Morbidity, mortality and body weight gain of surgically spayed, yearling Brahman heifers

Objective To determine morbidity and mortality rates in yearling heifers spayed by two methods under commercial conditions in northern Australia. Design In study 1,600 Brahman heifers were allocated to one of three treatments: physical restraint and ear-tagging (Control); physical restraint, ovariectomy by the Willis dropped ovary technique, ear-tagging and ear-marking (WDOT); or electroimmobilisation, ovariectomy via flank incision, ear-tagging and ear-marking (Flank). Heifers were monitored post spaying. Mortalities occurred at unanticipated times, so study 2 investigated their timing and cause in similar WDOT-spayed heifers (n = 574). Results In study 1, morbidity on the day of spaying was 6.0% in the Flank and 2.7% in the WDOT group (not statistically different). Spayed heifers showed behaviours indicative of acute pain/discomfort in the 6 h post spaying. Body weights and gains were significantly lower in the spayed compared with control heifers at days 21 and 42, and 5% of flank wounds were not healed at day 42. Mortalities were 0%, 1.5% and 2.5%, respectively, for Control, WDOT (3 estimated to have occurred on day 11) and Flank (2 on the day after spaying and 1 on each of days 5, 11 and 22). In study 2, the mortality was 0.5%, all within 4 days of spaying. Conclusions In yearling heifers, WDOT spaying resulted in lower morbidity and short-term mortality compared with flank spaying. Both methods compromised the health and welfare of some animals for up to 4 days and body weight gains were reduced during the 6 weeks post spaying.     

肉牛运输应激危害及动物福利化预防措施

肉牛的运输福利是关乎内蒙古地区畜牧业发展的重要因素之一,作为畜牧业大省,内蒙古地区每年都进行大量的调运肉牛操作,不规范的运输会引起动物发生应激反应,进而使肉品质的下降。因此在实际生产中应注重运输环节的动物福利问题。文章通过总结实践和经验,分析了内蒙古地区肉牛运输中存在的问题及其危害,并提出了运输过程中的福利化预防措施,以其为改善肉牛运输福利提供参考。     

The assessment of the effect of presenting a companion's face picture on social isolation stress using saliva sampling in cows

The effect of presenting a companion's face picture on social isolation stress was assessed by saliva sampling in cows. Three Japanese Black test cows and another companion cow were used. At 09.00 hours, one of the test cows was housed in an experimental pen with the companion in a neighboring pen. At 11.30 hours, the test cow was socially isolated by taking the companion out the neighboring pen. At 12.00 hours, the test cow was exposed to one of four treatments until 15.00 hours; presenting a blank picture (P‐Blank), a white‐ground picture of the companion's face (P‐Com) or an unfamiliar Holstein's face (P‐Hol), or the companion in the neighboring pen and a blank picture (Com). The cows were randomly exposed to all treatments. The cows' saliva were sampled for measuring salivary cortisol and chromogranin A concentrations (Sa‐Cort, Sa‐ChA) at 11.30, 12.00, 12.30 and 14.00 hours. At 12.00 hours, Sa‐ChA was higher than that at 11.30 hours (P < 0.01). At 12.30 hours Sa‐ChA of Com and P‐Com were lower than that of P‐Blank (P = 0.09, P = 0.08). At 14.00 hours Sa‐Cort of Com was lower than that of P‐Blank (P < 0.01), but Sa‐Cort of P‐Com was higher than that of P‐Blank (P < 0.01). It is suggested that P‐Com might decrease isolation stress only a short time, but afterward induced stress in cows.     

我国肉牛业动物福利的现状及发展建议

当前我国肉牛业正处于积极向上发展的良好势头。在肉牛产业化生产中充分重视动物福利要求,提高牛肉产品的质量,在更大范围和更深层次上参与国际竞争是肉牛业发展的必然趋势。本文就我国肉牛生产中存在的系列动物福利问题进行剖析和阐述,具体包括初生犊牛护理、育成牛和架子牛的饲养、育肥牛场的管理、出栏牛的运输和屠宰问题。继而针对该系列问题,提出当前我国肉牛产业化生产中应采取的对策和建议措施,以提高从业人员的动物福利意识,促进肉牛生产中动物福利工作的开展。为我国肉牛业从容应对国际动物福利贸易壁垒,提升国际市场竞争力提供借鉴和指导。     

