Effects of dietary olive oil on growth performance, carcass parameters, serum characteristics, and Fatty Acid composition of breast and drumstick meat in broilers

Olive oil and its derivatives for promoting performance, health, and struggling thermal stress effects on broilers

Olive oil (OL) production is the most significant agro-industrial business and has a high impact on the economy of numerous Mediterranean countries. However, OL extraction results in massive amounts of byproducts, including a solid residue (olive cake or olive pomace) and an aqueous stage (olive mill wastewater), which have serious environmental effects due to their hazardous nature and excessive organic content. Despite these byproducts causing environmental pollution, they can be applied for animal feeding. According to the literature, OL or its derivatives have been used to promote broiler performance, feed utilization, and health status in broilers as growth promoters or protein sources. Furthermore, using OL and its derivatives could improve heat resistance in stressed broilers via struggling thermal stress effects. In this framework, we highlighted the use of OL and its byproducts in broiler feeding to promote performance and health status. Additionally, the role of these byproducts and OL in combating thermal stress is investigated for sustainable strategy and promoting circular economy in broiler industry.

The physiological function of squalene and its application prospects in animal husbandry

Squalene, which is a natural triterpenoid unsaturated hydrocarbon, is abundant in shark liver and plant seeds. Squalene has various physiological functions such as being anti-inflammatory and antioxidant. This paper reviews the physiological functions of squalene and its application prospects in livestock and poultry production, with a view to providing a theoretical basis for its in-depth application in animal husbandry.

Assessing different oil sources efficacy in reducing environmental heat-stress effects via improving performance, digestive enzymes, antioxidant status, and meat quality

Adding oil to the feed of genetically improved broilers is necessary to provide energy requirements, in addition to enhancing metabolism, growth performance, immune response. This study aims to reveal the effect of adding different oil sources in the diets of broilers exposed to environmental heat stress on performance, digestibility, oxidative status, plasma lipids, fatty acids content, and meat quality. Six hundred twenty-five one-day-old broiler chicks were randomly distributed to five groups as follows: the first group fed a diet without oil (CON) as a control, while the second to the fifth group fed a diet containing soy oil (SO), corn oil (CO), olive oil (OO), and fish oil (FO), respectively. Results indicated a significant deterioration in growth performance, carcass traits, and oxidative state with a significant decrease in carcass quality in heat-stressed chickens fed the CON diet. Results showed increased growth, enhanced feed conversion ratio, and carcass dressing in broilers fed the oil-supplemented diet compared to the control diet, however, the digestive enzymes activity was not affected by receiving an oil-supplemented diet. The best performance was in chickens fed OO and SO, compared with FO and CO. Plasma aspartate aminotransferase (AST), and alanine aminotransferase (ALT) increased in broilers fed an oil-supplemented diet. Plasma high-density lipoprotein (HDL), and superoxide dismutase (SOD) remarkably increased in broilers fed OO, whereas the malondialdehyde (MDA) decreased compared to the other groups. Adding different dietary oil sources enhanced the breast muscle's fatty acid composition. Broiler diets supplemented with oils positively affected meat quality by enhancing color measurements, and TBA values, while the best were in chicken fed OO. It was concluded that adding dietary oil at 3% in the diets of broiler chicken exposed to environmental heat stress positively affected growth performance, enhanced oxidative status, and meat quality, best results were in broilers fed a diet that included olive oil.

Application of botanical products as nutraceutical feed additives for improving poultry health and production

Poultry is one of the most consumed sources of animal protein around the world. To meet the global demands for poultry meat and eggs, it is necessary to improve their nutrition to sustain the poultry industry. However, the poultry industry faces several challenges, including feedstuff availability, the banning of antibiotics as growth promoters, and several environmental stressors. Therefore, there is a critical need to include available nutraceuticals in the diet to sustain the poultry industry. Nutraceuticals are natural chemical substances that positively influence animal physiological and productive traits. Botanical products (such as fenugreek seeds, ginger roots, and olive leaves) are among the most commonly used nutraceuticals and are gradually gaining popularity in the poultry industry due to their immense benefits in nutrition and therapeutic properties. They can be added to the diet separately or in combination (as a natural antioxidant and immunostimulant) to improve poultry health and production. Botanical products are rich in essential oils and essential fatty acids, which have multiple benefits on the animal's digestive system, such as activating the digestive enzymes and restoring microbiota balance, enhancing poultry health, and production. These nutraceuticals have been shown to stimulate the expression of several genes related to growth, metabolism, and immunity. In addition, the essential oil supplementation in poultry diets up-regulated the expression of some crucial genes associated with nutrient transportation (such as glucose transporter-2 and sodium-glucose cotransporter-1). Previous studies have suggested that supplementation of botanical compounds increased broiler body weight and hen egg production by approximately 7% and 15%, respectively. Furthermore, the supplementation of botanical compounds enhanced the reproductive efficiency of hens and the semen quality of roosters by 13%. This review article discusses the significant effects of some botanical products in the poultry industry and how they can benefit poultry, especially in light of the ban on antibiotics as growth promoters.

