Nutritional Programming of Intrauterine Development: A Concept Applicable to the Horse?

Human epidemiological observations and studies of experimental animals have shown that low birth weight is associated with adult phenotypes characterized by abnormalities in cardiovascular, metabolic, and endocrine function. In human populations, these changes can lead to overt degenerative diseases such as hypertension and type 2 diabetes. Because fetal growth depends primarily on the nutrient supply, the associations between birth weight and adult phenotype have been linked to poor nutrition in utero. The fetal supply of nutrients and oxygen depends on both the availability of these substances in the mother and the functional capacity of the placenta to supply them to the fetus. This review takes a comparative approach to examining the nutritional programming of adult physiological phenotype in mammals with emphasis on the horse where possible. It considers the role of maternal nutritional state and placental function in these processes and discusses the cellular and molecular mechanisms operating in utero that are responsible for the epigenetic regulation of phenotypical diversity.     

Effects of oocyte-derived growth factors on the growth of porcine oocytes and oocyte–cumulus cell complexes in vitro

During oocyte growth and follicle development, oocytes closely communicate with cumulus cells. We examined the effects of oocyte-derived growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), on the growth and acquisition of meiotic competence of porcine oocytes collected from early antral follicles (1.2–1.5 mm). First, we confirmed that GDF9 and BMP15 mRNAs were expressed almost exclusively in the oocytes. Oocyte–cumulus cell complexes (OCCs) collected from early antral follicles were cultured in growth medium supplemented with 0–100 ng/ml of GDF9 or BMP15 for 5 days. GDF9 dose-dependently increased the OCC diameter, while BMP15 did not. GDF9 and BMP15 had no significant effects on oocyte growth (P > 0.05). When OCCs that had been cultured with 50 and 100 ng/ml BMP15 were subjected to a subsequent maturation culture, they expanded fully by gonadotropic stimulation and 49% and 61% of oocytes matured to metaphase II (MII), respectively. In contrast, GDF9 did not promote cumulus expansion, and < 10% of oocytes matured to MII. Based on the difference in cumulus expansion, we compared the expression of luteinizing hormone/choriogonadotropin receptor (LHCGR) and follicle stimulating hormone receptor (FSHR) mRNAs in cumulus cells. The level of LHCGR mRNA was increased in cumulus cells of the BMP15 group, although there were no significant differences in FSHR mRNA levels among the groups. These results suggest that GDF9 promotes the growth of OCCs and that BMP15 promotes LHCGR mRNA expression in cumulus cells during oocyte growth culture, which may contribute to cumulus expansion and oocyte maturation.     

Microbial protein formation of different carbohydrates in vitro

The aim of this study was to investigate the microbial protein yield of different pure carbohydrates to contribute to a more precise prediction of the microbial protein formed in the rumen. In a first experiment, sucrose, wheat starch, microcrystalline cellulose and citrus pectin were incubated for 8 and 24 hr in the modified Hohenheim gas test (HGT) system (3 runs × 2 syringes) including gas production, ammonia and short‐chain fatty acid concentration measurements. Ammonia values were used for estimation of the microbial protein formation. In a second experiment, the same substrates were incubated for 96 hr in the HGT system (2 runs × 3 syringes) and gas production was measured after 2, 4, 6, 8, 12, 16, 24, 30, 36, 48, 60, 72 and 96 hr of incubation to obtain the fermentation kinetics and the time of half‐maximal gas production (t_1/2) of the substrates. The substrates differed considerably in their fermentation kinetics, and therefore, comparison on the basis of t_1/2 was chosen as the most meaningful. At t_1/2, microbial protein yield [g/kg dry matter] was higher for cellulose than for sucrose and pectin and higher for starch than for sucrose. The microbial protein expressed in g/L gas production was higher for starch and cellulose than for sucrose and pectin at t_1/2. Effects of carbohydrates related to ruminal pH may remain undetected in in vitro trials.     

Describing the growth and molt of modern domestic turkey (Meleagris gallopavo) primary wing feathers

The use of feathers as noninvasive physiological measurements of biomarkers in poultry research is expanding. Feather molting patterns and growth rates, however, are not well described in domestic poultry. These parameters could influence the measurement of these biomarkers. Therefore, the objective of this study was to describe the juvenile primary feather molting patterns and feather growth rates for domestic turkeys. The 10 primary wing feathers of 48 female turkeys were measured weekly from week 1 (0 d of age) to week 20. Feathers were manually measured, and the presence or absence of each primary feather was recorded weekly. Generalized linear mixed models were used to investigate if feather growth differed between the primary feathers. The molting of the juvenile primary feathers followed a typical descending pattern starting with P1 (5 wk of age), while P9 and P10 had not molted by the end of the study (20 wk of age). The average feather growth rate was 2.4 cm/wk, although there was a significant difference between the 10 primary feathers (P < 0.0001, 2.1 to 2.8 cm/wk). Over time, feather growth followed a pattern where the growth rate reaches a peak and then declines until the feather is molted. The results of this study provide a critical update of patterns of molting and feather growth in primary wing feathers of modern turkeys. This can have implications for the interpretation of physiological biomarkers, such as the longitudinal deposition of corticosterone, in the feathers of domestic turkeys.     

