《毕业论文（设计）长白青猪的繁殖规律初探.doc》由会员分享，可在线阅读，更多相关《毕业论文（设计）长白青猪的繁殖规律初探.doc（8页珍藏版）》请在三一办公上搜索。
1、长白青年猪的繁殖规律初探王松均(杭州市种猪试验场 311115)1长白青年猪性行为发展11公猪 小公猪3月龄时就有爬跨行为发生，前脚紧抱其他猪，后躯向前挺进，阴茎在包皮内微微转动。4月龄时阴茎前端与包皮分离，爬跨时勃起伸出，有时会有少量透明液体滴出，但无成熟精子。6月龄左右方有成熟精子而具有生育能力。12母猪 小母猪4月龄后可能会出现外阴红肿现象，但行动安静无其他发情症状，也不接受公猪爬跨，不成周期性发生。556月龄时有明显的发情症状，过程完整，随后就成周期性发生，具有生育能力。据屠宰发情后的母猪平均红体数1354221个，范围1117个。2长白青年猪繁殖期的管理21公猪 青年公猪在培育期宜采
2、用小群饲养，与其他猪的身体接触有利于公猪正常性行为的发展，有利于公猪使用的调教，但不宜和母猪同舍饲养。达到性成熟后(即7月龄左右)则应单栏饲养，以防乱爬乱交造成生殖器损伤。 青年公猪初次配种不能选择比其大的母猪，不仅爬跨不易，还可能会发生不让公猪爬跨、咬打公猪而造成该公猪的性抑制。选择受配状况好、肢蹄健壮的母猪有助于调教的成功。后备公猪初次配种时往往慌张犹豫，或乱拱乱爬，行为不正常。这时要进行适当辅助，帮助其树立信心，调整位置，纠正姿势培育良好的习惯。调教时间太长并无帮助，一次不应超过20分钟。一次不成功第二天再进行。让后备公猪在观摩后进行调教易获得成功。个别公猪数次调教后仍对母猪只嗅闻、不爬
3、跨，可考虑淘汰处理。调教应选择清晨采食前进行，调教过程中切忌态度粗暴，以免造成性抑制。调教成功后要让其连续交配3次(每天或隔天1次)，巩固成果。在后备公猪配种或采精中，要使整个射精过程完成，不要强行中止，射精完毕后任其自己从母猪背上或台猪上爬下来，让其从性兴奋中缓过来再驱赶。 青年公猪开始配种后往往会出现精神亢奋、食欲减退现象。除配种外应避免和其他公、母猪过多的接触，减少外界干扰，栏内不能有其他可供爬跨物，防止自淫现象发生。22母猪 青年母猪在群居的状态，并进行适当的室外运动均对正常出现初情有利。长白猪生性好斗，群体大时经常会因位次调整而争斗，影响生长、延迟初情期的到来，故每群以不超过10头为
4、宜。适当的室外运动不但能使猪多接触到阳光的新鲜空气、锻炼体质，对小母猪的性机能发育也是有益的，发情征状明显、过程正常。放牧运动4月龄后就可开始进行。 影响母猪发情的因素还有营养不良或太肥胖，群内强弱过于悬殊，环境温度过高，疾病和伤残。这些都要在营养控制、饲养管理、猪舍设施等方面加以注意。 在青年母猪该达到初情月龄即556月龄时，让其与公猪有经常的接触。如每天让公猪在青年母猪舍走廊里自由走动1小时，能诱使初次发情。3长白青年猪的配种31公循 考虑到尽量少影响公猪的发育，开配以不小于8月龄，体重不低于135 kg为好。此时配种时间约36分钟，精液量不足100毫升。10月龄则分别增至610分钟和15
5、0毫升。长白公猪不耐受连续配种，青年公猪每周配种当不超过4次，否则会因为活精子输出量的减少而影响受胎率、产仔数，也会因配种过度食欲减退、生长受阻、精神不振、性欲减退。初始使用的公猪要注意检查其配种能力。除要检查其生殖器是否正常，性欲是否旺盛外，必须检查精液品质。长白青年公猪对热应激非常敏感，在高温季节的半个月内即可表现出来，从精子活力下降到精子数量减少甚至无精。当高温季节过去，要13个月才有可能渐趋正常。损害严重的甚至不可逆转。可能有些疾病也是产生死精的原因。有些表面看似正常的青年公猪精液品质却不合格是造成母猪返情的重要原因之一。 32母猪321长白母猪的发情征状与适配期的确定3211外阴变化
6、：先是淡红继而呈桃红色，轻度肿胀，以后红肿渐甚再慢慢转为暗红至淡红，肿胀也随之消退。长白青年猪中以中度红肿为主并过程明显完整的约占76；另有21在发情过程中始终只表现轻度红肿；还有3在发情时外阴无任何变化。3212分泌物变化：在外阴红肿达到高峰时可见半透明乳白色少量黏液流出，在有公猪试情时更容易看到。有504的猪被观察到这种现象，而其中的767开始出现在接受配种的前一天或当天。如量多而色黄有腥臭味则表示有炎症存在，不宜配种应及时治疗。仅在配种后有白色或淡黄色少量分泌物仍属正常，不必过虑。3213行为变化：随着外阴进行性变化开始显得不安，时时起立，来回走动，乱拉粪尿，继而对同栏猪追逐爬跨，用手压
7、背静立不动并有弓背反应，触摸胁部、臀部，尾渐上举。当公猪来临时非常敏感，发出嗷嗷叫声，紧挨公猪身旁。当外阴色转淡、肿消退，上述行为逐渐消失，归于平静。3214食欲变化：发情的长白母猪大多在采食时有不安现象，也有一部分减食的，停食几乎没有。 这些还是与其他猪种相类似。3215适配期的确定 长白青年母猪平均发情期为53天，范围为211天，变异很大。若以接受公猪爬跨为标志分为发情的前、中、后期，50以上呈(1、2、1)，(2、2、1)，(1、2、2)，(2、2、2)，(3、2、1)排列。受配期2天的占624，只一天的也有21。 了解长白青年母猪发情表现的规律再借助于公猪试情就能比较准确地掌握适配期。
