海西地区人工草地生产布局探讨

海西地区指州辖天峻县、乌兰县、都兰县、德令哈市、格尔木市以及西部大柴旦、冷湖、茫崖三镇,覆含柴达木盆地。畜牧业是海西州支柱产业之一,草地是其发展的基础,畜牧业发展需要人工草地生产支持,科学布局人工草地对于安全高效发展草地畜牧业具有积极重要的现实意义。     

Utilization of soybean meal as an alternative protein source in the Mediterranean yellowtail, Seriola dumerili

The availability of defatted soybean meal as a substitute for fish meal was evaluated in juvenile (450 g on average) yellowtail fed diets containing several levels of soybean meal (from 20 to 50%). After 153 days, liveweight averages were 980, 925, 795 and 670 g for fish fed diets in which fish meal was partially substituted with 20, 30, 40 and 50% soybean meal, and feed conversion ratios were 2.79, 3.09, 4.57 and 6.52, respectively. Regression analysis showed a negative effect of inclusion of soybean, although fish fed diets containing 20% and 30% of soybean did not present statistical differences and grew significantly more, and had a better feed conversion ratio, than fish fed 40 or 50% diets. Likewise, muscle protein level was lower and lipid content was higher in fish fed 20 or 30% soybean. No differences were obtained for protein digestibility coefficients of experimental diets.     

Oestrus detection techniques and insemination strategies in Bos indicus heifers synchronised with norgestomet-oestradiol

SUMMARY Oestrus was synchronised in 57 Bos indicus heifers using norgestometoestradiol and pregnant mare serum gonadotrophin. Oestrus was detected by observations made at six-hourly intervals, using oestrogen-treated and chin-ball harnessed steers, heatmount detectors, tail-paint and visual observation. Heifers were inseminated once at either a fixed time of 49.2 ± 0.4 h (mean ± SE; n = 29) after implant removal or 12.6 ± 1.5 h (n = 28) after oestrus was detected. The mean (± SE) time to the onset of oestrus was 47.1 ± 1.9 h, while 90% of heifers recorded in oestrus were detected within 66 h of implant removal. Heatmount detectors were significantly more efficient at detecting oestrus than chin-ball harnessed steers, tail paint or visual observation (P < 0.001). A higher pregnancy rate was obtained in heifers inseminated after oestrus detection compared with heifers inseminated at a fixed-time (57.1 vs 34.5%; P = 0.043) and a higher pregnancy rate was obtained in heifers classified as easy to inseminate compared with heifers classified as difficult to inseminate (57.8 vs 0%, P < 0.001). We conclude that heatmount detectors are an efficient means of detecting oestrus in synchronised B indicus heifers and that pregnancy rates can be increased when insemination follows oestrus detection compared with a fixed-time insemination regimen.     

工厂化两苗互作育苗麦后机械化移栽棉花的生长发育及产量特点

为了推广与发展麦后移栽棉种植模式,在大田条件下,研究了工厂化两苗互作育苗麦后机械化移栽棉花的生长发育及产量特点.结果表明:营养钵育苗麦后移栽春棉、工厂化两苗互作育苗麦后移栽春棉和夏棉的子棉产量和霜前子棉产量相当.与麦套移栽春棉相比,麦后移栽棉花的生育进程有所推迟,子棉产量降低4.2％～4.7％,霜前花率降低0.9～1.3个百分点;但与麦后直播夏棉相比,麦后移栽棉花显著增产57.3％～58.2％,霜前花率提高约19个百分点;与麦后直播春棉相比,麦后移栽棉花显著增产62.1％～63.0％,霜前花率提高约20个百分点.此外,棉花麦后移栽,有利于小麦全幅播种和机械收获,且小麦产量比套种田小麦增产25％以上(P＜0.05),同时,棉花工厂化两苗互作育苗实现了专业化、商业化和规模化育苗,有利于棉花机械移栽.可见,工厂化两苗互作育苗麦后机械化移栽春棉和夏棉可以取代传统营养钵育苗麦后移栽.     

The development and integrity of equine pre‐antral follicles cultured in vitro with follicle‐stimulating hormone (FSH) supplementation

This study investigated the effects of different concentrations of FSH (10, 50, 100 and 200 ng/ml) in supplemented MEM+ on the development of equine pre‐antral follicles that were cultured in vitro for 2 or 6 days. The ovaries (n = 5) from mares in seasonal anoestrus were collected from a local abattoir. Ten ovarian tissue fragments of approximately 3 × 3 × 1 mm were obtained from each animal. The fragments were cultured in situ for 2 days (D2) or 6 days (D6) in MEM+ or MEM+ supplemented with FSH at four different concentrations, establishing the following 11 groups: control (D0); MEM + (D2); MEM + (D6); MEM + 10 ng/ml of FSH (D2); MEM + 10 ng/ml of FSH (D6); MEM + 50 ng/ml of FSH (D2); MEM + 50 ng/ml of FSH (D6); MEM + 100 ng/ml of FSH (D2); MEM + 100 ng/ml of FSH (D6); MEM + 200 ng/ml of FSH (D2); and MEM + 200 ng/ml of FSH (D6). Follicles were observed in only 9.65% (388 of 4,018) of the histological sections. Of the 861 follicles evaluated, 488 were in the primordial stage, and 373 were in various developmental stages; 59.7% were morphologically normal. Regarding the integrity of the pre‐antral follicles, the groups with 100 ng/ml FSH of 2‐days culture as well as 50, 100 and 200 ng/ml FSH of 6‐days culture provided the best results. In conclusion, the in vitro culture of abattoir‐derived equine ovarian fragments presented better morphological integrity when supplemented with FSH for 6 days, in comparison with the MEM culture group. However, no clear effects were observed with FSH regarding the promotion of activation from a primordial to a developing follicle.     

放线菌Act1对连作西瓜枯萎病的防治效果

为了探索放线菌制剂Act1对连作西瓜枯萎病的防治效果及其对西瓜根际微生物含量的影响,采用大棚小区田间试验,以不接种放线菌制剂Act1为对照,以播种期接种和定植期接种为处理,研究不同处理对西瓜生长、枯萎病发生及其根域微生态的影响。结果表明:接种放线菌制剂的处理均能显著降低连作西瓜枯萎病的发生率,其中育苗期接种防效最显著,达到52.17%;育苗期接种放线菌制剂Act1显著促进了植株的生长;并增加了西瓜根区细菌和放线菌的数量,降低了真菌的数量且A/F、A/B、B/F与对照相比分别增加了1.38～5.5、1.53～5.25、1.29～1.75倍。接种放线菌制剂Act1的处理均能显著防治连作西瓜枯萎病的发生并改善根际微生物的组成。