The effects of accustoming to handling during the finishing period and weaning status on stress responses to transport, and carcass and meat quality in Kivircik lambs

Comparison of the effects of production and processing parameters on the eating quality of lamb

While many separate research studies have investigated the effect of production and processing factors on eating quality of lamb, the relative impact of these parameters has been difficult to ascertain. In this study, the effect of eighteen production and processing factors on the eating quality of Welsh Lamb was compared, using meat from 624 lambs and assessments by 1920 UK consumers. Four experimental trials provided a balanced assessment of production and processing factors: muscle, breed type, lamb gender, ageing, finishing diet, season, carcase hanging and packaging method. The effect of other parameters was assessed using the combined data: farm type, individual farm, liveweight gain, abattoir, slaughter date, carcase weight, carcase conformation, carcase fat grade, age at slaughter, and transport time. The Meat Standards Australia protocol for consumer panels was used to provide a consistent methodology for comparing the effect on palatability of different treatments and factors and the interactions between them. The three factors that had the most significant effect on consumer sensory quality were muscle, season and individual farm. While the differences between muscles are well known, the effects of season within the 1st year and individual farm have not been widely reported. Meat from mid-season lambs received the highest scores for sensory quality while differences in sensory quality between meat from different farms were pronounced and unexplained; further research is needed to evaluate the role of genetics and/or microflora. Younger age and higher intramuscular fat content also gave improved eating quality, with gender and conformation grade having a small effect. Of the postslaughter factors, ageing to 14 or 21 days, gave significantly better eating quality than 7 days ageing, as did hanging "cross-legged" and vacuum packing, compared with Achilles hanging and modified atmosphere packaging, respectively. There was a significant muscle × hanging method interaction, with the greatest effect of "cross-legged" hanging observed in the loin. There was no significant effect of lamb finishing diet, abattoir, preslaughter daily liveweight gain or transportation time on any of the consumer sensory scores. The main factors tested that provide practical scope for improving the eating quality of lamb were ageing of the meat, carcase hanging and meat packaging. If the reasons for inter- and intra-farm differences in lamb quality can be elucidated, this may provide further management tools for improving the quality and consistency of lamb quality.

Development of Plastic/Gelatin Bilayer Active Packaging Film with Antibacterial and Water-Absorbing Functions for Lamb Preservation

In order to extend the shelf life of refrigerating raw lamb by inhibiting the growth of microorganisms, preventing the oxidation of fat and protein, and absorbing the juice outflow of lamb during storage, an active packaging system based on plastic/gelatin bilayer film with essential oil was developed in this study. Three kinds of petroleum-derived plastic films, oriented polypropylene (OPP), polyethylene terephthalate, and polyethylene, were coated with gelatin to make bilayer films for lamb preservation. The results showed significant improvement in the mechanical properties, oxygen, moisture, and light barriers of the bilayer films compared to the gelatin film. The OPP/gelatin bilayer film was selected for further experiments because of its highest acceptance by panelists. If the amount of juice outflow was less than 350% of the mass of the gelatin layer, it was difficult for the gelatin film to separate from lamb. With the increase in essential oil concentration, the water absorption capacity decreased. The OPP/gelatin bilayer films with 20% mustard or 10% oregano essential oils inhibited the growth of bacteria in lamb and displayed better mechanical properties. Essential oil decreased the brightness and light transmittance of the bilayer films and made the film yellow. In conclusion, our results suggested that the active packaging system based on OPP/gelatin bilayer film was more suitable for raw lamb preservation than single-layer gelatin film or petroleum-derived plastic film, but need further study, including minimizing the amount of essential oil, enhancing the mechanical strength of the gelatin film after water absorption.

Carcass Characteristics and Meat Quality of Karacabey Merino lambs Reared under Triticale and Oat Pastures Compared with Stall-Fed Lambs

Fifty-eight Karacabey Merino lambs were used to study the effects of feeding system (triticale pasture, oat pasture, or stall-fed), birth type (single or multiple), gender (male or female), and birth year (2016 or 2017) on various carcass and meat quality characteristics. Stall lambs had higher conformation (CS) and fatness (FS) scores, and higher meat L* and h* values than the two pasture groups, possibly due to higher fat content, while oat pasture lambs had the most tender meat. Single-born lambs had higher CS, FS, and Longissimus thoracis muscle section area, while females had higher subcutaneous and non-carcass fat deposits than their counterparts. Both single-born lambs and 2016-born lambs had higher meat a* and C* values than their counterparts. In conclusion, a pasture-based feeding system is more suitable for Karacabey Merino lambs than a stall feeding system, if lean meat and/or meat products are preferred. However, it should not be ignored that stall-fed lambs showed a better fattening performance in terms of conformation and fatness, during the same period.

Effects of adding rumen-protected palm oil in diet on milk fatty acid profile and lipid health indices in Kivircik ewes

This study aimed to determine the effect of the addition of rumen-protected palm oil making up 3% of the ration on lipid health indices and milk fatty acid composition of Kivircik ewes'. Kivircik ewes at two years of age, the same parity, lactation stage, and the same bodyweight (52.57 ± 5.80 kg) were chosen for this purpose. Two groups were formed, in which the control group was fed a basal diet without feed supplementation, whereas the treatment group received rumen-protected palm oil which corresponded to 3% of the ration. In order to protect palm oil, it was coated with calcium salts. Treatment increased the palmitic acid (C16:0) content of milk compared to the control group (P < 0.05) and tended to increase saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) (P = 0.14). An increase in SFA and MUFA was attributed to an increase in palmitic acid and oleic acid (C18:1), respectively (P < 0.05). Results indicated that the omega-6/omega-3 ratio (n-6/n-3) ranged between 0.61 and 2.63. The inclusion of palm oil in the diet tended to increase desirable fatty acids (DFAs) regardless of the week of milk sampled (P = 0.42). Treatment did not improve the atherogenicity index (AI), thrombogenicity index (TI), health-promoting index (HPI), and hypocholesterolemic/hypercholesterolemic (h/H) ratio. Results showed that adding rumen-protected palm oil is a plausible method to meet the energy intake of ewes required during lactation without negatively affecting lipid health indices.