Use of red grape pomace and Aloe vera gel as nutraceuticals to ameliorate stocking density-induced stress in commercial male broilers

The combined effect of Aloe vera gel (AVG) administered through drinking water and dietary red grape pomace powder (RGP) on growth performance, physiological traits, welfare indicators, and meat quality in densely stocked broilers was evaluated. A total of 750, two-week-old male Ross 308 broilers (317.7 ± 10.12 g live weight) were randomly assigned to 25 cages, with each cage as an experimental unit. The broilers were stocked at a density of 30 birds per cage with a floor space of 1.32 m2. Dietary treatments were a standard grower or finisher diet (CON); CON containing 30 g RGP /kg diet plus either 1 (GPA1), 2 (GPA2), 3 (GPA3), or 4% (GPA4) AVG in drinking water. Treatment GPA1 promoted higher (P < 0.05) overall weight gain and overall feed conversion ratio (FCR) than CON. Positive quadratic effects (P < 0.05) were noted for mean corpuscular hemoglobin, basophils, 24-hour breast meat yellowness, chroma, and hue angle. The GPA2 group had the lowest (P < 0.05) gait score while the CON group had the highest score. Concurrent supplementation with a 30 g RGP /kg diet plus 1% AVG in drinking water enhanced weight gain, FCR, and finisher weight of densely stocked broilers. However, AVG doses beyond 1% did not enhance performance and physiological traits in densely stocked broilers.

Comparative genomics and proteomics analysis of phages infecting multi-drug resistant Escherichia coli O177 isolated from cattle faeces

The increasing prevalence of antimicrobial-resistant (AMR) pathogens has become a major global health concern. To address this challenge, innovative strategies such as bacteriophage therapy must be optimised. Genomic characterisation is a crucial step in identifying suitable phage candidates for combating AMR pathogens. The aim of this study was to characterise seven phages that infect the Escherichia coli O177 strain using a whole genome sequencing. The analysis of genome sequences revealed that these phages had linear dsDNA, with genome sizes spanning from 136, 483 to 166,791 bp and GC content varying from 35.39 to 43.63%. Taxonomically, the phages were classified under three different subfamilies (Stephanstirmvirinae, Tevenvirinae, and Vequintavirinae) and three genera (Phapecoctavirus, Tequatrovirus, and Vequintavirus) within the class Caudoviricetes. In silico PhageAI analysis predicted that all the phages were virulent, with confidence levels between 96.07 and 97.26%. The phage genomes contained between 66 and 82 ORFs, which encode hypothetical and putative functional proteins. In addition, the phage genomes contained core genes associated with molecular processes such as DNA replication, transcription modulation, nucleotide metabolism, phage structure (capsid and tail), and lysis. None of the genomes carried genes associated with undesirable traits such as integrase, antimicrobial resistance, virulence, and toxins. The study revealed high genome and proteome homology among E. coli O177 phages and other known Escherichia phages. The results suggest that the seven phages are new members of the genera Phapecoctavirus, Tequatrovirus, and Vequintavirus under the subfamilies Stephanstirmvirinae, Tevenvirinae, and Vequintavirinae, respectively.

Stocking density-induced changes in growth performance, blood parameters, meat quality traits, and welfare of broiler chickens reared under semi-arid subtropical conditions

Broiler production in semi-arid tropics must contend with high levels of heat stress, which have implications on stocking density, bird welfare, and profitability. Under these conditions, optimal stocking densities are likely to be lower than expected, thus must be experimentally determined. Therefore, this study investigated growth performance, haematology, serum biochemistry, carcass and meat quality, sizes of internal organs, and stress biomarkers in response to different stocking densities in broilers reared under semi-arid subtropical conditions. Five hundred, day-old Ross 308 broilers (44.0 ± 5.24 g live-weights) were randomly distributed to 25 replicate pens (1.32 m² floor space each) to create five stocking densities: 1) 10 birds/pen (SD10); 2) 15 birds/pen (SD15); 3) 20 birds/pen (SD20); 4) 25 birds/pen (SD25); and 5) 30 birds/pen (SD30). There was a linear decrease (P < 0.05) in overall feed intake and weight gain in weeks 2 and 3 as stocking density increased. However, weight gain showed positive and negative quadratic responses (P < 0.05) in weeks 5 and 6, respectively, as stocking density increased. No linear or quadratic effects (P ˃ 0.05) were observed for overall feed conversion ratio, haematological parameters, and meat quality traits in response to stocking density. Symmetric dimethylarginine, alanine transaminase, and albumin levels quadratically increased (P < 0.05) in response to increasing stocking densities. Serum glucose and thigh weight were not affected (P < 0.05) while final body, drumstick, breast, and wing weights linearly declined with stocking density. Increasing stocking density linearly reduced (P < 0.05) the weights of gizzard, proventriculus, caecum, and colon. Stocking density had no effect (P ˃ 0.05) on latency-to-lie. It was concluded that higher stocking densities compromised feed intake, resulting in poor weight gains. Based on weight gain trends observed in week 5, it was determined that Ross 308 broilers should be reared at no more than 20 birds/pen (~15 birds/m² or 27.27 kg/m²) under the experimental ambient conditions compared to the much higher globally accepted industry standard of 20 birds/m².

Prospects of dietary seaweeds and their bioactive compounds in sustainable poultry production systems: A symphony of good things?

Modern poultry production systems face numerous economic, environmental, and social sustainability challenges that threaten their viability and acceptability as a major source of animal protein. As scientists and producers scramble to find cost-effective and socially acceptable solutions to these challenges, the dietary use of marine macroalgae (seaweeds) could be an ingenious option. Indeed, the incredible array of nutritive and bioactive compounds present in these macroscopic marine organisms can be exploited as part of sustainable poultry production systems of the future. Incorporating seaweeds in poultry diets could enhance feed utilization efficiency, growth performance, bird health, meat stability and quality, and consumer and environmental health. Theoretically, these benefits are mediated through the putative antiviral, antibacterial, antifungal, antioxidant, anticarcinogenic, anti-inflammatory, anti-allergic, antithrombotic, neuroprotective, hypocholesterolemic, and hypoglycemic properties of seaweed bioactive compounds. Despite this huge potential, exploitation of seaweed for poultry production appears to be constrained by a variety of factors such as high fibre, phenolics, and ash content. In addition, conflicting findings are often reported when seaweeds or their extracts are used in poultry feeding trials. Therefore, the purpose of this review paper is to collate information on the production, phytochemical components, and nutritive value of different seaweed species. It provides an overview ofin vivoeffects of dietary seaweeds as measured by nutrient utilization efficiency, growth performance, and product quality and stability in poultry. The utility of dietary seaweeds in sustainable poultry production systems is explored, while gaps that require further research are highlighted. Finally, opportunities that exist for enhancing the utility of seaweeds as a vehicle for sustainable production of functional poultry products for better global food and nutrition security are presented.

