Rony Geers

The effect of short distance transport under commercial conditions on the physiology of slaughter calves; pH and colour profiles of veal

The objective of this study was to examine the effect of the position of calves on the truck (back or front compartment) and other aspects of short distance transport on the welfare of cattle and meat quality parameters. A total of 158 Dutch Fresian calves, aged 28 weeks, were followed during 17 transports from 12 different farms to the slaughterhouse. Heart rate was monitored throughout the transport time and the night before. Blood samples were taken the day before transport in the home pen and at debleeding in the slaughterhouse. The samples were analysed for cortisol, lactate, glucose, creatine kinase and non-esterified fatty acids. Carcass pH and temperature and meat colour were measured in the musculus longissimus thoracis. The heart rate of the animals increased 80% during loading and 72% during unloading and remained high during transport (38%) (P<0.001). The heart rate increased 3% more for the animals travelling in the back compartment and remained higher during transport (P<0.05). The plasma concentration of cortisol, lactate and creatine kinase increased (P<0.001) after transport. The plasma cortisol increased more for the animals travelling in the front compartment (P<0.05). The pH1 was lower for the animals travelling in the front compartment (P<0.001) and the pH difference (pHu minus pH1) was larger for animals travelling in the back compartment (P<0.001). The meat colour of the calves travelling in the front compartment was lighter (P<0.01). A longer fasting period resulted in a darker meat colour (P<0.01). A longer lairage time resulted in a higher increase of creatine kinase (P<0.05).

An analysis of data relating to pig carcass quality and indices of stress collected in the European Union

Information from about 5500 pigs killed in five European countries was used to examine the relation of different measures of carcass and meat quality to one another and their relation to biochemical indices of stress in blood collected at slaughter. There were large differences in the prevalence of potentially PSE meat in pigs from the five countries and evidence of a wide range of stress encountered at slaughter. Relationships between the same measurements made in different muscles were generally good and consistent between countries. There were no apparent relationships between indices of stress and characteristics associated with PSE meat. In contrast, greater stress tended to be reflected in more DFD meat. Based on the association between the level of skin blemish and increased muscle ultimate pH values a probable factor contributing to this was fighting between mixed groups of unfamiliar animals.

Effect of unloading, lairage, pig handling, stunning and season on pH of pork

A total of 12,725 pigs originating from 90 transports were followed up at 17 Belgian commercial slaughterhouses. The effects of several pre-slaughter parameters concerning transport, unloading, lairage, pig handling, stunning and season on fresh meat quality based on pH measurements 30 minutes (min) after slaughter were investigated. Meat quality was measured on 4285 pigs. Ten pre-slaughter parameters had a significant effect on meat pH after separate introduction of the variable as a fixed effect in the model. Simultaneous analysis of these variables in the global model revealed that the pH was influenced by four main risk factors, namely the mean noise level produced during unloading, the percentage of panting pigs, the use of an electric prod and season. Meat quality in terms of the percentage of potentially PSE carcasses was better in summer than spring or autumn and could be explained by a lower observed pre-stunning stress in summer.

Effect of rate of pH decline on muscle enzyme activities in two pig lines

Muscle enzyme activities were measured in m. transversus abdominis (TA) samples of two pig lines, differing in stress sensitivity and in breeding objectives. Animals of line one were stress sensitive and selected for a high carcass lean content (LEAN), those of line two were homozygous stress resistant and selected for maximum live weight gain (GROWTH). Muscle samples of 16 pigs per line were excised at 1 h and sampled at 3 h post mortem. Boars, gilts and barrows were almost equally represented. Pigs of line GROWTH had a higher fat and lean tissue gain (P<0.01) and a lower carcass lean content (P<0.001) than those of line LEAN. Lower activities of μ-calpain, m-calpain, pyroglutamyl aminopeptidase I, acid lipase and neutral phospholipase were measured in TA muscle samples of line LEAN compared with line GROWTH (P<0.05). Activities of dipeptidyl peptidase IV and acid phospholipase tended to be somewhat lower for line LEAN, whereas activities of calpastatin, cathepsin (B+L) and cathepsin D were not different. Sex-class effects were analogous to line effects. Significant correlation coefficients between activities of several enzymes and pH values 1 h post mortem, both within and across lines, suggest that lower enzyme activities are a consequence of a more pronounced denaturation due to a faster post mortem pH decline.

Validation of a behavioral observation tool to assess pig welfare

Accurately measuring and monitoring of animal behavior is an important factor when assessing on-farm animal welfare. First we developed a feasible and simple method aiming at consistently on-farm measuring of pigs behavior. This test should cover a broad range of welfare-related pig behavior. The reaction towards a novel object, startling, tail and ear biting, play and aggressive behavior, stereotypies, coughing, sneezing, skin lesions, defecation, urination and cleanliness of body and pen are included. The development of accurate measures of on-farm behavior first requires the reliability assessment of the procedure. Therefore, the methodology was tested in a first part by three observers scoring simultaneously and independently pre-defined behavioral characteristics of 108 group-housed fattening pigs. The inter-observer repeatability of the measures was calculated using intraclass correlation coefficients, which ranged from 0.7 to 1. In a second part, the objective was to validate the behavioral characteristics against salivary cortisol, urinary epinephrine and norepinephrine and production traits. Salivary cortisol concentrations significantly increased in ear-bitten pigs and in pigs with tail lesions. Growth rate significantly dropped when cortisol levels rose. An age effect was also found. The percentage of animals approaching the novel object is positively correlated with the urinary epinephrine concentration. Pigs defecating during the test showed significantly higher epinephrine levels. Urinary norepinephrine concentration decreased significantly with age. Faster growing animals and animals with tail lesions showed significantly higher levels of norepinephrine. Pen dirtiness and number of animals per pen were associated with higher norepinephrine concentrations. Finally, barrows had higher norepinephrine concentrations than sows.