8、当发情母猪外阴由鲜红刚转暗或淡，肿稍退出现微皱，有少量半透明乳白色黏液流出；行为由叫噪不安转为相对平静，有时呈现呆立，身体微颤；饲养员进入猪栏移臀部靠近，推之不动，压背有弓背反应，尾上举；接受公猪爬跨，这当为适宜配种期。322应注意的异常发情 因为长白青年母猪个体间差异比较大，有如下几种情况应引起注意：3221安静发情：无任何发情征状，当公猪去试情时不奔逃，接受爬跨，如发现早，配种及时，也能受胎。3222短促发情：有发情征状，但不明显，发情期短，受配期也短，容易疏忽漏配或配种偏迟。只要掌握适时，产仔数也不少。3223断续发情：发情l2天后又征状消失，隔23天后转入正常发情，配种、受孕与其他猪再
9、无异。这类现象极少。3224长发情：发情期特别长，受配期也可达56天，在连配3天后注射黄体酮，部分也能受胎。3225不接受爬跨：长白青年母猪对配偶选择性比较强，体质健壮，性欲旺盛的公猪容易受到青睐，而体格较小，性欲不很强的公猪，不但不让其爬跨，甚至对其咬打。发生这种情况应立即更换公猪。也有的在整个发情期间一直不接受爬跨，奔走逃避。这要综合其他征状选择适配期采用人工辅助的强制配种或人工受精，大多能受胎。也有的在下一个情期会完全正常。3226配种时出血：少量的出血难以完全避免，也不影响受胎。而数量多，母猪痛感强必须立即停止配种。 一般为了更保险一点，往往是受配期几天就配种几次，但配种次数的增加并未
10、对窝产仔数带来好处。对408头母猪记录的分析，配种1、2、3次的窝产仔数和窝活仔数均元显著差异，而情期受胎率差别非常大，分别为8023、9258、和9412，反映出一次配种的适配期较难准确掌握。 根据多年的实践，长白青年母猪在8月龄，体重在120千克以上配种较为适宜。此时一般均在第三个情期，有较多的排卵数。经过妊娠期可得到4060千克净增重，对自身的生长、胎儿的发育均有利，使哺乳期维持较高的泌乳有了一定的体贮。再延迟配种虽然可获得较多的产仔，不过增加数量有限，还有难配的风险，并推迟了生产周期，经济上不合算。 长白猪是配种难度较大的一个猪种，主要是由于发情征状不明显，个体差异大，非正常发情多，青
11、年母猪更是突出。上述观察分析仅仅是初步的，表面肤浅的，有待于进行深层次的研究，充分揭示其内在规律。Editors note: Judson Jones is a meteorologist, journalist and photographer. He has freelanced with CNN for four years, covering severe weather from tornadoes to typhoons. Follow him on Twitter: jnjonesjr (CNN) - I will always wonder what it was like t
12、o huddle around a shortwave radio and through the crackling static from space hear the faint beeps of the worlds first satellite - Sputnik. I also missed watching Neil Armstrong step foot on the moon and the first space shuttle take off for the stars. Those events were way before my time.As a kid, I
13、 was fascinated with what goes on in the sky, and when NASA pulled the plug on the shuttle program I was heartbroken. Yet the privatized space race has renewed my childhood dreams to reach for the stars.As a meteorologist, Ive still seen many important weather and space events, but right now, if you
14、 were sitting next to me, youd hear my foot tapping rapidly under my desk. Im anxious for the next one: a space capsule hanging from a crane in the New Mexico desert.Its like the set for a George Lucas movie floating to the edge of space.You and I will have the chance to watch a man take a leap into
15、 an unimaginable free fall from the edge of space - live.The (lack of) air up there Watch man jump from 96,000 feet Tuesday, I sat at work glued to the live stream of the Red Bull Stratos Mission. I watched the balloons positioned at different altitudes in the sky to test the winds, knowing that if
