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.     

Seasonal and sex differences in area preference and behavior of young cattle just after long distance transport

To determine seasonal and sex differences in behavioral motivation of cattle just after long transport, 54 Japanese Black × Holstein cattle were observed at 5 min intervals for 2 h just after 25‐h transport by road and ferry. The stocking pen (12.0 × 9.5 m) consisted of an eating area (near a feeding alley), a drinking area (near water bowls) and a resting area (all areas except for other two areas). First, the effect of season was determined with heifers in summer (n = 12: 7.9 ± 0.6 months of age; 292.0 ± 18.5 kg) and autumn (n = 19: 8.2 ± 0.6 months of age; 295.8 ± 15.5 kg). The mean temperature on the observation day was 28.5 (max: 34.5, min: 24.5)°C in summer and 20.3 (max: 26.5, min: 16.4)°C in autumn. Percentage of cattle staying in each area was different by season (χ² = 22.0; P < 0.01). In summer, the percentage of cattle staying in the drinking area (26.7%) was greater than the expected percentage (16.7%). Percentage of cattle staying in the eating area was greater in both seasons (31.3% in summer and 53.6% in autumn) than the expected percentage (16.7%). However, the mean percentage of cattle performing each behavior was not significantly different by season. Secondly, the effect of sex was determined with steers (n = 23: 7.6 ± 0.6 months of age; 301.9 ± 20.7 kg) and heifers (n = 19: same as above) in autumn. Although the percentage of cattle staying in each area was different by sex (χ² = 20.2; P < 0.01), the percentages of steers (25.5%) and heifers (53.6%) staying in the eating area were both greater than the expected percentage (16.7%). However, percentage of animals performing each behavior was not different by sex. These results recommend to stockpersons that they should install additional troughs for hay and water into a pen just after long distance transport, since the number of cattle that can eat and drink at the same time was limited.     

Seasonal changes in digestibility, passage rate and rumen fermentation of alfalfa hay in sika deer (Cervus nippon) under restricted feeding

To investigate seasonal variations in the digestive functions of sika deer, five female sika deer were provided with an amount of alfalfa hay cubes equivalent to voluntary food intake during winter. We measured the rate at which the food passed through the digestive tract, digestibility and rumen fermentation during the summer (August), autumn (November), winter (February) and spring (May). Total mean retention time in the digestive tract during summer and autumn was numerically longer than that in winter and spring, but the difference did not reach significance. Organic matter and fiber were less digestible in summer and autumn than in winter and spring (P < 0.05), whereas the digestibility of the dry matter tended to vary with the seasons (P < 0.1). Ruminal pH values seasonally changed (P < 0.01), and were the lowest in autumn. The concentration of ruminal ammonia‐nitrogen differed significantly among the seasons (P < 0.05), increasing in winter and decreasing during spring and summer. The numbers of protozoa changed significantly among the seasons (P < 0.05), being higher in autumn than in winter and spring, and intermediate in summer. The concentration of total volatile fatty acids was not seasonally affected, but the molar percentages of propionic acid and butyric acid significantly changed according to season (P < 0.05 and P < 0.01, respectively), and the ratio of acetic to propionic acid tended to change with the seasons (P < 0.1). The results of this study suggested that the digestive functions in sika deer, fed a commercial diet at a restricted level, differed notably among the seasons and these variations might partially be due to environmental effects.     

Seasonal diet composition and forage selectivity of Boer goats in a semi-arid gypsophilous grassland

Botanical and chemical compositions of Boer goat diets, determined with repeated collection of forage samples taken from the goat’s mouth, were studied in a gypsophilous grassland during four seasons of the year. Ten pluriparous goats were used to collect selected forage species. Shrubs were a minor dietary component throughout the year (<7.5%). Goats selected more (p?<?0.01) grass during autumn and winter (34.2–37.8%) than during spring (21.2%) and summer (29.0%). During all seasons goat diets were dominated by forbs (>59%). Diets were lowest (p?<?0.05) in percentage of crude protein during spring, summer and autumn (13.2?±?3.5, 13.2?±?2.4 and 14.2?±?3.9, respectively) than winter (17.5?±?2.9) with levels above the recommended quantities for goats throughout the year. In vitro dry matter digestibility of forages selected by goats did not differ between seasons (range 47.4–53.3%). It was concluded that in this particular ecosystem goats preferred forb species over grasses across all seasons. In addition, goats maintained relatively stable diet quality by forage-class mixing of diets.     

