Marija Dokmanovic

The effects of lairage time and handling procedure prior to slaughter on stress and meat quality parameters in pigs

Lairage time (short - 8min to 2.7h, n=28 vs. long - 14 to 21.5h, n=72) and pig handling (gentle - no use of stick or electric prod, pig not slipping, falling, nor emitting high-pitched vocalizations vs. rough - where any of these occurred) effects on pig stress and meat quality were measured. Blood lactate and cortisol, plus post-mortem pH (pH60min; pH24h), temperature (T60min), drip loss, sensory and instrumental color and meat quality for the longissimus dorsi, pars lumbalis derived meat were determined. Carcass rigor mortis and skin damages were measured. Lairage time significantly affected blood lactate, carcass rigor mortis, skin damages, drip loss, color and meat quality. Handling procedure influenced blood lactate, pH60min and T60min. Long lairage was more stressful, and was detrimental to carcass quality, but caused better meat quality compared to short lairage. Rough handling was related to higher lactate and lower meat quality.

Correlations among Stress Parameters, Meat and Carcass Quality Parameters in Pigs

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

INVESTIGATION OF THE EFFICACY OF IMMUNOCASTRATION AIMED AT THE PREVENTION OF SEX ODOUR IN BOAR MEAT

Disadvantage of meat known as boar taint is caused by steroids, androstenone being of particular importance, as well as indole and its derivatives, among which the best known is skatole. The common practice in Europe, in order to control these changes in meat, is castration without anesthesia. This intervention causes pain and stress to animals, thus undermining animal welfare. Many countries considering animal welfare try to find the alternative solutions in order to avoid castration. The alternative to surgical castration and possible solution to the problem of sex odour in the meat, as well as androstenone and skatole contents decrease in the boars fat is immunological castration of boars (immunocastration). Average skatole content in fat tissue of boars was significantly higher (0.21±0.03 μg/g) compared to skatole content in fat tissue of the castrates, or immunocastrates (0.12±0.02 μg/g). In adipose tissue of the castrates and immunocastrates there was no significant difference in the average content of skatole. The content of androstenone in the adipose tissue of immunocastrates was below detection limits, and the average androstenone level in adipose tissue of boars was 0.66±0.13 μg/g. The obtained results show that immunocastration is justified in consideration of the meat quality and can completely replace castration in male animals, which is in compliance with the preservation of animal welfare in rearing fattening young boars.

Effect of lairage time, behaviour and gender on stress and meat quality parameters in pigs.

The objective of this study was to determine the effects of lairage time (short vs. long), behavior (aggressive vs. non-aggressive) and gender (gilts, barrows and boars) on stress and meat quality parameters in pigs (n = 100). In the group with short lairage, aggressive behavior of gilts and boars was observed. At exsanguination, blood samples were collected and levels of blood lactate and plasma cortisol were determined. Post mortem pH value, temperature, drip loss, sensory and instrumental color and meat quality class were determined on the muscle Longissimus dorsi. Higher blood lactate concentration (P < 0.05) and skin blemish score (P <0.001), lower temperature (P < 0.05) and drip loss (P < 0.01), as well as darker, less red and yellow meat color (P < 0.001) were found after long lairage compared to short lairage. Gilts had higher plasma cortisol concentrations than barrows (P < 0.05), while barrows had lower skin blemish scores (P < 0.05) than gilts and boars after long lairage. The highest incidence of PSE (pale, soft and exudative) meat was observed in barrows (100.00%) and boars (91.67%) after short lairage, while the lowest incidence of PSE meat was found in barrows (28.89%) after long lairage. Aggressiveness affected meat temperature, as aggressive pigs had higher meat temperature (P < 0.05) than non-aggressive pigs.

Relationships among pre-slaughter stress, rigor mortis, blood lactate, and meat and carcass quality in pigs

Abstract The aim of this study was to examine the relationships among pre-slaughter stress, rigor mortis, blood lactate, and meat and carcass quality in 100 pigs (cross between Naima sows and hybrids P-76 PenArLan boars). Before slaughter lairage time, handling and pig behavior were assessed for each animal. At exsanguination blood concentrations of lactate and cortisol were determined, while post-mortem were assessed: initial and ultimate pH value, temperature, drip, sensory and instrumental colour and marbling. On the carcasses the degree of rigor mortis and skin damage score were estimated, as well as carcass quality parameters. More developed (p<0.01) rigor mortis was observed after long lairage compared to short lairage. Higher intensity of rigor was found in pigs with higher blood lactate level (p<0.05) and with a greater thickness of subcutaneous fat tissue (p<0.05) and lower lean meat content (p<0.01). Higher blood lactate level was observed after long lairage compared to short (p<0.05) and after rough handling compared to gentle handling (p<0.01). In the group with blood lactate from 10 to 15 mmol/l meat temperature and skin blemishes score increased, while in the group with the highest blood lactate concentration (>15 mmol/l) initial pH decreased and L* value increased. These results suggest that in groups with higher blood lactate concentrations meat quality deteriorates.

The scope and structure of the production and catch of fish in Serbia in the period from 2006. to 2012.

Fish represents a significant source of animal proteins in the diet of people in a large part of the world. The market in Serbia is supplied from its own production (carp and trout fish ponds) and catch from open waters. However, the largest part of the fish on the market is imported. Average area under carp fish ponds from 2006. to 2012. was 8,417 hektars, and under trout fish ponds was 49,900 square meters. Average annual production of carp fish species in this period was 7,228 tons, and of trout was 923 tons. In open waters of Serbia, the catch (from both professional and sport fishing) is averagely 3,745 tons of fish. The biggest catch of fish in open waters refers to goldfish, then carp and bream, while lower catch refers to white bighead. The objective of this investigation was to determine the scope and structure of fish catch and production in Serbia from 2006. to 2012. The data on fish catch and production were taken from Statistical Yearbook of the Republic of Serbia. [Projekat Ministarstva nauke Republike Srbije, br. TR 31011]

Assessment of welfare conditions during stunning of pigs with respect to the day of the week.

Proper stunning is important in order to ensure animal welfare and to improve meat quality. The conditions in which the stunning is performed and the result of procedure may vary in practice due to numerous factors. The aim of this study was to examine the effectiveness of the stunning procedure with respect to the day of the week. The experiment was conducted on 100 pigs of different genetic origin and of different age and live weight during 5 working days (20 pigs per day). Stunning procedure was assessed through the following parameters: placing of electrodes at the proper position on the head; application of energized electrodes; voltage, amperage and frequency of the current; duration of current application and interval from stunning to bleeding; presence of tonic, clonic convulsions, as well as rhythmic breathing and re-stunning. In this study, improper electrode placement was observed in 40-70% of pigs, application of energized electrodes in 5-45% of pigs, duration of current application from 6,90 to 17,55 seconds, and the interval from stunning to bleeding from 48,62 to 91,25 seconds, the presence of tonic and clonic convulsions, and rhythmic breathing in 65-85%, 45-75% and 10- 75% of pigs. The stunning procedure was repeated in 5-15% of pigs. In addition, the deterioration of most of the parameters at the end of the week was observed. These results suggest unsuccessful stunning of pigs as a consequence of insufficient staff training, and their fatigue at the end of the week. .