Simultaneous pre-treatment of dietary Moringa oleifera leaf meal with polyethylene glycol and fibrolytic enzymes: Effect on growth performance, physiological indices, and meat quality parameters in jumbo quail

The utility of Moringa oleifera leaf meal (MOLM) as a source of biologically active substances and nutrients for Jumbo quail is limited by high concentrations of condensed tannins and fiber. Simultaneous application of polyethylene glycol (PEG), a tannin-binding compound, and exogenous fibrolytic multi-enzymes could ameliorate antinutritional effects of condensed tannins and fiber thus improving MOLM utilization in quail diets. This study investigated the effect of pre-treating dietary MOLM with PEG and fibrolytic enzymes on live performance, blood parameters, visceral organs, and carcass and meat quality characteristics in Jumbo quail. A total of 381, two-week-old quail chicks (57.5 ± 3.95 g live-weight) were randomly distributed to six dietary treatments replicated six times. The treatments were: T1 = a standard grower diet containing untreated MOLM (10%); T2 = a standard grower diet containing MOLM (10%) pre-treated with 5.4% PEG; and a standard grower diet containing MOLM (10%) pre-treated with 5.4% PEG and 1.25% (T3), 1.50% (T4), 1.75% (T5) and 2.0% (T6) fibrolytic multi-enzymes. Graded levels of enzymes did not induce linear or quadratic effects for overall feed intake, feed conversion efficiency, hematological, carcass, and meat quality parameters in response to increasing fibrolytic enzyme levels. However, weight gain in week 3 quadratically responded [R2 = 0.117, P = 0.043]. Three-week old birds reared on T3 had lower (p &lt; 0.05) weight gains (40.9 g/bird) than those reared on the other treatment groups. Birds reared on T6 diet had longer caecum (14.1 cm) than those reared on T2, T3, T4 and T5 whose caeca lengths did not differ (P &gt; 0.05). Birds reared on diet T5 had shorter small intestines (59.5 cm) than those reared on T1 and T2 diets. It can be concluded that simultaneous pre-treatment of dietary MOLM with PEG and fibrolytic enzymes did not improve live performance, blood parameters, and carcass and meat quality traits, but affected some visceral organ sizes in Jumbo quail.

Data on complete genome sequence and annotation of two multidrug resistant atypical enteropathogenic Escherichia coli O177 serotype isolated from cattle faeces

Atypical enteropathogenic E. coli belonging to the serotype O177 is a rare strain found in ruminants, especially cattle. When compared to shiga toxin producing E. coli (STEC) O157 and non-O157 STEC (O26, O45, O103, O104, O111, O121, and O145) serotypes, the antimicrobial resistance, virulence factors, and genomic structure of E. coli O177 are poorly understood. Therefore, in this article, we present the whole genome sequence data of two aEPEC E. coli O177 isolates (E. coli O177_CF-154-A and E. coli O177_CF-335-B) generated using Illumina MiSeq platform. The raw data were generated, cleaned, and assembled using Trimmomatic and SPAdes. Genome data analysis yielded 5,112,402 and 5,460,435 bp, comprising contigs 101 and 191 with GC contents of 50.7% and 50.5% for E. coli O177_CF-154-A and E. coli O177_CF-335-B, respectively. Prokaryotic Genome Annotation Pipeline (PGAP) and Rapid Annotation using Subsystem Technology (RAST) showed that the complete genome of E. coli O177_CF-154-A contained 5040 coding sequences (CDS), 5146 genes, 4896 proteins, 90 RNAs, and 78 tRNA while that of E. coli O177_CF-335-B contained 5463 CDS, 5570 genes, 5230 proteins, 92 RNAs, and 80 tRNA for. A total of 426 and 425 subsystem features with 5190 and 5662 CDS were obtained for E. coli O177_CF-154-A and E. coli O177_CF-335-B, respectively. Several genes encoding virulence and antimicrobial resistance were identified in both genomes. Complete genome sequence data of both isolates have been deposited in the National Center for Biotechnology Information (NCBI), GenBank: accession numbers, VMKH00000000 (E. coli O177_CF-154-A) and VMKG00000000 (E. coli O177_CF-335-B). This data can be used as a reference for determining the virulence and antimicrobial resistance in E. coli O177 isolates from different sample sources.

Effect of dietary red grape pomace on growth performance, hematology, serum biochemistry, and meat quality parameters in Hy-line Silver Brown cockerels

Red grape (Vitis vinifera L.) pomace’s (RGP) beneficial bioactive compounds could improve growth and meat quality traits in chickens and thus valorize RGP waste that is usually disposed in landfills to the detriment of the environment. This study investigated the effect of RGP inclusion in diets of Hy-line Silver Brown cockerels on physiological and meat quality responses. Five isonitrogenous and isocaloric diets were formulated by mixing a standard grower diet with RGP at 0 (G0), 15 (G15), 30 (G30), 45 (G45) and 60 g/kg (G60). A total of 250, 5-week-old cockerels (304.6 ± 6.57 g live-weight) were evenly allocated to 25 pens replicated 5 times per experimental diet. No linear and quadratic trends (P > 0.05) were observed for overall feed intake, body weight gain, feed conversion ratio, and meat quality traits as dietary RGP levels increased. Erythrocytes linearly decreased (P < 0.05), whereas mean corpuscular hemoglobin and urea linearly increased (P < 0.05) with RGP levels. There were significant quadratic effects for glucose, phosphorus, total protein, albumin, globulin, and cholesterol, from which a maximum RGP inclusion level was calculated to be 43 g/kg. In conclusion, dietary red grape pomace had no adverse effect on physiological parameters and meat quality traits of Hy-line Silver Brown cockerels. However, including red grape pomace beyond 43 g/kg could compromise serum biochemical parameters of the birds.

