Dairy Cattle Evaluation

Lactation persistency is defined as the ability of a cow to maintain its milk production level over time, often calculated as the ratio of current month's production to the previous month's production.

In cattle, sperm typically remain viable in the reproductive tract for approximately 24 hours after insemination, which dictates the timing for optimal fertilization.

Legumes like alfalfa and clover contain high levels of soluble proteins that can cause frothy bloat in cattle when grazed.

Each teat of a cow has a single streak canal (or teat canal) through which milk is expelled.

NFC stands for Non-forage Carbohydrates, which are carbohydrates that are not part of the structural fiber of the forage.

The American Guernsey Cattle Club was the first dairy breed association to utilize computers for its breed registry records.

FARAD stands for Food Animal Residue Avoidance Databank, a project that provides information on drug withdrawal times in food animals.

Pregnancy in cows can typically be detected by rectal palpation starting around 35 days, though some experienced practitioners can detect it slightly earlier.

Subclinical mastitis is considered the most costly form because it is persistent, often goes undetected, and causes a significant cumulative reduction in milk yield.

Green hay indicates that the forage was harvested and dried quickly, preserving its nutrient content. Beta-carotene is a pigment associated with green color and is a precursor to Vitamin A.

NPN stands for nonprotein nitrogen, which refers to compounds like urea that ruminants can use to synthesize microbial protein in the rumen.

Water is the most essential nutrient for animal survival and health. Cattle can survive weeks without food but only days without water. Water is required for all physiological processes: digestion, nutrient transport, temperature regulation, waste removal, and milk production (milk is ~87% water. While protein, vitamins, and minerals are vital, water is the immediate survival requirement. Option D has a typo spelling 'Minerals' as 'Minerials'.

The Total Performance Index (TPI) is a genetic selection tool used in the dairy industry to rank animals based on a combination of production, type, and health traits.

The Farm Service Agency (FSA) is an agency of the United States Department of Agriculture that implements agricultural policy and provides loans to farmers.

Bovine Somatotropin (BST) is a hormone that, when administered via injection, typically follows a 14-day cycle to maintain increased milk production.

Citrate is fermented by specific bacteria in dairy products like buttermilk to produce diacetyl, which provides the characteristic buttery flavor.

Stainless steel is the industry standard for milk-contact surfaces because it is durable, corrosion-resistant, and easy to sanitize.

A nose ring provides a point of leverage, allowing handlers to restrain and control the movement of large, potentially dangerous bulls.

Reproductive efficiency is primarily limited by the ability to accurately detect when a cow is in heat and the biological success rate of fertilization (conception).

Colostrum is significantly more nutrient-dense than mature milk, containing approximately twice the calcium concentration.

While digestion begins in the rumen, the primary site for the enzymatic breakdown and absorption of dietary fats in the dairy cow is the small intestine.

There is an inverse relationship between milk volume and milk fat percentage due to the dilution effect as production increases.

Feed costs typically account for the largest portion of the operating expenses in a dairy operation, often ranging from 40 to 60 percent of total costs.

Sorghum and Sudan grass species can accumulate cyanogenic glycosides, which convert to prussic acid (hydrogen cyanide) when the plant is stressed or wilted, causing rapid poisoning.

Low-line systems allow milk to flow downward from the udder to the milk line, which reduces the vacuum lift required and improves milking efficiency.

Maintaining a proper forage-to-concentrate ratio is essential for rumen health and milk fat production; 40/60 is a common target for high-producing cows.

Intravenous (IV) injection involves delivering medication directly into the bloodstream via a vein, allowing for rapid systemic distribution.

Large plastic bags (ag-bags) are a common and efficient method for storing silage, as they provide an airtight environment necessary for fermentation.

USDEC stands for the United States Dairy Export Council, a non-profit organization that works to increase the global demand for U.S. dairy products.

In dairy cattle conformation, the topline consists of the chine (thoracic vertebrae area) and the loin (lumbar vertebrae area).

NMPF stands for the National Milk Producers Federation, which represents the interests of dairy farmers in the United States.

In the Holstein classification system, an 'Excellent' rating is assigned to cows scoring 90 points or higher on the official scorecard.

The Brown Swiss breed originated in the mountainous regions of Switzerland, which is in the central part of the European continent.

A Total Mixed Ration (TMR) requires a mechanical mixer (truck or trailer mounted) to ensure that all ingredients are blended uniformly so the cow cannot sort the feed.

Bovine Somatotropin (BST) is a hormone that stimulates milk production. Research consistently shows that cows treated with supplemental BST typically exhibit an increase in milk yield of approximately 10 to 15 percent.

Degradable intake protein (DIP) is broken down by the microbial population residing in the rumen. This microbial fermentation allows the cow to utilize nitrogen sources for protein synthesis.

