انتشار و چاپ مقالات در نشریات معتبر با نمایه بین المللی ISI


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- ۰۸ تیر ۹۴ ، ۱۲:۲۷
انجام پروژه های عملی همزمان سازی فحلی با سیدر استرالیایی و هورمون PMSG
چرخه فحلی در میش 17 روز است که اصطلاحا چند چرخه ای یا (پلی استروس) نامیده میشود. این روش یعنی القای همزمانی فحلی در میش که موجب باروری در داخل یا خارج از قصل جفت گیری میباشد.این کار با استفاده از یک سری هورمونها طی یک برنامه زمان بندی شده امکان پذیر است. همچنین بعنوان یک ابزار مدیریتی در افزایش و لهلود راندمان تولید مثلی کاربرد دارد. از فواید همزمان سازی فحلی استفاده بهینه از قوچهای برتر با استفاده از تلقیح مصنوعی که نتیجه ان زایش اکثر میشها در یک زمان کوتاه و معین. در سراسر دنیا روشهای مختلفی برای همزمان سازی فحلی بکار میرود که هر یک دارای مزایا و معایبی میباشد فعالیت جنسی در گوسفند به هورمونها و واکنش های غدد مترشحه مربوط است برای همزمان نمودن فحلی بایتی با تجویز معین هورمونها فعالیت تخمدان را تغییر داده و میشها را اجبارا وادار به فحلی نمود .6-8 هفته قبل از جفت گیری میش باید اماده باشد. اگر میش بره دارد حدود 1.5 ماه قبل از جفت گیری بره از شیر گرفته شود. بهتر است تا 4 هفته بعد از تلقیح میشها تحت نظارت باشند و از هر گونه وارد شدن استرس به انان جلوگیری شود.در 4 هفته بعد از تلقیح بناید از واکسیناسیون و قرصهای ضد انگل استفاده شود مگر شرایط خاص بلا مانع میباشد.
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At this stage in life, you likely know where babies come from. However, did you know that some animals can make clones of themselves and reproduce sexually too? In this lesson, you'll learn more about sexual reproduction and early vertebrate development.
In this lesson, you'll learn the series of steps necessary to produce a fully functional sperm cell. You'll also look at the structure of a sperm cell and see how it's equipped to venture forth into new territory.
Did you know that a human female already has all of the oocytes that she will make in her entire life before she is even born? In this lesson, you'll learn how the human body produces an ovum through the process of oogenesis. You'll also learn how polar bodies help to ensure that female gametes are of high quality even though they are not produced in high quantities.
This lesson on the early stages of mammalian development covers the processes following fertilization, such as cleavage, the morula formation and blastula formation. Watch to learn what the inner cell mass, trophoblast cells and blastocyst are, as well as their functions within embryonic development.
This lesson will cover the journey the mammalian embryo first makes after it has been fertilized. Learn how maternal blood moves through the embryo, and how the placenta is formed.
Have you ever wondered how a baby eats before it's born or if babies go to the bathroom while still inside their mother? In this lesson, you will learn about the placenta and how it works to ensure a fetus stays well-nourished and healthy before birth.
From a chick developing inside an egg to a human baby growing in its mother's womb, all developing vertebrates rely on a support system to protect them, feed them, supply them with oxygen, remove wastes, and do much, much more to ensure that the embryo grows and develops into a fully functional organism. In this lesson, you'll learn about the different parts of that support system and some of the things that they do.
Gastrulation is a key process in embryonic development - it's how a simple ball of cells begins to grow into a fully functioning being! Watch this lesson to learn about a key process in the development of almost all multicellular organisms.
Have you ever wondered how different parts of a developing embryo know what kind of tissue to become? What prevents two heads from developing on the same embryo, or for that matter, what ensures that a head develops at all? A small group of cells called Spemann's organizer determines the fates of the cells around them.
The discovery and characterization of Spemann's organizer was a significant achievement in the field of developmental biology, but this small piece of the dorsal lip is only the tip of the iceberg when it comes to coordinating the differentiation of all of the various tissue types in a growing embryo. In this lesson, you'll learn about concentration gradients and how they can be used to create various combinations of signaling molecules in different parts of the embryo.
From signaling molecules to transcription factors and gene expression, in this lesson you'll learn what it takes for a cell to differentiate. You'll also learn some of the ways a cell can make sense of different combinations of signaling molecules and how these combinations can be used to guide a cell through the process of differentiation.
Over the years, scientists have developed several methods to label and track groups of cells as they develop. These types of experiments are called fate mapping studies. In this lesson, you'll learn the basics of fate mapping and see how technology has allowed scientists to improve fate mapping techniques.
Scientists use a variety of tools to track the sizes of populations. Survivorship curves are one of the tools they use. In this lesson, we will view examples of survivorship curves to determine what they mean.