Effect of Pre-Treating Dietary Green Seaweed with Proteolytic and Fibrolytic Enzymes on Physiological and Meat Quality Parameters of Broiler Chickens

The use of seaweeds as nutraceuticals in chicken diets is limited by high fibre levels and low protein digestibility. Therefore, we tested the effect of pre-treating dietary seaweed (Ulva sp.) with a combination of protease and fibrolytic enzymes on physiological and meat quality parameters of Cobb 500 broilers. Five dietary treatments were formulated by including untreated (T1); fibrolytic (12 g/kg) enzyme-treated (T2); fibrolytic (12 g/kg) and protease (5 g/kg) enzyme-treated (T3); fibrolytic (12 g/kg) and protease (10 g/kg) enzyme-treated (T4); fibrolytic (12 g/kg) and protease (15 g/kg) enzyme-treated (T5) seaweed (35 g/kg) in a standard broiler diet. Three hundred, two-week-old chicks (239.3 ± 8.57 g live weight) were evenly distributed to 30 replicate pens to which the diets were then randomly allocated. Birds fed diet T1 had the highest feed intake (1144.5 g/bird). Neither linear nor quadratic trends were recorded for growth performance and carcass traits in response to protease pre-treatment levels. Gizzard weight linearly increased, while symmetric dimethylarginine, calcium, meat pH24, and hue angle24 quadratically responded to protease levels. Diet T1 promoted the lowest serum phosphorus levels (3.37 mmol/L). In conclusion, pre-treatment of seaweed with a combination of protease and fibrolytic enzymes did not improve diet utilization, physiological parameters, and meat quality in broilers.

Complete replacement of maize grain with sorghum and pearl millet grains in Jumbo quail diets: Feed intake, physiological parameters, and meat quality traits

In sub-Saharan Africa, the use of maize (Zea mays L.) grain as an energy source in poultry feeds has become unsustainable due to competing demands and suboptimal growing conditions for the maize crop. Sorghum (Sorghum bicolor Moench L.) and pearl millet (Pennisetum glaucum) grains are potential sustainable alternatives, given their tolerance to local growing conditions. Therefore, this study evaluated the effect of total replacement of maize grain with whole or crushed sorghum and pearl millet grains on feed intake, and physiological and meat quality parameters of Jumbo quail. Five experimental diets were formulated by completely replacing crushed maize grain in a commercial grower diet (CON) with whole sorghum (WSG), crushed sorghum (CSG), whole millet (WMG), or crushed millet (CMG). Three hundred and fifty, two-week-old Jumbo quail chicks (74.7 ± 8.81 g live-weight) were evenly distributed into 35 replicate pens to which the experimental diets were allotted. Statistically similar (P > 0.05) weight gain and FCE values were observed between birds reared on the control and pearl millet-based diets. However, birds fed with sorghum-based diets had the lowest FCE and weight gain. Blood parameters fell within the normal ranges reported for healthy quail. Birds fed the whole sorghum grain diet had the least (P < 0.05) serum calcium and higher monocytes, cholesterol, and alkaline phosphatase (ALP) concentrations compared to those reared on the control diet. Compared to the control, the whole sorghum-containing diet reduced (P < 0.05) carcass, breast, wing, thigh, drumstick, liver, gizzard, and large intestine weights of the birds. Complete replacement of maize grain with pearl millet grain (whole or crushed) did not compromise feed intake, growth performance, and meat quality traits of the Jumbo quail birds. However, whole sorghum grain reduced growth performance of the birds.

An Assessment of the Viability of Lytic Phages and Their Potency against Multidrug Resistant Escherichia coli O177 Strains under Simulated Rumen Fermentation Conditions

Preslaughter starvation and subacute ruminal acidosis in cattle are known to promote ruminal proliferation of atypical enteropathogenic Escherichia coli strains, thereby increasing the risk of meat and milk contamination. Using bacteriophages (henceforth called phages) to control these strains in the rumen is a potentially novel strategy. Therefore, this study evaluated the viability of phages and their efficacy in reducing E. coli O177 cells in a simulated ruminal fermentation system. Fourteen phage treatments were allocated to anaerobic serum bottles containing a grass hay substrate, buffered (pH 6.6–6.8) bovine rumen fluid, and E. coli O177 cells. The serum bottles were then incubated at 39 °C for 48 h. Phage titres quadratically increased with incubation time. Phage-induced reduction of E. coli O177 cell counts reached maximum values of 61.02–62.74% and 62.35–66.92% for single phages and phage cocktails, respectively. The highest E. coli O177 cell count reduction occurred in samples treated with vB_EcoM_366B (62.31%), vB_EcoM_3A1 (62.74%), vB_EcoMC3 (66.67%), vB_EcoMC4 (66.92%), and vB_EcoMC6 (66.42%) phages. In conclusion, lytic phages effectively reduced E. coli O177 cells under artificial rumen fermentation conditions, thus could be used as a biocontrol strategy in live cattle to reduce meat and milk contamination in abattoirs and milking parlours, respectively.

Effect of seaweed-containing diets on visceral organ sizes, carcass characteristics, and meat quality and stability of Boschveld indigenous hens

Seaweeds are functional feed ingredients that have antioxidant, antimicrobial, and growth-boosting properties that can improve poultry product quality. This study, therefore, investigated the effect of graded levels of green seaweed meal (Ulva spp.) (SWM) on visceral organ sizes, carcass characteristics, and meat quality and stability of Boschveld indigenous hens. A total of 275, four-week-old female chicks (202.4 ± 6.65 g of live weight) were reared on 5 isocaloric and isonitrogenous diets formulated by adding SWM at a concentration of 0 (SW0), 2 (SW20), 2.5 (SW25), 3 (SW30), and 3.5% (SW35). Birds were humanely slaughtered at 14 wk of age. Cecum weight linearly increased (R² = 0.366, P = 0.002), whereas proventriculus (R² = 0.205, P = 0.025) and duodenum (R² = 0.242, P = 0.010) weights linearly decreased with SWM levels. Neither linear nor quadratic trends (P > 0.05) were observed for carcass traits, meat quality parameters, and shelf life indicators in response to dietary SWM levels. Repeated-measures analysis showed a significant time × diet interaction effect on meat redness (a∗). After 24 h of storage, meat from hens fed with SW35 (2.47) diet had a higher a∗ value than meat from hens fed with SW30 diet (0.48). However, the inclusion of SWM promoted similar (P > 0.05) shelf life indicators as the control diet for the rest of the 7-d storage period at room temperature. In conclusion, dietary inclusion of SWM had no adverse effect on visceral organ size, carcass and meat quality traits, and meat stability of Boschveld indigenous hens.