Impacts of shade on cattle well-being in the beef supply chain

Shade is a mechanism to reduce heat load providing cattle with an environment supportive of their welfare needs. Although heat stress has been extensively reviewed, researched, and addressed in dairy production systems, it has not been investigated in the same manner in the beef cattle supply chain. Like all animals, beef cattle are susceptible to heat stress if they are unable to dissipate heat during times of elevated ambient temperatures. There are many factors that impact heat stress susceptibility in beef cattle throughout the different supply chain sectors, many of which relate to the production system, that is, availability of shade, microclimate of environment, and nutrition management. The results from studies evaluating the effects of shade on production and welfare are difficult to compare due to variation in structural design, construction materials used, height, shape, and area of shade provided. Additionally, depending on operation location, shade may or may not be beneficial during all times of the year, which can influence the decision to make shade a permanent part of management systems. Shade has been shown to lessen the physiologic response of cattle to heat stress. Shaded cattle exhibit lower respiration rates, body temperatures, and panting scores compared with unshaded cattle in weather that increases the risk of heat stress. Results from studies investigating the provision of shade indicate that cattle seek shade in hot weather. The impact of shade on behavioral patterns is inconsistent in the current body of research, with some studies indicating that shade provision impacts behavior and other studies reporting no difference between shaded and unshaded groups. Analysis of performance and carcass characteristics across feedlot studies demonstrated that shaded cattle had increased ADG, improved feed efficiency, HCW, and dressing percentage when compared with cattle without shade. Despite the documented benefits of shade, current industry statistics, although severely limited in scope, indicate low shade implementation rates in feedlots and data in other supply chain sectors do not exist. Industry guidelines and third-party on-farm certification programs articulate the critical need for protection from extreme weather but are not consistent in providing specific recommendations and requirements. Future efforts should include: updated economic analyses of cost vs. benefit of shade implementation, exploration of producer perspectives and needs relative to shade, consideration of shade impacts in the cow–calf and slaughter plant segments of the supply chain, and integration of indicators of affective (mental) state and preference in research studies to enhance the holistic assessment of cattle welfare.     

Physical conditions in a cattle vehicle during spring and autumn conditions in Japan, and reactions of steers to long distance transport

The objective of this study was to investigate transportation conditions and behavioral and physiological responses of beef steers to long distance commercial transport in Japan. In spring (May) and autumn (September), eight (16 in total) Japanese Black × Holstein steers (7.8 ± 0.6 month of age; 310.3 ± 13.9 kg) were transported by truck. The transport distance was 1013.1 km (25 h including lairage periods) comprising 627.6 km (6.4 h) on expressways, 143.5 km (3.5 h) on arterial roads and 242.0 km (10.5 h) by ferry. The loading space of the truck gave a space allowance of about 1.62 m²/head. Internal temperature (±SD) and humidity (±SD) of the truck were 14.7 ± 4.7°C and 72.7 ± 22.4% in spring, 24.4 ± 2.8°C and 70.8 ± 14.4% in autumn. Vibration acceleration (±SD) of the truck in the longitudinal direction was greater in spring (?0.19 ± 0.43 m/s²) than in autumn (?0.15 ± 0.20 m/s²) (P < 0.05). There were no effects of season and driving conditions on the internal noise. Internal airflow velocity (±SD) of the truck was greater in spring (0.75 ± 0.70 m/s) than in autumn (0.45 ± 0.40 m/s) (P < 0.05), and it was greater while moving on expressways (0.77 ± 0.40 m/s) and arterial roads (0.63 ± 0.61 m/s) than when parked (0.16 ± 0.26 m/s) (both P < 0.05). Steers lay down more frequently while moving on expressways than the expected frequency (χ² = 121.9, P < 0.01). Steers were oriented parallel to the direction of travel (to the front cabin: 27.9%; to the tailgate: 23.4%) more frequently than the expected probability (12.5%). Blood glucose concentration, serum ALT activity and plasma cortisol concentration were greater in spring than in autumn (all P < 0.05). Serum pH was higher in autumn than in spring (P < 0.01). Blood glucose concentration was significantly higher at the market before transport, and serum total protein, triiodothyronine and total cholesterol concentrations were also significantly higher at the market and just after transport than 1 week after transport (all P < 0.05). However, the other physiological measurements such as plasma cortisol and blood lactate concentrations, serum pH and heart rate did not change after transport. The results indicate that in Japanese spring and autumn conditions, long distance transport with appropriate conditions including low stocking density and enough lairage time with provision of food and water might not cause severe stress for steers.     

