Beef Cattle
Frequently Asked Questions
Scientific answers based on NASEM 2016 and NRC standards, prepared by Doç. Dr. Mehmet ÇOLAK
FCR (Feed Conversion Ratio) is feed consumed (kg dry matter) divided by live weight gain (kg). Typical target values are adaptation period: 5-7 kg dry matter/kg gain, growing period: 6-8 kg dry matter/kg gain, and finishing period: 7-10 kg dry matter/kg gain. FCR is influenced by breed (for example, Charolais and Limousin often perform better), sex (males usually outperform females), starting age, and ration energy density. Under Turkish conditions, values may be 10-15% higher than NASEM 2016 references because of climate and breed differences. The VetKriter Feedlot Performance Calculator estimates FCR automatically.
ADG (Average Daily Gain) = (final feedlot weight - starting feedlot weight) / days on feed. Under Turkish conditions, common targets are crossbred males: 1.2-1.5 kg/day, pure breeds such as Simmental or Limousin: 1.4-1.8 kg/day, and native breeds: 0.8-1.1 kg/day. If ADG is <0.8 kg/day, ration quality, health status, and management should all be reviewed. For an accurate ADG calculation, animals should be weighed at the beginning and end of the period at the same time of day and in a fasted state.
The adaptation period usually lasts 21-28 days. During this time, the rumen microbial population adapts to a higher-energy ration. Forage proportion should be reduced gradually: 60-70% in week 1, 50-60% in week 2, 40-50% in week 3, and 15-20% in the finishing phase. Abrupt ration changes during adaptation can lead to ruminal acidosis. Feed should not run out, water must be freely available, and cattle should be observed daily. BRD risk is highest during the adaptation period, so vaccination and stress control are especially important.
Ruminal acidosis develops when rumen pH falls below 5.5 in high-carbohydrate diets. Subclinical SARA usually means pH 5.5-5.8 and often reduces feed efficiency without obvious dramatic signs. Acute acidosis is more severe and may be fatal. Prevention includes keeping forage at not less than 15% of the ration, using buffers such as sodium bicarbonate (150-200 g/head/day), making gradual diet transitions, using TMR to reduce selective feeding, maintaining constant feed access, and keeping particle size appropriate (NDF particle size >1.18 mm).
Optimal starting weight depends on breed and production goal. Male calves of improved breeds: 180-220 kg at 6-8 months of age. Crossbred males: 150-200 kg. Native breeds: 120-180 kg. If starting weight is too low (<150 kg), the feeding period becomes long and costs increase. If it is too high (>300 kg), the risk of excess fat deposition and lower carcass efficiency increases. In Turkey, the most common practical starting range is 180-220 kg. Health checks, parasite control, and vaccination should always be completed before the feeding period starts.
Liver abscesses usually develop when ruminal acidosis damages the rumen wall and allows Fusobacterium necrophorum to reach the liver. In intensive feedlot cattle, slaughterhouse data show a prevalence of about 10-30%. Prevention includes controlling ruminal acidosis through adequate forage and buffering, using products such as virginiamycin or tylosin where legally and veterinary-approved, making gradual ration transitions, and maintaining constant feed access. Liver abscesses lower carcass value and reduce overall economic performance.
Break-even price = total cost / (final live weight × dressing percentage). Total cost includes purchase cost, feed cost, labor, veterinary expenses, and general overhead. Example: starting animal 200 kg × 80 TL/kg = 16,000 TL. Feed cost: 150 days × 8 kg dry matter/day × 12 TL/kg dry matter = 14,400 TL. Total cost is about 32,000 TL. If final live weight is 500 kg and dressing percentage is 58%, carcass weight is 290 kg. Break-even price becomes 110 TL/kg carcass. The VetKriter break-even calculator performs this analysis automatically.
Water is one of the most critical determinants of feedlot performance. Daily water intake is usually 40-80 liters/day, depending on temperature, dry matter intake, and growth rate. In hot weather (>30°C), water consumption may increase by 50%. If water intake drops, dry matter intake also falls and ADG declines. Water quality guidelines include TDS <3,000 mg/L, nitrate <100 mg/L, sulfate <500 mg/L, and pH 6.5-8.5. One drinker should ideally serve fewer than 20 animals, and drinkers should be cleaned at least once daily.
According to NASEM 2016, feedlot cattle have two main energy needs: 1) maintenance energy (NEm), based on metabolic body size (BW^0.75), and 2) gain energy (NEg), based on target ADG. A 500 kg animal needs about 8.5 Mcal NEm/day. For an ADG of 1.5 kg/day, approximately 5.5 Mcal NEg/day is needed. In finishing diets, the target energy density is usually 1.55-1.65 Mcal NEg/kg dry matter. The VetKriter feedlot calculator estimates these values automatically.
