Effects of dietary coated cysteamine hydrochloride on meat quality in finishing pigs

Abstract Text:

Cysteamine is used as a feed supplement in animal production to promote growth rate and improve feed efficiency. Coated cysteamine hydrochloride (CC) target releases cysteamine in small intestine and protects gastrointestinal mucosa from oxidative damage. However, little information is known regarding the effects of CC supplementation in carcass characteristics and meat quality. The aim of present study was to investigate potential effects of cysteamine supplementation on growth performance, carcass characteristics and meat quality in finishing pigs. A total of 144 crossbred finishing pigs (87.60 ± 0.20 kg) were assigned randomly to one of the two dietary groups, with eight pens/group (nine pigs/pen). Pigs were fed with a basal diet containing 0 (control) and 70 mg/kg CC for 29 days. The CC was supplied by King Techina Group (Hangzhou, China), containing 27 % cysteamine hydrochloride. One pig from each pen was selected randomly to be killed by exsanguination after electrical stunning. Longissimus dorsi sample was collected and stored at 4℃ for meat quality measurement. Muscle pH was determined by the electrometric method using a Testo 205 thermometer (Testo, Germany) at 1 h, 24 h and 48 h postmortem Meanwhile, meat color (L* = lightness, a* = redness, b* = yellowness) was measured by a chromameter at 24 h and 48 h after slaughter. The meat tenderness from longissimus dorsi was measured with tenderometer, and longissimus dorsi heme pigment estimation (myoglobin, oxygen-myoglobin, and metmyoglobin) was conducted based on Krzywick's method (1982). MDA was determined by commercial reagents (Nanjing Jiancheng Bioengineering Institute, Nanjing, China) according to the manufacturer’s instructions. We find that dietary CC has trend to increase average daily gain and decrease feed conversion rate (0.05 < P < 0.1). Compared with control diet, supplementation of CC increased carcass weight, lean rate and eye muscle area of finishing pigs by 8.9%, 15.9% and 11.9%, respectively. Dietary CC increased the tenderness of longissimus dorsi significantly (P < 0.05). There were no significant differences on the meat color lightness and yellowness, content of oxygen-myoglobin, metmyoglobin and MDA between groups. But the redness of meat color and the relative contents of myoglobin increased by CC supplementation (P< 0.05). Collectively, 70 mg/kg coated cysteamine hydrochloride diet shows positive effect on growth performance, tenderness and meat quality in finishing pigs; in particular, coated cysteamine hydrochloride improves the meat color by regulating content of myoglobin in longissimus dorsi.

Keywords: cysteamine, finishing pigs, meat quality