Cattle Reproduction Unit Plan PDF

+-----------------------------------+-----------------------------------+ | Unit Plan | | +===================================+===================================+ | Instructor: | Ms. Beverlin | +---...

+-----------------------------------+-----------------------------------+ | Unit Plan | | +===================================+===================================+ | Instructor: | Ms. Beverlin | +-----------------------------------+-----------------------------------+ | Course: | Animal Science | +-----------------------------------+-----------------------------------+ | Unit Name: | Cattle Reproduction | +-----------------------------------+-----------------------------------+ | Estimated Time: | 2 Weeks | +-----------------------------------+-----------------------------------+ | | | +-----------------------------------+-----------------------------------+ | Objectives | 1\.  Students will identify and | | | categorize the male and female | | | reproductive organs of cattle. | | | | | | 2\.  Students will analyze the | | | functions of major organs in | | | the male and female | | | reproductive systems. | | | | | | 3\. Students will describe how | | | size, maturity level, and | | | health status affect the | | | reproductive efficiency of | | | cattle. | | | | | | 4\. Students will identify and | | | categorize natural and | | | artificial breeding methods and | | | summarize genetic inheritance | | | in cattle. | | | | | | 5\. Students will evaluate | | | animals for breeding readiness | | | and soundness. | +-----------------------------------+-----------------------------------+ | Objective 1: Students will | | | identify and categorize the male | | | and female reproductive organs of | | | cattle. | | +-----------------------------------+-----------------------------------+ | Standards: | 5.1.1 - Identify and categorize | | | the male and female reproductive | | Standard 5.0 | organs of the major animal | | | species. | | Apply principles of animal | | | reproduction to achieve desired | | | outcomes for performance, | | | development and/or economic | | | production | | +-----------------------------------+-----------------------------------+ | Daily Objectives: | 1\. Students will be able to | | | identify female reproductive | | | organs | | | | | | 2.Students will be able to | | | identify male reproductive organs | +-----------------------------------+-----------------------------------+ | Objective 1: | Students will be able to identify | | | female reproductive organs | +-----------------------------------+-----------------------------------+ | Content Outline: | The ability of a cow or heifer to | | | successfully mate, conceive, give | | | birth, and raise a healthy calf | | | each year is essential for | | | profitable and sustainable beef | | | production. A good understanding | | | of anatomy and physiology of both | | | the male and female is helpful in | | | successfully managing | | | reproduction. | | | | | | Where is the cervix, Uterus, | | | vagina, vulva, uterine horns, | | | oviducts, bladder, ovary and | | | blind pouch. | | | | | | The outermost portion of the | | | reproductive tract is the vulva. | | | | | | The area from the vulva to the | | | beginning of the cervix is known | | | as the vagina | | | | | | The fornix vagina is a 360-degree | | | pocket that surrounds the opening | | | of the cervix | | | | | | The cervix has protruding | | | internal folds that interlock to | | | further aid in protection of the | | | uterus | | | | | | The uterus in cattle is composed | | | of three distinct regions: the | | | uterine body and two uterine | | | horns. Following the cervix, the | | | uterine body remains a single | | | tube. The uterine body is | | | approximately 1 inch in length | | | and functions as a "common area" | | | of the two uterine horns that | | | follow. | | | | | | The oviducts are connected to the | | | ends of each uterine horn and | | | function as a bridge between the | | | uterine horn and the ovary | | | | | | The ovaries are components of the | | | tract that are not tubular. | +-----------------------------------+-----------------------------------+ | Objective 2: | Students will be able to identify | | | male reproductive organs | +-----------------------------------+-----------------------------------+ | Content Outline: |  | | | | | | The reproductive tract of the | | | bull consists of the testicles, | | | secondary sex organs, and three | | | accessory sex glands. These | | | organs work in concert for | | | formation, maturation and | | | transport of spermatozoa, which | | | are eventually deposited in the | | | female reproductive tract. The | | | secondary sex organs are the | | | epididymis, vas deferens and | | | penis. The three accessory sex | | | glands include the seminal | | | vesicles, prostate and | | | bulbourethral gland | | | | | | One or both testicles | | | occasionally fail to descend into | | | the scrotum during embryological | | | development and are retained in | | | the body cavity. This condition | | | is known as cryptorchidism. | | | Hormone production by cryptorchid | | | males is near normal and the male | | | develops and behaves like a | | | normal male but will generally be | | | sub fertile. This condition is | | | genetically inherited; therefore, | | | such males should not be used for | | | breeding. | | | | | | The epididymis is a compact, | | | flat, elongated structure closely | | | attached to one side of the | | | testicle. It is divided into | | | three regions, the head, body and | | | tail.  | | | | | | The many tubules entered the head | | | of the epididymis from the | | | testicle unite to form a single | | | tubule some 130 to 160 feet in | | | length. This tubule is convoluted | | | and packed into the 6- to 8-inch | | | epididymis | | | | | | The vas deferens, also known as | | | ductus deferens, emerges from the | | | tail of the epididymis as a | | | straight tubule and passes as | | | part of the spermatic cord | | | through the inguinal ring into | | | the body cavity. | | | | | | The two-vas deferens eventually | | | unite into a single tube, the | | | urethra, which is the channel | | | passing through the penis. The | | | urethra in the male serves as a | | | common passageway for semen from | | | the reproductive tract and urine | | | from the urinary tract. | | | | | | Two of the accessory glands are | | | found in the general region where | | | the vas deferens to unite to | | | become the urethra. | | | | | | The sigmoid flexure is an | | | anatomical structure that | | | provides a means by which the | | | penis is held inside the sheath | | | except during time of service. | | | Strong retractor muscles hold the | | | penis in the "S" shaped | | | configuration. | +-----------------------------------+-----------------------------------+ | Essential Question/Unit Objective | | | 2: Students will analyze the | | | functions of major organs in the | | | male and female reproductive | | | systems. | | +-----------------------------------+-----------------------------------+ | Standards: | 5.1.1 - Identify and categorize | | | the male and female reproductive | | Standard 5.0 | organs of the major animal | | | species. | | Apply principles of animal | | | reproduction to achieve desired | 5.1.2 - Analyze the functions of | | outcomes for performance, | major organs in the male and | | development and/or economic | female reproductive systems. | | production | | +-----------------------------------+-----------------------------------+ | Daily Objectives: | 1.Students will identify and | | | describe female reproductive | | | organ functions | | | | | | 2\. Students will identify Male | | | Reproductive Organ Functions | | | | | | 3\. Students will be able to | | | identify the hormones involved | | | in the reproductive process | +-----------------------------------+-----------------------------------+ | Objective 1: | Students will dentify and | | | describe female reproductive | | | organ functions | +-----------------------------------+-----------------------------------+ | Content Outline: | The **hypothalamus** controls | | | several body processes and | | | behaviors along with reproductive | | | processes. Body temperature, | | | concentration and components of | | | body fluids, and the drive to eat | | | and drink are just a few | | | functions of the hypothalamus. It | | | is classified as a neuroendocrine | | | gland since it sends and receives | | | neural signals through the | | | nervous system and hormonal | | | messages through the endocrine | | | system. | | | | | |  The pituitary is divided into | | | two distinct regions: the | | | anterior and posterior | | | pituitaries. Each region secretes | | | various hormones that direct body | | | processes. Some of these hormones | | | are responsible for reproductive | | | events, while others control | | | growth, metabolism, and water | | | balance. | | | | | | The body of the **uterus** of the | | | cow is short, while the **uterine | | | horns** are relatively long and | | | well developed. The fertilized | | | embryo moves from the oviduct | | | into the uterine horn, where | | | fetal and maternal membrane | | | development begins. This newly | | | developing fetus grows within a | | | layer of membranes called the | | | placenta, through which | | | nourishment from the dam | | | diffuses. This point of interface | | | is called the placentome. It is | | | made of the joining of the | | | caruncle (maternal) and cotyledon | | | (fetal). There is no direct blood | | | connection between the fetus and | | | the dam in the bovine placenta, | | | but rather a complex system that | | | selectively allows certain | | | molecules to pass from the | | | maternal side of the placenta to | | | the fetal side and vice versa. It | | | also provides nutrients and | | | carries waste products from the | | | fetus. | | | | | | The **cervix** is a denser | | | structure that contains more | | | connective tissue. The bovine | | | cervix is often described as | | | having a "turkey neck" feel when | | | palpated. It has thick walls and | | | a small opening, or cervical os. | | | The cervix softens and relaxes | | | around the time of estrus, the | | | period of sexual receptivity. | | | Cervical softening allows a | | | passageway for sperm at mating | | | and also for expulsion of the | | | fetus at the time of birth. | | | During pregnancy, the cervix is | | | filled with a thick mucus | | | secretion known as the cervical | | | plug. This provides a physical | | | barrier between the vagina and | | | the uterus, in order to protect | | | placental structures and the | | | developing fetus. In the days | | | prior to