Meta‐analysis of the energy and protein requirements of hair sheep raised in the tropical region of Brazil

The objective of this study was to estimate, through mathematical models, energy and protein requirements for maintenance and gain of hair sheep raised in the tropical region of Brazil. To determine the equation parameters, a meta‐analysis of seven independent experiments of nutrient requirements was performed, comprising a total of 243 experimental units (animals), which were conducted under tropical conditions, using hair sheep in growing and finishing phases and endowed of the following quantitative data for each animal: body weight (BW ), empty body weight (EBW ), average daily gain (ADG ), empty body gain (EBG ), heat production (HP ), metabolizable energy intake (MEI ), retained energy (RE ), metabolizable protein intake (MPI ) and body protein content. The regression equations generated were as follows: for Net Energy for maintenance, (NE _m): ; for Net Energy for gain, (NE _g): ; for Metabolizable Protein for maintenance,(MP _m): MPI _(g/day) = 24.8470 (±7.3646) + 560.28 (±99.6582) × EBG _(kg/day); for Net Protein for gain, (NP _g): . The NE _m requirement was 0.246 MJ EBW^?0.75 day^?1. The metabolizable energy for maintenance requirement was 0.391 MJ EBW^?0.75 day^?1. Considering an ADG of 100 g, the NE _g requirement ranged from 0.496 to 1.701 MJ/day for animals with BW ranging from 10 to 40 kg respectively. The efficiencies of use of the metabolizable energy for maintenance and gain were 0.63 and 0.36 respectively. The MP _m requirement was 3.097 g EBW^?0.75 day^?1. Considering an ADG of 100 g, the NP _g requirement ranged from 12.4 to 10.5 g/day for animals with BW ranging from 10 to 40 kg respectively. The total metabolizable energy and protein requirements were lower than those reported by the NRC and AFRC systems. Thus, our results support the hypothesis that nutrient requirements of hair sheep raised in tropical regions differ from wool sheep raised in temperate regions. Therefore, the use of the equations designed in this study is recommended.     

三江源区高寒草原土壤湿度变化特征及与气候因子的关系

利用青海省三江源区兴海县牧业气象站1999-2016年高寒草原土壤湿度、牧草生育期资料,分析了高寒草原土壤湿度的年、季变化特征以及牧草生长季不同生育期土壤湿度的变化特征及与气候因子的关系。结果表明:高寒草原0-10、10-20、20-30、30-40和40-50 cm土壤湿度均随年际延长呈增加趋势,春季除40-50 cm土层外,其他各层土壤湿度均随年际延长呈显著增加趋势(P<0.05)。高寒草原牧草生长季的土壤相对湿度随年际延长呈显著上升趋势(P<0.05),且与生长季降水量之间呈极显著正相关关系(P<0.01)。随着气候变化,牧草抽穗、开花、成熟和枯黄期的土壤相对湿度随年际延长呈显著增加趋势(P<0.05)。牧草抽穗期、枯黄和全生育期的土壤湿度与气温呈显著负相关关系(P<0.05)。高寒草原牧草生长季土壤湿度的增加有利于草地植被生长。     

水分条件对巴音布鲁克高寒湿地CO_2排放的影响

在新疆天山中部巴音布鲁克天鹅湖高寒湿地,以苔草(Carex tristachya)为主要建群种的样地为研究对象,利用英国PP-systems公司生产的便携式土壤呼吸测定系统(CIRAS-2-SRC)研究了不同地表水分条件对天鹅湖高寒湿地夏季土壤CO2排放的影响。结果表明,1)湿润区的生物量大于干燥区;干燥区土壤CO2排放高于湿润区,干燥区土壤CO2排放日变化曲线为单峰曲线,CO2排放最高点出现在当地14:00-16:00,最高值为1.185 0g CO2·m-2·h-1;湿润区土壤CO2排放日变化曲线为双峰曲线,两个峰值分别出现在12:00和16:00,最高值为1.024 0g CO2·m-2·h-1。2)不同水分条件下生物量中凋落物含量影响土壤CO2排放。土壤温度是CO2排放的主要限制因子,且地表干燥区CO2排放与土壤温度的相关性更显著(P0.01)。土壤湿度与CO2排放相关性不显著(P湿润区=0.997,P干燥区=0.409)。     