Nutritional significance and health benefits of omega-3, -6 and -9 fatty acids in animals

The balance between omega-3 (ω-3), omega-6 (ω-6) and omega-9 (ω-9) fatty acids (FAs) is very important because these types of oils constitute essential components for the formation of the cell membrane, also they are precursors for a large number of substances in the body. One of the most important strategies for improving the increment of polyunsaturated FAs in poultry and animal meat is the dietary administration of these FAs. Additionally, the different sources of ω-3 or 6 in the diet improve the performance, public health and physiological aspects including anti-oxidative properties and immunity. ω-3 FAs have anti-inflammatory characteristics due to their ability to reduce cytokines liberation. High-level of ω-6 FAs is always associated with an increased incidence of dangerous disorders like depression and heart disease. These FAs showed a tremendous series of beneficial impacts like improved cholesterol levels and a decreased occurrence of coronary heart diseases. This article includes some information on the use of ω-3, ω-6 and ω-9 FAs in animal and human diets. These oils are vital for the physiological and health aspects, and the information mentioned here will improve our understanding of the functions and roles of these FAs in the body.

Olive pomace oil and acid oil as alternative fat sources in growing-finishing broiler chicken diets

The aim of the present study was to investigate the effect of dietary supplementation of olive pomace oil and olive pomace acid oil, which are rich in monounsaturated fatty acids (FA) but differ in free FA content, on growth performance, digestibility and FA profile of abdominal fat and breast meat. A total of 3,048 one-day-old mixed-sex broiler chickens (Ross 308) were randomly distributed into 24 pens and 3 dietary treatments (8 replicates per treatment). Experimental diets were administered for growing (from 22 to 29 d) and finishing (from 30 to 39 d) periods, consisting of a basal diet supplemented with 6% (as-fed basis) palm oil (PO), olive pomace oil (O), or olive pomace acid oil (OA). Animals fed O achieved the lowest feed conversion ratio (P < 0.01), together with the highest AME value (P = 0.003), but no differences were observed between OA and PO. Regarding FA digestibility, O and OA showed higher values than PO for all FA in both apparent ileal digestibility (AID) and apparent total tract digestibility. Comparing the AID between O and OA, no differences were observed for total FA, monounsaturated FA, or polyunsaturated FA, but animals fed OA showed lower AID values for saturated FA than those fed O (P < 0.001). The FA profile of abdominal fat and breast meat reflected that of the diet, with higher monounsaturated FA and lower saturated FA in animals fed O and OA compared to those fed PO. In sum, the inclusion of both olive pomace oil and acid oil in growing-finishing broiler chicken diets led to great performance parameters and high FA digestibility values, together with an enrichment with monounsaturated FA in abdominal fat and breast meat compared to the use of palm oil. However, a better AID of saturated FA and feed conversion ratio is achieved with O compared to OA.

Reproductive parameters and weight gain of roosters fed with waste oil from olive culture

Waste oil from olive oil extraction industry was used, instead of soybean oil, in heavy roosters’ diet in order to evaluate birds’ reproductive parameters. A total of forty roosters were housed individually in boxes with 1.2 m². Two experimental diets were used: control diet, based on corn, soybean meal, and soybean oil; and test diet, where soybean oil was totally replaced by waste oil. In order to verify weight gain and feed intake, animals were individually weighed weekly. Seven semen collections were performed with fifteen-day interval. Reproductive variables analyzed sperm volume, motility, concentration, and morphology. No statistical difference (p > 0.05) was observed between treatments at the different collection periods for the variables sperm volume, motility, and concentration. There was a statistically significant difference between treatments for body weight in periods three (p = 0.04), and seven (p = 0.04). Statistical differences (p = 0.01) were also observed between treatments for abnormal sperm morphology. Among collection periods, statistical difference was observed for motility (p = 0.00), and sperm concentration (p = 0.01). Total replacement of soybean oil by waste oil from olive oil extraction in young heavy roosters’ diets does not affect sperm volume, motility, and concentration; reduces defects in sperm tail, and promotes better weight gain control.

