Phases of the cattle industryThere are three phases of the Cattle Industry; Cow/Calf, Stocker/Yearling, and Feedlot Phase. In the cow-calf phase, the cow gives birth and nurses the calf until the calf is six to ten months old or approximately 400-650 lbs. The next phase is the stocker-yearling phase. At this phase, the cow would approximately be 600-850 lbs. The last phase is the feedlot phase. At this phase, the cow would approximately be 900-1300 lbs.
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Digestive System |
Cattle are true ruminants, which means that they have a stomach with four compartments. The Rumen, Reticulum, Omasum, and Abomasum make up the compartments of the stomach. The rumen is a huge fermentation vat. When we feed cattle, we are actually feeding the bacteria and protozoa that live in the rumen. These bacteria and protozoa then feed the animal with by products of fermentation. The rumen is also lined with papilli, which increases surface area for absorption of nutrients. The next compartment is the reticulum. It receives feed stuffs from the esophagus and sends these to the rumen. The reticulum also receives partially digested feeds from the rumen and sends these to the omasum. The omasum is the next compartment of the stomach. It is characterized by its "many folds" that looks like the pages in a book. This structure serves to absorb the water from rumen contents. It also produces a grinding action that helps break feed stuffs down into smaller particle sizes. The last compartment of the stomach is the abomasum. This is where feed travels after it leaves the omasum. It is also the true gastric pit, which is similar to the stomach of a human. Rumination allows the animal to forage and eat food rapidly, and then store for later digestion. There are four steps to rumination. The first step is regurgitation. This is when reverse peristalsis carries food to the mouth. The next step is remastication. In this step, bolus is rechewed in a more slower and deliberate mechanism. The third step is reinsalivation. This step adds more saliva to the digesta. The last step of rumination is redeglutition. This is when reswallowing bolus and liquids occurs. After reswallowing, the rumen contracts to move swallowed bolus into the rumen. The digestion process then continues, like it would for a human, through the small intestine, large intestine, and end at the anus.
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Reproductive System |
There are five parts that make up the female reproduction tract; ovaries, oviduct, uterus, cervix, and vagina. There are two ovaries that produce eggs and the female sex hormones, estrogen and progesterone. The infundibulum directs the egg into the oviduct, also known as the Fallopian tube. This is where fertilization occurs. After leaving the oviduct, the egg travels into the uterus. The uterus is the site of implantation and development of the embryo. At the posterior end of the uterus is the cervix. The cervix is a "gate keeper" for the uterus. Last is the vagina. It is the female organ of copulation at mating, birth canal during parturition, and serves as an exit passage for urine. When the female is in heat, the vagina becomes very moist to accept the semen. During the rest of the cycle, the vagina tends to be sticky or dry. On average, a female cow is in heat for 12 hours and the length of her estrous cycle is 21 days. Her approximate time of ovulation is 30 hours after onset of estrus and her gestation period is 283-297 days. There are four parts that make up the male reproduction tract; testicles, epididymis, vas deferens, and penis. The testicles are responsible for the production of sperm cells and the hormone testosterone. A sperm cell unites with the eggs to make the fertilized embryo. Sperm cells mature in the epididymis. The epididymis of a bull is approximately 100 feet in length. The vas deferens is responsible for delivering sperm from the epididymis to the urethra. The urethra is a muscular canal extending from the bladder through the penis and is responsible for final delivery of the semen. Bulls have an enlargement in the vas deferens called the ampulla. The ampulla is a holding area for sperm cells that are ready to ejaculate. A bull's ejaculate volume is 3-8 milliliters. Lastly, the penis is the male organ of copulation and provides a passage way for both urine and semen. Parturition starts with softening and dilation of the cervix and the start of uterine contractions. This stage usually lasts from two to six hours in cows. The second stage ends with the expulsion of the fetus and associated membranes. Cows very typically spend two hours in this stage. The last stage is the expulsion of the placenta. In this stage, cows can require as little as 30 minutes, but more typically require three to five hours.
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