Seasonal prevalence of coccidiosis in industrial broiler chickens in Faisalabad, Punjab, Pakistan

The present paper reports the prevalence of coccidiosis in industrial broiler chickens in Faisalabad, Punjab, Pakistan to determine the occurrence of different species of Eimeria in the area and to assess their correlation with the environmental conditions including temperature, humidity and rainfall. The study was conducted from January 2009 to December 2010. Examination of chicken guts revealed 43.89% (n = 3,283/7,480) prevalence of coccidiosis. The highest prevalence (27.04%) was recorded of Eimeria tenella followed by Eimeria maxima (22.42%), Eimeria acervulina (19.89%) and Eimeria necatrix (4.02%). The prevalence of disease was significantly higher (P < 0.05) in autumn (60.02 ± 4.38) followed by summer (47.42 ± 2.92), spring (36.92 ± 2.27) and winter (29.89 ± 3.43). Likewise, prevalence of different species of Eimeria also varied (P < 0.05) in different seasons of the year except that of E. necatrix. A strong correlation (P < 0.05) of environmental conditions with the overall and species-wise prevalence of coccidiosis was recorded except E. necatrix.     

Seasonal habitat requirements of Lemon Dove (Aplopelia larvata) in coastal forest: camera-trap surveys of a reclusive species

The modification of natural habitats requires behavioural plasticity, which may be challenging for ‘specialist’ species. Quantifying habitat requirements and behavioural responses of specialists to landscape transformation is thus a priority for baseline data to inform conservation practices. Using camera-trap surveys of the forest-dependent Lemon Dove Aplopelia larvata in conjunction with detailed microhabitat-scale covariates, we assessed habitat use during two periods in the year: autumn–winter and spring–summer (which largely encompassed peak breeding). We used occupancy modelling of forest-structural covariates to produce models of the probability of occupancy and detection of Lemon Doves in patches of the Indian Ocean Coastal Belt Forest of South Africa. The average occupancy and detection probability as indicated by the top-performing models was 0.39 ± 0.08 and 0.26 ± 0.05, respectively, during autumn–winter, and 0.37 ± 0.08 and 0.25 ± 0.04, respectively, during spring–summer. Although occupancy and probability of detection remained relatively constant between seasons, there was seasonal variation in the influence of individual covariates for both measures. The overall trend of positive influences on Lemon Dove occupancy was that of complex and diverse habitat structures and high plant species richness. The specific covariates that influenced occupancy positively during spring–summer may reflect the ecological requirements for nestling provisioning for both dietary needs and an avoidance of potential disturbance. Thus, while Lemon Doves may be less habitat-specific during autumn–winter, conservation management plans for safeguarding the breeding success of the species are advised to ensure adequate protection of large forest patches with complex and diverse interior structures and minimal disturbance.     

Bovine growth hormone gene polymorphism affects stress response in Japanese Black cattle

We investigate the associations between growth hormone (GH) gene polymorphism and behavioral and physiological responses to stressors and learning ability in Japanese Black cattle. Flight distance test was conducted in the first experiment. Steers with haplotype C of GH gene polymorphism avoided human approaches at a significantly greater distance than ones without haplotype C (C: 1.9 ± 0.9, non‐C: 1.0 ± 0.2 m, P < 0.05). An open‐field test was conducted in the second experiment. Behavioral responses did not differ significantly between steers with and without haplotype C. Increases of heart rates to dropping of iron pipes was significantly higher in steers with haplotype C (C:161.7 ± 21.8, non‐C:130.7 ± 31.3%, P < 0.05). Despite basal serum concentrations not being different between steers with and without haplotype C, serum cortisol in blood sampling immediately after severe confinement in a race tended to be higher in steers with haplotype C (P = 0.1). The maze test was conducted as the third experiment. There was no difference in performance in the maze test between steers with and without haplotype C. It is concluded that genetic polymorphism of GH may affect stress responses through GH concentration in steers.     