16、they would just line up in a vertical straight line we would be go for launch.I feel this mission was created for me because I am also a journalist and a photographer, but above all I live for taking a leap of faith - the feeling of pushing the envelope into uncharted territory.The guy who is going
17、to do this, Felix Baumgartner, must have that same feeling, at a level I will never reach. However, it did not stop me from feeling his pain when a gust of swirling wind kicked up and twisted the partially filled balloon that would take him to the upper end of our atmosphere. As soon as the 40-acre
18、balloon, with skin no thicker than a dry cleaning bag, scraped the ground I knew it was over.How claustrophobia almost grounded supersonic skydiverWith each twist, you could see the wrinkles of disappointment on the face of the current record holder and capcom (capsule communications), Col. Joe Kitt
19、inger. He hung his head low in mission control as he told Baumgartner the disappointing news: Mission aborted.The supersonic descent could happen as early as Sunday.The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, w
20、ith no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher
21、 than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause), he can expect a lot of turbulence.The balloon will slowly drift to the edge of space at 120,000 feet (22.7 miles/36.53 kilometers). Her
22、e, Fearless Felix will unclip. He will roll back the door.Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, hell be traveling fast, so d
23、espite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water,
24、he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes its not needed. Instead, he plans to deplo
25、y his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.Even if
26、everything goes as planned, it wont. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).It might not be the moon, but Kittinger free fell from 102,800 feet in 1960 - at the dawn of an infamous space race that captured the hearts of many. Baumgartner will attempt to break that record, a feat that boggles the mind. This is one of those monumental moments I will always remember, because there is no way Id miss this.
