Alteration of the temporal association between courtship audio and visual components affects female sexual response

Some multimodal signals—that is, occurring in more than one sensory modality—appear to carry additional information which is not present when component signals are presented separately. To understand the function of male ring dove's (Streptopelia risoria) multimodal courtship, we used audiovisual playback of male displays to investigate female response to stimuli differing in their audiovisual timing. From natural courtship recordings, we created a shifted stimulus where audio was shifted relative to video by a fixed value and a jittered stimulus, where each call was moved randomly along the visual channel. We presented 3 groups of females with the same stimulus type, that is, control, shifted, and jittered, for 7 days. We recorded their behavior and assessed pre- and post-test blood estradiol concentration. We found that playback exposure increased estradiol levels, confirming that this technique can be efficiently used to study doves’ sexual communication. Additionally, chasing behavior (indicating sexual stimulation) increased over experimental days only in the control condition, suggesting a role of multimodal timing on female response. This stresses the importance of signal configuration in multimodal communication, as additional information is likely to be contained in the temporal association between modalities.     

Synchronization of Chaotic Systems Employing the Theory of Application of Linear Time-varying Impulsive Differential Equations

Employing the stability theory of linear non-autonomous impulsive differential equations, some sufficient conditions for the synchronization of unified chaotic systems and Lorenz chaotic systems are derived. This method can be applied to most of chaotic systems. The numerical simulations also demonstrate the efficiency of impulsive control.     

Effect of Chronic Administration of Oxytocin on Corpus Luteum Function in Cycling Mares

The objective of this study was to determine if intramuscular administration of 60 units of oxytocin once daily for 29 days, regardless of when treatment was initiated during the estrous cycle (i.e., without monitoring estrous behavior and/or detecting ovulation), would induce prolonged corpus luteum (CL) function in cycling mares. Mares were randomly assigned to two groups: (1) saline-treated control (n = 7) and (2) oxytocin-treated (n = 9) subjects. Control mares received 3 cc of saline, and oxytocin-treated mares received 60 units (3 cc) of oxytocin intramuscularly for 29 consecutive days. Treatment was initiated in all mares on the same day (day 1), independent of the day of the cycle. Jugular blood samples for determination of progesterone concentration were collected three times weekly (M, W, and F) for 21 days before treatment was initiated to confirm that all mares had a luteal phase of normal duration immediately before treatment. Beginning on the first day of treatment, blood samples were collected daily for eight days and then three times weekly through day 80. Mares were considered to have prolonged CL function if serum progesterone remained >1.0 ng/mL continuously for at least 25 days after the end of the treatment period. The proportion of mares with prolonged CL function was higher in the oxytocin-treated group than in the saline-treated group (7/9 vs. 1/7, respectively; P < .05). Three of the seven oxytocin-treated mares that developed prolonged CL function initially underwent luteolysis within 4–7 days of the start of oxytocin treatment and then developed prolonged CL function after the subsequent ovulation during the treatment period. In the other four oxytocin-treated mares that developed prolonged CL function, progesterone remained >1.0 ng/mL throughout the treatment period and into the post-treatment period. All mares with prolonged CL function maintained elevated progesterone concentrations through at least day 55 of the study. In conclusion, intramuscular administration of 60 units of oxytocin for 29 consecutive days effectively prolonged CL function in mares, regardless of when treatment was initiated during the estrous cycle. Importantly, this represents a protocol for using oxytocin treatment to prolong CL function that does not require detection of estrous behavior or day of ovulation.     

Intravaginal administration of estradiol benzoate capsule for estrus synchronization in goats

Estrus synchronization requires multiple treatments of hormonal drugs, requiring considerable time and cost. The aim of the present study was to develop an estrus synchronization protocol using intravaginal administration of estradiol benzoate (EB) capsules in goats. Two types of capsules were prepared: an EB capsule that melted immediately after administration and a sustained-release (SR) EB capsule that dissolved slowly and reached a peak after 24 h. Goats with functional corpus lutea were intramuscularly treated with prostaglandin F_2α (PG). At 24 h after PG administration, goats were administered 1 mg of EB solution intramuscularly (PG + 24IM; n = 6) or 1 mg of EB capsule intravaginally (PG + 24EB; n = 6). The SR EB capsule was administered intravaginally at the time of PG administration (PG + SR; n = 6). The control group (n = 6) received only PG. All groups showed estrus within 72 h after PG administration. The onset of estrus did not differ significantly between the PG + 24IM and PG + SR groups but was earlier than in the control group. Estradiol concentration in the PG + SR group peaked at 11.5 ± 6.1 h after EB and PG administration. Peak estradiol concentrations were not significantly different between the PG + 24IM and PG + SR groups (78.0 ± 25.8 and 64.0 ± 38.1 pg/ml, respectively), and were higher than the PG + 24EB and control groups (27.3 ± 8.8 and 14.6 ± 6.1 pg/ml, respectively). These results suggest that intravaginal administration of an EB capsule with a sustained-drug release base is applicable for estrus synchronization, as an alternative to intramuscular administration.     