Efficacy of novel phages for control of multi-drug resistant Escherichia coli O177 on artificially contaminated beef and their potential to disrupt biofilm formation

Contaminated beef is a prominent source of foodborne pathogens such as Escherichia coli O177. Susceptibility of nine multi-drug resistant E. coli O177 strains against eight individual phages and six phage cocktails was assessed using polystyrene microplate titer plate. Further, 180 beef samples were independently inoculated with E. coli O177 cells in triplicates and treated with eight individual phages and six phage cocktails to determine their efficacy in inhibiting bacteria growth at 4 °C over a 7-day incubation period. Results revealed that all E. coli O177 strains were susceptible to the phages. A significant log reduction in viable E. coli O177 cell counts was observed on beef samples upon phage treatment over the 7-day incubation period. Two individual phages and three phage cocktails reduced E. coli cell counts to levels below the detection limit (1.0 log₁₀ CFU/g). Log reduction of viable E. coli cell counts ranged from 2.10 to 7.81 CFU/g for individual phages and from 2.86 to 7.81 CFU/g for cocktails. Individual phages and phage cocktails inhibited E. coli O177 biofilm formation with phage cocktails showing high efficacy. Furthermore, phage cocktails showed greater efficacy in destroying pre-formed biofilm than individual phages. Based on these findings, we concluded that phage cocktails developed in this study could be used to reduce E. coli O177 contamination and extend the shelf-life of stored raw beef.

Nutrient Digestibility, Growth Performance, and Blood Indices of Boschveld Chickens Fed Seaweed-Containing Diets

Simple Summary

Sustainable intensification of indigenous chicken strains is largely constrained by the high cost of feed ingredients, thus limiting the growth of the poultry industry in developing countries. Inexpensive and readily available feed ingredients with nutraceutical properties such as seaweeds can be utilised to address this challenge. Seaweeds have been used in the food, animal, and pharmaceutical industries as a rich source of nutrients and bioactive compounds. Dietary inclusion of seaweeds in chicken diets has the potential to boost growth and enhance product quality. However, their feed value in indigenous chicken diets is largely unknown. This study investigated the effect of graded levels of green seaweed (Ulva spp.) meal (SWM) on apparent nutrient digestibility, feed intake, growth performance, and blood parameters of Boschveld indigenous chickens, a South African chicken breed. The inclusion of seaweeds boosted feed intake and overall body weight gain but had no effect on nutrient digestibility and efficiency of feed utilisation. Blood parameters were also not affected, except for red blood cell indicators. It was concluded that green seaweeds have the potential to be included in diets of Boschveld indigenous chickens.

Abstract

Seaweeds possess a wide range of bioactive compounds that can be beneficial in sustainable intensification systems. This study explored the effect of green seaweed (Ulva spp.) meal (SWM) on apparent nutrient digestibility and physiological responses of Boschveld indigenous chickens. Two-hundred and seventy-five hens (202.4 ± 6.65 g live-weight; 4-weeks-old) were reared on five isoenergetic and isoproteic diets formulated by adding SWM at 0 (SW0), 20 (SW20), 25 (SW25), 30 (SW30), and 35 g/kg (SW35). Neutral detergent fibre digestibility quadratically responded (R² = 0.244; p = 0.042) to SWM levels. No significant dietary influences were observed on apparent nutrient digestibility values. Repeated measures analysis showed significant diet × week interaction effect on weekly feed intake and growth performance. Dietary inclusion of SWM increased (p < 0.05) feed intake and overall body weight gain but not feed conversion efficiency. No significant linear and quadratic trends were observed for blood parameters except for basophils (R² = 0.172; p = 0.047), which linearly declined with SWM levels. Dietary SWM inclusion only influenced (p < 0.05) mean corpuscular volume, mean corpuscular concentration, and mean corpuscular haemoglobin concentration. We concluded that seaweeds have the potential to be used as a feed ingredient for indigenous chickens.

Polyethylene glycol inactivates red grape pomace condensed tannins for broiler chickens

1. This study was conducted to investigate the effect of inactivating GP condensed tannins using graded levels of polyethylene glycol (PEG) on feed intake, physiological, carcase, and meat quality traits of male Cobb 500 broilers. 2. Three hundred, two-week old, male Cobb 500 broilers (334.6 ± 21.43 g live weight) were allocated to 30 pens carrying 10 birds each. Five isonitrogenous and isoenergetic diets were formulated for grower (14-35 d) and finisher (36-42 d) phases by diluting a commercial broiler diet with untreated GP (PEG0) at 6.5% (w/w) or with the same amount of GP but pre-treated with PEG at 2.5% (PEG1), 5% (PEG2), 10% (PEG3) or 15% (w/w) (PEG4) and randomly allocated to pens in a four-week feeding period. 3. Feed intake, weight gain, feed conversion efficiency (FCE), and blood, carcase and meat quality parameters were determined. Weekly weight gain and FCE linearly (P < 0.05) increased in week 4 and linearly (P < 0.05) decreased in week 6 in response to PEG treatment levels. 4. Mean corpuscular volume linearly (P < 0.05) decreased in response to PEG levels, whereas blood urea nitrogen/creatinine ratio, urea, total protein, globulin and cholesterol showed quadratic trends in response to PEG levels. Spleen and ileum weights tended (P < 0.1) to linearly decrease with PEG levels. Heart weight and meat redness tended (P < 0.1) to quadratically respond to increasing levels of PEG. 5. It was concluded that PEG treatment partially inactivated GP condensed tannins without compromising the health status of broiler chickens. An optimum PEG inclusion level could not be determined for feed intake, weight gain and FCE. However, the presence of other antinutrients such as fibre and low molecular weight phenolics in GP may be responsible for the linear decreases observed in this study.

Effects of soil type on density of trees and nutritive value of tree leaves in selected communal areas of South Africa

This study aimed to describe the distribution and nutritive value of woody species growing in clay-loamy and red-brown sand from selected localities of North West, South Africa. Three 2.2 km transects, radiating from homesteads, which served as replicates, were established at each of four selected grazing areas. Nine 10 × 10 m homogenous vegetation units (HVU), 20 m apart, were marked in each transect. Woody plant density, height and canopy cover (CC), were recorded, and chemical properties and degradability via in vitro ruminal fermentation of harvested leaves were measured. Raisin bush (Grewia flava), Buffalo thorn (Ziziphus mucronata) and Camel thorn (Vachellia erioloba) were the common species across both soil types. Soil type influenced (P <0.05) plant density, CC, total tree equivalent (TTE) and plant height. Areas with red-brown sandy soil had higher (P <0.05) total plant density (827.7 plant/ha), CC (9.6%) and TTE (2886.4 TTE/ha) than those with clay-loamy soil. Vachellia erioloba leaves in clay-loamy soil had the highest (P <0.05) crude protein content (151.2 g/kg DM). Leaves of Searsia lancea species that were harvested from both the clay-loamy and red-brown sandy soils had the highest (P <0.05) amounts of condensed tannins (0.915 AU550/200 mg and 0.917 AU550/200 mg, respectively). Searsia lancea leaves had the lowest (P <0.05) in vitro ruminal nitrogen degradability values in both soil types. The leaves of Z. mucronata and G. flava leaves have potential as protein supplements for ruminants owing to their higher crude protein content and in vitro ruminal N degradability. Keywords: canopy cover, feeding value, plant height, semi-arid, species diversity, tree equivalent

