Stress In Beef Cattle Research Articles

Gentle touching in early life reduces avoidance distance and slaughter stress in beef cattle

This study investigated the effect of gentle touching applied during the early life of suckler beef calves on avoidance distance on-farm and stress reactions at the abattoir. Twenty-seven Limousin crossbred calves were assigned to a treatment (n=13) or a control group (n=14) balanced by sex and day of birth. Gentle touching, using the TTouch© method, began on the second day post partum and was continued on the following 2 days. Additional touching was conducted on 3 non-consecutive days during the following 3 weeks in the home pen. Each treatment lasted for 10min and was repeated once after 30min. Individual avoidance distance was assessed 6 times. Following this test, all voluntary approaches towards the test person were recorded. All animals were slaughtered at 10 months of age. Behaviour was observed during lairage and in the stunning chute. Blood samples were taken during exsanguination at the abattoir, and concentrations of cortisol, lactate and glucose were analysed. Samples of the Musculus longissimus dorsi were subjected to cooking loss measurements, Warner Bratzler shear force and meat colour traits. The treatment calves showed smaller avoidance distances (P<0.001) than the control calves. The treatment cattle showed less avoidance behaviour in the stunning box (P<0.01), and the cortisol level of the touched animals tended to be lower (P=0.055). The Warner Bratzler shear force of the cooked muscle was lower in the touched than in the control animals (P<0.05). In conclusion, the treatment animals were less fearful towards humans and showed less stress-related behaviour at the abattoir. Fewer stress related reactions at the abattoir can be the reason for improved tenderness of touched animals’ meat. We conclude that early gentle touching of beef cattle has long-term persistent effects, reduces fear towards humans, and may increase meat quality.

Quality of handling and holding yard environment, and beef cattle temperament: 2. Consequences for stress and productivity

This experiment assessed the effects of different quality and quantity of handling and quality of the holding yard environment on the productivity and physiological parameters indicative of stress in beef cattle. One-hundred-and-forty-four steers were given one of three human handling and yarding experiences on six occasions during a 12-month grazing period post-weaning (backgrounding): Good handling/yarding, Poor handling/yarding and Minimal handling/yarding. At the end of this phase the cattle were lot-fed for 78 days, with no handling/yarding treatments imposed, before being transported for commercial slaughter. Temperament was assessed by flight speed (FS) and a fear of humans (FOH) test, which measured the proximity to a stimulus person (ZA), the closest approach to the person (CA) and the amount the cattle moved around the test arena (TT). Mid-way through backgrounding, the Minimal treatment group was heavier than the Good, which was heavier than the Poor (mean weights 207, 201 and 194 kg, respectively; P = 0.05; LSD = 5.4), but by the end of backgrounding there was no difference between treatments and treatment did not affect liveweight during lot-feeding. At the end of backgrounding, plasma cortisol levels were significantly lower ( P < 0.001) in the Good treatment group compared to the Poor and Minimal groups but at the end of lot-feeding there was no significant difference between the groups. Treatment affected plasma non-esterified fatty acid levels in backgrounding ( P = 0.060) and lot-feeding ( P = 0.046) with levels being higher in the Minimal than the Good and Poor groups (backgrounding: 0.52, 0.44 and 0.47 nmol/L, respectively; SE 0.02; lot-feeding: 0.46, 0.41 and 0.41 mmol/L, respectively; LSD = 0.05). Significant weak to moderate ( r-value <0.50) negative correlations were found between FS and average daily gain, but there were no consistent correlations between measures from the FOH test and productivity. FS and TT were weakly positively correlated with plasma l-lactate, glucose and cortisol levels, and CA was weakly to moderately negatively correlated with l-lactate and glucose levels. The results indicate that, whilst being imposed, the Good treatment reduced stress and the Poor treatment negatively impacted on liveweight gain. Minimal handling/yarding appeared to cause the cattle to experience stress, perhaps because of the relative novelty of being handled and confined. This work also confirms previous findings that cattle with high FS have poorer liveweight gains under both pasture and feedlot conditions and FS has some value as a predictor of productivity. Correlations also indicated that agitated cattle show a heightened arousal and stress responses when being handled. Fear of humans, as assessed by ZA, CA and TT, did not adversely affect productivity.

Effects of Tasco in Alleviation of Heat Stress in Beef Cattle

A study was conducted to evaluate the influence of Ascophyllum nodosum (Tasco) on rectal temperature, respiration rates, and in situ NDF disappearance in cattle exposed to elevated ambient temperature. Twenty-four Angus crossbred steers (average BW = 300.6 kg) were randomly assigned to treatments using a 2 × 2 factorial arrangement: 1% Tasco vs. no Tasco (control), and thermoneutral (TN) vs. heat load (HL) conditions. Three steers in each room were assigned to the Tasco vs. control treatment. In period 1 (10 d), steers were acclimated to chambers at TN (19°C) conditions. Subsequently, for periods 2 and 3, HL was maintained at a daytime high of 36°C and a nighttime low of 19 and 31°C, respectively. For period 4, temperature conditions (TN and HL treatments) were reversed and period 2 HL conditions were imposed. In periods 2 (P < 0.09) and 4 (P < 0.05), Tasco lowered DMI. In period 2, the control steers had greater (P < 0.0001) differences between maximum and minimum rectal temperatures than steers in the Tasco treatment; this difference occurred between d 4 and 8 for the HL group. In periods 2 and 3, the maximum and minimum differences in respiration rate values were greater (P < 0.05) under HL conditions for the Tasco vs. control treatment. In period 4, the maximum respiration rate response to HL tended to be greater (P = 0.07) under HL conditions for the control vs. Tasco treatment. In period 2, a trend existed for steers in the Tasco treatment to have a greater (P < 0.1) rate of in situ NDF disappearance than control steers. In conclusion, Tasco appeared to reduce rectal temperature for 3 to 4 d.