Allele frequencies of gene polymorphisms related to economic traits in Bos taurus and Bos indicus cattle breeds

Allele frequencies of 10 representative polymorphisms for beef and milk traits were investigated for a total of 240 animals from Bos taurus and Bos indicus breeds, including two Japanese groups (Japanese Black and Japanese Brown), two East Asian groups (Korean and Mongolian), three European groups (Holstein, Angus and Hereford) and a Bos indicus group in South Asia (Myanmar, Laos and Cambodia). The Japanese Black revealed unique genetic construction in GH, FASN and SREBP‐1 and the other Asian populations show intermediate frequencies between European and Japanese populations. The Bos indicus group showed low favorable allele frequencies in most of the genes. The study showed the variability and distribution of 10 genes affecting economic traits among world representative cattle breeds. The genetic information would contribute to elucidating the genetic background for worldwide cattle breeds and the possibility of improvement using the markers.     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis)

This study was conducted to determine and compare the live traits, carcass yield and the physical, chemical, processing and sensory properties of meat from 20 Brahman grade cattle (crossbred cattle) and crossbred water buffalo (Philippine carabao × Murrah, Bulgarian or Indian) with an average age and weight of 29 months and 434 kg, respectively. The animals were fed a similar diet for 180 days before slaughter. A survey was performed to establish consumer meat preference between the two species. Live weights before slaughter of the two species were found to be different (P < 0.05) with the crossbred water buffalo showing higher bodyweight. However, the crossbred water buffalo had a lower (P < 0.05) dressing yield based on hot carcass weight and chilled carcass weight. The lower dressing yield of crossbred water buffalo can be attributed to its higher (P < 0.05) weights of edible and non‐edible slaughter by‐products. The chilled carcass yield of the forequarters and hindquarters from crossbred cattle and crossbred water buffalo were comparable when expressed as percent of live weight and chilled carcass weight. The estimated lean yield was higher in crossbred cattle than crossbred water buffalo. Crude protein, ash, fat, cholesterol, myofibrillar, sarcoplasmic and insoluble protein contents of the beef and carabao meat were all similar. Water holding capacity, pH, muscle fiber diameter, tenderness, firmness and marbling score in carabeef were all comparable to the beef. Redness was found to be higher (P < 0.05) in carabeef than the beef as measured with a color meter. The consumer meat preference survey showed that 55.9% selected the beef while 44.1% preferred carabeef. The color and amount of fat on the outside of the beef sample were primary in buyer selection.     

Questionnaire investigation to clarify the occurrence rate and characteristics of maternal rejection behavior in Japanese black cattle (Bos taurus)

We conducted a questionnaire investigation among breeding farmers to clarify the actual conditions of maternal rejection in Japanese Black cattle. We asked keeping experience of maternal rejective cows and compared occurrence patterns, rejective behavior manners, birth assistance methods, colostrum feeding method for calves, parity and rearing conditions of the cows. We found that 24% of the farms had kept rejective cows and 6% of the cows in these farms indicated maternal rejections. The most common occurrence pattern was ‘Occurred from the first birth (65.6%)’ and behavior manner was performing no maternal grooming with aggressive behavior (75%). Almost all the farmers assisted in each parturition (P < 0.05). There was not a significant difference among the colostrum feeding methods, but a significant difference in the rearing conditions of the cows, except for the cows with no data (P < 0.005). The parity of the rejective cows did not significantly differ in association with rejective behavior manners, birth assistance methods, colostrum feeding methods or rearing conditions. These results suggest that the occurrence rate of maternal rejection in Japanese Black cattle was approximately 6% and many of the rejective cows continuously performed no maternal grooming with aggressive behavior.     