calving, the cervical | | | plug is expelled, and the | | | cervical opening begins to | | | dilate. | | | | | | The **vagina** serves as a | | | receptacle for the male's penis | | | during natural mating. In natural | | | mating, semen is deposited in the | | | vagina near the cervix. In | | | artificial insemination, a | | | catheter is inserted in the | | | vagina and manipulated through | | | the cervix, allowing a smaller | | | number of sperm cells to be | | | deposited on the uterine side of | | | the cervix. Urine is discharged | | | from the urinary bladder through | | | the urethra, which opens into the | | | base of the vagina. The region | | | behind the urethral opening is | | | called the vestibule and is a | | | common passageway for both the | | | urinary and reproductive systems. | | | The external opening of the | | | vagina is called the vulva. | +-----------------------------------+-----------------------------------+ | Objective 2: | Students will be able to identify | | | Male Reproductive Organ Functions | +-----------------------------------+-----------------------------------+ | Content Outline: | Location of the testicles | | | exterior to the body cavity is | | | essential for normal sperm | | | formation, which occurs only at 4 | | | degrees to 5 degrees below body | | | temperature. The scrotum provides | | | physical protection to the | | | testicle and helps regulate the | | | temperature for optimum | | | spermatozoa development. This | | | regulation is done by | | | coordination of three structures: | | | a temperature-sensitive layer of | | | muscle (tunica dartos) located in | | | the walls of the scrotum, which | | | relaxes when hot and contracts | | | when cold; the external cremaster | | | muscle within the spermatic cord, | | | which controls the proximity of | | | the testicle to the body by | | | lengthening or shortening | | | depending on environmental | | | temperature; and a | | | counter-current temperature | | | exchange regulated by a blood | | | flow process known as the | | | pampiniform plexus, which is a | | | coil of testicular veins that | | | provide an effective mechanism | | | for cooling arterial blood | | | entering the testicle and | | | transferring its heat to the | | | venous blood leaving the | | | testicle. | | | | | | Four major functions occur in the | | | epididymis, including the | | | transport of the developing sperm | | | cells from the testicle to the | | | vas deferens; the concentration | | | of the sperm by absorption of | | | surplus fluids; the maturation of | | | the developing spermatozoa; and | | | the storage of viable sperm cells | | | in the epididymis tail. If sexual | | | activity is slowed, resorption of | | | sperm cells from the epididymis | | | tail occurs. | | | | | | Spermatozoa are transported | | | further along the reproductive | | | tract to the pelvic region | | | through the vas deferens by | | | contraction of the smooth muscle | | | tissue surrounding this tubule | | | during ejaculation. Bulls may | | | also be sterilized by a vasectomy | | | in which a section of the vas | | | deferens is removed so that sperm | | | cannot pass to the outside of the | | | body. | | | | | |  The urethra in the male serves | | | as a common passageway for semen | | | from the reproductive tract and | | | urine from the urinary tract. | | | | | | Secretions from these glands make | | | up most of the liquid portion of | | | the semen. In addition, the | | | secretions activate the sperm to | | | become motile. The seminal | | | vesicles consist of two lobes | | | about 4 to 5 inches long, each | | | connected to the urethra by a | | | duct. The prostate gland is | | | located at the neck of the | | | urinary bladder where it empties | | | into the urethra. The prostate is | | | relatively small in the bull, as | | | compared to other species, and | | | does not produce a very large | | | volume secretion. | | | | | | The third accessory gland, the | | | Cowper's glands, are small, firm | | | glands located on either side of | | | the urethra. The clear secretion | | | that often drips from the penis | | | during sexual excitement prior to | | | service is largely produced by | | | these glands and serves to flush | | | and cleanse the urethra of any | | | urine residue that may be harmful | | | to spermatozoa. | | | | | | The penis is the organ of | | | insemination. Spongy-type | | | material within the penis is | | | filled with blood during sexual | | | arousal, resulting in erection of | | | the organ. The end of the penis | | | is the glans penis and is richly | | | supplied nerves, which are | | | stimulated during copulation to | | | induce ejaculation. | +-----------------------------------+-----------------------------------+ | Objective 3: | Students will be able to identify | | | the hormones involved in the | | | reproductive process | +-----------------------------------+-----------------------------------+ | Content Outline: | Female: | | | | | | Reproduction in the female is | | | controlled by numerous hormones | | | secreted from specialized glands | | | called endocrine glands. These | | | secretions are produced in the | | | glandular cells and pass into the | | | blood and lymph systems for | | | transport to specific parts of | | | the body where they produce their | | | function. | | | | | | The | | | hormone, **estradiol** (or **estr | | | ogen**) | | | is produced by the granulosa | | | cells of the follicle. Estradiol | | | has various effects, including: | | | | | | - Development and function of | | | the secondary sex organs | | | | | | - Receptivity to mating during | | | and other behaviors | | | associated with estrus | | | | | | - Rate and type of growth, | | | especially relative to | | | deposition of fat | | | | | | - Regulation of puberty | | | attainment and length of the | | | postpartum anestrous period | | | | | | **Progesterone**, secreted by | | | the corpus luteum, suppresses | | | ovulation of a dominant | | | follicle and the associated | | | secretion of high levels of | | | estradiol. Therefore, | | | elevated levels of | | | progesterone prevent a cow | | | from coming into heat. | | | Progesterone is necessary for | | | preparing the uterus to | | | receive the fertilized ovum | | | and maintains the proper | | | uterine environment for | | | continuation of pregnancy. | | | | | | Ovarian hormone production is | | | controlled by gonadotropic | | | hormones from the anterior | | | pituitary. | | | Follicle-stimulating hormone | | | (FSH) and luteinizing hormone | | | (LH) are released from the | | | pituitary and travel to the | | | ovary. The hypothalamus | | | releases | | | gonadotropin-releasing | | | hormone (GnRH) to regulate | | | FSH and LH. FSH promotes the | | | growth of follicular waves, | | | while LH helps develop a | | | dominant follicle. An LH | | | surge at estrus onset | | | triggers ovulation and the | | | formation of a new corpus | | | luteum. | | | | | | **ESTRUS CYCLE:** | | | | | | The cow\'s reproductive cycle | | | lasts about 21 days, but it | | | can range from 17 to 24 days. | | | During this cycle, the cow\'s | | | reproductive system prepares | | | for pregnancy. If | | | fertilization doesn\'t happen | | | or pregnancy isn\'t | | | maintained, the cow returns | | | to estrus. Figures 2 and 3 | | | illustrate the ovarian | | | changes and events in a | | | typical 21-day cycle without | | | pregnancy. | | | | | | | | | | | | - **Days 0 to 1**\ | | | The cow is in for estrus | | | (standing heat) on Day 0 for | | | an average of 18 hours. | | | Shortly after onset of | | | estrus, a surge of LH is | | | released by the pituitary | | | gland. About 30 hours after | | | the start of the standing | | | heat, the mature dominate | | | follicle ruptures (ovulates). | | | | | | - **Days 1 to 2**\ | | | The cells that formerly lined | | | the follicle change and | | | become the luteal cells of | | | the corpus luteum. This | | | change in cell forms is | | | caused by hormonal action, | | | primarily that of LH. | | | | | | - **Days 2 to 5**\ | | | The corpus luteum grows | | | rapidly in both size and | | | function. Numerous follicles | | | may be seen on the ovary at | | | this stage, but by Day 5 they | | | have begun to regress. | | | | | | - **Days 5 to 16**\ | | | The corpus luteum grows and | | | reaches its peak around Day | | | 10, releasing progesterone, | | | which blocks LH release from | | | the pituitary gland. During | | | this time, the ovaries are | | | mostly inactive except for | | | the corpus luteum and some | | | follicular development. A | | | dominant follicle matures, | | | but high progesterone levels | | | prevent estrus and ovulation. | | | | | | - **Days 15-17**\ | | | The corpus luteum regresses | | | rapidly due to luteolytic | | | activity of the uterus caused | | | by the release of the | | | hormone, prostaglandin F~2a~. | | | | | | - **Days 18 to 2**\ | | | The corpus luteum is almost | | | non-functional and this | | | releases the blocking action | | | of progesterone. Of the | | | several follicles that | | | commence growth, one becomes | | | more prominent by a surge in | | | rapid growth and activity. As | | | the dominant follicle grows, | | | it secretes increasing | | | amounts of estradiol. The | | | remainder of the follicles | | | regress. | | | | | | - **Day 21 or 0**\ | | | As the dominant follicle | | | releases more estradiol and | | | the corpus luteum produces | | | less progesterone, the cow | | | enters estrus (Day 0). High | | | estradiol levels trigger an | | | LH release at the end of | | | estrus, causing the mature | | | follicle to release the ovum. | | | The remaining tissue becomes | | | a new corpus luteum (Days 1 | | | and 2), and progesterone | | | becomes the dominant hormone | | | again. | | | | | | Male: | | | | | | The testicle functions as an | | | endocrine gland because of | | | its production of the male | | | hormone, testosterone, by the | | | interstitial cells. | | | Testosterone has several | | | major functions: | | | | | | | | | | | | - Responsible for development | | | and maintenance of the male | | | reproductive tract | | | | | | - Causes the development and | | | maintenance of the secondary | | | sex characteristics | | | associated with masculinity, | | | such as the crest and heavily | | | muscled shoulders of a bull | | | | | | - Major factor in the normal | | | sex drive and behavior of the | | | male | | | | | | - It increases muscular and | | | skeletal growth | | | | | | - It is essential for normal | | | sperm formation. | | | | | | Testicular function in bulls | | | is influenced by hormones | | | from other glands. The same | | | gonadotropic hormones (LH and | | | FSH) that