Mario Gambacorta

Influence of dietary conjugated linoleic acids (CLA) and age at slaughtering on meat quality and intramuscular collagen in rabbits.

To assess the effects of dietary conjugated linoleic acids (CLA) on meat composition and intramuscular collagen (IMC), 144 New Zealand White rabbits, half males half females, 55 days old (1.8 kg LW), were assigned to three weight- and sex- balanced groups and given the following dietary supplements: 0.5% sunflower oil, (C); 0.25% sunflower oil plus 0.25% CLA (T1); and 0.5% CLA (T2). The CLA was prepared from sunflower oil and contained 65% CLA isomers, half cis-9, trans-11 and half trans-10, cis-12. Six males and six females from each group (total 36) were slaughtered at 76, 90 and 104 days of age (corresponding to 2.5, 2.8, and 3.1 kg BW, respectively). The lean fraction was higher and the water content significantly higher in the meat of T2 compared to C and T1 for all ages combined. At the third slaughtering (104 days) the meat fat content was significantly lower in group T2. For all ages combined, IMC content, IMC hydroxylysylpyridinoline (HLP) concentration (index of collagen cross-linking) and IMC maturity (HLP/IMC) were significantly lower in the intermediate supplementation group (T1) compared to C and T2, and were also lower in animals slaughtered at 90 days. CLA supplementation has limited effects on the chemical composition of rabbit meat, with positive effects on meat texture and tenderness after supplementation up to 35 days at 0.25%, and a significant decrease in fat content only at high slaughter weight and high supplementation level (0.5%).

The effect of dietary energy and vitamin E administration on performance and intramuscular collagen properties of lambs.

The effect of different dietary energy levels, with or without injections of vitamin E, on growth, carcass traits and intramuscular collagen (IMC) characteristics of growing lambs was studied. Twenty-four Ile de France ram lambs were evaluated in a 2×2 factorial design involving different DL-α-tocopheryl acetate injections (C, control=0 and V=150IU/wk, i.m. for eight wk) and energy level (N, normal=7.61 and L, low=6.47MJ/kg DM). Growth and slaughter performance, and IMC characteristics were not influenced by diet. DL-α-tocopheryl acetate increased ADG during suckling, while it did not affect live weight, carcass weight and dressing percentage. Vitamin E injections reduced carcass shrinkage but also had a negative effect on pelvic limb percentage. The Longissimus muscle pH values were higher in V than in C lambs. DL-α-tocopheryl acetate reduced IMC maturity and muscle hydroxylysylpyridinoline crosslink concentration, more markedly in lambs fed low energy diets.

Effects of slaughter weight and sex on carcass traits and meat quality of Casertana pigs reared outdoors

Abstract The effects of different slaughter weights (W) and sex (S) on carcass traits and longissimus dorsi meat quality (pH, WHC, colour, cholesterol and collagen) of Casertana pigs were studied. Thirty-six pure breed Casertana pigs, 24 barrows (B) and 12 gilts (G), were evaluated in a 2x2 factorial design involving different slaughter live weights (L, 125.6 kg; H, 152.5 kg) and S (B and G). H pigs had higher carcass weight (P<0.01), dressing percentage (P<0.05), ham yield (+ 7.9 %; P<0.01), lean meat cuts (P<0.01) and backfat thickness (+13.3%; P<0.05), and lower (P<0.01) loin yield and fatty cuts. W did not affect pH and WHC. L pigs produced lighter (P<0.01) and more yellow meat (P<0.01), while H pigs showed lower (P<0.01) hue value. Cholesterol content resulted higher (P<0.05) in H pig meat. Collagen properties were affected by W. Compared to G, B had higher dressing percentage (P<0.05) and backfat thickness (P<0.01), smaller loin area (P<0.01), slightly lower (P<0.08) loin yield and less (P<0.01) lean cuts. S did not affect any meat quality traits.

Superovulation and embryo production in ewes using a commercial p-FSH

The effectiveness of a commercial porcine pituitary extract (p-FSH) with a 1:1 FSH/LH ratio was assessed on ovarian response and embryo yield in ewes. During the breeding season, 60 Altamurana ewes were synchronized with FGA-impregnated intravaginal sponges and subdivided into four treatment groups (n = 15). Beginning 24 h before sponge removal, ewes were treated with 250 (Group 1), 500 (Group 2), 750 (Group 3) or 1000 IU p-FSH (Group 4) administered in a series of four decreasing doses over a period of 36 h. The ewes were monitored for estrus every 4 h, with ovarian response and embryos evaluated on the seventh day following sponge removal. No differences were found among the treatments in incidence of estrus and ovulation. Although treatment with 250 IU p-FSH produced the fewest ovulations, animals in this group yielded a higher (P < 0.01) number of viable embryos, a lower (P < 0.01) number of unfertilized ova, and a lower (P < 0.05) incidence of unovulated follicles and abnormal corpora lutea when compared with animals treated with 750 or 1000 IU p-FSH, while treatment with 500 IU p-FSH yielded intermediate results. It is concluded that the commercial porcine pituitary extract (Pluset) at moderate doses (250 IU) is suitable for superovulation in ewes as it induces a high ovulatory response and transferable embryo yield.