Behavioral and performance response associated with administration of intravenous flunixin meglumine or oral meloxicam immediately prior to surgical castration in bull calves

The objective of this study was to determine the effects of flunixin meglumine or meloxicam on behavioral response and performance characteristics associated with surgical castration in crossbred bulls. Intact male Bos taurus calves (n = 252; averaging 176 kg) were randomly allocated into one of three treatment groups within pen: control (CON), flunixin meglumine (FLU; 2.2 mg/kg intravenous injection), or meloxicam (MEL; 2.0 mg/kg per os). The individual animal was the experimental unit. Calves were individually weighed on days 0 and 14 of the trial to evaluate performance outcomes. On study day 0, treatments were administered, according to their random allocation, immediately prior to surgical castration using the Henderson tool method. Visual analog scale (VAS) assessment and categorical attitude score (CAS) were collected on days −1, 0 (6 h post-castration), 1, 2, 3, and 4 in the study. The VAS was assigned using a 100 mm horizontal line with “normal” labeled at one end of the line and “moribund” at the other end of the horizontal line. The masked observer assigned a mark on the horizontal line based upon the observed severity of pain exhibited by that individual animal. The CAS was assigned by the same observer using five different categories with a score of 0 being “normal”. Average daily gain tended (P = 0.09) to be associated with the treatment group, and MEL had a greater (P = 0.04) average daily gain through day 14 compared with CON. A significant (P < 0.01) treatment by day interaction was indicated for VAS score, and MEL had lower VAS scores on days 0, 1, 2, and 3 post-castration compared with CON; FLU had lower VAS scores on days 0 and 1 compared with CON. A significant treatment by day interaction was not present (P = 0.25) for CAS. The FLU had lesser percent CAS ≥1 (17.5%; P = 0.05) compared with CON (29.4%); MEL has lesser percent CAS ≥1 observations (14.9%; P = 0.01) compared with CON. The median VAS increased as CAS was more severe. Results indicated MEL and FLU calves temporally improved behavioral responses following surgical castration with positive numerical trends for a 14 d average daily gain (ADG). The VAS system appeared to be an effective method of subjective evaluation of pain in beef calves in this study. Route of administration, duration of therapy, and low relative cost make oral meloxicam a reasonable analgesic treatment in calves when administered at the time of surgical castration.     

Effect of time of progesterone supplementation on serum progesterone and the conception rate of cooled Holstein heifers during the summer

To investigate the effects of progesterone supplementation at two different times on serum progesterone (P₄) concentration, conception rate and resynchronization of cooled Holstein heifers in summer, 90 heifers were randomly assigned to two groups: (i) heifers subjected to TAI (timed artificial insemination) and progesterone supplementation from days 4 to 14 after TAI (S_1; n = 45); and (ii) heifers under the same TAI protocol as S₁ and progesterone supplementation from days 17 to 22 after TAI (S₂; n = 45). The groups S₁ and S₂ were cooled 10 days before and 21 days after TAI. Respiratory rate, body surface temperature, vaginal temperature and rectal temperature recorded during the experiment were not different (P > 0.05) between S₁ and S₂ groups. Progesterone concentration was not different (P > 0.05) in S₁ compared to S₂. The conception rates on days 30 and 55 were similar between groups (P > 0.05). Progesterone supplementation did not increase either conception rate or concentrations of P₄ in heifers during the summer. Heifers not pregnant to first service in the group S₂ were resynchronized (77.7%) for a second breeding.     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

The objective of this study was to compare the carcass and meat quality in crossbred cattle and crossbred water buffalo at the same younger age and fed with high roughage in the Philippines. Ten crossbred cattle and 10 crossbred water buffalo, with an average age of 22 months (18–24 months) were used in this experiment. The animals were fed a similar diet, which consisted of 85% Napier or Para grass and 15% concentrate mixture on a dry matter basis, for 180 days before slaughter. Slaughter weight of the crossbred water buffalo was higher (P < 0.05) than that of the cattle, although the dressing percentage was significantly (P < 0.01) lower for the former than for the latter. The estimated lean yield was higher (P < 0.05) in crossbred cattle than crossbred water buffalo. The muscle fiber diameter of loin in buffalo meat was smaller (P < 0.05) than that in cattle. In regard to carcass and meat quality, the crossbred water buffalo was comparable or slightly superior to the crossbred cattle in tenderness, sensory score of color (P < 0.01) and flavor (P < 0.05). These results clearly indicate that at a younger age and even under high roughage‐based fattening rations, crossbred water buffalo are able to produce good quality meat, which will be by no means inferior to that of crossbred cattle in the Philippines.     