Heart girth is a standard anatomical measurement used in livestock to estimate body weight when a scale is unavailable. It is highly correlated with the animal's mass.

In mammals, including cattle, the sex chromosome configuration for males is XY, while females are XX. The Y chromosome carries the SRY gene responsible for male development.

Transrectal ultrasonography is a common diagnostic tool for pregnancy. While it can detect structures earlier, 28 to 30 days is the standard window for reliable pregnancy confirmation in dairy cattle.

The reticulum is located adjacent to the diaphragm and the heart. Because of this proximity, ingested foreign objects like wire or nails can puncture the reticulum and damage the heart, leading to hardware disease.

Structural carbohydrates, such as cellulose and hemicellulose, provide rigidity to plants. These are found primarily in the cell wall, which gives the plant its structure.

Lactogenesis is the physiological process of the mammary gland transitioning to a state of active milk secretion, typically occurring around the time of parturition.

A tarsal hygroma is a fluid-filled swelling on the hock joint, commonly caused by trauma or pressure from hard surfaces. It is colloquially referred to as a swollen hock.

The Global Dairy Agenda for Action focuses on reducing the carbon footprint of the dairy sector. This includes efforts to mitigate greenhouse gas emissions, primarily carbon-based compounds like methane and carbon dioxide.

Cattle erupt their permanent incisors in pairs. The final pair (the corners) erupts around 4 years of age, indicating the animal is at least that old.

In dairy nutrition, NSC stands for Nonstructural Carbohydrates. These include sugars, starches, and pectins, which are highly fermentable energy sources.

IPM stands for Integrated Pest Management, which is a broad-based approach that integrates practices for economic control of pests.

The freezing point of normal milk is approximately -0.525 degrees Celsius (around 31 degrees F). If the freezing point is higher (closer to 32 degrees F), it indicates that water has been added to the milk, diluting the solutes.

Black leg is a bacterial disease caused by Clostridium chauvoei. It is characterized by gas accumulation (crepitus) under the skin and typically leads to sudden death.

A calcium to phosphorus ratio of 2:1 is generally considered optimal for dairy cattle to prevent metabolic disorders like milk fever and to support skeletal health.

The pulsator is the component of the milking machine that controls the vacuum cycle, alternating between the milking and massage phases for the teat cups.

Dairy cows are diurnal grazers and typically consume the majority of their feed intake during daylight hours, often associated with their grazing behavior and management routines.

The duodenum is the first section of the small intestine, which follows the abomasum in the ruminant digestive tract.

Fumonisins and zearalenone are toxic compounds produced by certain molds (fungi) that can contaminate feedstuffs. These are classified as mycotoxins.

Calves are born with no passive immunity. It is critical to feed colostrum within the first few hours of life, with 6 hours being a common target for optimal absorption of antibodies.

A typical annual culling rate for a commercial dairy herd ranges from 25 to 30 percent, accounting for reproductive failure, health issues, and production performance.

Heritability for milk production is generally considered to be around 0.25 to 0.30 (25-30 percent). This means that about 30 percent of the variation in milk production is due to genetics.

A manure press or screw press is a mechanical system used to separate liquid from solid manure, allowing for easier handling and storage of the solid fraction.

In cattle, ovulation typically occurs approximately 10 to 15 hours after the end of standing heat, which is about 28 to 32 hours after the onset of estrus.

The Milking Shorthorn is a versatile breed known for its variety of colors, including red, white, roan, and spotted patterns. Other breeds like Holsteins are typically black and white, while Ayrshires are cherry red or mahogany and white.

Copper sulfate is a standard chemical used in footbaths to treat and prevent foot rot and digital dermatitis in dairy cattle. It acts as an astringent and antiseptic to harden the hoof tissue.

Fat corrected milk (FCM) is a standard method used to adjust milk production records to a common fat percentage (usually 4 percent). This allows for a fair comparison of cows that produce different volumes and fat concentrations.

Casein is the primary protein found in milk and is the essential component that coagulates to form the curd during the cheese-making process. Low somatic cell counts (SCC) generally indicate higher quality milk with better processing properties.

Milk fever, or hypocalcemia, is clinically referred to as parturient paresis. It occurs when a cow cannot mobilize enough calcium from its bones to meet the demands of lactation shortly after calving.

An intramuscular (IM) injection is administered directly into the muscle tissue. This allows for relatively rapid absorption compared to subcutaneous injections.

In a 1 to 5 body condition scoring (BCS) system, 1 represents an emaciated cow, while 5 represents an extremely fat or obese cow. A score of 3 is typically considered ideal or average.

SCR stands for Sire Conception Rate. It is a genetic evaluation tool used to compare the fertility of bulls used in artificial insemination programs.

For upright, top-unloading silos, corn silage should be harvested at approximately 62 to 65 percent moisture. Higher moisture can lead to seepage, while lower moisture can cause poor packing and mold growth.

