broilers fed a diet containing 3% DBG had significant higher of digestion coefficients for crude protein than those fed on the other experimental diets. Based on growth performance and health status, 3% or 9% DBG may be the optimum percentages for inclusion in the diets of poultry until six weeks old. In addition, DBG exerted several health benefits in meat, which would be reflected positively on human health. <![CDATA[<b>Ammonia levels on <i>in vitro </i>degradation of fibrous carbohydrates from buffel grass</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300019&lng=&nrm=iso&tlng= This study was carried out to examine the degradation dynamics of neutral detergent fibre (NDF) and the profile of volatile fatty acids that originate from the fermentation of buffel grass (Cenchrus ciliaris, L.) with various levels of ammonia in the growth medium. The treatments consisted of six levels of ammonia in the growth medium (0, 5, 10, 15, 20 and 30 mg/dL), which were obtained by adding urea. These in vitro incubation times were evaluated in three replicates per time for 0, 3, 6, 9, 12, 24, 36, 48, 72 and 96 hours. Rumen concentrations of acetate and propionate responded quadratically to the ammonia levels. The treatment with 15 mg/dL of ammonia nitrogen in the rumen fluid provided mean acetate and propionate contents of 57.6 mM and 23.1 mM, respectively. Urea addition elevated the degradation rate of potentially degradable fraction of NDF (pdNDF) from 2.5% to 20.1% in comparison with the treatment without urea and to a reduction in estimated discrete lag time from 0.34 to 2.31 hours. Urea supplementation increased the specific microorganism growth rate from 2.6% to 20.1%. At the end of the incubation trial, NDF degradation showed a quadratic response, with maximum value obtained at 17.76 mg/dL of ammonia in the rumen fluid. Urea improves the degradation dynamics of NDF from deferred buffel grass and increases the concentrations of acetate and propionate. <![CDATA[<b>Effect of shackling, electrical stunning and halal slaughtering method on stress-linked hormones in broilers</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892019000300020&lng=&nrm=iso&tlng= The objective of this study was to evaluate the effect of shackling and halal slaughter with head-only electrical stunning (ES) using water bath or no stunning (NS) on plasma levels of adrenaline (AD), noradrenaline (NAD) and corticosterone (CORT) levels of broiler chickens. Male and female broiler chickens (Cobb 500) 38 days old from a commercial farm in Johore, Malaysia, were placed in plastic crates (0.80 χ 0.60 χ 0.31 m) at 10 birds per crate, and transported for 2.5 hours in an open truck. The ambient temperature during transportation was 25 to 27 °C. Upon arrival at a commercial processing plant, a total of 50 male broiler chickens (2.2 - 2.5 kg) were randomly selected from the flocks that were delivered, transferred to different five crates (10 birds per crate) and held in a lairage for 2 to 3 h. Blood samples were collected at various points, namely after lairaging (P1) (first sampling point for both ES and NS chickens, regarded as basal values), shackling (P2) (second sampling point for both ES and NS chickens), stunning (P3) (third sampling point for ES chickens), and ventral neck incision in stunned (P4) (fourth sampling point for ES chickens) and no stun (P5) (third sampling point for NS chickens). Ten birds were sampled at each sampling point (50 birds in total). Both stunned and no stun birds were shackled. Results show that shackling (P2) did not significantly affect the AD, NAD and CORT levels. However, electrical stunning elevated both the AD and CORT levels significantly, but not NAD. Neck cut had negligible effect on the AD and NAD in NS and ES broilers, but significantly increased CORT compared with the basal CORT value. In conclusion, the study demonstrated that head-only electrical stunning using a water bath might elevate AD and CORT. The study concluded that, as measured by AD and NAD, slaughter with or without stunning may not induce a physiological stress response in broilers.