Topic 13 Requirements for Maintenance and Lactation

Therefore, the energy density of the diet is important to assess and keep within a range that factors in palatability, consistency, moisture, stomach fill and concentrations of all the other nutrients. If the energy density is too high, the animal will

decrease its food intake to meet its energy requirement, leading to a potential deficiency in several nutrients.

Another way to explain the relationship between % CP requirement and growth is to understand that

grams of protein required per unit weight is highest after birth and decreases linearly as the animal matures and protein accretion slows down.

Generally, amino acids are not limiting in cats and dogs when sufficient animal products are included. Animal products are typically higher in amino acid concentrations compared to plant products because they are mainly composed of

proteins while plants have a large carbohydrate component, as discussed in Module 1. In addition, animal products are often of higher protein quality compared to plant-based proteins.

CP and AA requirements and form of expression: The guaranteed analysis provides the CP concentration (%) of the diet, rather than grams amount. But animals do not eat "percentage", they eat

quantities (g, kg, ounces, lbs, etc.) to meet their requirements. The requirement on a daily gram basis is the true, correct requirement for the animal.

Growth: Adjustment factor exists for the ME requirement for growth in dogs because of the extreme variation in

weight and time to reach adulthood between small breeds and large breeds of dogs, as presented in Table 5. *Cats reach maturity within very close range of time, and therefore no adjustment is applied (Table 6).

Essential amino acids:

Arginine, Arg: Always essential for felids, no matter the stage of their life cycle. Histidine, His Lysine, Lys Isoleucine, Ile Leucine, Leu Methionine, Met: Relatively lower in legume proteins; a diet heavily composed on plant-based proteins such as legume grains (pulses and soybean) will likely require Met supplementation (DL-Met) Phenylalanine, Phe Threonine, Thr Tryptophan, Trp Valine, Val Taurine, Tau: Tau is not an amino acid, it is an amino sulfonic acid, but it is often listed with amino acids or vitamins. It is essential for felids at all times. Although not officially recognized as essential in canids, conditions can render taurine less available to dogs (see next paragraph). *beta-amino sulfonic acid or amino sulfonic acid *taurine does not participate in protein synthesis - has an effect by itself

Table 2 presents the CP and AA requirements (%) of growing, reproducing, and adult cats. There is no large variation in mature weight across breeds of cats. Most cat dry formulations contain how many kcal ME?

"Presumes a caloric density of 4,000 kcal ME/kg, as determined in accordance with Model Regulation PF9. Formulations greater than 4,000 kcal ME/kg must be corrected for energy density; formulations less than 4,000 kcal ME/kg need not be corrected for energy. Formulations of low-energy density should not be considered adequate for reproductive needs." Most cat dry formulations contain 4,000 kcal ME.

Conditionally essential amino acids:

Arginine: puppies and growing dogs where approximately 50% of the Arg is produced de novo, and thus 50% must be present in the diet to meet demand for protein synthesis during growth. Adult dogs show deficiency symptoms when fed a diet devoid of Arg, indicating that Arg is required in the diet. Cysteine: essential when the diet contains inadequate quantities of methionine Tyrosine: essential when the diet contains inadequate quantities of phenylalanine Taurine is essential in dogs when the diet is limiting in methionine or cysteine, or the overall digestibility of the diet is reduced. *grain free dog foods: should we add taurine?

Basal metabolic rate is related to the total body surface area and is expressed as

BW^0.75

Essentiality of amino acids: An essential amino acid is an amino acid that

Cannot be synthesized de novo at a rate matching the demands for productive function and maintenance, and therefore must be present in the diet

Proteins and amino acids: Cats and dogs are non-ruminant animals and have what requirement rather than protein req?

Amino acid

How is energy measured or quantified?

Energy in an organic substance can be measured directly with direct calorimetry using a modern bomb calorimeter and capturing the heat released (see supplementary info document on energy). Energy requirement of an animal can be determined directly by measuring the heat generated by an animal or indirectly by measuring the O2 and CO2 exchange. Energy requirements for in cats and dogs have been determined using a combination of different approaches, including titration studies by feeding graded levels of energy and monitoring weight and health, long term feed intake and weight maintenance assessment, and indirect calorimetry.

What is energy?

