# Carcass Yield and Meat Quality of Broiler Chicks Supplemented with Yeasts Bioproducts
## 4 Discussion
Furthermore, the raw broiler meat is strongly correlated with physical-chemical characteristics and meat functional properties, depending on the post-slaughtering treatments [9] and sarcoplasmic myoglobin content [40,41]. The chemical proximate analysis (total protein, fat, moisture, and collagen) was significantly influenced by the dietary supplementation. The broiler breast and thigh meat moisture were significantly higher on the experimental groups supplemented with SC (0, 0.6, and 1 g/kg feed). The highest values of moisture and fat content could be attributed to the growth promoting effect of SC and correlated with the final live body weight. The lowest fat content was observed in the 1.3 g/kg diet supplemented group, indicating that a higher supplementation dosage of SC might not only influence the final body weight but also the meat fat content. It is postulated that higher levels of SC administration could negatively influence the growth performance and the meat quality, due to the high levels of nucleic acids, disturbing the protein metabolism. Supplementing the experimental broiler diets with high protein sources (SC) significantly decreased the meat protein content, when compared with the negative control group (\(p<0.05\)). Opposite to our findings, [PERSON] et al. 's [35] results indicate that the dietary supplementation of live SC could positively modulate the meat protein content. A possible explanation could be connected with the SC amino acids content, which has higher levels of lysine, leucine, and methionine [42], and lower cystine levels [43], when compared with the soybean meal. In broiler diets, the most important and expensive component is the protein source, and it is known that the ideal vegetal resource is soybean meal, having all essential amino acids, especially those that birds need the most: sulphuric amino acids lysine, methionine and cystine [44]. Meat collagen is an important attribute for broiler meat quality and it is the main abundant protein in the broiler chicks' connecting tissues and body [45], and directly contributes to the meat tenderness and gumminess [46]. In our study, the results show that dietary SC supplementation (0.6, 1, and 1.3 g/kg diet) on broiler chicks' diets significantly increases the meat collagen, when compared with the negative control group. Lysine, glycine, and proline are the major amino acid constituents in the collagen [47]. We strongly believe that the SC dietary supplementation influenced the meat collagen synthesis, due to the supplementary levels of lysine and proline, enhancing the hydroxyproline and hydroxylysine accumulation, thus the collagen formation. The RM dietary supplementation had significantly increased the broiler breast meat moisture and fat content, when compared with the negative and positive control groups (\(p<0.05\)). There is a deficit of information regarding the chemical proximate composition of the broiler chicks' diet supplemented with inactive RM, and indeed, with lyophilize lysates pigment yeasts. To the best of our knowledge, this is the first study about the effects of dietary RM supplementation on broiler chicks' meat quality attributes and carcass yields. Therefore, future studies are needed to determine the effects of inactive yeasts dietary supplementation on broiler metabolism, thus the meat proximate chemical composition. Meat textural profile analysis is generally associated with meat processing proprieties [48] and consumer eating satisfaction [26]. This current study revealed similar textural properties (\(p>0.05\)) for all broilers' breast and thigh meat samples. All the texture parameters were highly correlated with each other (\(0.83<r<0.99\), \(p<0.05\)), except for resilience which was correlated significantly only with cohesiveness, gumminess, and chewiness (\(0.52<r<0.66\), \(p<0.05\)).