NASEM 2016 uses a metabolizable protein (MP) system. In the growing phase (300-400 kg), MP requirement is roughly 800-1000 g/day. In the finishing phase (400-550 kg), it is about 700-900 g/day. Dietary crude protein is commonly 13-15% of dry matter in growing diets and 11-13% in finishing diets. Sources of bypass protein include corn gluten meal, blood meal, and fish meal. Excess protein increases nitrogen excretion, raises feed cost, and contributes to environmental load.
Forage and NDF are essential for rumen health. In finishing diets, the NDF concentration should generally remain at least 15-17% on a dry matter basis. If NDF falls below 12%, the risk of acute ruminal acidosis becomes very high. Physically effective NDF (peNDF) is especially important because long fiber sources such as straw help maintain rumen buffering. Common forage sources include corn silage, wheat straw, and barley straw. In Turkey, corn silage is the most common forage used in feedlot diets. In TMR systems, forage and concentrate must be mixed uniformly.
Macrominerals (dry matter basis): calcium 0.57%, phosphorus 0.28%, magnesium 0.10%, potassium 0.60%, and sodium 0.10%. Trace minerals (mg/kg dry matter): zinc 30, copper 10, manganese 20, selenium 0.1, and iodine 0.5. Vitamins: vitamin A 2200 IU/kg dry matter, vitamin D 275 IU/kg dry matter, and vitamin E 15-25 IU/kg dry matter. Selenium and vitamin E work together to help prevent white muscle disease. Selenium deficiency is common in Turkey, so supplementation is often important.
Corn silage is the main forage source in many feedlot rations. Key quality parameters include dry matter 30-35% (harvest timing is critical, usually late milk to early dough stage), pH 3.8-4.2, NDF 40-48%, ADF 25-30%, starch 28-35%, and NDF digestibility >50%. Aflatoxin B1 should remain below 20 ppb. Harvesting too early or too late can reduce silage quality significantly. Silage analysis should be used to optimize the ration.
Growth-promoting implants containing estrogenic, androgenic, or progestagenic compounds may improve feedlot performance by about 10-20% and can improve FCR. Potential advantages include greater ADG, improved feed efficiency, better carcass yield, and lower cost per kg gain. Disadvantages include export restrictions to the EU, negative consumer perception, and problems if applied incorrectly. Their legal status and market destination must be considered carefully. They should only be used under veterinary supervision.
Carcass yield is calculated as (hot carcass weight / live weight) × 100. Under Turkish conditions, average yield is usually 52-58%. Important factors include breed (improved beef breeds such as Charolais and Limousin usually outperform local breeds), sex (males generally exceed females), finishing duration, diet energy density, and pre-slaughter management. Fasting for 12-24 hours before slaughter reduces rumen fill. Good stress management is also essential, because pre-slaughter stress increases the risk of dark cutting beef (DFD).
Meat quality is assessed using several parameters. pH should generally be <5.8 at 24 hours postmortem; a high pH is associated with DFD beef. Color should be bright red. Marbling (intramuscular fat) contributes to flavor and tenderness. Water-holding capacity should be good, with low drip loss. Tenderness can be assessed by Warner-Bratzler shear force, ideally <4.5 kg. Marbling can be improved with energy-dense finishing diets, longer finishing periods, and appropriate breed or crossbreeding choices.
BRD is one of the most important disease complexes in feedlot cattle. Risk factors include transport stress, mixing cattle from different sources, overcrowding, and sudden weather change. Prevention generally includes: 1) vaccination at entry (IBR, BVD, BRSV, PI3, Mannheimia), 2) metaphylaxis in high-risk groups when justified, 3) stress control during transport and handling, 4) adequate ventilation, and 5) daily observation for early detection. BRD can create major economic loss because of treatment costs, reduced ADG, and mortality.
Lameness can significantly reduce feedlot performance. Common causes include digital dermatitis, sole ulcers, white line disease, and interdigital necrobacillosis. Management should include regular hoof care (often every 6 months), footbaths such as 5% formalin or 5% copper sulfate, and keeping floors dry and clean. Early detection and treatment are essential. Animals with lameness scores of 2-3 should be treated promptly. If lameness prevalence exceeds 5%, herd-level intervention is usually needed.
Heat stress (THI > 72) reduces feedlot performance. Effects include lower dry matter intake, reduced ADG, poorer FCR, and weaker immunity. This is an important issue in Turkey during summer. Management strategies include fans and sprinklers, access to shade, feeding during the cooler early morning and late evening hours, increasing dietary energy density with fat supplementation when appropriate, providing electrolytes such as potassium and sodium, and ensuring abundant water. High-quality feed is especially important because heat stress lowers digestive efficiency.