A subcutaneous (SQ or SC) injection is administered in the space between the skin and the muscle. This is a common route for many vaccines and medications.

The Babcock test is a historical and foundational method used to determine the percentage of butterfat in milk by using sulfuric acid to digest the milk proteins and release the fat.

Staph Aureus, Strep Uberis, and Klebsiella are common pathogens that cause mastitis, an inflammation of the udder. These bacteria can be contagious or environmental in origin.

Manufacturers of total mixed ration (TMR) mixers generally recommend a mixing time of 3 to 6 minutes to ensure a uniform blend without over-processing the forage particles.

A cryoscope measures the freezing point of milk. Because added water raises the freezing point of milk closer to 0 degrees Celsius, this device is used to detect adulteration.

Milk is composed primarily of water, which makes up approximately 87 percent of its total volume. The remaining 13 percent consists of fat, protein, lactose, and minerals.

The standard dry period for a dairy cow is 60 days. This period allows the udder tissue to regenerate and the cow to recover body condition before the next lactation.

The normal body temperature for a healthy adult dairy cow ranges from 101.0 to 102.5 degrees Fahrenheit, with 101.5 degrees being the standard average.

Vitamin K is essential for the synthesis of proteins required for blood clotting (coagulation). A deficiency can lead to prolonged bleeding times.

Oxytocin is the hormone responsible for milk letdown. During the milking process, a healthy cow will release oxytocin into the bloodstream to cause the contraction of the alveoli in the udder.

Salmonellosis is often associated with stress in dairy cows, and the period immediately following calving is a high-stress time. Infections are most commonly observed within the first 10 days postpartum.

The switch is the tuft of long hair located at the very end of a cow's tail. It is used to swat flies and insects.

To optimize lifetime production and reproductive efficiency, dairy heifers should be bred at approximately 15 months of age, provided they have reached the target weight (65 percent of adult weight).

The isoelectric point is the pH at which a protein has no net charge and becomes least soluble. For casein, this occurs at a pH of 4.6, which is why milk curdles when it becomes acidic.

High potassium intake interferes with magnesium absorption and calcium metabolism. Specifically, it inhibits the cow's ability to mobilize calcium from bone reserves, increasing the risk of milk fever.

The Jersey and Guernsey breeds both originated in the Channel Islands between England and France. They are well known for producing milk with high butterfat and protein content.

Niacin is commonly supplemented in the diets of transition cows to help manage energy balance and reduce the risk of ketosis. It helps improve liver function and fat metabolism during the critical period around calving.

Pest predators, such as parasitic wasps used for fly control in dairy barns, are known to have a foraging range of approximately 80 yards to locate their hosts.

HTST stands for High-Temperature Short-Time, which is a common method of pasteurization used in the dairy industry to ensure milk safety by heating it to a specific temperature for a short duration.

Monitoring urine pH in close-up cows is a standard practice to manage the risk of milk fever. A target pH range of 6.0 to 6.5 indicates that the dietary cation-anion difference (DCAD) program is effectively acidifying the cow's system.

Brown midrib (BMR) corn silage is bred to have lower lignin content. Since lignin is a structural component that limits fiber digestibility, reducing it increases the energy availability and digestibility of the silage.

In the official Holstein classification system, a score of 85-89.9 points is designated as Very Good. Scores below this are Good Plus or lower, while 90 and above is Excellent.

The Holstein classification system uses specific ranges to describe a cow's conformation. A score of less than 70 is classified as Poor.

Lactation, the production of milk by mammary glands to nourish offspring, is a defining biological characteristic of the class Mammalia.

A rapid exit barn is designed so that cattle leave milkers via an alley wide enough to allow 2 or more cows to exit simultaneously. This design improves cow flow and reduces milking time. It is not about sidewalls, fire safety, or having no milking stalls. The key feature is efficient exit from milking positions.

RHA stands for Rolling Herd Average, which is a standard metric used in the dairy industry to track the average production of a herd over the previous 12 months.

To produce one pound of milk, the cow's udder must have approximately 400 to 500 pounds of blood pass through it to supply the necessary nutrients.

Grass Tetany, also known as hypomagnesemia, is a metabolic disorder caused by a deficiency of magnesium in the diet, often occurring when cattle graze on lush, rapidly growing spring grass.

Neospora caninum is a protozoan parasite that is recognized as one of the most common infectious causes of abortion in dairy cattle worldwide.

Fats contain approximately 2.25 times the energy density of carbohydrates or proteins, making them the most concentrated energy source in a dairy ration.

Ovarian cysts in cattle are categorized based on their structure and function as either follicular cysts (thin-walled, produce estrogen) or luteal cysts (thick-walled, produce progesterone).

Weaver Syndrome, or Bovine Progressive Degenerative Myeloencephalopathy, is a hereditary neurological disease most commonly associated with the Brown Swiss breed.