Growth, Carcass and Meat Quality of Casertana, Italian Large White and Duroc x (Landrace x Italian Large White) Pigs Reared Outdoors

To compare growth, skeletal development, carcass traits and meat quality of different genotypes, 10 Casertana (CT), 10 Italian Large White (LW) and 10 Duroc x (Landrace x Italian Large White) (DU) crosses, barrows of 90 days of age, were allotted to the same outdoor rearing and feeding conditions. Live weight was recorded and average daily gain (ADG) was calculated. At slaughter (330-day-old) dressing and lean percentages were determined; backfat thickness and loin eye depth were measured. Carcasses were dissected into commercial cuts. Water holding capacity, pH and colour (45 min and 24 h post-mortem) were measured. Longissimus lumborum muscle samples were collected for cholesterol, α-tochopherol and intramuscular collagen (IMC) analyses. CT compared to DU and LW had the lowest growth rate and skeletal development. Casertana showed higher backfat thickness, lower lean cut/fatty cut ratio and less lean meat (P<0.05). Loin eye depth differed among genotypes with LW>DU>CT (P<0.05). CT showed higher red colour of the meat than DU and LW (P<0.05). CT compared to LW had the highest hydroxylysylpiridinoline (HLP) crosslink concentration and HLP/IMC ratio, and a lower IMC amount (P<0.05). Casertana pigs produced meat that could be tougher than that from the improved breed, but more acceptable from the technological point of view. At eleven months of age bone weight, length and diameter were clearly genetic type-related; differently, the bone maturity was similar among the genotypes studied.

Effect of different sperm concentrations on the post-thaw viability and motility of turkey spermatozoa cryopreserved by the pellet method

Abstract The effects of different prefreezing semen concentrations on post-thawing quality of turkey semen cryopreserved with the pellet method were investigated. Ten pooled semen samples were each divided into 6 subsamples and diluted with Tselutin extender to obtain a final concentration of 0.5, 1, 2, 3, 4 and 5x109/mL respectively. Subsamples were cooled, added with 8% of dimethylacetamide as cryoprotectant and, after 5 minutes of equilibration, seminal aliquots of 80 μL were directly dropped into a liquid nitrogen bath to form frozen pellets. Thawing was performed in few seconds at 75°C. Sperm motility (Accudenz® swim-down test), viability (SyBr-Propidium Iodide staining) and sperm susceptibility to osmotic stress (Hyposmotic-water test) were assessed. Cryopreservation caused an overall loss of sperm quality, however differences in seminal parameters due to the different sperm concentration were observed in turkey spermatozoa after thawing: spermatozoa diluted to 4x109/mL showed significant higher values in mobility, viable and osmotic resistant spermatozoa compared to the other concentrations. This study showed that the post-thaw quality of turkey semen cryopreserved by pellets method was affected differently in relation to prefreezing sperm concentration.

Influence of vitamin E treatment starting time on lamb meat quality

Riassunto Effetto del momento di somministrazione della vitamina E sulla qualità della carne di agnello. Ventiquattro agnelli maschi di razza Merinizzata Italiana furono suddivisi secondo un modello fattoriale 2x2 per valutare gli effetti del trattamento i.m. con DL-α-tocoferil acetato (C = controllo; V = 5 dosi settimanali da 250 UI) e dell’età d’inizio del trattamento (A = 26 d; B = 35 d) sullo sviluppo scheletrico e su alcuni indicatori di qualità della carcassa e della carne. Gli animali furono macellati dopo una settimana dalla fine del trattamento vitaminico. La vitamina E, in particolare quando somministrata a partire da 35d di età, incrementò la maturità scheletrica, lo sviluppo muscolare e la capacità di ritenzione idrica della carne; tuttavia, gli agnelli trattati evidenziarono una minore incidenza del coscio. Gli agnelli macellati a 70d di età mostrarono un longissimus più sviluppato e produssero carni di colore più intenso e meno luminose.

The He-Ne laser irradiation improves the quality of stored rabbit semen

Abstract The aim of the study was to investigate the effect of different energy doses of Helium-Neon (He-Ne) laser irradiation on rabbit semen quality during 48 h of storage. From 30 commercial hybrid bucks semen was collected by artificial vagina. The ejaculates of bucks were pooled (3-4 ejaculates/pool) and in total 8 semen pools were used. Each pool was divided into four aliquots. One sample was not irradiated (control), the other ones were irradiated with a single mode continuous He-Ne laser wave (wavelenght 632,8) and exposed to the following energy doses: 3.96, 6.12 and 9 J/cm2 respectively. Samples were kept at 15° C during laser irradiation. They were subsequently stored again at the same temperature for a further 48 h. Samples were evaluated for sperm motility (Accudenz procedure), sperm viability (SyBr-PI procedure) and acrosome integrity (PSA-FITC procedure) at 3,24 and 48h of storage. Laser irradiation at all energy doses utilized significantly improved motility (P>0.01), viability (P>0.01) and acrosome integrity (P>0.05) than in control either at 24 and 48 h of storage. Moreover, the energy dose of 6.12J/cm2 recorded a better semen quality during storage compared to the 3,96 and 9J/cm2 ones respectively. No significant differences for measured seminal quality parameters were found at 3h; this might be due to the fact that irradiation treatment requires a longer period of time to determine modification on semen quality. The present study shows that laser irradiation, as shown in a previous research for turkey semen, seems to improve the quality of rabbit semen stored for up 48h even if higher energy doses were utilized. Therefore, the irradiation laser might be a useful technique to enhance quality of stored rabbit semen, although further studies are need.