Display of a peer's face picture enhances the preference for a pen in preference testing in cows

Using preference testing, we investigated the effect of a brush and a peer's face picture on the welfare of breeding beef cows. Four cows were used in experiment 1 and another four cows were used in experiment 2. An experimental barn consisted of two 3.5 square-meter pens, and a corridor measuring 1.6 m wide and 1.3 m long. During the experiment, either side of the pens were treated. In experiment 1, straw bedding was placed in a treated pen (condition B) in the first two trials, a brush was added in the treated pen (condition BB) in the next two trials, and a peer's face picture was displayed in the treated pen (condition BBF) in the last two trials. In experiment 2, condition B was applied for the first two trials, a peer's face picture was displayed in the treated pen (condition BF) in the next two trials, and condition BBF was applied for the last two trials. Each cow was housed alone from 09.00 hour to 15.00 h in the experimental barn during the six trials. The cows stayed in the treatment pen longer than in the non-treatment pen under all conditions in experiments 1 and 2. In experiment 1, the mean total time spent in the treatment pen was longer under condition BBF than under conditions B and BB. In experiment 2, the mean total time spent in the treatment pen was shorter under condition B than under conditions BF and BBF. The mean percentage of time spent ruminating was greater under condition BBF than under condition B. It is concluded that the cows preferred the peer's face picture in the isolated condition of preference testing in this study.     

Monitoring changes in back fat thickness and its effect on the restoration of ovarian activity and fertility in Bos indicus cows

With the objective of testing the hypothesis if animals with a stable layer of body fat (FAT) during the peripartum have a better chance of becoming pregnant after calving, fifty‐nine multiparous Brahman cows in their last trimester of pregnancy were used. Animals averaged four parturitions and were stocked at a rate of 1.25 animal units per hectare and divided into two groups depending on the time postpartum (dpp) that the intravaginal releasing device CIDR was inserted; Group 1 (<30 dpp; n = 30) received the implant at 25.2 ± 4.21 and withdrawn 9 days later. Group 2 (≥30 dpp; n = 29) received the CIDR at 38.41 ± 5.8. Animals were AI at detected oestrus until 170 dpp and calculated as pregnant at first service or requiring more than one service (1s and >1s), not pregnant but cycling (not pregnant) and those not cycling at all (anestrus). The FAT measurements were taken twice each month from the last trimester of gestation until 96 dpp. The onset of ovarian activity was monitored through blood levels of progesterone (P4) at days 14 and 9 prior to CIDR insertion and days 10, 13, 30 and 33 after CIDR withdrawal. Animals pregnant did not have any major changes in their fat thickness. In contrast, cows pregnant in the group ≥30 dpp had changes in their FAT homoeostasis, and pregnant animals in the 1s and >1s groups did not show differences in dorsal back fat in the last trimester of pregnancy and early postpartum. In contrast, animals not pregnant and in anestrus FAT values decreased considerably after parturition. Overall, fertility was 49%, but 18% of all the animals remained anestrus losing FAT. Thus, animals with adequate metabolic conditions will have a better chance of pregnancy regardless of the time postpartum when the reproductive programme starts.     

Investigation of in vitro measurable sperm attributes and their influence on electroejaculated bull semen with a fixed‐time artificial insemination protocol in Australian Bos indicus cattle

Increasing use of fixed‐time artificial insemination (FTAI) in beef cattle production has presented an opportunity for the use of fresh or chilled semen as an alternative to standard cryopreserved semen. The objective of this study was to examine in vitro sperm function and pregnancy rate of electroejaculated semen, chilled and stored for 48 hr, compared to conventionally cryopreserved semen with an optimized FTAI protocol in Brahman cattle. Semen from three Brahman bulls was collected, and aliquots were extended in either chilled (at 5°C) or frozen (LN₂) in a Tris‐egg yolk extender base with 2.4% or 7.0% glycerol, respectively. Semen samples were assessed 48 hr after collection or post‐thaw and warming, for sperm motility, in vitro sperm function and fertilizing ability, and used in a FTAI programme. The overall pregnancy rates was significantly different (p < .01) after FTAI with frozen (n = 173; 53.2%) and chilled semen (n = 174; 31.6%). In contrast, the in vitro sperm assessment showed that the chilled semen had significantly faster motility (p < .05), a higher proportion of progressively motile spermatozoa (p < .05), with significantly higher proportions of acrosome intact, viable spermatozoa (p < .01). This study showed that reasonable pregnancy rates in Brahman cattle can be achieved using FTAI with chilled semen collected using electroejaculation and stored for up to 48 hr. However, improvements in semen extenders are required in consideration of semen collection method to improve the longevity of sperm fertilizing ability to significantly increase FTAI output using chilled storage of bull semen.     