Partial replacement of soybean products with canola meal in indigenous chicken diets: size of internal organs, carcass characteristics and breast meat quality

While the use of canola meal (CM) as an alternative to soybean meal in broiler diets is well-documented, there is no information on the utility of this valuable by-product for slow-growing indigenous chickens. This study was, therefore, conducted to evaluate the effects of partially replacing soybean products in a chicken grower diet with graded levels of CM on carcass characteristics, relative organ sizes and meat quality in Potchefstroom Koekoek (PK) cockerels. A total of 175 PK cockerels (342.6 ± 15.2 g body weight, 5 wk old) were randomly allocated to 25 pens. Five isonitrogenous and isoenergetic grower diets containing 0, 3.75, 6.25, 8.75, and 17.5% of CM were then randomly allocated to the pens (experimental units). After 12 wk of feeding, chickens were slaughtered to measure carcass traits, size of internal organs and meat quality traits. There were no effects of graded levels of CM on carcass weights. Wing weight increased quadratically [y = 6.27(±0.23) + 0.23 (±0.063) x-0.009 (±0.0003) x2; R2 = 0.28] in response to incremental levels of dietary CM. Drumstick, vertebrae, liver, and small intestine weights linearly increased (P < 0.05) in response to incremental levels of dietary CM. Redness (a*), initial meat pH (pHo), and shear force linearly increased (P < 0.05) but lightness (L*) and water holding capacity decreased with an increase in CM inclusion levels. However, there were no significant linear and quadratic trends for yellowness (b*), ultimate pH (pHu), drip loss, and cooking loss in response to incremental levels of CM. There were also significant quadratic trends for mineral contents of the meat with the exception of iron (Fe). It can be concluded that inclusion of CM in place of soybean products had no negative impact on carcass traits, organ size and meat quality traits of indigenous PK chickens.

Characterization of Lytic Bacteriophages Infecting Multidrug-Resistant Shiga Toxigenic Atypical Escherichia coli O177 Strains Isolated From Cattle Feces

The increasing incidence of antibiotic resistance and emergence of virulent bacterial pathogens, coupled with a lack of new effective antibiotics, has reignited interest in the use of lytic bacteriophage therapy. The aim of this study was to characterize lytic Escherichia coli O177-specific bacteriophages isolated from cattle feces to determine their potential application as biocontrol agents. A total of 31 lytic E. coli O177-specific bacteriophages were isolated. A large proportion (71%) of these phage isolates produced large plaques while 29% produced small plaques on 0.3% soft agar. Based on different plaque morphologies and clarity and size of plaques, eight phages were selected for further analyses. Spot test and efficiency of plating (EOP) analyses were performed to determine the host range for selected phages. Phage morphotype and growth were analyzed using transmission electron microscopy and the one-step growth curve method. Phages were also assessed for thermal and pH stability. The spot test revealed that all selected phages were capable of infecting different environmental E. coli strains. However, none of the phages infected American Type Culture Collection (ATCC) and environmental Salmonella strains. Furthermore, EOP analysis (range: 0.1-1.0) showed that phages were capable of infecting a wide range of E. coli isolates. Selected phage isolates had a similar morphotype (an icosahedral head and a contractile tail) and were classified under the order Caudovirales, Myoviridae family. The icosahedral heads ranged from 81.2 to 110.77 nm, while the contractile tails ranged from 115.55 to 132.57 nm in size. The phages were found to be still active after 60 min of incubation at 37 and 40°C. Incremental levels of pH induced a quadratic response on stability of all phages. The pH optima for all eight phages ranged between 7.6 and 8.0, while at pH 3.0 all phages were inactive. Phage latent period ranged between 15 and 25 min while burst size ranged from 91 to 522 virion particles [plaque-forming unit (PFU)] per infected cell. These results demonstrate that lytic E. coli O177-specific bacteriophages isolated from cattle feces are highly stable and have the capacity to infect different E. coli strains, traits that make them potential biocontrol agents.

Growth performance and carcass characteristics of finishing male lambs fed barberry pomace-containing diets

Barberry (Berberis vulgaris) fruits contain bioactive compounds with antimicrobial, antioxidant and hepatoprotective effects. The inclusion of barberry pomace (BP) in finishing diets could potentially enhance growth performance and carcass characteristics of sheep. To test this hypothesis, 21 male Balouchi lambs (24.5 ± 4 kg initial live weight; 5 ± 0.6 months of age) were randomly assigned to three BP-containing experimental diets to determine their effects on feed intake, live weight gain and carcass characteristics. The experimental diets were formulated to meet nutrient requirements for a targeted daily weight gain of 200 g as follows: (1) control diet (BP0), (2) control diet in which 7.5% of alfalfa hay and wheat straw were replaced with BP (BP75), (3) control diet in which 15% of alfalfa hay and wheat straw were replaced with BP (BP150). Lambs were fed the experimental diets for 75 days during which feed intake and live weight changes were recorded. At the end of the feeding period, lambs were fasted for 16 h, weighed and then slaughtered in order to determine carcass characteristics. Experimental diets had no effect on feed intake and growth performance of lambs. Similarly, diets had no effect (p > 0.05) on weight of carcass, commercial cuts (neck, shoulder, loin, leg, fat-tail, brisket, flank) and non-carcass components (head, skin, feet, lung and trachea, heart, liver, spleen, gastro-intestinal, kidney, bladder and testicles) but linearly increased (p < 0.05) warm and cold dressing percentage as well as heart weight. These results do not support the hypothesis that feeding BP-containing diets enhances growth performance and carcass characteristics of male Balouchi lambs. However, inclusion of BP had no negative effects on animal performance and carcass characteristics.

