Term
| Why are all types of nutrients biologically needed by animals? |
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Definition
Classic roles
-nutrients serve as movers, initiating factors, building blocks and provide metabolic fuels
e.g. AA make proteins, Ca/P in bones, glucose for lactose
Indirect Stimulatory Roles
e.g. D-glucose and L-AA's stimulate blood circulating levels of hormones & growth factors
Newly Recognized Roles
-act as metabolic stimuli & signaling ligands to maintain biological functions and enhance productivity |
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Term
| How are essential nutrient requirements determined and established in animals by the empirical approach? Draw diagram |
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Definition
Essential nutrient requirements are established by conducting dose-response experiments without partitioning nutrient requirements in animals into further sub-components, e.g. maintenance vs productivity.
-can have multiple endpoints
e.g. practical, biochemical or clinical, weight gain, plasma urea nitrogen
-optimal response endpoint determined via broken line or curve-linear analysis
-can be used to determine all nutrient requirements |
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Term
| How are essential nutrient requirements determined and established in animals by the factorial approach? Draw diagram |
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Definition
Essential nutrient requirements are established by conducting dose-response experiments with partitioning nutrient requirements in animals further into the sub-components of nutrient requirements for maintenance, productivity, efficiency of nutrient utilization.
-one specific endpoint: nutrient retention/balance
-considers digestion, absorption and utilization of the nutrient
-optimal response endpoint determined via broken line or curve-linear analysis\
-used to determine requirements for energy and essential amino acids |
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Term
| Why do field poultry nutritionists need to refer to peer-reviewed journal publications for new info in formulating poultry diets, especially for newly released strains of poultry? |
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Definition
-NRC information on poultry is from 1994, very dated
-broiler chicks grow much faster now, shipped at 6wks of age vs previous 8wks
-need a higher nutrient concentration in their diet to meet the needs for rapid growth
-different production systems now e.g. free run, need more energy than battery cages |
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Term
| What available feed energy system is used in poultry? What is their diet? |
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Definition
-MEn & TMEn
Energy requirement are defined for laying hens in cages.
-suitable energy feeds should include 60-80% cereal grain (e.g. corn grain) and 15-25% plant protein supplement (e.g. soybean meal)
-can increase energy density with an animal fat-oil blend |
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Term
What available feed energy system is used in swine?
Poultry?
What is their diet? |
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Definition
DE, ME and NE -defined under housing conditions that allow limited voluntary activity, for lean breeds
-MEn & TMEn Energy requirement are defined for laying hens in cages.
-suitable energy feeds should include 60-80% cereal grain (e.g. corn grain) and 15-25% plant protein supplement (e.g. soybean meal)
-can increase energy density with an animal fat-oil blend |
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Term
| What are the major feeding phases for broiler chickens? |
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Definition
0-3 wks - Starter Phase
4-6 wks - Grower Phase
6-8 wks - Finisher Phase
*new strains reach market weight closer to 6wks to these feeding phases are adjusted to meet nutritional requirements for growth |
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Term
| What are the major feeding phases for growing turkeys? |
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Definition
0-4 wks
4-8 wks
8-12 wks (male) 8-11 wks (female)
12-16 wks (male) 11-14 wks (female)
16-20wks (male) 14-17 wks (female)
Breeders in holding and laying hens have separate nutrient requirements |
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Term
| What are the major feeding phases for growing pigs? |
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Definition
3-4 wks - Suckling, important for colostrum!
