Increasing Dietary Lysine Increases Final pH and Decreases Drip Loss of Broiler Breast Meat

Abstract

Responses to increased dietary Lys concentrations were evaluated on 1,584 Ross 308 male broilers between 21 and 42 d of age housed according to 2 bird densities. The experimental design was composed of 8 factorial treatments: 2 bird densities (22 or 44 broilers/ 1.7 m(2) pen) x 4 true digestible (TD) Lys levels (0.83, 0.93, 1.03, and 1.13%). There were 6 repetitions per treatment. Birds were weighed individually at d 21 and 42. Feed consumption was recorded per pen. Body weight gain and feed conversion were calculated over the experimental period. Forty-eight broilers per treatment were dissected at 42 d of age. Final pH and drip loss during storage were measured on the pectoralis major. Density adversely affected feed intake (169 +/- 1 and 160 +/- 1 g/d with 22 and 44 birds per pen, respectively, P < 0.05), growth rate (97.4 +/- 0.5 and 91.0 +/- 0.7 g/d, P < 0.05), and feed conversion (1.730 +/- 0.008 and 1.760 +/- 0.006, P < 0.05). Except for feed intake, there was no interaction between the effects of bird density and dietary Lys. An increase in dietary TD Lys from 0.83 to 0.93% resulted in an increased growth rate (from 91.8 +/- 1.6 to 95.5 +/- 0.8 g/d, P < 0.05), improved feed conversion (from 1.783 +/- 0.008 to 1.742 +/- 0.009, P < 0.05), and increased breast meat yield (22.0 +/- 0.1% to 22.7 +/- 0.2%, P < 0.01). Performance and body composition traits were not significantly improved for concentrations of TD Lys higher than 0.93%. However, final breast pH increased from 0.83 up to 1.03% TD Lys in the diet (6.02 +/- 0.01 vs. 5.91 +/- 0.01, P < 0.05), and drip loss correlatively decreased (0.85 +/- 0.03% vs. 1.10 +/- 0.06, P < 0.05). This result opens new way of research for the definition of an amino acid requirement and on metabolic pathways involved in variations of breast muscle pH.

Growth responses of breast and leg muscles to essential amino acids in broiler chicks

“…Moreover, Moran and Bilgili (1990) demonstrated that the proportions of breast and thigh increased with Lys at the expense of back both on a raw and a cooked basis. It should be noted that the Lys level of the diet may increase the breast quantity as well as breast meat quality but the Lys requirement for improving breast quality may be higher than that for breast meat yield (Berri et al, 2008). Based on sensitivity analysis in the present study, one can see that dThr had less effect on BM in comparison with dLys and dMet.…”

The response in growth performance, relative organ weight, blood profiles, and meat quality to dietary threonine: lysine ratio in broilers

“…Most studies have emphasized the AA requirements and growth performance (Berri et al 2008), but have rarely considered AA requirements in relation to meat properties. Berri et al (2008) reported that an increase in dietary Lys from 0.83 to 1.03% increased the final breast meat pH from 5.91 to 6.02, while muscle drip loss exhibited relatively symmetrical variations. It is well established that, as the final pH increases, water-holding capacity is improved (Barbut 1997).…”

Brown rice, selenium yeast and ?-tocopherol acetate in chicken’s diet: effects on meat quality

“…The difference in weight corresponding to DL was expressed as a percentage of the initial weight of the sample (BERRI et al, 2008). Only the 1st and 5th day of storage were used in the DL calculation.…”

“…The pH of the post-mortem muscle also has a strong influence on meat quality, including the WHC and the colour (YOUNG et al, 2004). In general, the WHC of meat is closely related to the muscle pH, and the higher the pH, the higher the WHC of the meat (ZHANG; BARBUT, 2005;BERRI et al, 2008). Furthermore, there is a strong correlation between low pH and the paleness of breast muscle (FLETCHER, 1999) and low WHC (DRANSFIELD; SOSNICKI, 1999).…”