Valorization of Red Grape Pomace Waste Using Polyethylene Glycol and Fibrolytic Enzymes: Physiological and Meat Quality Responses in Broilers

Simple Summary

Red grape pomace (GP) waste, although rich in beneficial phenolic compounds, is traditionally disposed in landfills and through incineration, resulting in environmental pollution. The revalorization of GP as a source of nutrients and bioactive compounds in chicken diets is an environmentally sustainable and lower-cost alternative to current disposal methods. This approach has the potential to improve food and nutrition security while providing health benefits to consumers of poultry products. Unfortunately, the amount of GP that can be included in broiler diets is limited by fiber and condensed tannins found in this agro-waste. These compounds reduce the digestibility of GP in chickens, resulting in poor bioavailability of the beneficial bioactive compounds. Strategies are, therefore, required to ameliorate the effects of fiber and condensed tannins. This study investigated whether pre-treating GP with polyethylene glycol (PEG) and a cellulolytic enzyme mixture (Viscozyme^®) would improve feed intake, physiological parameters, carcass characteristics and meat quality parameters of broilers. It was concluded that PEG treatment successfully ameliorated the anti-nutritional effects of condensed tannins. However, the cellulolytic enzyme treatment was ineffective against GP fiber.

Abstract

The amount of grape pomace (GP) waste that can be included as a functional feed in broiler diets is limited by anti-nutritional compounds such as fiber and condensed tannins. This study evaluated the effect of pre-treating GP with polyethylene glycol (PEG) and a cellulolytic enzyme mixture on physiological and meat quality parameters of broilers. Cobb 500 broilers (249.2 ± 20.31 g live-weight) were reared on five isoenergetic and isonitrogenous diets: 1. Commercial chicken diet (CON); 2. CON containing untreated GP at 100 g/kg (dGP); 3. CON containing 100 g/kg GP pre-treated with PEG (50 g/kg) (dPEG); 4. CON containing 100 g/kg GP pre-treated with enzyme (1 g/kg) (ENZ); and 5. CON containing 100 g/kg GP pre-treated with PEG (50 g/kg) and enzyme (1 g/kg) (PENZ). Overall body weight gains were similar in broilers reared on the CON, dPEG, ENZ and PENZ diets but lower in dGP chickens. The meat of birds reared on dPEG, ENZ, dGP and CON had a similar water-holding capacity, which was lower than in PENZ chickens. Diets influenced the size of duodenum, ileum, jejunum and caeca. Polyethylene glycol treatment promoted similar body weight gains and hot carcass weights as the commercial control diet, suggesting that the anti-nutritional effects of condensed tannins were successfully ameliorated.

The First Isolation and Molecular Characterization of Shiga Toxin-Producing Virulent Multi-Drug Resistant Atypical Enteropathogenic Escherichia coli O177 Serogroup From South African Cattle

Atypical enteropathogenic E. coli (aEPEC) is a group of diarrhoeagenic Escherichia coli with high diversity of serogroups, which lack the bundle-forming pili (BFP) and genes encoding for shiga toxins. The aim of this study was to isolate, identify and determine virulence and antibiotic resistance profiles of aEPEC O177 strains from cattle feces. A total of 780 samples were collected from beef and dairy cattle and analyzed for the presence of E. coli O177. One thousand two hundred and seventy-two (1272) presumptive isolates were obtained and 915 were confirmed as E. coli species. Three hundred and seventy-six isolates were positively confirmed as E. coli O177 through amplification of rmlB and wzy gene sequences using multiplex PCR. None of these isolates harbored bfpA gene. A larger proportion (12.74%) of the isolates harbored hlyA gene while 11.20, 9.07, 7.25, 2.60, and 0.63% possessed stx₂, stx₁, eaeA, stx_2a, and stx_2d, respectively. Most of E. coli O177 isolates carried stx₂/hlyA (9.74%). Furthermore, 7.40% of the isolates harbored stx₁/stx₂ while 7.09% possessed stx₁/stx₂/hlyA genes. Only one isolate harbored stx₁/stx₂/hly/eaeA/stx_2a/stx_2d while 5.11% of the isolates harbored all the four major virulence genes stx₁/stx₂/hlyA/eaeA, simultaneously. Further analysis revealed that the isolates displayed varied antimicrobial resistance to erythromycin (63.84%), ampicillin (21.54%), tetracycline (13.37%), streptomycin (17.01%), kanamycin (2.42%), chloramphenicol (1.97%), and norfloxacin (1.40%). Moreover, 20.7% of the isolates exhibited different phenotypic multi-drug resistance patterns. All 73 isolates harbored at least one antimicrobial resistance gene. The aadA, streA, streB, erm, and tetA resistance genes were detected separately and/or concurrently. In conclusion, our findings indicate that environmental isolates of aEPEC O177 strains obtained from cattle in South Africa harbored virulence and antimicrobial resistance gene determinants similar to those reported in other shiga-toxin producing E. coli strains and suggest that these determinants may contribute to the virulence of the isolates.

Nutrient digestibility, haemo-biochemical parameters and growth performance of an indigenous chicken strain fed canola meal-containing diets

Canola meal (CM) is a potential alternative dietary protein source for indigenous chickens but its utility may be limited by anti-nutrients such as fibre and phytochemical compounds. This study, therefore, explores the effects of replacing soy-based feedstuffs (SB) with graded levels of CM on apparent nutrient digestibility, growth performance and haemo-biochemical parameters in Potchefstroom koekoek (PK) cockerels. Five isonitrogenous and isoenergetic diets were formulated by replacing 0 (CM), 3.75 (CM1), 6.25 (CM2), 8.75 (CM3) and 17.5% (CM4) of SB with CM. One hundred and seventy-five cockerels (342.6 ± 15.2 g live weight, 5 weeks old) were evenly distributed into 25 replicate pens to which experimental diets were randomly allocated. Feed intake, apparent nutrient digestibility, weight gain, feed conversion ratio and protein efficiency ratio (PER) were determined. Blood was collected for serum and haematological analysis at 16 weeks of age. There was a significant quadratic trend [y = 2.56 (± 0.067) + 0.04 (± 0.019)x - 0.002 (± 0.0010)x²] for average weight gain from which an optimum canola inclusion level was calculated to be 7.8%. Neutrophils linearly increased (P < 0.05) with CM levels, but there were no significant linear and quadratic trends for serum biochemical components with the exception of total calcium and triglycerides, which decreased linearly in response to incremental levels of CM. However, feed intake, feed utilisation efficiency, growth performance and serum biochemistry parameters were not affected by experimental diets. Based on weight gain response, it was concluded that replacing soy-based dietary ingredients with CM in poultry diets up to 7.8% does not result in adverse effects on diet utilisation, growth performance and health status of PK cockerels.