3-5kg Weaning phase 1
5-10kg Weaning phase 2
10-20kg Weaning phase 3 (starters)
20-50kg Growing phase
50-80kg Earling finishing phase
80-120 (110 Canada) Late finishing phase
Creep diets offered to suckling pigs prior to weaning for adaptation |
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Term
| Why are nutrient requirements and diet formulations for dogs & cats based on their age groups rather than body weight ranges or their breeds? |
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Definition
-different breeds of cats & dogs have different metabolic rates, different nutrient requirements e.g. Chihuahua vs Great Dane
-requirements vary greatly between breeds and body weights, it's more accurate to formulate diets based on stage of maturity |
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Term
| Discuss what the bioavailable feed energy system is used in dog and cat nutrition and their diet formulations. What is the typical energy source & protein supplement |
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Definition
ME kcal/kg DM feeds (separate for dogs and cats)
-diets are mostly made of highly digestible animal proteins therefore this a urine loss of urea (N), correct for that loss to get ME
-Can’t use NE because dogs and cats are housed in different environments hence they are out of their thermoneutral zones
-do best fed white meat, e.g poultry not red
-select cereal grain or sugar, e.g. sucrose or maltose, corn
-less than 55% corn for dogs, 10% for cats
-do not typically need a fat-oil blend |
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Term
| Discuss why a limited amount of cereal grains can be included in dog and cat diet formulation? Discuss why diet extrusion is usually needed to produce commercial dog and cat compound diets. |
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Definition
Not very palatable to dogs and cats and also cereal grains are not very tolerable to dogs and cats. Further processing of cereal grains is needed to improve its digestibility
Extrusion:
-gelatinizes starch to help digestion
-powders bulky feed ingredients (cats don't have molars equipped to grind)
-sterilizes pathogenic bacteria from animal protein supplements |
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Term
| Discuss why it is essential to include essential fatty acids omega 3 and polyunsaturated fatty acids in fish and shrimp diets in their artificial rearing practices. |
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Definition
-are incapable of de novo fatty acid synthesis, need to get these fatty acids from their diet
-membranes are also very fluid, need more fatty acids to maintain this fluidity
-artificial rearing means they can't feed on natural sources (algae and seaweed) so we need to supply it in their diet |
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Term
| Discuss what the available feed energy system is used in fish and shrimp nutrition and their diet formulations |
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Definition
Use DE
-only N loss is through through ammonia which contains little combustible energy
-do not have to convert to urea like mammals.
-can’t use ME because we don’t need to correct for urinary N losses because ammonia and N-compounds are excreted through gills and not urine
-can’t use NE because fish and shrimps are housed in a variety of water or environmental temperature hence they are not in their thermoneutral zone |
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Term
| Discuss why only a limited amount of cereal grains can be included in fish and shrimp diet formulations? Discuss why fish and shrimp prefer to use high levels of oil and high quality feed protein and amino acids in their diets to maintain their metabolism and growth |
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Definition
Cereal grains are not digested well
Their brain can use amino acids as an energy substrate as well (they can handle ammonia toxicity very well) therefore not requiring as much glucose in the diet. Have a lower metabolic rate and use oils/protein for growth/maintenance. |
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Term
| Discuss how nutrient requirements and ration formulations are classified for horses across various breeds and production and physiological phenotypes |
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Definition
Grouped into 5 mature body frame categories (200, 400, 500, 600 and 900kg)
Various feeding phases within each body weight frame
Suckling (up to 3 months)
5 different growing stages (4-24 months)
Adults in no work
Adults in work
Male reproducing
Pregnant mares
Lactating mares |
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Term
| Discuss what the available feed energy system is used in horse and rabbit nutrition and their ration formulations |
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Definition
Horses: Mcal/horse/day; DE
Rabbits: kcal/kg; DE (crude fibre used)
Can't use NE as they are out of their thermoneutral zones |
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Term
| Discuss why it is important to estimate voluntary dry matter feed intake in formulating rations for horses |
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Definition
-ensure satiety
-animals will eat until they have enough energy to sustain themselves
-need to ensure that their DM intake also meets the nutritional requirements of other nutrients e.g. micro/macrominerals, protein etc.
