Effect of intramuscular injections of DL-α-tocopheryl acetate on growth performance and extracellular matrix of growing lambs

Abstract

The effect of intramuscular injections of vitamin E on growth, carcass traits, intramuscular collagen (IMC) characteristics and decorin of growing lambs was studied. A total of 24 15-day-old Ile de France suckling male lambs were divided into two groups and weekly intramuscular injections of DL-α-tocopheryl acetate (control group, 0 IU; Vitamin E treatment, 150 IU) were given until the lambs were 64 days old. Lambs were individually weighted at 15, 29, 43, 57 days of age and at slaughter (71 days old). Dry matter intake and average daily weight gain were recorded. Hot and cold carcass weights were recorded and dressing percentages were calculated after dressing and chilling (2°C to 4°C for 24 h). Carcass shrink losses were calculated as well. Longissimus muscle (LM) pH and area were measured. The pelvic limb was removed and its percentage was calculated based on cold carcass weight. IMC and decorin analyses were assessed on LM and semimembranosus muscle (SM). DL-α-tocopheryl acetate treatment reduced ( P < 0.05) collagen maturity and increased ( P < 0.05) decorin in both LM and SM muscles of growing lambs, while it did not affect IMC content. In addition, vitamin E did not influence growth, carcass weight, dressing percentage, carcass shrink losses and area of LM but decreased ( P < 0.05) the pelvic limb percentage. The LM pH values were higher ( P < 0.05) in vitamin group than in control group. Furthermore, different IMC characteristics between the muscles ( P < 0.01) were apparent. Multiple intramuscular injections of DL-α-tocopheryl acetate influence extracellular matrix in lambs, which could affect meat tenderness.

The Modes of Vitamin E Administration and Its Role on Meat Quality: A Mini-Review

“…Some works have demonstrated a beneficial effect of vitamin E treatment on growth traits in lambs (900 IU DL-α -tocopheryl acetate, Gentry et al, 1992; 15 mg vitamin E per lamb per day, Macit et al, 2003a). Conversely, other authors (1500 IU α -tocopherol, Birch et al, 1994; 1200 IU DL-α -tocopheryl, Maiorano et al, 2007) observed a lower carcass weight and a negative effect on carcass wholesale cut weights in lambs injected with vitamin E. In addition, in our recent study (Maiorano et al, 2015a) we found that vitamin E did not influence growth, carcass weight, dressing percentage, carcass shrink losses and area of longissimus muscle but had a negative effect on pelvic limb percentage. It has been also reported that vitamin E-treated lambs had lower leg and shoulder weights (Birch et al, 1994) compared with control lambs.…”

“…The higher score in tenderness of meat from treated lambs could be due to higher heat soluble connective tissue with cooked meat, favoured by the action of DL-α-tocopheryl acetate that slows collagen maturation and reduce tenderness muscle index (µg of Hydroxylysylpyridinoline crosslinks/mg of intramuscular collagen, Maiorano et al, 2001Maiorano et al, , 2007. In our recent study (Maiorano et al, 2015a) conducted on Ile de France suckling male lambs, we found that the DL-α-tocopheryl acetate treatment reduced collagen maturity (HLP/collagen) and increased decorin in the longissimus muscle of growing lambs, while it did not affect intramuscular collagen (IMC) content. Maiorano et al (1999Maiorano et al ( , 2007 focused on the effect of vitamin E on collagen and demonstrated that intramuscular injections of DL-α-tocopheryl acetate (total dose of 1000 and 1200 IU/animal) given to lambs (slaughtered at 40 days and 70 days old) may increase collagen solubility and reduce the IMC maturity.…”

Enrichment of Dairy-Type Lamb Diet with Microencapsulated Omega-3 Fish Oil: Effects on Growth, Carcass Quality and Meat Fatty Acids

“…To calculate empty BW, the digestive contents were subtracted from the slaughter weight. Immediately, the hot carcasses were weighed and stored at 4 °C for 24 h. Dressing yield was determined by dividing fasting weight by cold carcass weight [ 19 ]. The cold carcass was weighed before sawing the backbone vertically into two symmetrical halves.…”