不同种植密度和施肥水平对大豆籽粒品质的影响

本试验自2002年开始至2004年止，从种植密度和施肥水平两方面对大豆脂肪、蛋白质含量的影响进行了分析。结果表明：种植密度对大豆籽粒的脂肪、蛋白质含量具有显著的影响，相关性分析结果显示，种植密度与大豆籽粒的脂肪含量存在着负相关性，与籽粒中的蛋白质含量之间为正相关。中国品种的脂肪含量受种植密度的影响大于美国品种，而中国品种的蛋白质含量受种植密度的影响小于美国品种。蛋脂总含量受种植密度的影响较小，并且不存在品种间的差异性。磷酸二铵的施用量与大豆籽粒脂肪含量和蛋白质含量之间没有显著的相关性，但是中美品种的品质对磷酸二铵施用量的反应不同。磷酸二铵的施用量与中国品种的脂肪含量、蛋白质含量和蛋脂总含量呈正相关，而与美国品种的脂肪、蛋白质含量和蛋脂总含量呈负相关，但相关程度均不显著。     

Impact of Buserelin Acetate or hCG Administration on the Day of First Artificial Insemination on Subsequent Luteal Profile and Conception Rate in Murrah Buffalo (Bubalus bubalis)

This study was designed to investigate the impact of buserelin acetate (BA) or human chorionic gonadotropin (hCG) administration on the day of first artificial insemination (AI) on subsequent luteal profile (diameter of corpus luteum (CL) and plasma progesterone) and conception rate in Murrah buffalo. The present experiment was carried out at two locations in 117 buffalo that were oestrus‐synchronized using cloprostenol (500 μg) administered (i.m.) 11 days apart followed by AI during standing oestrus. Based on treatment (i.m.) at the time of AI, buffalo were randomly categorized (n = 39 in each group) into control (isotonic saline solution, 5 ml), dAI‐BA (buserelin acetate, 20 μg) and dAI‐hCG (hCG, 3000 IU) group. Out of these, 14 buffalo of each group were subjected to ovarian ultrasonography on the day of oestrus to monitor the preovulatory follicle and on days 5, 12, 16 and 21 post‐ovulation to monitor CL diameter. On the day of each sonography, jugular vein blood samples were collected for the estimation of progesterone concentrations. All the buffalo (n = 117) were confirmed for pregnancy on day 40 post‐ovulation. The conception rate was better (p < 0.05) in dAI‐BA (51.3%) and dAI‐hCG (66.7%) groups as compared to their control counterparts (30.8%). Furthermore, the buffalo of dAI‐hCG group had improved (p < 0.05) luteal profile, whereas the buffalo of dAI‐BA group failed (p > 0.05) to exhibit stimulatory impact of treatment on luteal profile when compared to control group. In brief, buserelin acetate or hCG treatment on the day of first AI leads to an increase in conception rate; however, an appreciable impact on post‐ovulation luteal profile was observed only in hCG‐treated Murrah buffalo.