Administering an appeasing substance to beef calves at weaning to optimize productive and health responses during a 42-d preconditioning program

This experiment evaluated the impacts of administering a bovine appeasing substance (BAS) to beef calves at weaning on their performance, physiological responses, and behavior during a 42-d preconditioning program. Eighty calves (40 heifers and 40 steers; 90% British × 10% Nellore) were weaned at 233 ± 2 d of age (day 0); ranked by sex, weaning age, and body weight (BW); and assigned to receive BAS (IRSEA Group, Quartier Salignan, France; n = 40) or placebo (diethylene glycol monoethyl ether; CON; n = 40). Treatments (5 mL) were topically applied to the nuchal skin area of each animal following dam separation. Within treatment, calves were allocated to one of eight drylot pens (four pens per treatment; pen being the experimental unit) and received a free-choice total mixed ration (TMR) from day 0 to 42, intake of which was assessed daily. Live behavior observations were conducted on days 1, 2, 4, 8, 16, and 32. Temperament was assessed and blood samples were collected via jugular venipuncture on days −21, 0, 3, 7, 14, 28, and 42. Hair samples were collected from the tail switch on days 0, 14, 28, and 42. Calves were vaccinated against bovine respiratory disease viruses on days −21 and 0. Average daily gain from day 0 to 42 did not differ between treatments (P = 0.57) but was greater (P = 0.05) in BAS vs. CON calves from day 0 to 28. Intake of TMR was greater (P = 0.05) during the first week for BAS vs. CON calves (treatment × week; P = 0.08). The mean proportion of calves feeding simultaneously and performance of social and play behaviors were greater (P ≤ 0.05) for BAS vs. CON calves. Escape attempts were greater (P < 0.01) for BAS vs. CON calves on day 1 (treatment × day; P = 0.03). Exit velocity was greater (P = 0.04) for CON vs. BAS calves on day 14 and tended (P = 0.10) to be greater for CON vs. BAS calves on day 7 (treatment × day; P = 0.03). Mean plasma concentrations of haptoglobin were greater (P = 0.02) in CON vs. BAS calves. Hair cortisol concentrations were greater (P = 0.05) in CON vs. BAS calves on day 14 (treatment × day; P = 0.03). Mean serum concentrations of antibodies against bovine viral diarrhea virus were greater (P = 0.02) in BAS vs. CON calves. Collectively, BAS administration to beef calves at weaning alleviated stress-induced physiological reactions, improved temperament evaluated via chute exit velocity, enhanced humoral immunity acquired from vaccination, and appeared to have accelerated adaptation to novel management scheme and environment.     

The relationship between responsiveness of first-lactation heifers to humans and the behavioral response to milking and milk production measures

The human–animal relationship can influence how an animal responds to situations involving humans and affect animal well-being and production. The objectives of this research were to (1) determine if there is a relationship between the behavioral reactivity of New Zealand dairy heifers toward humans and the behavioral response to cluster placement during milking and milk production measures and (2) determine if this relationship changes as heifers become habituated to the milking process. A total of 150 primiparous heifers were randomly selected from 3 commercial dairy farms. Approximately 1 month before calving, 2 behavioral tests, avoidance distance in response to an approaching human and exit speed from a restraint, were performed on 50 heifers at each farm. For each heifer, behavioral observations were recorded during the morning milking period (during the first and sixth weeks of lactation). Behaviors recorded during cluster placement at milking included flinching, stepping, and/or kicking (FSK). Milk yields, milking durations, and average milk flow rates were recorded for each individual heifer during the first and sixth weeks of lactation. Avoidance distance and exit speed were positively correlated (P < 0.001). The FSK response during cluster placement was negatively (P < 0.01) correlated with exit speed during week 6 of lactation, but there was no relationship (P > 0.05) between avoidance distance and FSK. Avoidance distance was positively (P < 0.005) correlated with milk flow rates during weeks 1 and 6 of lactation and milk yields (P < 0.01) during week 6 of lactation. However, there was no relationship (P > 0.05) between exit speed and milk yields, durations, or flow rates. Furthermore, the FSK response was negatively (P < 0.05) correlated with milk yield during weeks 1 and 6 of lactation. Therefore, the behavioral response of heifers toward humans and the milking process appears to be related to milk production measures.     