regulate ovarian | | | functions in cows also | | | regulate testicular functions | | | in bulls. LH and FSH are | | | released from the pituitary | | | gland and stimulate the | | | testicles to produce | | | testosterone. Testosterone | | | then acts on the germ cells | | | in the seminiferous tubules | | | to form primordial sperm | | | cells. FSH is necessary for | | | the maturation of spermatids | | | into fully developed sperm | | | cells. Testosterone is also | | | essential for the normal | | | functioning of male accessory | | | glands. | +-----------------------------------+-----------------------------------+ | Essential Question/Unit Objective | | | 3: Students will describe how | | | size, maturity level, and health | | | status affect the reproductive | | | efficiency of cattle. | | +-----------------------------------+-----------------------------------+ | Standards: | 5.1.3 - Compare and contrast how | | | age, size, life cycle, maturity | | Standard 5.0 | level and health status affect | | | the reproductive efficiency of | | Apply principles of animal | male and female animals | | reproduction to achieve desired | | | outcomes for performance, | 5.1.4 - Assess and describe | | development and/or economic | factors that lead to reproductive | | production. | maturity | +-----------------------------------+-----------------------------------+ | Daily Objectives: | 1\. Students will describe how | | | the size of cattle affects | | | their reproductive efficiency | | | | | | 2\. Students will explain how | | | the maturity level of cattle | | | influences their reproductive | | | efficiency | | | | | | 3\. Students will explore and | | | discuss how the health status | | | of cattle impacts their | | | reproductive efficiency. | +-----------------------------------+-----------------------------------+ | Objective 1: | Students will describe how the | | | size of cattle affects their | | | reproductive efficiency | +-----------------------------------+-----------------------------------+ | Content Outline: | Weight lost during the breeding | | | season should be restored during | | | the off period. However, over | | | conditioning should be avoided, | | | because fat deposition in the | | | scrotal neck is associated with | | | impaired testicular function | | | resulting from disrupted | | | thermoregulation mechanisms. | | | | | | Poor body condition is associated | | | with reduced income per cow, | | | increased postpartum interval, | | | increased dystocia, and lower | | | weaning weight. | | | | | | Cows calving earlier in the | | | calving season allows cows more | | | time to cycle prior to breeding | | | season, breed earlier and heavier | | | calves at weaning.  | | | | | | High energy demands occur in cows | | | during the postpartum period, | | | when milk production intensifies, | | | and body fat and energy reserves | | | drop. This period of high milk | | | production is also associated | | | with forthcoming pregnancy. A | | | decrease in the body condition | | | score  | | | | | | How does body condition affect | | | | | | - Natural breeding | | | | | | - A.I | | | | | | - Birthing process (calve to | | | big / pulling) | | | | | | - Milk production | | | | | | The recommended BCS at calving | | | for mature cows and young (first | | | and second calving) cows are 5 | | | and 6  | | | | | |  | +-----------------------------------+-----------------------------------+ | Objective 2: | Students will explain how the | | | maturity level of cattle | | | influences their reproductive | | | efficiency | +-----------------------------------+-----------------------------------+ | Content Outline: | In heifers and mature cows that | | | have given birth, the start of | | | ovarian activity after giving | | | birth is important for | | | determining how long it will be | | | until they calve again. | | | | | | cows in the US typically give | | | birth for the first time [when | | | they are around two years | | | old](https://s3.amazonaws.com/ass | | | ets.cce.cornell.edu/attachments/1 | | | 6154/How_many_calves_does_a_cow_h | | | ave_in_a_lifetime.pdf?146582752). | | | | | | Because of the seasonal calving | | | pattern within beef cow herds, | | | heifers invariably are either 2 | | | or 3 years at the time of first | | | calving. Puberty in cattle has | | | recently been comprehensively | | | reviewed | | | | | | A consistent decline in | | | performance was found after 12 | | | years of age in a Florida study, | | | although cows vary tremendously | | | | | | The data would indicate that cows | | | are consistent in the rebreeding | | | performance through about 8 years | | | of age. A small decline was noted | | | in 1983 as cows aged from 8 to 10 | | | years of age. | | | | | | There is no set age when a cow | | | suddenly becomes unable to give | | | birth. The age differs for each | | | individual animal based on their | | | genetics, their environment, and | | | their diet. | | | | | | Heifers can become pregnant | | | younger than 12 months, but an | | | early pregnancy can cause health | | | complications and limit the | | | number of years she can | | | successfully breed. | +-----------------------------------+-----------------------------------+ | Objective 3: | Students will explore and discuss | | | how the health status of cattle | | | impacts their reproductive | | | efficiency. | +-----------------------------------+-----------------------------------+ | Content Outline: | An excellent herd health program | | | is an important component of | | | overall management for | | | reproductive efficiency, as | | | health can significantly impact | | | the reproductive performance of | | | cattle as well as the value of | | | the calf crop. Failure to protect | | | against disease and detrimental | | | environmental factors can result | | | in reduced pregnancy rates, | | | stunted calf growth, or costly | | | treatment in a given year. Long | | | term effects, such as permanent | | | infertility or inadequate immune | | | development in replacement | | | animals, are also a threat. | | | | | | Biosecurity practices are | | | essential to reducing exposure to | | | diseases capable of causing | | | abortion or infertility. The | | | introduction of new animals to | | | the breeding herd is one of the | | | primary sources of disease | | | transfer.  | | | | | | Main Health Issues: | | | | | | - Infections | | | | | | - Diseases | | | | | | - Biosecurity | | | | | | - Parasite control | | | | | | - Immunity in calving | | | | | | Protection of neonatal calves | | | from conditions like scours is | | | often achieved by vaccinating | | | dams prior to calving and relying | | | on the transfer of maternal | | | antibodies in colostrum. Prior to | | | weaning, calves should be | | | vaccinated against infectious | | | bovine rhinotracheitis (IBR), | | | bovine viral diarrhea (BVD), | | | parainfluenza-3 (PI3), bovine | | | respiratory syncytial virus | | | (BRSV), and clostridial disease | | | via a 7-way clostridial vaccine | | | (Blackleg, etc).  | | | | | | Pre-breeding vaccinations should | | | be administered to **cows and | | | heifers** entering the breeding | | | herd 30 to 60 days prior to | | | breeding. This will allow an | | | adequate window of time for | | | immunity to develop and mitigate | | | any risk to reproductive | | | performance caused associated | | | with the increased stress of a | | | systemic response required to | | | develop immunity. | | | | | | Evaluation of semen quality, | | | scrotal circumference, condition, | | | and overall physical structure of | | | all herd **bulls** should be | | | conducted during the pre-breeding | | | period | | | | | | This ties back into body | | | condition / size and maturity or | | | age because all these effects an | | | animal's health as well as | | | nutrition. | +-----------------------------------+-----------------------------------+ | Essential Question/Unit Objective | | | 4: Students will identify and | | | categorize natural and artificial | | | breeding methods and summarize | | | genetic inheritance in cattle. | | +-----------------------------------+-----------------------------------+ | Standards: | 5.3.1 - Identify and categorize | | | natural and artificial breeding | | Standard 5.0 | methods (e.g., natural breeding, | | | artificial insemination, estrous | | Apply principles of animal | synchronization, flushing, | | reproduction to achieve desired | cloning, etc.) | | outcomes for performance, | | | development and/or economic | 5.3.2 - Analyze the materials, | | production. | methods and processes of | | | artificial insemination | | | | | | 5.3.3 - Demonstrate artificial | | | insemination techniques. | | | | | | 5.2.1 - Summarize genetic | | | inheritance in animals. | +-----------------------------------+-----------------------------------+ | Daily Objectives: | 1\. Students will identify | | | natural breeding methods used | | | in cattle. | | | | | | 2\. Students will categorize | | | various artificial breeding | | | methods, such as artificial | | | insemination and embryo | | | transfer. | | | | | | 3\. Students will summarize how | | | genetic inheritance works in | | | cattle, including basic | | | principles of genetics and how | | | traits are passed from parents | | | to offspring. | +-----------------------------------+-----------------------------------+ | Objective 1: | Students will identify natural | | | breeding methods used in cattle. | +-----------------------------------+-----------------------------------+ | Content Outline: | During natural breeding, a sire | | | can produce semen that is | | | theoretically a lot more than | | | what is needed for that single | | | female. Thus, there is a | | | potential wastage of semen in | | | natural breeding. | | | | | | Make sure the bull is a | | | calving-ease bull if you want to | | | naturally breed heifers, or a | | | herd bull that is selected to | | | improve your cow-herd, not | | | disprove it.  | | | | | | Pros: | | | | | | - Less labor intensive | | | | | | - Less risky than AI | | | | | | - Cheaper | | | | | | - More realistic choice for | | | most operations | | | | | | Cons: | | | | | | - Typically, a longer calving | | | season | | | | | | - It takes longer to introduce | | | new genetics | | | | | | - Less uniformity within the | | | herd | | | | | | Conversely, maintaining a bull | | | for natural service may seem like | | | a simpler option, especially for | | | smaller operations. Keeping a | | | bull can lead to higher | | | conception rates compared to AI, | | | which has been a determining | | | factor for many who opt to | | | continue with this method. There | | | are, however, additional | | | considerations like the bull\'s | | | upkeep, the potential for disease | | | transmission, and the genetic | | | bottleneck that arises from using | | | a single bull over an extended | | | period. | | | | | | Natural service relies on a bull | | | being present with the cows | | | during the breeding season. It | | | requires different management | | | strategies, such as ensuring the | | | bull\'s health, virility, and | | | ability to cover the number of | | | cows in the herd. The duration of | | | the breeding season should be | | | defined to maintain a consistent | | | calving season, which aids in | | | management and can enhance | | | reproductive performance overall. | +-----------------------------------+-----------------------------------+ | Objective 2: | Students will categorize various | | | artificial breeding methods, such | | | as artificial insemination and | | | embryo transfer. | +-----------------------------------+-----------------------------------+ | Content Outline: | Artificial insemination (AI) in | | | cattle is a breeding technique | | | where semen from a bull is | | | manually placed into a cow's | | | reproductive tract. It's a way to | | | get cows pregnant without using a | | | live bull on your ranch. | | | | | | Artificial insemination helps us | | | use the minimum required semen to | | | fertilize the egg. In this way, a | | | single ejaculate can be diluted | | | and extended to create many | | | doses. Artificial insemination | | | also helps us carry out multiple | | | inseminations of females in | | | different geographical locations | | | simultaneously. | | | | | | Create a highly selective gene | | | pool and control the effects of | | | inbreeding. Since a single male | | | can produce many offsprings, one | | | can select a few males with | | | required genetic traits for | | | insemination. This helps increase | | | the selection intensity. | | | | | | Creates genetic diversity and can | | | introduce new breeds and colors | | | into your heard to experiment | | | with different cattle. | | | | | | Look for cattle in heat to breed | | | on time | | | | | | - Patches | | | | | | - Trackers | | | | | | - Chalk | | | | | | The best times of the day to | | | observe cattle for heat detection | | | are early in the morning and at | | | the last daylight in the evening | | | | | | Artificial insemination allows | | | ranchers to use semen from | | | top-quality bulls that would be | | | too expensive or impractical to | | | own. This means you can introduce | | | excellent genetic traits into | | | your herd without the cost of | | | purchasing and maintaining elite | | | bulls. | | | | | | A.I also increases safety for | | | farmers/ ranchers and their heard | | | | | |  | +-----------------------------------+-----------------------------------+ | Objective 3: | Students will summarize how | | | genetic inheritance works in | | | cattle, including basic | | | principles of genetics and how | | | traits are passed from parents to | | | offspring. | +-----------------------------------+-----------------------------------+ | Content Outline: | Punnet Squares | | | | | | - a tool used in genetics to | | | predict the possible traits | | | of offspring from two | | | parents. It shows how genes | | | from each parent can combine | | | and helps visualize the | | | chances of inheriting | | | specific traits. | | | | | | Each animal inherits one allele | | | from the sire and one allele from | | | the dam. For example, coat color | | | is determined by alleles, with | | | black being dominant over red. | | | | | | All these traits should be | | | considered when thinking about | | | genetic inheritance: | | | | | | - Reproductive Performance or | | | Fertility | | | | | | - Maternal Ability | | | | | | - Growth Rate | | | | | | - Feed Efficiency | | | | | | - Body Measurements | | | | | | - Longevity | | | | | | - Carcass Merit | | | | | | - Conformation or Structural | | | Soundness | | | | | | Different traits that will be | | | passed down: | | | | | | - Coat color | | | | | | - Meat marbling | | | | | | - Polled vs non-polled | | | | | | - Genetic mutations | | | | | | - Temperament | | | | | | A genetic defect is a mutation | | | that results in an allele with an | | | undesirable phenotype (i.e. | | | disease or trait). Some mutations | | | result in gross hereditary | | | defects such as abnormalities in | | | skeleton, body form, and body | | | functions. | | | | | |  | +-----------------------------------+-----------------------------------+ | Essential Question/Unit Objective | | | 5: Students will evaluate animals | | | for breeding readiness and | | | soundness | | +-----------------------------------+-----------------------------------+ | Standards: | 5.3.1 - Identify and categorize | | | natural and artificial breeding | | Standard 5.0 | methods (e.g., natural breeding, | | | artificial insemination, estrous | | Apply principles of animal | synchronization, flushing, | | reproduction to achieve desired | cloning, etc.) | | outcomes for performance, | | | development and/or economic | | | production. | | +-----------------------------------+-----------------------------------+ | Daily Objectives: | 1\. Students will learn the | | | signs and criteria for | | | determining if an animal is | | | ready for breeding, including | | | physical and behavioral | | | indicators. | | | | | | 