Improving the nutritional quality and shelf life of broiler meat by feeding diets supplemented with fermented pomegranate (Punica granatum L.) by-products

Linking key husbandry factors to the intrinsic quality of broiler meat

Broiler farming is the fastest-growing animal production sector and broiler meat is the second most-consumed meat in the world. The intensification of broiler production often has a negative impact on the meat quality and carcass characteristics. Consumers, however, expect a quality product from animals reared extensively on farms providing good animal welfare, often intuitively associated with extensive farming practices. Therefore, this literature review investigates how the critical factors contributing to the degree of extensiveness of broiler production affect the quality of meat. We used the data from scientific articles published in the years 2012-2021 to analyze the effect of diet (n = 409), genetics (n = 86), enrichment (n = 25), and stocking density (n = 20) on meat quality and carcass characteristics. Minerals and microelements supplementation in the diet improved all the meat quality aspects: sensory, physical, and chemical in most studies. Minerals and enzymes in the diet had beneficial effects on carcass characteristics, unlike feed restriction and ingredient substitutions. The impact of outdoor access on meat quality and carcass characteristics was most frequently examined, in contrast to the use of perches or effects of litter quality. Overall, enrichment did not affect the meat's sensory or physical parameters, but outdoor access improved its lipid composition. Lower stocking density deteriorated intramuscular fat content, decreased tenderness and juiciness, yet lowered cooking and drip loss, and increased carcass and breast muscle yields. When it comes to genetics, in general, slow growing broiler strains have better meat quality parameters, especially regarding yellowness (b*), redness (a*), cooking and drip loss. Our review shows that the factors which contribute to extensiveness of broiler production systems and birds' welfare also affect meat quality and the carcass characteristics.

Herbal Plants Application in Organic Poultry Nutrition and Production

Background:

Medicinal plants and natural feed additives are the most important alternatives in animal production, especially broiler production, due to the ban on the use of certain antibiotics, their cost-effectiveness and harmful residual effects.

Objective:

In this mini-review article, some important medicinal herbs and plants with positive effects on organic broiler production have been highlighted.

Methods:

A literature search was conducted in Science Direct, Google, Google Scholar, Springer, Medline and PubMed.

Results:

Medicinal plants such as ginger, ginkgo, thyme, ponderosa pine, soybean, forsythia, peppermint, Chinese star anise, astragalus, mistletoe, schisandra, cumin, capsicum, garlic, hooker chives, artichoke, Borreria latifolia, zataria, pomegranate, turmeric, lingzhi, Lippia javanica, neem, oriental chaff flower, mulberry leaf, goji berry, Aloe vera, pumpkin, grape, common nettle, marigold, coriandrum, Citrus sinensis, Alisma canaliculatum, Persian hogweed, Eucommiaulmoides, bamboo leaf extract, rosemary, Morina citrifolia, chestnut, green tea, wild mint, clove, sumac, satureja, ashwagandha, Lonicera japonica, Acacia, liquorice, Artemisia annua, milk thistle, cinnamon, black cumin and etc. have positive effects on organic broiler production.

Conclusion:

Herbal medicines lead to increased body weight due to a higher feed intake and a higher feed conversion ratio, and improve antioxidant activity of broiler chickens based on their phenolic compound contents. The combination of medicinal herbal additives also has a positive impact on broiler production. In organic broiler production with the usage of herbal plants, reducing hormones, growth promoters and antibiotics should be organized as well as considering appropriate organic feed management and higher production.

The effect of stocking rate and supplementary selenium on the fatty acid composition and subsequent peroxidisability of poultry muscle tissues

Selenium (Se) plays a crucial role in protecting biological materials from oxidative damage through the action of the selenoprotein glutathione peroxidase (GSH-Px), and the effectiveness of this protection is often dependent upon Se supply. Recent evidence has indicated that GSH-Px mRNA expression can be upregulated in response to potential oxidative damage risk, and that this upregulation is independent of Se supply. The current study aimed to determine the effect of Se supplementation, stocking rate and tissue fatty acid profile on GSH-Px activity in breast and thigh tissue of commercial broilers. A total of 168 Ross 308 broiler chicks were enrolled onto the study. Prior to enrolment, birds were brooded as a single group and received a starter diet containing no additional Se. The study was a 2 × 2 factorial design comprising of two levels of dietary Se (high Se, 0.5 mg/kg total Se, low Se background Se only), and two stocking rates (high, 30 kg/m², and low, 15 kg/m²). At 15 days of age, birds were blocked by live weight and randomly allocated to one of the four treatments, with six pen replicates per treatment. At 42 days of age, one bird was randomly selected from each pen replicate, euthanased and breast and thigh tissue harvested. GSH-Px activity, thiobarbituric acid reactive substances (TBARS), and fatty acid (FA) content of these tissues were determined. There was no effect (P > 0.05) of stocking rate on GSH-Px activity or TBARS. GSH-Px activity did not differ between tissue types but was greater in high Se birds (P < 0.001) compared to low Se. TBARS concentrations were greater in thigh tissue (P < 0.001), and these thigh concentrations were greater in high Se birds (P < 0.05). There were marked differences between breast and thigh tissue in most FAs (P < 0.001), with breast generally containing greater proportions of polyunsaturated FA, so that breast tissue had a higher (P < 0.001) peroxidisability index (PI) than thigh. A positive correlation between GSH-Px activity and PI in the thigh tissue of high Se birds (Pearson Correlation 0.668; P = 0.025) may indicate that increasing susceptibility to peroxidisation in lipid-rich tissues may also upregulate GSH-Px activity in Se-replete birds. This study suggests that ensuring adequate dietary selenium could be a useful tool to mitigate adverse effects on meat quality caused by oxidation, particularly in lipid-rich meat.

Effect of raw and fermented pomegranate pomace on performance, antioxidant activity, intestinal microbiota and morphology in broiler chickens

The present study was conducted to investigate the effects of raw (PP) and fermented pomegranate pomace (FP) on performance, antioxidant activity, caecal microbiota and ileal morphology in broiler chickens. A total of 175 male broiler chicks were allocated to five treatment groups with five replicates and seven birds per replicate in a completely randomised design. Dietary treatments included a soy-corn based diet (control), diets supplemented with PP at 5 (5PP) and 10 g/kg (10PP), and diets supplemented with FP at 5 (5FP) and 10 g/kg (10FP). Dietary PP and FP did not change the body weight and feed conversion ratio. Moreover, dietary PP and FP did not alter the serum glutathione peroxidase, superoxide dismutase, and catalase levels but decreased malondialdehyde (p < 0.05) in breast meat. Caecal Clostridium perfringens count was decreased in broiler chickens of groups 10PP, 5FP and 10FP (p < 0.05). However, PP and FP had detrimental effects on the ileum morphology of broiler chicks. The villus height was decreased in the 10PP, 5FP and 10FP groups compared with the control group (p < 0.01). Crypt depth was higher in the 5PP and 10FP groups than control and 10PP groups (p < 0.01). The villus height to crypt depth ratio was also decreased in 5PP, 5FP, and 10FP groups (p < 0.01). These results suggest that PP and FP have the potential to be used in broiler diets as antioxidant and antimicrobial agents. However, detailed studies should be conducted to investigate the underlying reasons for the detrimental effects on ileal morphology.

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0-35 d broiler chicken diets. 2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source. 3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0-35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001). 4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.