Environmental factors and interval from the introduction of rams to estrus in postpartum Saint Croix sheep

The objective of this study was to determine whether season and total rainfall during the breeding season, sheep parity, and/or litter size affect the interval from the introduction of rams to estrus (IRE) in hair Saint Croix sheep in northeastern Mexico. An analysis was made of 874 services performed during 9 years, introducing the rams into the sheep flock after an isolation period of 60 days during the postpartum period. Estrus was recorded twice daily during 35 days. Year and season influenced significantly on the interval between ram introduction and estrus length (P < 0.01). Winter IRE length (7.9 ± 0.1 days) was shorter than in the other three seasons (11.1 ± 0.2, 11.1 ± 0.1, and 16.2 ± 0.2 days in summer, autumn, and spring, respectively) (P < 0.01). An interaction was observed between rainfall and season, then by rainfall between 0 and 100 mm, IRE was shorter (P < 0.05) in winter (6.8 ± 0.3 days), and by rainfall between 100 and 199 mm, IRE was shorter (P < 0.05) in autumn (10.2 ± 0.5 days); however, when rainfall was beyond 200 mm, IRE length was shorter (P < 0.01) in summer (4.8 ± 0.5 days) than in autumn (14.5 ± 0.3 days). The IRE length was also longer in first lambing ewes (P < 0.05) and was not affected by litter size. In the present study, several factors, including the breeding season, rainfall and parity, directly influenced the interval between the male introduction and the onset of estrus by Saint Croix hair sheep.     

南方地区发酵床奶牛舍四个季节舍内环境卫生指标比较

试验旨在比较分析南方地区发酵床奶牛舍四个季节舍内环境卫生指标。主要测定了舍内温度、相对湿度、噪音、细菌密度、氨气浓度和温湿度指数等指标并分析了其间的相关性。结果表明:温度在四季间差异显著(P<0.05),夏季高达32.43℃,冬季低至1.53℃;春季、夏季和秋季的相对湿度显著高于冬季(P<0.05);温湿度指数(THI)在四季间差异显著(P<0.05);夏季和冬季的噪音显著高于春季和秋季(P<0.05);春季和秋季的细菌密度显著高于夏季和冬季(P<0.05);夏季氨气浓度为3.92 mg/m^3,显著高于其他季节的(P<0.05)。相关分析表明,一年中,牛舍温度与THI呈正高度相关关系(P<0.01),其余指标间相关性不高(|r|<0.70)或不相关(P>0.05)。另外,季节内的环境指标相关性分析表明:秋、冬季的温度和THI间皆呈正相关(P<0.01),冬季的温度与细菌密度呈正相关(P<0.05);春季的THI、噪音和细菌密度三者之间均呈正相关(P<0.05);秋季的氨气浓度与噪音高度也呈正相关关系(P<0.01)。综上,南方地区发酵床奶牛舍内,四季的环境卫生指标均达到了卫生标准,但夏季THI较高为85.36,奶牛易处于中度热应激状态。     

Habitat use and home range of black-backed jackals (Canis mesomelas) on farmlands in the Midlands of KwaZulu-Natal,South Africa