2.Students will perform physical | | | examinations on animals to assess | | | their overall health and | | | suitability for breeding, | | | focusing on body condition and | | | structural soundness. | | | | | | 3.Students will analyze the | | | reproductive histories of animals | | | to determine their breeding | | | soundness, including past | | | pregnancies, calving intervals, | | | and any reproductive issues. | +-----------------------------------+-----------------------------------+ | Objective 1: | Students will learn the signs and | | | criteria for determining if an | | | animal is ready for breeding, | | | including physical and behavioral | | | indicators. | +-----------------------------------+-----------------------------------+ | Content Outline: | Overview of objective 4 | | | | | | The rate of maturity, being | | | carcass maturity, is not directly | | | related nor determine when a | | | heifer is ready to breed. Carcass | | | maturity is when bone and muscle | | | growth plateau\'s off and fat | | | begins to be laid down. | | | | | | 7 to 9 months of age, it is best | | | to wait until they are around 13 | | | to 15 months of age before you | | | can breed them. This is because | | | it allows them to grow more, | | | increase their pelvic area and | | | gain enough condition that can | | | allow them to sustain themselves | | | throughout gestation. | | | | | | The heifer must also be at least | | | 60% to 65% of the average mature | | | weight of the cowherd before she | | | can be bred.  | +-----------------------------------+-----------------------------------+ | Objective 2: | Students will perform physical | | | examinations on animals to assess | | | their overall health and | | | suitability for breeding, | | | focusing on body condition and | | | structural soundness. | +-----------------------------------+-----------------------------------+ | Course Content: | It is important to choose a | | | location for examination with | | | proper restraint, good lighting | | | and the ability to place a pail | | | of water or other tools where | | | other animals will not bother | | | with them. Always let an animal | | | calm down before examining them | | | if you had to move them to a | | | restraining location. | | | | | | *Normal Cow:* Alert, Bright | | | With the group Head up Ears | | | up Standing straight Walks | | | flat footed Chewing cud Moves | | | well Gets up easily | | | | | | *Problem Cow*: Slow, Dull Alone | | | Head low Ears drooping | | | Hunched up Favors one leg | | | Does not chew cud Slow getting | | | around Laying down alone | | | Holds tail out Grinds teeth | | | Extends neck Kicks at belly | | | Breathes with mouth open | | | | | | Step 1 Exam from behind | | | | | | - Temperature | | | | | | - Gut Fill | | | | | | - Manure consistency | | | | | | - Breathing | | | | | | - Vulva | | | | | | Step 2 Exam on Left Side | | | | | | - Heart - Skin Test | | | | | | - Lungs - Ruman | | | | | | Step 3 Exam on Right Side | | | | | | - Heart - jugular vein | | | | | | - Windpipe - udder | | | | | | - Wither pinch | | | | | | Step 4 Exam from Head | | | | | | - Ears - Nose | | | | | | - Eyes - Mouth | | | | | | [Physical Exam Cover | | | Sheet.pub](https://nydairyadm | | | in.cce.cornell.edu/uploads/doc_55 | | | 4.pdf) | | | | | | Bull Exam: | | | | | | - Physical | | | | | | - Reproductive tract | | | | | | **Table 1. Minimum Scrotal Circ | | | umference by Age** | | | ------------------------------- | | | -------------------- ------------ | | | --- | | | **Age (months)** | | | **Size (cm)* | | | * | | | \24 | | | 34 | | | Source: Chenoweth et al., 1992. | | | | | | | | | All the semen should be tested | | | before every breeding year | +-----------------------------------+-----------------------------------+ | Objective 3: | Students will analyze the | | | reproductive histories of animals | | | to determine their breeding | | | soundness, including past | | | pregnancies, calving intervals, | | | and any reproductive issues. | +-----------------------------------+-----------------------------------+ | Course Content: | Know the essentials of beef | | | cattle record keeping to | | | determine the best system for | | | your operation. | | | | | | Records are a vital component to | | | achieving a more advanced level | | | of management for a beef cattle | | | producer. Beef cattle record | | | keeping is a technique and tool | | | to document and analyze precise | | | information for an operation. | | | | | | Different approaches to record | | | keeping can be taken. These | | | include tracking whole herd or | | | individual animals and using | | | written or technology-based | | | methods. The system chosen should | | | be practical in application, | | | provide unique animal | | | identification that is permanent | | | and easily recognizable, and work | | | to maintain and increase | | | efficiency and profitability | | | | | | Maintaining whole-herd records | | | requires recording cow, bull, and | | | calf inventories at each phase of | | | the yearly production cycle, | | | recording weaning or market | | | weights, and using that data to | | | monitor herd performance. | | | Standard performance analysis | | | (SPA) measurements, initiated by | | | the National Cattlemen's Beef | | | Association (NCBA), provide an | | | analysis of whole-herd | | | performance. | | | | |