Common feed additives include ionophores (monensin, lasalocid), which improve rumen fermentation, can improve FCR by 5-10%, and help reduce bloat and acidosis risk. Virginiamycin may help reduce liver abscesses and improve feed efficiency. Beta-agonists (zilpaterol, ractopamine) can increase muscle deposition and reduce fatness, but they are banned in the EU. Buffers such as sodium bicarbonate and magnesium oxide help stabilize rumen pH. Enzymes such as cellulase and amylase may improve fiber digestion. All additives should be used under veterinary guidance and according to legal regulations.
In a TMR system, all feed ingredients are mixed and fed together. Recommended mixing order is: 1) dry forage such as straw, 2) silage, 3) concentrate ingredients, 4) mineral-vitamin premix, and 5) liquid ingredients such as molasses or fat. Mixing time is usually 3-5 minutes; excessive mixing reduces particle size too much. Particle size can be checked using a Penn State Particle Separator: >19 mm 2-8%, 8-19 mm 30-50%, and <8 mm 40-60%. TMR should ideally be prepared fresh each day.
Molasses is a by-product of the sugar industry and is commonly used in feedlot diets. Advantages include providing rapidly fermentable energy, supporting rumen microbes, improving palatability, reducing dustiness, and serving as a carrier for urea or other supplements. Disadvantages include high potassium content, which may influence DCAD, and excessive use (>10%) may cause diarrhea. The usual inclusion rate is about 3-8% of ration dry matter. Sugar beet molasses is widely available and economical in Turkey.
Parasites can significantly reduce feedlot performance. Internal parasites are often controlled at feedlot entry with products such as ivermectin or doramectin. Coccidiosis (Eimeria spp.) is especially important in younger cattle. External parasites such as ticks, flies, and lice increase stress and may transmit disease. Ivermectin can help control both internal and external parasites. A common entry protocol includes antiparasitic treatment together with vaccination and vitamin-mineral support. Rotation of anthelmintic classes is recommended to reduce resistance pressure.
Optimal slaughter weight depends on breed, sex, and market demand. Under Turkish conditions, common target weights are 550-650 kg for improved-breed males, 480-550 kg for crossbred males, and 380-450 kg for native breeds. Higher slaughter weights often increase carcass yield, but also increase fat deposition. The economic optimum is usually reached when ADG begins to decline, often above 500-550 kg. Market price, feed cost, and ADG should all be evaluated together when deciding the best slaughter time.
Bloat develops when rumen gas cannot be released normally. Foamy bloat is especially associated with lush legume grazing such as alfalfa and clover. Free-gas bloat may occur with esophageal obstruction or reduced rumen motility. Prevention includes feeding dry forage before turnout on legumes, using poloxalene when indicated, avoiding grazing very lush wet pasture early in the morning, and being cautious with diets high in legumes. Emergency treatment may require trocar decompression or oral antifoaming agents, with veterinary intervention when necessary.
Feed cost usually represents 60-70% of total feedlot cost. Cost-saving strategies include using local and seasonal feeds such as corn silage and grain by-products, testing feeds to avoid unnecessary supplementation, improving FCR, reducing feed waste through better bunk and waterer design, taking advantage of bulk purchasing, growing some feed on-farm, and using by-products such as beet pulp or cottonseed meal where appropriate. The VetKriter break-even calculator can help evaluate overall profitability.
Animal welfare is both an ethical and legal requirement. The Five Freedoms remain the basic framework: freedom from hunger and thirst, from discomfort, from pain/injury/disease, freedom to express normal behavior, and freedom from fear and distress. Practical requirements include adequate space per animal (at least 3-4 m²/head), clean and dry flooring, proper ventilation, and regular health monitoring. For export programs to the EU, certification systems such as GlobalG.A.P. or similar schemes may also be required.
Systematic record keeping is essential for profitability. Important parameters include starting and final weights, daily feed intake, ADG and FCR, health records such as disease, treatment, and drug use, vaccination and parasite-control dates, mortality and culling records, and cost-revenue analysis. Digital tools such as the VetKriter feedlot performance calculator can help interpret these data. Farms that do not keep records tend to identify problems late and cannot evaluate profitability accurately.
Selenium and vitamin E work together in antioxidant defense. Clinical signs of deficiency include white muscle disease (nutritional muscular dystrophy), especially in young animals, reduced immunity, and reproductive problems. Because many Turkish soils are low in selenium, supplementation is often necessary. Prevention typically includes selenium at 0.1-0.3 mg/kg dry matter, preferably partly in organic form, and vitamin E at 15-25 IU/kg dry matter, with higher support during stress periods. Injectable selenium plus vitamin E at the beginning of the feeding period is commonly used.
All answers on this page are prepared based on NASEM 2016 and current JAS/Livestock Science articles.
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