Effects of Replacing Yellow Corn with Olive Cake Meal on Growth Performance, Plasma Lipid Profile, and Muscle Fatty Acid Content in Broilers

Simple Summary

Yellow corn is a grain frequently utilized in broiler diets. Moreover, the new era of the corn-ethanol industry for biofuel production has increased the divergence of energy applications of corn. These uses have considerably increased corn prices over the past few years. Using byproducts may be one of solutions to this problem. Olive cake meal (OCM) is a byproduct obtained from olive oil factories after olive oil is extracted. It has a high nutritional value, especially in regard to metabolizable energy. OCM has been used successfully in livestock and poultry feeding as an alternative to energy sources such as corn, without any adverse effects on performance. Hence, the current study investigated the effects of replacing yellow corn with OCM on the growth, nutrient utilization, selected blood parameters, and muscle fatty acid profile of broilers. Four hundred and eighty one-day-old male broiler chickens (Ross 308) were divided into four experimental groups (a control group, and groups with 5%, 10%, and 20% of corn replaced with OCM). The results revealed that replacing 10% of corn with OCM in the diet improved growth performance and reduced abdominal fat and liver malondialdehyde (MDA) and increased high density lipoprotein (HDL).

Abstract

The current study focused exclusively on evaluating the effects of replacing corn with olive cake meal (OCM) in the diet of broilers on their growth performance, abdominal fat, selected plasma parameters, and muscle fatty acid (FA) content. A total of 480 one-day-old male broiler chickens (Ross 308) were divided into four treatment groups with 12 replicates/treatment. The control group was fed the base diet, whereas the second to fourth groups were fed diets of corn with 5%, 10%, and 20% contents of OCM, respectively. Broilers fed with the 5% and 10% OCM diets showed better body weight (p = 0.04) and feed conversion ratio than the 20% OCM group (p < 0.048). Both nitrogen retention and ether extract digestibility were not improved by replaced corn with OCM. Replacing corn with OCM led to a decreased abdominal fat percentage (p = 0.023) compared with the control group. Birds in the OCM groups showed the lowest total cholesterol values (p = 0.038). The breast muscle (musculus pectoralis superficialis) content of oleic and linoleic, linolenic, and arachidonic acids was significantly high in birds fed with OCM diets. However, their palmitic acid level was significantly decreased. Vitamin E was increased by increasing the OCM level. Thus, we concluded that replacing corn with OCM, especially at a 10% level, is more effective than other replacement levels in improving growth performance, plasma lipid profile, and muscle FA content, as well as in causing a reduction in abdominal fat in broilers.

Dietary squalene supplementation alleviates diquat-induced oxidative stress and liver damage of broiler chickens

The aim of this study was to explore the protective effects of squalene supplementation on growth performance, oxidative status, and liver function of diquat-challenged broilers. One hundred forty-four 1-day-old male Ross 308 broiler chicks were allocated to 3 groups, and each group consisted of 6 replicates of 8 birds each. The three groups were as follows: 1) nonchallenged broilers fed with a basal diet (control group), 2) diquat-challenged broilers fed a basal diet, and 3) diquat-challenged broilers fed with a basal diet supplemented with 1.0 g/kg of squalene. Broilers were intraperitoneally injected with 20 mg/mL of diquat solution at a dosage of 1 mL/kg of BW or an equivalent amount of saline at 20 d. Compared with the control group, weight gain and BW change rate during 24 h after injection were decreased by diquat challenge (P < 0.05), and the diquat-induced compromised growth performance was improved by squalene supplementation (P < 0.05). Diquat administration reduced plasma superoxide dismutase activity and increased malondialdehyde accumulation and glutathione peroxidase activity in both plasma and the liver (P < 0.05). In contrast, plasma glutathione peroxidase activity in diquat-challenged broilers was reduced by squalene supplementation (P < 0.05). The hepatic glutathione level was reduced by diquat administration (P < 0.05), whereas its level in plasma and the liver of diquat-challenged broilers was increased by squalene supplementation (P < 0.05). The relative liver weight of broilers was increased by diquat challenge (P < 0.05), with its value being intermediate in the squalene-supplemented group (P > 0.05). The plasma aminotransferase activities and total bilirubin concentration were increased by diquat challenge (P < 0.05), which were reduced by squalene supplementation (P < 0.05). The mRNA abundance of hepatic nuclear factor erythroid 2–related factor 2 (P < 0.05) was upregulated by diquat treatment, regardless of squalene supplementation. The mRNA abundance of hepatic glutathione peroxidase 1 and B-cell lymphoma/leukemia 2–associated X protein was upregulated by diquat challenge (P < 0.05), which was reversed by squalene administration (P < 0.05). Squalene increased NAD(P)H quinone dehydrogenase 1 mRNA abundance and decreased caspase 3 mRNA abundance in the liver of diquat-challenged broilers (P < 0.05). The results suggested that squalene can increase weight gain, improve oxidative status, and alleviate liver injury in diquat-challenged broilers.