Effect of dietary inclusion of safflower meal on ruminal fermentation, growth performance, carcass characteristics, and meat quality of lambs

This study examines the effect of including graded levels of safflower meal (SM) [0 (SM0), 150 (SM15), or 200 g kg−1 dry matter (SM20)] in diets of Katahdin–Pelibuey lambs on ruminal fermentation, growth performance, and meat quality. Experimental diets were randomly allocated to 24 lambs (29.25 ± 0.55 kg) in a 60 d feeding trial. On day 30, rumen fluid was collected from each sheep at 0, 3, and 6 h after morning feeding to measure pH, ammonia, and volatile fatty acids. Feed intake, nutrient digestibility, growth performance, carcass characteristics, and meat quality were also measured. Feed intake, ruminal volatile fatty acids concentration, dry matter, and crude protein digestibility were not affected (P > 0.05) by diets. Lambs fed on SM15 had higher (P < 0.05) ruminal pH at 3 and 6 h post feeding compared with those on SM0 and SM20. Inclusion of SM increased (P < 0.05) ruminal ammonia concentration at 3 and 6 h post feeding; however, daily gain decreased with increasing levels of SM. Diets did not affect (P > 0.05) carcass and meat quality traits. Feeding SM-containing diets resulted in similar feed utilization, carcass characteristics, and meat quality to the control diet while improving ruminal fermentation parameters.

A multi-strain probiotic administered via drinking water enhances feed conversion efficiency and meat quality traits in indigenous chickens

Whereas the use of probiotics is commonplace in commercial production of improved chicken strains, little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic (containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 10⁸ cfu/mL), administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 five-week-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet (CON; commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet (ANTIB; commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water (PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water (PROB50). There was a significant (P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher (P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower (P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant (P > 0.05) effect on overall feed intake, overall weight gain and haemato–biochemical parameters of cockerels. Gizzard and spleen weights were similar (P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter (P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger (P < 0.05) breast weight than those in PROB25 group. Cockerels in ANTIB and PROB50 groups had greater (P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar (P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest (P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower (P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.

Effects of dietary humic acid and enzymes on meat quality and fatty acid profiles of broiler chickens fed canola-based diets

Objective

This study was conducted to assess the effect of potassium humate and enzymes (Xylanase+Amylase+Protease) inclusion in diets on carcass characteristics, meat quality and fatty acid profiles of broilers fed canola-based diets.

Methods

Two hundred and twenty broilers randomly allotted to 5 dietary treatments: the control (commercial broiler diet); CM (17.5% canola meal inclusion); CMEnz (17.5% CM inclusion+0.3 g/kg Axtra XAP); CMPh (17.5% CM inclusion+1.5% Potassium Humate, PH); and CMEnzPh (17.5% CM inclusion+1.5% PH+0.3 g/kg Axtra XAP) were slaughtered at day 42 for assessment of carcass and meat quality parameters.

Results

Diet had no effect on carcass traits apart from breast muscle weight and breast muscle index. The highest breast muscle weight was observed in broilers fed CMEnz (487.6±17.5 g) followed by those fed the control diet (474.37±17.5 g). Diet also had no significant dietary effect on pH, temperature, drip loss and shear force values of the breast muscle. However, diet significantly affected meat colour and water-holding capacity. Broilers in the control and CMPh groups (52.94±0.67 and 52.91±0.67) had the highest (p<0.05) values for lightness (L*), whilst those fed CMEnzPh had the lowest value (47.94±0.67). In contrast, CM group had the lowest (p<0.05) value for redness (a*) with CMEnzPh group having the highest values. The proportion of polyunsaturated fatty acids (PUFAs), n-6 and n-3 fatty acids and the PUFA/saturated fatty acid ratio were increased in CM-based diets containing enzymes and humic acid.

Conclusion

It can, therefore, be concluded that CM can be included in broiler diets in the presence of enzymes and humic acid with positive effects on meat quality and important fatty acids that are beneficial to the health of consumers.

Growth performance, blood parameters, carcass characteristics and meat quality traits in Potchefstroom Koekoek chickens fed Lippia javanica leaf meal

Lippia javanica leaves may have nutraceutical bioactivity and thus could be a viable alternative to antibiotic growth promoters in poultry diets. To test this hypothesis, a feeding trial was carried out to determine the effects of dietary inclusion of Lippia javanica leaf meal (LJ) on growth performance, blood parameters, carcass characteristics and meat quality of indigenous Potchefstroom Koekoek (PK) chickens. The leaf meal was used to dilute a commercial chicken grower diet at a rate of 25 or 50 g/kg diet. Two additional experimental diets, a positive control (commercial chicken grower diet with antibiotics, CON+) and a negative control (commercial chicken grower diet without antibiotics, CON-), were also formulated. Feed intake and growth performance were measured over a period of 13 weeks before slaughtering for carcass and meat quality measurements. Blood was collected in week 11 to determine haematological and serum biochemical parameters. Diet had no effect on overall FCE but significantly (P < 0.05) affected bilirubin, alanine aminotransferase (ALT), aspartate transaminase (AST), sodium, potassium, cholesterol and magnesium levels in blood. When included at 50 g/kg, LJ increased carcass weight (P < 0.05). Meat from CON- (6.07) and LJ50 (6.08) chickens had a higher pH than from CON+ (5.9) and LJ25 (5.8) chickens. Breast muscle in CON- chickens had higher (P < 0.05) lightness (L*) value (53.2) compared to chickens fed on other diets. It was observed that meat from LJ25 chickens had the highest for redness value (2.3). It was concluded that L. javanica leaf meal can be included up to 50 g/kg in Potchefstroom koekoek chicken diets without causing negative effects on the birds' feed intake, utilisation and weight gain. Diet-induced changes observed in blood parameters and meat quality fell within the expected normal ranges for indigenous chickens.

Accuracy of two optical chlorophyll meters in predicting chemical composition and in vitro ruminal organic matter degradability of Brachiaria hybrid, Megathyrsus maximus, and Paspalum atratum

The objective of this study was to determine the accuracy and reliability of 2 optical chlorophyll meters: FieldScout CM 1,000 NDVI and Yara N-Tester, in predicting neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), acid detergent insoluble nitrogen (ADIN) and in vitro ruminal organic matter degradability (IVOMD) of 3 tropical grasses. Optical chlorophyll measurements were taken at 3 stages (4, 8 and 12 weeks) of regrowth in Brachiaria hybrid, and Megathyrsus maximus and at 6 and 12 weeks of regrowth in Paspalum atratum (cv. Ubon). Optical chlorophyll measurements showed the highest correlation (r = 0.57 to 0.85) with NDF concentration. The FieldScout CM 1,000 NDVI was better than the Yara N-Tester in predicting NDF (R² = 0.70) and ADF (R² = 0.79) concentrations in Brachiaria hybrid and NDF (R² = 0.79) in M. maximus. Similarly, FieldScout CM 1,000 NDVI produced better estimates of 24 h IVOMD (IVOMD_24h) in Brachiaria hybrid (R² = 0.81) and IVOMD_48h in Brachiaria hybrid (R² = 0.65) and M. maximus (R² = 0.75). However, these prediction models had relatively low concordance correlation coefficients, i.e., CCC >0.90, but random errors were the main source of bias. It was, therefore, concluded that both optical chlorophyll meters were poor and unreliable predictors of ADIN and ADL concentrations. Overall, the FieldScout CM 1,000 NDVI shows potential to produce useful estimates of IVOMD_24h and ADF in Brachiaria hybrid and IVOMD_48h and NDF concentrations in M. maximus.

