Endometrial gene expression in primiparous dairy cows at the end of the voluntary waiting period is affected by nutrition: Total mixed ration vs increasing levels of herbage allowance

The study postulated that differential nutritional management during the early lactation period would be reflected in endometrial expression of genes related to embryo growth at the end of the voluntary waiting period. Thus, the effect of the combined use of total mixed ration (TMR) and grazing under different herbage allowances during the first 75 days post‐partum (DPP) on endometrial gene expression was evaluated in primiparous dairy cows. Cows were blocked by body weight, age and body condition score and randomly assigned to three grazing treatments: high (HA, 30 kg DM per cow per day), medium (MA, 15 kg DM per cow per day) and low (LA, 7.5 kg DM per cow per day) herbage allowance (mixed pasture, 2,600 kg DM per ha) plus 8 kg DM of supplement or TMR (55% forage, 45% concentrate) fed ad libitum (TMR) from calving to 75 DPP. At 57 DPP, cows were synchronized for oestrus (day 0, 68 DPP) and at day 7, endometrial biopsies were obtained. The nutritional treatment did not affect insulin, IGF‐1 and leptin concentrations on days 0, 4 or 7. Expression of IGF1, IGFBP3, IGFBP4, ADIPOR1 and ADIPOR2 mRNA was significantly affected by the nutritional treatment. Endometrial IGF1 and IGFBP4 mRNA were twofold greater in TMR and HA than MA and LA cows. Expression of IGFBP3 and ADIPOR1 mRNAs was greater in TMR and HA than MA cows, but did not differ from LA cows. All groups had greater expression of ADIPOR2 mRNA than MA cows. This study provided solid evidence of the importance of nutritional management during early lactation on uterine environment at the end of the voluntary waiting period. The greater expression of genes related to embryo growth and uterine function (IGF system, progesterone and adiponectin receptors) in cows fed diets maximizing energy intake suggests a favourable environment for embryonic growth, which may explain the improved reproductive performance of cows in good energy balance.     

后备小母牛限饲的可行性

<正>因为要在佛罗里达反刍动物营养讨论会上做一个题为《小母牛限饲方案》的报告,笔者查阅了大量的相关文献,对此有了较深的认识,本文是该报告的梗概。过去的40年里,生长小母牛的饲养方案经历了多个阶段     

Seasonal changes in a deep‐water fish assemblage in response to monsoon‐generated upwelling events

The coastal shelf of the Gulf of Oman experiences periodic upwelling events during the summer months that are driven by the southwest monsoon. It is unclear what role these events play in the spatial and temporal distribution of the region’s fish assemblage. We carried out trials on two different video techniques to characterize the habitat and fish assemblage along the continental shelf margin near Muscat, Oman. Exploratory surveys with a drift stereo‐video revealed three main habitat types: Sand, Reef and Megabenthos. Three areas were chosen for additional sampling using stereo‐BRUVS (‘baited’ remote underwater‐video systems). On two separate occasions (November 2005 and March 2006) replicate stereo‐BRUVS were deployed in each area stratified by the main habitat types. For each teleost and elasmobranch species encountered on the video, an estimate of total body length and the relative abundance (MaxN_i) was made. The stereo‐BRUVS recorded a wide range of demersal and pelagic teleosts including species of conservation interest such as sharks, rays and groupers. The drift stereo‐video recorded significantly fewer species than the stereo‐BRUVS (N = 15 versus N = 43). Species diversity from the stereo‐BRUVS increased by 96% in March 2006 (N = 41) compared to November 2005 (N = 23), a pattern consistent at all three areas. The structure of the overall fish assemblage (using canonical analysis of principal coordinates analysis) was highly variable both in time and space. There was ample evidence of strong habitat associations, particularly with depth and seasonal shifts in abundance and diversity. We argue the upward migration of oxygen‐depleted water into the shallow depths during the late monsoon displaces the demersal fish community along this coast.     

鹿蹄草等中草药对油桃采后褐腐病抑制效果研究

在离体和活体条件下,测定鹿蹄草、厚朴等中草药单剂及鹿蹄草为主的各中草药复配组合对油桃采后褐腐病菌的抑制效果。结果表明:11号(鹿蹄草+厚朴+大黄),14号(鹿蹄草+高良姜+虎杖)复配组合在离体试验中抑菌效果最好,10 mg/mL浓度的抑制率分别达到89.77%,85.50%;两种组合的最小抑菌浓度(MIC)分别是1.25,2.5 mg/mL;最小杀菌浓度(MBC)分别是2.5,5.0 mg/mL。活体抑菌测定结果表明,11号和14号复配组合对油桃褐腐病菌有不同程度延缓侵染和抑制作用,但不能完全防治;0.05 mg/mL扑海因与11号组合20 mg/mL,0.10 mg/mL扑海因与11号组合10 mg/mL均能完全抑制褐腐病菌在油桃果实上的发生和蔓延。     