Black-backed jackals (Canis mesomelas) are an abundant mesopredator on farmlands (croplands and rangelands) across South Africa. Given their adaptability in a changing anthropogenic landscape, knowledge of spatial movements can provide important ecological information on the species. We captured, collared and monitored five black-backed jackals in the Midlands of KwaZulu-Natal to determine their home range and habitat use in farmlands. The 95% fixed kernel (95% FK) home range sizes were large, showing a marked seasonal variation in movement. One adult male dispersed 150?km over two seasons (winter and spring) and thereafter settled into a home range that it maintained. Transient home ranges of males and juveniles were larger than resident home ranges. The mean resident home ranges (95% FK) across seasons for adult males, adult female and juvenile males were 11.4 ± 4.3 km², 5.6 ± 0.36?km² and 2.15 ± 0.45?km², respectively. The mean transient home ranges (95% FK) of all the seasons for adult and juvenile males were 1 181.93 ± 575.81 km² and 104.27 ± 35.64?km², respectively. Adult jackal preferred croplands in spring, summer and autumn but avoided croplands in winter. Variable habitat use and large home ranges in our study confirmed the species’ ability to adapt to agricultural areas.     

Carcass characteristics of Hanwoo (Korean cattle) from different sex conditions, raising altitudes and slaughter seasons

This study was carried out to investigate the carcass characteristics of Hanwoo (Korean cattle) from different sex conditions, raising altitudes and slaughter seasons. The total number of cattle used in this study was 3608 heads which comprised of 1336 bulls and 1660 steers. The data was analyzed according to sex condition (bull and steer), raising altitude (low: 0–100 m and high: 700–800 m) and slaughter season (spring, summer, autumn and winter). At 24 h post-slaughter, the carcasses were weighed and evaluated for carcass traits according to the Korean carcass grading standard by an official grader. Carcass weight, ribeye area, yield index and grade, and meat color, firmness and maturity scores of carcass from bulls were significantly higher (P < 0.001) than those from steers. Inversely, the backfat thickness, marbling score and quality grade of carcass from steers were significantly higher (P < 0.001) than those from bulls. The maturity score of carcass from a high area was significantly higher (P < 0.01) than that from a low area. The ribeye area of carcass from summer was significantly smaller (P < 0.05) than that from other seasons. The maturity score of carcass from the summer season was highest among that from other seasons and the lowest was that from the winter season. Marbling score and carcass quality grade from the winter season were highest among those from other seasons and the lowest were those from the autumn season. There were no significant interactions between sex condition and raising altitude on carcass traits except the ribeye area. There were significant interactions between sex condition and slaughter season on marbling score and carcass quality grade. There were no significant interactions between raising altitude and slaughter season on all of the carcass traits. There were significant interactions among sex condition, raising altitude and slaughter season on meat color score. It was concluded that sex condition affected muscle and fat depositions on the carcass, raising altitude affected maturity and slaughter season affected ribeye area, maturity and marbling.     

Effect of semen and donor factors on multiple ovulation and embryo transfer (MOET) in sheep

Multiple ovulation and embryo transfer (MOET) is an important tool in the sheep industry for increasing numbers of genetically superior individuals. The objective of this study was to evaluate the effect of semen source (frozen or fresh), the number of embryo collection procedures for each donor (NECP), the season in which embryo transfer and collection was performed, and the age and breed of the donor, on the number of recovered embryos and pregnancy rates after embryo transfer. The Alamos Genetics’ flushing station database was used. This consisted of 140 embryo collection procedures, from 53 Dorper and White Dorper sheep donors, aged between one and eight years, totalling 1,200 collected embryos. Neither the number of retrieved embryos nor the pregnancy rate was affected by the semen preservation method (fresh or frozen), NECP or the age and breed of donor. The season did not affect the number of collected embryos but had a significant effect (p < 0.05) on the recipient pregnancy rate, with higher pregnancy rates reported in the winter (65.57% ± 25.33%) compared with spring (37.11% ± 33.27%), summer (29.95% ± 28.33%) or autumn (35.03% ± 31.66%). There is an estimated increase of 98.4% and 71.5% of embryos recovered in the spring and summer seasons, respectively, when winter is used as reference. The survival of embryos is significantly higher when implanted during the breeding season, more specifically in winter. Embryo collection can be carried out throughout the year in sheep, but there may be a marginal advantage in the use of superovulation and fresh embryo transfer programmes in the autumn and winter.     

