Nowadays, phytogenic products have received great attention as a growth promoter due to their safety and environmentally friendly effect as a replacement for classical growth promoters such as antibiotics in animal nutrition. Thus, this research seeks the possibility of using fennel seed powder (FSP) as a dietary additive from 19 to 41 days of age on productive performance, carcass traits, meat quality, and production efficiency of broiler chickens raised under thermoneutral and chronic heat stress conditions. Thus, 216 one-day-old Ross-308 broiler chicks were divided into two equal groups. The first group was placed in an independent temperature-controlled room at 23 ± 2 °C. The broiler chicks from the second group were placed in a heat-stressed room and exposed to chronic heat stress conditions (32 ± 2 °C) for seven hours per day from 8 a.m. to 3 p.m. The experimental design was 2 × 3 factorial including two environmental temperatures (thermoneutral vs chronic heat stress) and three experimental diets that contained 0, 1.6, and 3.2% FSP. The chickens were randomly assigned to 18-floor pens per room temperature, representing six replicates per treatment and six birds per replicate. The results showed that dietary fennel seed powder during days 19–41 of age enhanced the growth rate of broiler chickens and improved breast meat redness and reduced temperature under chronic heat stress. In conclusion, 3.2% of fennel seed powder could be used as an agent for enhancing the broiler’s tolerance during chronic heat stress condition from 19 to 41 days of age. Moreover, it is necessary to study in further detail the nitrite and nitrate contents in FSP and their impacts on muscle redness (a*) as well as muscle temperature.

The effects of guanidinoacteic acid (GAA) supplementation on productive performance, pectoral myopathies, and meat quality of broilers were studied. Treatments consisted of corn/soybean-based diets with a GAA supplement (0%, 0.06%, and 0.12%). A total of 546 one-day-old Ross-308 males were randomly allocated to 42 floor pens with 14 replicates (13 birds/pens) for each treatment. The results showed that GAA at doses of 0.06% and 0.12% improved feed conversion, increased the percentage of normal breast, and decreased the severity of wooden breast. Breast muscle myopathy severity was positively correlated with heavy birds and negatively correlated with breast muscle creatine and glycogen. Breast muscle creatine and glycogen correlated positively with normal, less severe pectoral myopathies and meat quality. In conclusion, GAA supplementation improved broiler performance without exacerbating pectoral myopathy or affecting meat quality.

Food waste is one of the major global challenges that have adverse socioeconomic and environmental impacts. Therefore, studying food waste utilization potentials and minimizing its negative consequences becomes imperative. This study aims to assess the technical and economic potentials of substituting corn with unconventional extruded dried Arabic Bread waste (EDABW) in broilers’ diets, in terms of broilers’ performance, carcass characteristic, economic net returns, and income over feed cost (IOFC). One hundred eighty unsexed one-day-old broiler birds of Ross breed were distributed randomly in six treatments (0, 20, 40, 60, 80, and 100% EDABW group) of isocaloric and isonitrogenous diets in a completely randomized design with six replicated (5 chicks/replicate). The investigated traits were broilers’ performance (live body weight, total feed intake, total feed conversion ratio, and total weight gain. Other traits such as carcass weight, abdominal fat, edible offal (liver, heart, and gizzard), eviscerated (breast muscles, drum and thigh muscles, and wings) were weighed and expressed based on a live body weight. Results showed that the 20% replacement level of corn with EDABW generated the highest increase in the live body weight and the eviscerated carcass at about 4.24% g and 4.90%, respectively. On the other hand, the economic analysis showed potential reductions in the broilers’ diet cost and the total broilers' production cost as the levels of corn substitution with by unconventional EDABW increased. The reductions were estimated at 5.1%, 6.3%, 8.4%, 9.3%, and 9.9% at substitution levels of 20%, 40%, 60%, 80%, and 100%, respectively as compared to the control diet. The results also showed a potential increase in the net economic returns of broiler meat as the increase in substitution levels ranged between 3.5–06.8% and 4.3–8.3% as compared to the control diets using the average retail and wholesale prices of broiler meats, respectively. In addition, the maximum IOFC was estimated potentially at a 20% substitution level of corn with EDABW. Conclusively, the study results show promising technical and economic potentials for unconventional EDABW in broilers’ diets that could lead to a thriving industry of unconventional broilers’ diets with high net economic returns and maximum IOFC.

The objective was to elucidate the effects of dietary guanidinoacetic acid (GAA) supplementation on broiler performance, serum enzymes, oxidative biomarkers, mitochondrial activities, carcase traits, gross lesion of cardiac muscle and liver histopathology in broilers challenged with T₃-hormone. A total-of-192 one-day-old mixed sexed broilers were randomly assigned in a two factorial design, including two dietary treatments; control diet supplemented with or without T₃-hormone (1.5 ppm) and GAA diet (0.06%) supplemented with or without T₃-hormone (1.5 ppm). Each group was subdivided into eight replicates. Results showed interactions between GAAxT₃-hormone. GAA diet significantly mitigated the negative effect of T₃-hormone on serum total creatine kinase (CK), cardiac muscle (CK-MB), liver malondialdehyde (MDA) and superoxide dismutase (SOD), mitochondrial activities of cardiac muscle and liver histopathological lesion. In conclusion, GAA at a rate of 0.06% may have the potential to mitigate the negative effect of dietary T₃-hormone but could not reduce the ascites mortality at such inclusion rate.

This study was carried out to investigate the effect of dietary L-Threonine supplementation on broiler performance, carcass characteristics, duodenal histo-morphology and litter analysis. It was hypothesised that the overall broiler performance would be improved in threonine adequate diets with reduced environmental impact when using L-threonine supplementation. A total of 144-sexed Ross 308 broiler chicks were randomly allocated into 3 dietary treatments. Each treatment was replicated 6 times with 8 birds per replicate (4 male and 4 female). Treatment group 1 served as threonine deficient group, fed with a diet with all limiting amino acids met except threonine as no synthetic form was supplied. Treatment group 2 served as threonine adequate high crude protein, where L-Threonine adequacy was achieved with higher level of crude protein. Treatment group 3 served as L-Threonine adequate but achieved it through L-Threonine supplementation. Treatment effects on growth performance, carcass characteristics, intestinal morphology and litter quality were determined. Results compared to group 1 showed that group 3 at the end of the experimental period (28 days) had improved final body weight P < 0.05, live and carcass weights P < 0.01, dressing yields P < 0.05, relative wing weights P < 0.01 and relative heart weights P < 0.05. However, group 2 showed numeric improvement in all aforementioned parameters but not enough to show significance. Litter moisture and nitrogen content was affected by dietary L-Threonine fortification P < 0.05. The lowest moisture and nitrogen content were noticed in group 3. Meanwhile, group 2 showed the highest nitrogen and group 1 showed the highest moisture content among all groups. Intestinal villi length and villus: crypt ratio was affected by dietary treatments P < 0.001 and P < 0.05 respectively. Group 3 showed the highest villus length and villus: crypt ratio followed by group 2 and group 1. In conclusion correcting L-Threonine deficient diet by adding L-Threonine significantly improved live weight gain and carcass characteristics, while numerically improved feed conversion ratio and breast weight. Correcting the deficit by supplying crude protein had no significant effect. Additionally, dietary L-Threonine supplementation reduced environmental burden by reducing both litter nitrogen and moisture content.