Pharmacokinetics, safety and tissue residues of sustained-release sulfamethazine in sheep

Concentration-time profiles and the rates of absorption, extent of distribution and half-lives of sulfamethazine (SMZ), administered intravenously, orally as a water solution and as a sustained-release formulation (CalfSpan) were determined in 10 healthy sheep. The geometric mean half-life of elimination of i.v. SMZ was 10.8 h, compared to 14.3 h for the sustained-release preparation (CalfSpan) and 4.3 h for the oral water solution. Blood levels of SMZ were at or above 50 micrograms/ml for more than 48 h for CalfSpan, for 24 h after i.v. SMZ (100 mg/kg body wt), and for less than 24 h after p.o. SMZ (100 mg/kg body wt). The mean bioavailability of the oral SMZ solution was 58.3% (AUCp.o./AUCi.v.). The estimated bioavailability of the CalfSpan preparation was 52.5%. The safety of the sustained-release preparation was tested by dosing sheep with multiples (one, three and five times) of the recommended dose (one tablet, 8 g SMZ, per 20 kg body wt), once a day for 3 days. Clinical blood chemistries showed a significant increase in serum iron, and a decrease in serum phosphorus in animals treated at the 3x and 5x dose levels. Necropsies of the 5x dose animals did not show any gross signs that could be attributed to SMZ, and histological examination of tissues from the 5x animals revealed no organ pathology. Residues of SMZ in liver, fat, kidney and skeletal muscle were measured in 20 animals that received one bolus per 20 kg body wt. The results indicate that SMZ residues are cleared rapidly, and are at or below the tolerance level of 0.1 mg/kg within 8 days after dosing so that the 18-day withdrawal time used in cattle would provide an appropriate margin of safety if used in sheep.     

Attitudes and practices of Queensland dairy farmers to the control of the cattle tick, Boophilus microplus

Objective To determine practices for the control of cattle ticks on dairy farms in Queensland, the attitudes of farmers to tick infestations and to identify opportunities for and barriers against the introduction of non-chemical methods of tick control.
Design A survey of 199 dairy farmers from tick-infested parts of Queensland was undertaken by 20 dairy advisers and stock inspectors from October 1996 to June 1997. The sample was a proportional, random selection of dairy farms from four regions. A personal interview was conducted with each farmer and answers to 134 questions were obtained.
Results and conclusions Most farmers were not concerned by cattle ticks on their own farms, although they believed that ticks are important to the dairy industry. They were most concerned about the development of chemical resistance by cattle ticks. Inadequate facilities and lack of motivation appeared to be the factors most limiting to improving the methods of control. Most farmers claimed to have only small numbers of ticks at worst. Although a control program recom mended by the Queensland Dairyfarmers' Organisation was well regarded by farmers, few had adopted it. Many farmers saw no need to implement a strategic control program.     

Embryo Production in Superovulated Goats Treated with Insulin Before or After Mating or By Continuous Propylene Glycol Supplementation

Seventeen adult and cyclic Moxoto goats were synchronized using 60 mg MPA vaginal sponge for 11 days and 50 μg cloprostenol, 48 h before sponge removal, and superovulated with 120 mg pFSH i.m. in decreasing doses at 12 h intervals for three consecutive days. In seven goats, 0.2 IU/kg BW/day of long acting insulin was subcutaneously injected at same time as pFSH, and in the other five goats, the same dose of insulin was injected for three consecutive days starting 24 h after mating. Finally, five goats were supplemented with an oral dose of 80 ml/goat/day of propylene glycol continuously during the experiment. The animals were flushed at 7 days after mating and the embryos were classified based on International Embryo Transfer Society criteria. Blood samples were collected every 3 days for insulin assay. Administration of insulin raised the insulin levels of the goats (p < 0.05), whereas in the group treated with propylene glycol, insulin rate was different only between FSH treatment and after mating (p < 0.05). Similar rates of recovery for total (80.05 ± 9.78%) or transferable structures (61.03 ± 15.13%) were obtained. Treatment was not influenced (p > 0.05) by responsiveness to superovulation, which averaged 64%. By contrast, insulin treatments were shown to increase the number of embryos considered excellent with respect to goats supplemented with propylene glycol (p < 0.05). When insulin was given before mating, a strong relationship (r = 0. 90) (p < 0.05) between number of transferable embryo and ovulations was observed in the animals. In conclusion, superovulated goats treated with low doses of exogenous insulin resulted in an enhancement in embryo quality, which was related to changes in circulating insulin concentrations.