青海海南州土-草-畜系统中钼、硒的季节变化研究

结果表明:土壤和牧草中钼浓度秋季最高;血清中钼浓度的季节间差异不显著(P＞0.05),秋季最高,夏季最低;被毛中钼浓度夏季极显著高于冬春季和秋季(P＜0.01);日摄入量夏季极显著高于秋季(P＜0.01),秋季极显著高于冬春季(P＜0.01).土壤和被毛中硒浓度在三季间差异不显著(P＞0.05);牧草硒夏季最高;绵羊血清硒冬春季显著低于秋季(P＜0.05);被毛中硒在季节间差异不显著(P＞0.05);硒的日摄入量夏季极显著高于秋季(P＜0.01),秋季极显著高于冬春季(P＜0.01).     

The onset of puberty in Cameroon Dwarf goats kept as pets in northwestern Croatia

The aim of this study was to determine onset of puberty in Cameroon Dwarf goats (CDGs) kept as pets in northwestern Croatia by determining progesterone (PGS) and insulin‐like growth factor‐I (IGF‐I) levels in the blood by RIA methods. The first cyclic ovarian activity was estimated according to hormone profiles as determined in CDG in a moderate climate environment. Sixteen female CDG kids were kept in stables with access to pasture which provided space for exercise. The goat kids born in winter (December–January–February), spring (March–April–May), summer (June–July–August) and autumn (September–October–November) were assigned into four groups according to the season of the year of birth (n = 4 in each group). At 75 days of age at the initiation of the study, they weighed between 3.2 and 5.1 kg (4.24 ± 0.53 kg). The onset of ovulatory activity was determined by PGS and IGF‐I serum concentrations every 10 days starting from 75 days to 155 days of age. The onset of puberty in CDG kids occurred on average at 141.15 ± 2.66 days of age, but varied depending on the season of birth. All CDG kids born during summer were in heat by 155 days of age. In the other groups (kids born in autumn, winter or spring), one goat in each group was not in heat. Changes in blood serum PGS and IGF‐I concentrations during prepubertal and pubertal periods could aid in the evaluation of reproductive status and determination of the onset of puberty in CDG during all seasons of the year in a moderate climate region.     

Effects of an environmental enrichment using a drum can on behavioral, physiological and productive characteristics in fattening beef cattle

To evaluate the effects of environmental enrichment on behavioral, physiological and productive characteristics, 71 Japanese Black × Holstein steers (8 months of age; 299.5 ± 22.6 kg) were allocated to three pens in two repetitive experiments. Pen C (n = 11 and 12) consisted of a feeding alley for grain feed, a trough for dry hay, a water bowl and a resting space as a control pen. Pen D (n = 12 and 12) included a drum can (58 cm diameter × 90 cm height) containing hay. Pen GD (n = 12 and 12) included a drum can that was placed around artificial plastic turf (30 × 120 cm) for grooming. The drum cans were removed after 5 months of installation. Behavioral observations were made for 2 h at 10 min intervals after feeding on three successive days each month for 10 months. Agonistic interactions were also continuously observed for 1 h after feeding to assess the dominance order (DO). Sampling blood and measuring bodyweight were performed bimonthly. The steers used the drum can frequently for 3 months after installation (1st, 2nd, 3rd months vs 4 months, all P < 0.05). The frequency of total eating of grain feed and hay was higher in pen D and pen GD than in pen C (both P < 0.01), while it was lowest in pen GD after removal of the drum can (P < 0.05). Grooming at the drum can was observed more frequently in pen GD than in pen D (P < 0.05). After they finished eating the grain feed, they ate hay at the drum can that contained additional hay rather than at the trough for hay (P < 0.01). Plasma dopamine concentrations were higher in pen D than in pen C (P < 0.05), and serum triglyceride concentrations were higher in pen C than in pen GD (P < 0.05) during the installation of the drum can. After removal of the drum can, serum total cholesterol concentrations became higher in pen D and GD than in pen C (both P < 0.05). Average daily gain correlated positively with the frequency of eating hay at the drum can in pen D (r_s = 0.52, P < 0.01). In pen GD, the frequency of using the drum can correlated negatively with DO (r_s = ?0.59, P < 0.01). Carcass belly fat was thicker in pens D and GD than in pen C (both P < 0.01). In pen GD, the frequency of eating hay (r_s = 0.79, P < 0.01) and grooming at the drum can (r_s = 0.63, P < 0.05) correlated positively with the marbling score. Although social factor affected the steers using the drum can, installing it in the early fattening stage encouraged the steers to eat and groom there and resulted in better carcass characteristics through the prolonged physiological positive effects.     