香根草的栽培管理方法研究

香根草作为水土保持与环境治理植物目前在热带、亚热带地区得到越来越广泛的应用。然而，香根草不结实，只能通过无性繁殖，繁殖速度相对较慢。因此，如何加快香根草的繁殖速度便成了研究该植物的一个重要课题。目前各地所采取的繁殖栽培与管理方法各不相同。通过现场观测，并总结过去的繁苗经验，提出了8项应采取的栽培管理措施：1)苗圃应选在阳光充足、无遮荫的地段；2)苗圃地应土壤肥沃，宜沙不宜粘，不要有积水；3)注意施肥，磷肥与有机肥作基肥，复合肥作追肥；4)种植前将香根草地上部分剪至30～40cm，根系剪至5～15cm；5)考虑斜植，且种植深度要恰当；6)种植密度要合理；7)适度剪割，清除杂草；8)1年出苗。     

发挥进口贸易作用 促进经济协调发展——基于我国1978—2007年进口与经济增长关系的实证分析

改革开放以来,出口对我国经济增长的贡献几乎无人质疑,但进口是否促进了经济增长,却存在争论。笔者根据1978—2007年中国的进口和GDP数据,利用协整检验和因果关系检验等计量方法,对二者关系进行了检验,发现我国进口贸易与经济增长之间存在十分稳定且长期的动态均衡关系,进口增长对我国经济增长具有很强的促进作用。笔者据此联系当前国际国内形势提出了相应建议。     

Influence of feeding Tinospora cordifolia peripartum on lactation parameters in crossbred cows

For studying the effect of dietary supplementation of guduchi (Tinospora cordifolia) peripartum on lactation an investigation was conducted on 15 pregnant Karan Fries crossbred cows which were divided into two groups: treatment group of eight cows which were supplemented with guduchi at 60 g/day for 45 days prepartum and 120 g/day for 45 days postpartum; control group of seven pregnant cows which were not supplemented with guduchi. Jugular blood samples were collected from all cows during the periparturient period for analysis of various blood cell and plasma parameters. A significantly higher total leukocyte count, lymphocyte count, neutrophil count and neutrophil/lymphocyte ratio was recorded in the guduchi supplemented treatment group in comparison to untreated control cows throughout the experimental period. The increase of milk production over 305 days of lactation due to guduchi supplementation was significant (p < 0.05). A significant (p < 0.05) reduction in somatic cell count was also observed during the experimental period. Milk composition (fat, protein, lactose and SNF) was similar (p > 0.05) for both the groups. Plasma non esterified fatty acid (NEFA) concentrations were significantly higher (p < 0.01) in cows supplemented with guduchi throughout the course of study. Plasma concentration of growth hormone in the treated cows was also significantly higher beginning on the day of parturition up to 3 weeks postpartum (p < 0.05) in comparison to unsupplemented group.     

饲粮能量水平对德州驴生长性能、营养物质消化率及血清生化指标的影响

本研究旨在探讨饲粮能量水平对德州驴生长性能、营养物质消化率及血清生化指标的影响。试验选用健康的7～8月龄德州公驴36头,体重(123.9±5.0) kg,随机分为3个组,每组3个重复,每个重复4头驴。各组饲粮消化能水平分别为10.43 (低能组)、11.03 (中能组)和11.90 MJ/kg(高能组),粗蛋白质水平相近。预试期20 d,正试期40 d。结果表明：1)中能组和高能组的平均日增重显著高于低能组(P<0.05),且高能组的平均日增重显著高于中能组(P<0.05)。中能组和高能组的料重比显著低于低能组(P<0.05),且高能组的料重比显著低于中能组(P<0.05)。2)中能组和高能组的干物质、有机物和碳水化合物消化率显著高于低能组(P<0.05),且高能组的干物质、有机物和碳水化合物消化率显著高于中能组(P<0.05)。3)高能组的血清总蛋白、甘油三酯含量显著高于中能组和低能组(P<0.05)。中能组和高能组的血清白蛋白含量显著高于低能组(P<0.05),且高能组的血清白蛋白含量显著高于中能组(P<0.05)。中能组和高能...