Physiometabolic responses to road transport in weaned piglets for a short period and the effects of straw bedding

The aim of the study was to evaluate the physiometabolic responses to stress in hybrid suckling piglets that were weaned and transported at different ages on a paved road under two vehicle conditions: with and without a layer of straw bedding. The piglets were weaned and transported at the following ages: 8, 15 and 22 days. The duration of each trip was 1 h. The piglets in each group were further divided into two sub‐groups for two distinct experimental transport conditions: (1) over the road with straw bedding; and (2) over the same road but without straw bedding. A total of three repetitions were performed for each experimental condition. In order to assess their responses to weaning‐ and transport‐induced stress, the study evaluated a thorough physiometabolic blood profile. The 8‐ and 15‐day‐old piglets transported without straw bedding showed increases in their pCO2, blood glucose, blood lactate levels and the percentage of hematocrit, but a decrease of pO2 upon arrival (P < 0.05). In contrast, the 22‐day‐old piglets transported on the same road with straw bedding were able to re‐establish their blood concentrations of lactate, pCO2, pO2, Na+, K+, Ca2+ and pH during the trip (P < 0.05).     

Differences between carcass grades in some morphological, behavioral and physiological measurements at early and middle stages of fattening in crossbred steers

The differential variables for carcass grades were identified from morphological, behavioral and physiological measurements of young steers at a commercial farm. Thirty‐five Japanese Black × Holstein steers aged 6–10 months were randomly assigned to three pens. The steers had free access to ryegrass hay and a restricted amount of concentrate diet for the first 6 months of trial. They were then given oat straw ad libitum and an additional concentrate diet until slaughter. Behavioral observations (15 categories) were carried out once every 2 weeks for 2 h after feeding. Bodyweight was measured, blood sampled (for seven metabolic hormones and five metabolites), ultrasonic scanning conducted and physical measurements taken (10 parts for each animal) in months 1, 3 and 5 (early fattening stage, EFS) and in months 7, 9 and 11 (middle fattening stage, MFS) of the trial. Temperament scores during these procedures, entry order into restraint stalls, social rank and average daily gain were also assessed. A factor analysis and one‐way anova were used to identify clusters of variables which had different factor scores between carcass grades. As for the carcass yields, a cluster of chest girth and depth, bodyweight, withers and hip height, and rump length (P < 0.01), and a cluster of the frequency of scratching the body with facilities (P < 0.05) were identified as differential variables in the EFS. In the MFS, a cluster of concentrations of cortisol and epinephrine, and the frequency of eating straw were identified (P < 0.10). As for the carcass quality grade, a cluster of social rank, triglyceride concentration and the frequencies of stand‐chewing cud and eating hay, and a cluster of the frequency of investigating facilities (both P < 0.10) were identified in the EFS. In the MFS, a cluster of hip height, bodyweight, cannon circumference, chest depth, withers height and chest girth, and a cluster of the frequencies of eating a concentrate diet and stand‐chewing the cud, and social rank (both P < 0.10) were identified. In conclusion, bodyweight, chest girth and depth, withers and hip height were identified as good differential variables for future carcass grades of young steers. Facility enrichment that encourages steers to eat hay in the EFS, and to eat a concentrate diet in and after the MFS would be effective in upgrading carcass grades. High incidence of investigating and scratching the body with facilities and stand‐chewing the cud might lead to lower carcass grades.     

设施养殖肉牛应激反应综合症防治探讨

肉牛应激反应综合症在现代规模化设施养殖条件下发病率高,机体为动员大量能量来对付应激原的刺激而使分解代谢增强,合成代谢降低,出现负氮平衡,适应机能破坏,生理功能降低,内分泌和代谢失调,引发各系统机能紊乱甚至死亡.在前期病因和发病机理研究的基础上,对设施养殖肉牛应激反应综合症防治方法进行了探讨,提出了添加抗应激药物等综合防治措施.