Variation in population density of horn flies (Haematobia irritans irritans) (L.) (Diptera: Muscidae) in Nellore cattle (Bos indicus)

The population density of horn flies was evaluated in the year 1998 in the municipality of Ara?atuba, S?o Paulo Brazil, in relation to temperature and rainfall conditions. Two lots of 30 Nellore steers (Bos indicus) were used which had no insecticidal treatment and were naturally infested with horn flies. The infestations were assessed by two counting methods, i.e., the traditional estimate method and the filming method. The highest fly frequencies were recorded in spring, summer, autumn and the lowest frequencies were recorded in winter. The increase in fly number was positively correlated (P<0.05) with rainfall.     

Grassland research priorities: Ideas for the future

Abstract

Four levels of available dry matter (DM) were maintained on a continuously grazed irrigated Midmar Italian ryegrass (Lolium multiflorum Lam.) pasture by means of a “put‐and‐take” grazing procedure. The pasture was stocked with three successive sets of weaned lambs in winter, spring and early summer respectively. The relation between average daily gains (ADG) and available DM was positively linear At equivalent levels of available DM, gains were greater in spring than in either the winter and summer periods (P ≤0,01), but there were no differences in gains between winter and summer. There was a negative linear relation between average stocking rate (the rate required to achieve a given level of herbage availability) and available DM. Stocking rates in spring and summer were not significantly different, but both were higher (P≤0,01) than those in winter. Within the range of the differential treatments applied, relations between stocking rate and ADG were negatively linear, and there was an interactive effect (P≤0,01) between stocking rate and grazing period. Changes in ADG with a unit change in stocking rate were greatest in winter, intermediate in summer and least in spring. Gains/ha were curvilinearly related to available DM. The curves indicate that the amounts of available DM required for maximum gains/ha were least in spring, intermediate in summer and greatest in winter.

From a serial cutting trial conducted concurrently with the grazing, a growth rate curve was developed for Midmar ryegrass. This curve had two maxima, with the maximum growth rate in spring being more than double that in autumn. The in vitro digestible organic matter content and crude protein content decreased from 80,6% and 24,1% in autumn to 63,1% and 10,6%, respectively, in summer. Crude fibre content increased from 10,1 % in autumn to 30,1 % in summer.     

The separate effects of the nature of diet and grazing mobility on metabolic potential of muscles from Charolais steers