Influence of harvesting site on chemical composition and potential protein value of Acacia erioloba, A. nilotica and Ziziphus mucronata leaves for ruminants

This study was designed to evaluate the chemical composition, buffer N solubility, in vitro ruminal N degradation and in vitro ruminal biological activity of condensed tannins in Acacia erioloba, Acacia nilotica and Ziziphus mucronata leaves harvested from two sites (Masuthle communal grazing land and Molelwane private farm). Leaves were harvested, dried at 60 °C and milled. The highest crude protein (CP) content was found in leaves of Z. mucronata (177.7 g/kg DM). Leaves harvested from Masuthle had higher (p < 0.05) soluble phenolics (SPh) (44.6 g TAE/kg DM) compared to those harvested from Molelwane (29.8 g TAE/kg DM). In both Molelwane and Masuthle, leaves of A. nilotica had higher levels of condensed tannins (CT) (0.76 AU_550/200 mg and 0.52 AU_550/200 mg respectively) followed by A. erioloba and Z. mucronata, which did not differ (p > 0.05). Nitrogen degradability at 24 h was the same (p > 0.05) for all tree species but not at 12 and 36 h. No linear association (p > 0.05) was found between buffer-soluble N and in vitro ruminal N degradability in leaves with high SPh content. The largest polyethylene glycol (PEG) effect was in leaves of A. nilotica (448%) harvested from Masuthle after 36 h of incubation. Ziziphus mucronata leaves harvested from Molelwane had the least PEG effect at 48 h. There was no linear association (p > 0.05) between PEG effect and SPh for all incubation periods, but a positive relationship was observed between PEG effect and condensed tannins content. There was no linear association between solubility index (SI) and in vitro ruminal N degradability for tannin-rich leaves. It was concluded that higher browsing pressure in Masuthle communal rangeland resulted in leaves with higher levels of condensed tannins, which had higher in vitro ruminal biological activity, compared to those harvested from Molelwane.

The effects of Lippia javanica dietary inclusion on growth performance, carcass characteristics and fatty acid profiles of broiler chickens

This study was conducted to determine the effect of inclusion of fever tea (Lippia javanica) leaf meal in broiler diets on growth performance, carcass characteristics and fatty acid (FA) profiles over a 42-day feeding period. One hundred and eighty, one-day-old, broiler chicks were randomly allocated to the following four treatments: 1) negative control (commercial broiler diet only [Negcontrol]); 2) positive control (commercial broiler diet + prophylactic antibiotics [Poscontrol]); 3) commercial broiler diet without prophylactic antibiotics + 5 g of L. javanica per kg of feed (Ljav5) and 4) commercial broiler diet without prophylactic antibiotics + 12 g of L. javanica per kg of feed (Ljav12). Body weights (BW) and feed intake (FI) were recorded weekly and used to calculate feed conversion ratio (FCR) and average daily weight gain (ADG). At the end of the trial (day 42), all chickens were slaughtered at a local commercial abattoir for assessment of carcass characteristics and FA profiles of meat. The broilers fed L. javanica had significantly (P < 0.05) lower FI compared with the other two groups. However, the broilers in the Poscontrol and Ljav5 treatment groups had higher (P < 0.05) ADG, lower FCR and higher slaughter weights. L. javanica inclusion had no effect on the breast weight, thigh weight, carcass weight, and dressing percentage of the broilers. Most of the n-3 FA were not affected by diets except for the docosapentaenoic, which was found to be higher (P < 0.05) in the Ljav12 treatment group and the lowest in the Negcontrol. The broilers in the Negcontrol and Poscontrol groups had higher (P < 0.05) total saturated fatty acids (SFA). On the contrary, the L. javanica fed broilers had higher (P < 0.05) total polyunsaturated fatty acids (PUFA), total n-3 FA and PUFA:SFA ratio and also had significantly lower n-6:n-3 ratios compared with the other two treatment groups. No differences were observed with regards to total monounsaturated fatty acids (MUFA) and total n-6 FA. Overall, the findings from the study showed that inclusion of L. javanica in broiler diets at 5 g/kg feed has positive influences on growth performance, carcass characteristics and FA profiles of broiler meat.

Growth performance, hematology, and meat quality characteristics of Mutton Merino lambs fed canola-based diets

A 56-day feeding trial was carried out to evaluate the effect of feeding canola meal (CM) on growth performance, hematology, and meat quality parameters of lambs. Twenty lambs with an average body weight of 23 ± 2.64 kg were randomly assigned to five dietary treatments and fed in individual cages for 56 days. The soya bean meal (SBM) in the control ration was replaced with canola meal at 0 (CM0), 25 (CM25), 50 (CM50), 75 (CM75), and 100 % (CM100) inclusion levels. Average daily weight gain (ADWG) and average daily feed intake (ADFI) were significantly higher in the CM25 and CM50, respectively. Feed conversion ratio (FCR) (3.09-3.41) and slaughter weight (SLW) (33.2-34.7 kg) were, however, similar among the treatment groups. Diet had no effect on carcass length (78.7-83.7 cm) and ultimate meat pH (pHu) (5.70-5.81). Nevertheless, hot carcass weight (HCW) (16.5-18.7 kg) and cold carcass weight (CCW) (16.2-18.2 kg) were higher (P < 0.05) in the CM0 and CM50 treatment groups. The shear force measurements (1.67-2.17 kg) differed (P < 0.05) across treatments. There was no dietary effect on the lightness (L*) (33.5-35.8), redness (a*) (11.35-12.7), and yellowness (b*) (13.4-14.8) of meat. In conclusion, CM can completely replace SBM in lamb diets without any negative effects on growth performance, general health, and meat quality of Mutton Merino lambs.