The prevalence of PSE characteristics in pork and cooked ham - effects of season and lairage time.

A total of 180 pigs was slaughtered in the same slaughterhouse, but divided in six different trials distributed over Winter (December-March) and Summer (April-September). Meat quality measurements (pH, electrical conductivity, color and/or water-holding capacity) were carried out 30 min, 24 and/or 35h after slaughter in three different muscles: M. gracilis, M. semimembranosus and M. longissimus dorsi. A tendency towards a higher proportion of PSE meat during Summer was found in the examined muscles. Moreover a higher protein, higher dry matter content, a lower water/protein ratio and a lower slicing yield were found for the cooked hams suggesting a higher PSE prevalence in the Summer. A lairage time between 2 and 4h during Summer and less than 2h during Winter was related to a lower proportion of PSE meat. The correlation coefficients between the individual meat quality variables were moderate, but showed the predictive power of the pH measured 24h post-mortem in the M. gracilis for meat quality.

The effect of incubation temperature on pre‐ and post‐hatching development in chickens

Synopsis Chicks hatched from eggs incubated at two temperatures (36.8 °C, 37.8 °C) but similar humidities (30 mmHg during the first 18 d and 40 mmHg thereafter) were reared for 12 weeks in groups of six at 22 °C and in a relative humidity of 45 to 55%. The lower incubation temperature resulted in a longer incubation period. Female embryos utilised the energy of the egg better than males. A possible difference in the relationship between the post‐hatching development of males and females and pre‐hatching environmental conditions was indicated by a higher viability at 14 d and a higher body weight after 12 weeks of cocks incubated at 36.8 °C. There were significant effects of sex on food conversion efficiency. Results suggest that pre‐hatching temperatures may influence post‐hatching energy utilisation.

Validation of an infra-red sensor for oestrus detection of individually housed sows

Abstract Oestrus detection of sows is an important activity within pig husbandry. It takes about 30% of the overall labour input and financial losses related to non-productive days may vary considerably. Therefore, the principle of using an infra-red sensor has been evaluated to detect automatically oestrus of sows. A total of 58 multiparous individually housed sows were monitored from the day after the piglets were weaned. The infra-red sensor was mounted 50 cm above the front part of the sow’s body. Four parameters of body movement as quantified by the sensor’s output voltage were investigated: mean daily activity; standard deviation of mean daily activity; minimal; and peak value. The reference method was the standing behaviour before the boar and the inseminator. Four classes of behaviour were defined: (1) standing+increase of mean daily activity; (2) standing+no increase; (3) no standing+no increase; and (4) no standing+increase. Up to 80% of the sows could be classified correctly when using mean daily activity as the selection parameter. Up to 86% were classified correctly when daily peak activity was also included. Positive and false positive sows could be distinguished at the 95% level by using a canonical discriminant analysis. Increase of mean daily activity, increase of standard deviation and increase of daily peak activity were statistically significant explanatory variables of a logit function predicting the four classes of oestrous behaviour.

Diurnal variation in the thermal demand of growing pigs

Abstract 1. 1.|Six experiments, each with 15 or 16 pigs weighing 30–46 kg, were performed. Each lasted 30 or 36 days. Feeding levels were 93 g kg −0.75 (experiments 1 to 4) and 83 g kg −0.75 (experiments 5 and 6). Ambient temperature ( T a ) was changed in stepwise fashion every 2–3 days by 2 to 4 K between 23 and 8°C. Between steps T a remained constant (experiments 1–3 and 5) or fluctuated 2.5 K above and below the daytime and night time means (experiments 4 and 6) until 8°C. At each step heat production (HP) was measured continuously during successive 18-min periods over 24 or 48 h. 2. 2.|In experiments 1 and 2 HP increased below 13 to 14°C and in experiment 3 to 6 below about 20 to 23°C. 3. 3.|HP per day increased from 12.9 to 14.3 kJ kg −0.75 day and from 9 to 9.6 kJ/kg −0.75 day in the constant and fluctuating temperature regimes, respectively. 4. 4.|Data showed that the total thermal demand was less during the night than during daylight hours.

Behavior of piglets after castration with or without carbon dioxide anesthesia

Surgical castration of male piglets without anesthesia is a routine management practice conducted on commercial pig farms. For animal welfare reasons, it would be beneficial to develop methods of practical pain relief. The objective of this study was to evaluate the effect of providing CO₂ anesthesia before castration on the behavior of piglets for up to 8 d after castration in comparison with piglets castrated without anesthesia. In 3 successive replicates, the behavior of 186 male piglets castrated with (n = 95) or without (n = 91) anesthesia was observed for up to 8 d after castration. All piglets in a given replicate were castrated on the same day, before 8 d of age. Behavioral observations were carried out in accordance with a continuous focal sampling procedure that began immediately after castration and continued for a period of 1 wk. Barrows anesthetized with CO₂ before castration displayed more interactive behaviors during the overall observation period than the other barrows (P = 0.0412), which may indicate better welfare. Assessing all observation periods separately, differences in activity at the udder, lying, walking, and interactive behaviors appeared to support the beneficial effect of providing CO₂ anesthesia before castration. However, these differences varied over time between treatment groups. The most important conclusion was that piglets castrated with or without CO₂ anesthesia displayed behaviors indicative of pain and discomfort for up to 6 d after castration. Therefore, additional analgesia may be necessary to eliminate the long-term pain caused by castration even in piglets anesthetized with CO₂ before castration.