The objectives of the two experiments presented were to determine the separate effects of diet and mobility associated with grazing on the metabolic potential of muscles of Charolais steers reared at similar growth rates and slaughtered at the same age (31 months on average).Glycolytic [lactate dehydrogenase (LDH), phosphofructokinase (PFK)] and oxidative [β-hydroxyacyl-CoA dehydrogenase (HAD), citrate synthase (CS), isocitrate dehydrogenase (ICDH), cytochrome c oxidase (COX)] enzyme activities were measured spectrophotometrically in semitendinosus (ST), a glycolytic muscle, and rectus abdominis (RA), an oxidative muscle.In Experiment 1, 24 weaned steers were assigned to two groups: grazing grass (GG) and maize silage (MS). In Experiment 2, 30 weaned steers were assigned to five groups: grazing grass (GG), cut grass without walking (CG), cut grass with walking (CGW), maize silage without walking (MS) and maize silage with walking (MSW). Both experiments lasted for 2 years. All grass fed animals were fed grass silage during the two winter seasons. During the two summer seasons, GG steers were grazing and did not receive any supplementation while CG and CGW steers were fed indoor freshly cut grass alone. MS and MSW steers were fed maize silage indoor during the entire experiment. For the second summer before slaughter, half of the indoor fed steers on each type of diet (CGW and MSW groups) was submitted 7 days a week to a 5.2 km walk daily.At slaughter, carcass weight and composition did not differ between groups. Oxidative HAD, CS and ICDH enzyme activities were higher for GG, as compared with MS group, in RA muscle in both experiments (P < 0.05 to 0.01) and in ST muscle (P < 0.05) in Experiment 2. Muscles from the GG group were thus more oxidative than those of the MS group. It was further tested whether these effects could be specifically attributed to the nature of the diet or to differences in mobility. A cut grass diet (vs. maize silage) increased HAD and ICDH activities (P < 0.05) and mobility induced by walking increased HAD and CS (P < 0.01) activities. In conclusion, the more oxidative metabolic orientation of muscles of grazing steers originates from a combination of two effects: an increase mobility at pasture and a grass (vs. maize silage)-based diet.     

Effect of timing and type of supplementary grain on herbage intake,nitrogen utilization and milk production in dairy cows grazed on perennial ryegrass pasture from evening to morning

The present study aimed to clarify the effect of timing and type of supplementary grain in grazing dairy cows on herbage dry matter intake (HDMI), nitrogen utilization and milk production. Eight lactating cows were allowed to graze from evening to morning during three seasonal periods (spring, summer, autumn). They were randomly allocated to four treatments (timing: pre‐ (Pre) or post‐grazing (Post), for large grain allotments consisting of 75% of daily grain offered; grain type: barley or corn) in 4 × 4 Latin square designs in each period. In the spring period, HDMI was greater for cows fed corn than those fed barley (P = 0.005), whereas cows in the Pre treatment had a similar HDMI, higher (P = 0.049) urinary purine derivative concentration and greater (P = 0.004) milk yield compared with cows in the Post treatment. In the summer and autumn periods, timing treatments did not affect HDMI, nitrogen utilization or milk production, but cows supplemented with barley had higher urinary purine derivatives concentration (P < 0.05) and milk yield (P < 0.05) compared with those supplemented with corn. The results indicate that large grain allotments immediately before evening grazing during early grazing seasons increased ruminal microbial protein synthesis and milk production without reducing HDMI regardless of grain type.     

围栏对内蒙古达赉湖地区蒙原羚食物资源的影响

2007～2008年的春季、夏季、秋季、冬季前期及冬季后期,我们研究了围栏对内蒙古达赉湖地区蒙原羚食物资源的影响。研究结果如下：（1）地上生物量：春季、冬季前期、冬季后期围栏内地上生物量高于围栏外且差异显著（P〈0.05）,夏季、秋季差异不显著（P〉0.05）。（2）植物高度：春季围栏内植物高度高于围栏外且差异显著（P〈0.05）,夏季、秋季、冬季前期、冬季后期差异不显著（P〉0.05）。（3）植物盖度：春季、夏季、秋季、冬季前期、冬季后期围栏内植物盖度高于围栏外且差异显著（P〈0.05）。（4）生物多样性指数：植物丰富度春季差异不显著（P〉0.05）,夏季、秋季、冬季前期、冬季后期围栏内植物丰富度高于围栏外且差异显著（P〈0.05）;Shannon-Wiener指数春季差异不显著（P〉0.05）,夏季、秋季、冬季前期、冬季后期围栏内Shannon-Wiener指数高于围栏外且差异显著（P〈0.05）。研究结果表明在现有情况下,围栏有利于蒙原羚的保护。