Effects of graded levels of dietary squalene supplementation on the growth performance, plasma biochemical parameters, antioxidant capacity, and meat quality in broiler chickens

This study was conducted to evaluate the effects of dietary squalene supplementation on the growth performance, plasma biochemical indices, antioxidant status, and meat quality in broilers. Two hundred and forty 0-day-old male chicks were allocated into 5 groups of 6 replicates and were fed a basal diet supplemented with 0 (Control group), 250, 500, 1,000, or 2,000 mg/kg squalene for 42 d. Dietary squalene supplementation linearly increased weight gain and feed efficiency of broilers during the grower and overall periods (P < 0.05). Squalene linearly decreased 21-d malondialdehyde (MDA) level and 42-d glutathione peroxidase (GSH-Px) activity, and both linearly and quadratically decreased 42-d MDA level in plasma (P < 0.05). In contrast, squalene linearly increased plasma reduced form of glutathione (GSH) level on 21 and 42 d and superoxide dismutase activity on 42 d (P < 0.05). Squalene supplementation linearly decreased 21-d MDA accumulation but linearly increased GSH level on 21 d and 42 d and both linearly and quadratically increased 21-d GSH-Px activity in liver (P < 0.05). Supplementing squalene linearly increased pH value at 48 h and linearly decreased lightness at 48 h and 24-h drip loss of breast muscle (P < 0.05). The lightness at 24 h and cooking loss of breast muscle were both linearly and quadratically reduced by squalene (P < 0.05). Dietary squalene administration linearly decreased MDA accumulation but linearly increased GSH level and GSH-Px activity of breast muscle (P < 0.05). Compared with the control group, aforementioned growth performance, antioxidant-related parameters (except 42-d GSH-Px in plasma and breast and hepatic GSH), and meat quality were improved by squalene when its level was 1,000 and 2,000 mg/kg (P < 0.05), with their results being similar between these 2 groups (P > 0.05). It was concluded that squalene administration especially at a level of 1,000 mg/kg can improve growth performance, antioxidant status, and meat quality in broilers, providing insights into its application as a potential feed additive in broiler production.

Effects of dietary inclusion levels of palm oil on growth performance, antioxidative status and serum cytokines of broiler chickens

This study was conducted to investigate the effects of dietary palm oil inclusion levels on growth performance, serum antioxidative status and cytokines in Sanhuang broiler chickens. A total of 208 one-day-old female Sanhuang chickens were randomly allocated to four treatment groups with four replicates per group and of 13 birds each for a 42-day feeding trial. Dietary treatments were basal diet without palm oil (control) and diets containing 2%, 4% or 6% palm oil. During days 22 to 42 and the overall experimental period, chickens fed diets supplemented with 4% and 6% palm oil had a lower average daily feed intake (ADFI) (p = 0.019) and feed to gain ratio (F/G) (p = 0.031). Average daily gain (ADG) tended to be higher (p = 0.089) for palm oil inclusion treatments compared with the control treatment from days 1 to 42. Dietary 2% and 4% palm oil treatments significantly lowed serum malondialdehyde concentration on day 21 when compared to the control and 6% palm oil treatments (p = 0.027). Dietary 6% palm oil treatment significantly reduced the catalase (CAT) activity (p = 0.018) and total antioxidant capacity (T-AOC) (p = 0.027) in serum in comparison with the control treatment on day 21. No significant differences were observed in superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum among dietary treatments on day 21. There were no significant differences in T-AOC, CAT, SOD and GSH-Px activities among dietary treatments on day 42. Dietary inclusion of 4% and 6% palm oil significantly increased (p = 0.01) serum interleukin-1β (IL-1β) content, but improved transforming growth factor-β (TGF-β) content in serum on both days 21 and 42 (p = 0.032 and 0.022 respectively) as well as IL-10 content on day 42 (p = 0.022) when compared with the control treatment. Furthermore, dietary inclusion of 6% palm oil significantly reduced tumour necrosis factor-α (TNF-α) content on days 21 and 42 (p = 0.021 and 0.001 respectively) compared with the control treatment. These results suggest that dietary inclusion of 4% and 6% palm oil could improve the growth performance, modulate the balance between pro- and anti-inflammatory cytokines, and show limited effect on antioxidative status in Sanhuang broiler chickens.