-gut hormones, stretch receptors, nutrient sensors & taste receptors will tell the animal when they are 'full' |
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Term
| Discuss why it is essential for meeting trace mineral cobalt (Co) requirements for horses and rabbits in their ration and diet formulations? |
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Definition
| Cobalt is required in order for microbes in the gut to produce B12 (cobalamin) |
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Term
| Discuss why most B vitamin and vitamin K are not supplemented, whereas vitamins A,D and E are supplemented in horse ration and rabbit diet formulations |
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Definition
-small amounts of Vit A, D, E needed because they cannot synthesize
-Water-soluble vitamins are usually neglected because the horse and rabbit large intestine produce sufficient self supply of B vitamins via the large intestine
-Usually only thiamin and riboflavin are recommended by NRC (2007), but it is usually neglected
-Rabbits practice caprophagt as well, providing enough digestion of B vitamins. |
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Term
| Discuss how nutrient requirements and ration formulations are classified for beef cattle across various breeds and production and physiological phenotypes? |
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Definition
Grouped into phenotypes according to physiology & production type, then further divided based on growing stage, BW range, lactation, pregnancy etc
Neonatal suckling (2-24 hrs for colostrum)
Post natal suckling (1-3 weeks)
Weaning (50kg to 200kg)
Veal calves (40-150kg)
Growing-finishing (200-450kg in 50kg groups)
Beef bulls (300kg, 450kg, 500kg, 650kg, 700kg, 800kg)
Replacement heifers (9 phases, 1 for each month of pregnancy) |
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Term
| What year is the latest release of NRC for beef cattle? |
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Definition
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Term
| Discuss how nutrient requirements and ration formulations are classified for dairy cattle across various breeds and production and physiological phenotypes? |
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Definition
Generally grouped into high milk yield (large Holstein, 680kg) and small dairy breeds (Jersey, 454kg)
Further grouped according to physiological & production types (growing, lactation etc)
Neonatal suckling (liquid feeding, 2-24 hrs)
Post natal suckling (1-3wks)
Weaning calves (50-100/150kg small vs large breed)
Veal calves (40-150kg)
Non-bred heifers (100-300kg every 50 small breeds, 150-400kg large)
Bred heifers (300-450 small, 450-650 large) every 50kg group
Dry Cows (late in pregnancy)
Late transitioning dry cows
Early lactation (454kg or 680kg) 11 days
Mid lactation (454kg or 680kg) 3 months |
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Term
| What are veal calves fed? |
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Definition
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Term
| What are post-natal suckling calves fed? |
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Definition
| milk or milk replacers with creep feeding for adaptation |
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Term
| Discuss what the available feed energy system is used in beef and dairy nutrition and their ration formulations |
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Definition
| Beef/Dairy: NE (Mcal/cattle/day) |
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Term
| Discuss why it is important to know voluntary dry matter feed intake in formulating rations for beef and dairy cattle. |
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Definition
| Dry matter feed intake determines satiety. |
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Term
| Discuss why it is essential for meeting trace mineral cobalt requirements for both beef and dairy cattle in their ration formulations. |
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Definition
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Term
| Discuss why all B vitamins and vitamin K are not supplemented, whereas vitamin A, D and E are supplemented in beef and dairy ration formulations? |
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Definition
| B vitamins and K are synthesized by the rumens’ microflora however, Vit A,D,E are not able to be synthesized by those bacterias and the content level of those vitamins are low in bulky feed ingredients hence they need to be supplemented ! |
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Term
| What is veal (calf) cattle production and why it is particularly discussed in dairy cattle nutrition? |
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Definition
| Veal calf/ cattle is a male calf/cattle that is raised on milk based diet and it is destined for meat consumption and not breeding |
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Term
| How are nutrient requirements & ration formulations classified for small ruminant species? |
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Definition
Goats are special because they have biotypes. Goats have historically been used more for production in developing countries which has brought about classifications for biotypes over time. This means they are not classified via breeds but in how cultures and communities have used them.
Other animals are classified commonly with growth and production stages. |
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Term
| What available feed energy & protein sysems are used in small ruminant nutrition? |
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Definition
ME system (not net). These animals are typically not in their thermoneutral zone.
Use CP or MCP |
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Term
| Why do we need to know voluntary dry matter intake in small ruminants? |
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Definition
| Ratio is per head of animal per day. DMI needs to be considered/followed. |
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Term
| Why is it essential to meet trace mineral CO requirements in for small ruminants? |
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Definition
| Need cobalt for B12 synthesis. |
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Term
| Why are all B vitamins and Vit D, K not supplemented for small ruminants, whereass A & E are |
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Definition
| None of the B vitamins are needed. Vitamin D is not needed as with other ruminants. Apparently they get a lot of sun and have access to fresh grass. Only vitamins A and E need to be supplemented. Note that other micronutrients like Cu and Zn are often not tolerable to these animals since they are not true ruminants. Lack omasum and the abomasum is tubular |
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