性控冻精对同期发情奶牛输精效果观察

为观察奶牛养殖场应用同期发情后,实施性控冻精人工授精的效果进行试验。本试验设立性控组和常规组,分别进行人工授精,在相同饲养管理条件下观察两组试验奶牛配种、妊娠、产母犊情况。结果表明:同期发情率为81.43%,而且84.38集中在36h内;试验组奶牛产母犊率达94.12%,明显高于常规组55.56%的产母犊率,说明该性控冻精在奶牛性别控制中的效果明显,值得推广。     

不同时间断乳对母牦牛发情影响的观察

对带犊牦牛分别在8月1日、8月27日和10月12日进行断乳,结果Ⅰ组母牛共发情104头,发情率为69.33%,Ⅱ组母牛发情54头,发情率为36.00%,Ⅰ组比Ⅱ组多发情50头,高48.01%,差异性极显著(P<0.01)。Ⅲ组母牛发情4头,发情率4%。Ⅱ组比三组Ⅲ组多发情36头,高90%,差异性极显著(P<0.01)。Ⅰ组母牦牛发情率最高,持续时间长,Ⅱ组母牦牛只有一个发情高峰,持续比较短,Ⅲ组母牦牛发情率低,持续时间也短。     

Effects of syncrhonization between silk receptivity and pollen grain vigor on kernel sets of corn (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

Kernel sets in corn were affected by silk receptivity, pollen grain vigor, and the synchronization of silking and pollen shedding. Grain yield decrement was often caused by poor kernel set ability under field conditions. This study was conducted with two corn hybrids—Yedan 12 and Yedan 19—in both field and laboratory to observe silk receptivity, pollen vigor, synchronization of silking and pollen, and their effects on the kernel sets. The results showed that silk receptivity could be maintained over a relatively longer period of time after silks emerged, but both kernel set percentage and kernel weight decreased as silks aged when pollination occurred. Pollen grains that shed earlier had higher TTC-dehydrogenase activity, higher germination percentage, more rapid pollen tube growth rate, and higher percentage of kernel sets and kernel weight than those that shed later. The effect of delayed silking on kernel set ability was more significant compared with delayed pollen. Synchronization of silking and pollen shedding showed different characters in different hybrids: “partial overlapped” for Yedan 12 and “overlapped” for Yedan 19.     

萨能奶山羊在贵州的繁殖性能观测

对贵州牧草种籽繁殖场饲养的萨能奶山羊的初情期、初配年龄、发情周期、发情持续期、发情季节、妊娠期、产羔率、羔羊公母比例等八项繁殖性能指标进行观察测定,并与西北农业大学的萨能奶山羊进行比较分析,从而看出在贵州饲养的奶山羊具有明显的早熟性。     

繁殖控制技术在牦牛生产中的应用研究进展

繁殖特性是动物重要的生物学特性和经济性状,深入了解繁殖特性与家畜结构和功能之间的关系,可以最大限度地提高和改善家畜繁殖的管理方法.应用现代生物工程技术,将对牦牛的生产性能有大幅度地提高.笔者阐述了牦牛的繁殖特性和繁殖控制技术在牦牛生产中的应用研究进展.     

Treatment of fibroadenomatous hyperplasia in cats with aglépristone

Fibroadenomatous hyperplasia (FAH) is characterized by a rapid proliferation of mammary stroma and duct epithelium of 1 or more glands and predominantly affects younger female cats. Endogenous progesterone and exogenous progestogens play an important role in the genesis of FAH. The presence of progesterone receptors in fibroadenomatous tissue allows for targeted endocrine therapy with progesterone receptor blockers. We report on 22 young cats with FAH, none of which had responded to the withdrawal of progestogens or ovariectomy. The common signs were tachycardia (11 cats); skin ulceration, painful mammary glands, or both (16 cats); lethargy (8 cats); and anorexia (4 cats). The cats were treated with subcutaneous injections of the progesterone receptor blocker aglépristone on 1 (7 cats, 20 mg/kg) or 2 consecutive days (15 cats, 10 mg/kg/d) once weekly. All but 1 cat responded with a complete and lasting remission of signs after 1-4 weeks of treatment. Two cats had a short-term skin irritation at the site of the aglépristone injection. Two pregnant cats with FAH aborted after treatment with aglépristone and subsequently developed endometritis. In conclusion, the results of this study demonstrate that FAH in cats can be treated successfully with the progesterone receptor blocker aglépristone.