TRMM降水数据在省级尺度的应用研究——以辽宁省为例

利用1998年1月~2010年12月空间连续分布的TRMM卫星3B43月降水量资料,借助气候倾向率指数和GIS空间分析技术,以辽宁省为例,对TRMM数据在省级尺度的适用性进行验证,并对辽宁省近13年来降水时空分布及其变化特征进行定量化分析。结果表明,TRMM降水数据与观测数据之间的线性相关性很高,数据具有较高的精度;辽宁省年降水量主要为425~1 082 mm,且总体上表现为由全区东南向西北依次递减的趋势;年内降水主要集中在5~9月,该时期的降水量占全年降水总量的70%以上,其中,7月份的降水量最大,为全年降水量的20%,而2月份最小,不足全年降水量的2%,季节性变化明显;近13年间,辽宁省平均年降水量总体上呈增加趋势,但在夏季降水量呈现减少的趋势,其中辽西区和辽中区尤为明显,说明近13年来这些地区春夏连旱的现象比较严重。     

生产力发展与农村居民消费观念的变迁

介绍了我国农村地区生产力水平的发展现状,2004年中央惠农政策实施以来,农村地区生产力水平得到了迅速提升,主要表现在：农村劳动力文化素质的大幅度提升;农业生产机械的保有量不断增加;生产管理和决策水平不断提高。分析了生产力发展对农村居民消费观念变迁的推动作用：夯实了农村居民消费观念改变的物质基础;改善了农村居民的消费结构;提高了农村居民消费的社会化程度。提出了培育农村地区新的消费热点的对策建议：引导农村居民树立起现代消费理念;加大政策扶植力度;引导农村居民树立健康消费理念。     

江苏盐城首次记录到彩鹮

2020年5月4日在江苏盐城大丰麋鹿国家级自然保护区(120°47′—120°53′E,32°59′—33°03′N)记录到3只彩鹮。栖息地为一处浅滩水塘,3只彩鹮于水中觅食。以往曾宣布彩鹮在国内绝迹,本次记录填补了彩鹮在本地区的分布空白,证实了彩鹮在江苏省仍有分布。这一纪录或许说明本地区栖息地得到了有效的改善。     

The localization and expression of epidermal growth factor and epidermal growth factor receptor in bovine ovary during oestrous cycle

Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.     

南瓜新品种科栗1号的选育

科栗1号是以S31-1为母本、S4-1为父本配制而成的南瓜一代杂种。植株蔓生,长势中等;分枝较少,叶小,节间短;第1雌花节位第9节左右;嫩瓜扁圆形,瓜皮绿色覆绿色斑点和浅色纵条斑纹,老瓜皮墨绿色。嫩瓜单瓜质量0.5~1.5kg,果实横径9cm左右,纵径13cm左右,糯性好,粉质,品质佳;春季露地和秋季设施栽培嫩瓜产量1500~2000kg·(667m2)-1,早春设施栽培嫩瓜产量3000kg·(667m2)-1左右。适宜浙江省及栽培条件相似的地区推广种植。     

Influence of paricalcitol on renal tubulointerstitial fibrosis in diabetic nephropathy

AIM: To investigate the effect of paricalcitol (P) on renal tubulointerstitial fibrosis and the underlying mechanisms in diabetic nephropathy (DN).METHODS: DN rat model was induced by a single intraperitoneal injection of streptozotocin after fasting. The animals were randomly divided into 2 groups:the DN rats in paricalcitol-intervened group (group P) were injected intraperitoneally with paricalcitol dissolved in propylene glycol after the day when the model was induced successfully at a dose of 0.4 μg/kg (3 times a week); the DN rats in DN group (group D) were given isopyknic propylene glycol. Normal control group (group C) was also set up. The samples of blood, urine and renal tissue were collected after intervention of paricalcitol for 12 weeks. The biochemical indexes were measured. The renal tissues were used for pathologic observation and determining the expression of transforming growth factor-β1 (TGF-β1), Wnt-4, β-catenin and Klotho by immunohistochemistry and Western blotting. In addition, the correlation among the above indexes was analyzed.RESULTS: (1) Scr, BUN and 24 h urine protein increased significantly in group D compared with group C, while decreased in group P compared with group D (P<0.05). (2) The area of renal tubulointerstitial fibrosis increased in group D compared with group C, while decreased in group P compared with group D (P<0.05). (3) The expression of Klotho decreased, while the expression of TGF-β1, Wnt-4 and β-catenin increased in group D compared with group C (P<0.05). Compared with group D, the expression of Klotho increased, while the expression of TGF-β1, Wnt-4 and β-catenin decreased in group P (P<0.05). (4) The expression of Klotho was negatively correlated with the fibrosis area, TGF-β1, Wnt-4 and β-catenin (P<0.05).CONCLUSION: Paricalcitol inhibits renal tubulointerstitial fibrosis in DN by promoting the expression of renal Klotho, and inhibiting Wnt/β-catenin signaling pathway activation and TGF-β1 synthesis.