Acute stress induced by the preslaughter use of electric prodders causes tougher beef meat

Adrenergic activation and hormone release preslaughter is an inevitable outcome of the systems used to move cattle to slaughter. The aim of this experiment was to investigate the effects of acute preslaughter stress in beef cattle on postmortem muscle metabolism and the meat quality, including consumer-assessed eating quality. Eighty-four cattle were used on three separate days, with ‘mobs’ of four cattle allocated to either a ‘control’ (no electric goads used preslaughter) or a ‘stress’ (six prods given with an electric goad over 5–10 min) treatment at 15 min preslaughter. Cattle undergoing the ‘stress’ treatment had higher plasma lactate at slaughter. The prerigor pH and temperature, ultimate pH and temperature at rigor of the longissimus thoracis muscle were similar between treatments (P &gt; 0.05 for all). The water-holding capacity of the longissimus lumborum was reduced by the ‘stress’ treatment, as indicated by higher levels of water lost during suspension (drip loss), storage (purge) for 21 days and cooking (cooking loss at 1 day postslaughter) (P &lt; 0.05 for all). ‘Stress’ cattle produced longissimus lumborum muscle with similar sarcomere lengths and Warner–Bratzler shear force at 2, 6 and 21 days, compared to ‘control’ cattle (P &lt; 0.05 for all). The longissimus lumborum muscle of cattle undergoing the ‘stress’ treatment was rated less tender, less juicy, with a less acceptable flavour, a lower ‘liking’ and a lower MQ4 score (P &lt; 0.05 for all). The ‘bloomed’ surface colour (CIE L*, a*, b*) of the longissimus lumborum muscle at 2, 6 and 21 days postslaughter was similar between the ‘stress’ and ‘control’ treatments (P &gt; 0.05 for all). In conclusion, cattle subjected to acute preslaughter stress using electric goads produced meat which the consumer rated as tougher with inferior quality. The inferior quality induced by the acute stress treatment was associated with reduced water-holding capacity but was independent of muscle pH and temperature.

The influence of season on quality characteristics of hot-boned beef m. longissimus thoracis

Samples of m. longissimus thoracis (LT) muscle were randomly collected from 70 Omani beef cattle 1 h after slaughter between August 2001 and July 2002 in the Muscat Municipality central slaughterhouse to investigate the effect of seasonal parameters on meat quality during the hot and cool seasons of Oman. The collection period (12 months) was divided into two seasons according to ambient temperatures and relative humidity and termed: Cool Season (November–March with average temperature of 21.2±1.40 °C and 57.9±1.61% relative humidity) and Hot Season (April–October with average temperature of 34.3±1.67 °C and 48.8±7.57% relative humidity). The season had a significant effect on meat quality characteristics of the LT muscle. Muscles collected during the hot season had significantly ( P<0.001) higher ultimate pH values (6.24) with significantly ( P<0.001) lower Warner–Bratzler (WB) shear force values (10.12) than those collected during the cool season (5.54 and 15.58). In these hot-boned samples, there was a linear relationship between ultimate pH and WB shear values. Cooking loss was significantly ( P<0.001) higher for cool season samples (26.01%) than from hot season samples (19.75%). Beef from the hot season group had significantly ( P<0.001) darker meat than that of the cold season group, based on L* (31.45 vs 35.58), a* (18.53 vs 23.19) and b* (4.16 vs 6.40) colour measurements. There was a linear relationship between ultimate pH and cooking loss, L*, a* and b*. These results indicated that heat stress (>30 °C) lead to physiological stress in beef cattle, which in turn increased muscle ultimate pH and influenced related meat quality characteristics.

肉用牛の輸送ストレスに対する削蹄の効果

The purpose of this study is to determine effects of hoof trimming on transport-induced stress in beef cattle. Forty-one Japanese black steers were randomly divided into 2 groups: trimmed group (n=27) and untrimmed group (n=14). In the trimmed group, hoof trimming was repeated every 6 months, with the final trimming performed 3 months before shipment. The untrimmed group was not trimmed at all until shipment time. Before and after truck transportation to the shipping destination (57.8 km, 4 hours), the cattle were weighed, and their blood was sampled for hematological and biochemical analysis. The indices of transport-induced stress were creatine phosphokinase (CK) and cortisol. In both groups, CK and cortisolincreased after transportation. Increase in the parameters was lower in the trimmed group than in the untrimmed group. Lower CK activity in the trimmed group suggests that the physical demand for posture support during transport in the vehicle was more restricted in thetrimmed group. Plasma cortisol increased less in the trimmed group than in the untrimmed group. This could mean that periodical trimming effectively inhibits transport-induced stress in beef cattle.

Induction of heat stress in beef cattle by feeding the ergots of Claviceps purpurea.

Two groups of 4 Hereford steers were housed in a controlled environment room and exposed to simulated high summer temperatures. Both groups were fed a barley grain and hay diet ad libitum. The barley in one diet contained 0.5% w/w ergots of Claviceps purpurea. Within one week of feeding the ergot diet mean rectal temperature was significantly elevated (P less than 0.05) each afternoon (up to 41 degrees C) but returned to normal overnight. Elevated rectal temperature was accompanied by other signs of heat stress, reduced feed intake, body weight loss and depression or serum prolactin concentration. Symptoms disappeared within 1 week of ceasing to feed the ergot diet.