Energy is a measure of heat. It is as simple as that! Animals that generate more heat per unit of body weight (BW) are animals that require more energy per unit of BW.

Small and toy breeds have higher ratios of surface area to body weight and therefore tend to have a higher

Energy requirement per unit weight

Therefore, expressing energy requirement on a - corrects for this difference and allows the use of one correction factor across breeds

Metabolic body weight

On your own, using the table below, fill in the CP, amino acid concentration and amino acid concentration of the protein (g/16gN) of corn, rice, whole wheat grain, soy protein isolate, meat and bone meal, beef and chicken on a DM basis.

On your own, using the table below, fill in the CP, amino acid concentration and amino acid concentration of the protein (g/16gN) of corn, rice, whole wheat grain, soy protein isolate, meat and bone meal, beef and chicken on a DM basis.

Protein and amino acid requirements are expressed on a - basis when we formulate a diet to meet the requirement for a group of cats and dogs.

Percentage *Therefore, cat or dog food labels indicate the protein concentration of the diet on a percentage basis because the diets are formulated to meet requirements for thousands of cats or dogs of various sizes and feed intake capacities receiving the same product

Therefore, it is important to ensure that the amino acid requirements are met when the diet is formulated on a CP basis and particularly when it contains a significant amount of what products?

Plant-based

A conditionally essential amino acid is

an amino acid that can be synthesized de novo but in quantities that are not sufficient to permit maximal growth

A nutritionally non-essential or dispensable amino acid is

an amino acid that can be synthesized de novo in quantities that are not limiting to maintenance, growth, production, or performance

Allowances are made for normal daily activity using a factor of

130

Maintenance requirement can be estimated using

130 kcal/kg^0.75 BW and an adjustment factor for age (Table 5)

Note that all tables in the AAFCO publication indicate the following: "Presumes a caloric density of 4,000 kcal ME/kg, as determined in accordance with Model Regulation PF9. Formulations greater than 4,000 kcal ME/kg must be corrected for energy density; formulations less than 4,000 kcal ME/kg need not be corrected for energy. Formulations of low-energy density should not be considered adequate for reproductive needs." Most dog dry formulations contain how many kcal?

3,500 kcal ME

Because there is no large difference in size and shape across breeds of cats, the ME requirement for cats is based on body weight, with a maintenance requirement calculated as

60 kcal/kg BW

Energy requirements: maintenance Daily ME requirement for maintenance (i.e., adults) for dogs under thermoneutral environment varies from a range of

94 to 105 kcal/kg^0.7

Despite this wide in variation in adult weight, why is the % CP requirement the same across breeds?

For example, at maintenance (adult weight) the Pekingese may only requires 25 g of CP per day, and consume 140 grams of food, corresponding to a CP requirement of ~ 18 %. The Great Dane may require 144 g of CP per day, and consume 800 g of food, corresponding to a CP requirement of 18 %. Animals consume foods in quantities that meet their energy requirement. The daily energy requirement for a Pekingese at maintenance is about 500 kcal ME/day while that of a Great Dane is about 2,800 kcal ME/day. If the energy density of the diet is 3,500 kcal ME/kg, the amount needed for the Pekingese is about 140 grams (0.3 lb) per day while that of the Great Dane is 800 grams (1.8 lbs!) per day. The Pekingese only requires 25 grams of CP per day while the Great Dane requires 144 g CP /day. The Great Dane consumes over 5-fold what the Pekingese consumes to meet its ME requirement and as such meets its daily CP requirement.

First, let's examine the daily protein requirement in grams/day relative to the animal's weight (Figure 2).

Initially after birth, CP requirement (grams/day) is very low because the animal is very small and protein deposition is also small. As the animal grows, rate of protein deposition increases rapidly and so is the amount of protein required daily, until peak protein accretion rate is reached, corresponding to the highest level of protein requirement. As the animal gets closer to maturity, rate of protein accretion decreases (decreasing side of the curve), and eventually equals 0 when the animal reaches mature weight. At mature weight, the animal has reached protein and energy equilibrium and both the protein and energy retention are zero. The protein requirement (and energy) at this point is the requirement for maintenance. So, while the total gram intake is higher at maintenance than in early life, the intake of protein relative to the total amount of food consumed is lower.