Live Probiotic Lactobacillus johnsonii BS15 Promotes Growth Performance and Lowers Fat Deposition by Improving Lipid Metabolism, Intestinal Development, and Gut Microflora in Broilers

Numerous studies have focused on the beneficial effects of probiotics in animals. Even so, additional information should be obtained about the mechanisms by which a useful probiotic strain successfully exerts such beneficial effects. In this study, we evaluated the effect of the dietary supplementation of both live and disrupted Lactobacillus johnsonii (LJ) strain BS15 in broilers at different ages. Specifically, growth performance, lipid metabolism, gut microbiota, intestinal development, and digestive ability of the broilers were assessed. A total of 180 1-day-old Cobb 500 chicks were randomly distributed into three groups. These chicks were fed diets supplemented with 1 × 10⁶ colony-forming units (cfu) LJ per gram of feed (LJ group); 1 × 10⁶ cfu disrupted LJ per gram of feed (D-LJ group); and de Man, Rogosa, and Sharpe liquid medium (control group), respectively, throughout a 42-day experimental period. The results demonstrated that LJ supplementation of feed had a positive effect on the average daily gain and starter feed conversion ratio. In addition, LJ supplementation of feed decreased serum triglyceride and low-density lipid cholesterol levels, as well as abdominal fat deposition. LJ also reduced the mRNA levels of lipoprotein lipase in adipose tissue and stearoyl-CoA desaturase-1 in the liver. LJ diminished the mRNA quantities of the sterol regulatory element binding protein-1c and fatty acid synthase, as well as increased the level of serum high-density lipid cholesterol. LJ increased the mRNA quantities of peroxisome proliferator-activated receptor α, acyl-CoA oxidase in the liver, and carnitine palmitoyltransferase-1. LJ also improved the intestinal development and digestive ability mainly by increasing the villus height/crypt depth ratio in the ileum. The probiotic increased the levels of epidermal growth factor and insulin-like growth factor-1, as well as the activities of trypsin and lipase in the jejunum and ileum. LJ exerted beneficial effects on the intestinal flora. Specifically, LJ markedly enhanced the population of Bacteroidetes and Lactobacillus spp. Moreover, the probiotic reduced the population of Enterobacteriaceae and the Firmicutes/Bacteroidetes ratio. Slight changes caused by disrupted LJ were detected. These findings indicated that live LJ supplementation may promote growth performance and lower fat deposition in broilers.

Effect of a dietary probiotic, Lactobacillus johnsonii BS15, on growth performance, quality traits, antioxidant ability, and nutritional and flavour substances of chicken meat

To determine whether Lactobacillus johnsonii BS15 supplementation improves the growth performance and meat quality of broilers, 450 1-day-old male chicks (Cobb 500) were randomly divided into three groups: control group (basal corn-soybean diet), L-BS15 group (basal diet + 1 × 105 colony-forming unit BS15/g as feed), and H-BS15 group (basal diet + 1 × 106 colony-forming unit BS15/g as feed). These diets were fed for 42 days. Abdominal fat decreased (P < 0.05) as the concentration of BS15 increased. BS15 supplementation significantly increased the pH at 24 h after sacrifice and decreased drip loss and shearing force (P < 0.05), although meat colour and pH at 40 min after sacrifice remained unchanged. Antioxidant capacity and total protein and intramuscular fat levels were unchanged by the treatments, but BS15 supplementation significantly increased inosine monophosphate level and decreased total cholesterol and triglyceride levels (P < 0.05). The levels of proline, total amino acids, and flavour-related amino acids were increased (P < 0.05) by BS15 supplementation, but the levels of other amino acids did not change significantly. BS15 supplementation significantly decreased (P < 0.05) C16:0, C22:4n-6, and n-6 :  n-3 ratio and increased (P < 0.05) C18:3n-3, C20:5n-3,C22:6n-3, total polyunsaturated fatty acid (PUFA), n-3 PUFA and PUFA : saturated fatty acid ratio. These findings suggest that L. johnsonii BS15 supplementation improves the meat quality of broilers by increasing the shelf life and flavour and nutritional substances. In addition, BS15 supplementation can induce changes in fat deposits and fatty acid composition.