Re: Testing pollen sub
The Importance of Pet Food Digestibility and Palatability
Written by Dr. Jill Cline, Ph.D.
The Importance of Pet Food Digestibility and Palatability
Posted by ccspca on March 20, 2011 at 10:14 AM
Digestibility determines how much nutrition a food provides in a given volume, while palatability affects how appealing a food is to the animal. Both of these characteristics are important criteria when selecting the best food for your dog or cat.
What are digestibility and bioiavailability and how are they measured?
A food’s digestibility is the collective proportion of all nutrients in a food that is available to the dog or cat for absorption from the gut (intestine) into the bloodstream. Nutrient bioavailability is the proportion of the absorbed nutrients that are carried to target tissues and are available for use by the body. Because a highly digestible food provides a higher proportion of absorbed nutrients than a less digestible food, digestibility provides one measure of a food’s nutritional value and quality. In general, as the quality of ingredients in the food increases, so will the food’s digestibility and nutrient bioavailability.
Pet food companies measure the digestibility of their products using several tests, most of which include feeding trials. The food is fed to a group of dogs or cats for a selected period of time and the level of undigested matter excreted in the feces is measured and used to calculate nutrient digestibility. Although all reputable manufacturers conduct digestibility tests on their foods, the Association of American Feed Control Officials has not yet established a standard protocol for digestibility studies and does not allow the inclusion of digestibility claims on pet food labels. Commercial foods vary significantly in digestibility and ingredient quality, and so it can be difficult for pet owners to differentiate between super premium, premium and economy products. For example, the labels of two pet foods may have the same ingredient lists and guaranteed analysis panels, but when fed may have substantially different digestibilities (see below).
Total Protein vs. Digestible Protein
The pet food label provides an estimate of a food’s crude protein content on its guaranteed analysis panel. This measure reflects only the total amount of protein and does not indicate differences in protein digestibility between high and low quality protein sources. For example:
Dog Food A contains 21 percent crude protein and is 86.0 % digestible.
Dog Food B contains 23 percent crude protein and is 76.0 % digestible.
Food A: 21g protein/100g diet x 0.86 = 18.1g protein absorbed
Food B: 23g protein/100g diet x 0.76 = 17.5g protein absorbed
Although the crude protein value reported for Dog Food A is lower than that for Dog Food B, Dog Food A’s higher digestibility results in more protein being available to the dog, in a given volume of food.
What factors affect pet food digestibility?
A number of pet food characteristics influence nutrient digestibility. These include:
• Formula: The food’s formula refers to the type and quantity of different ingredients that are included in the product. Because pet food ingredients vary significantly in digestibility, the overall product formula is influenced by the digestibility and nutrient bioavailability of its various ingredients.
• Ingredient Quality: Overall pet food digestibility is increased by the inclusion of high quality ingredients and decreased when poor quality ingredients are included. For example, a pet food’s digestibility is decreased by the presence of poor quality protein, ash, certain types of dietary fiber, and phytate (a component of plant ingredients that decreases the availability of certain essential minerals in the diet).
• Processing: Proper processing techniques, cooking temperatures, and storage procedures support optimal nutrient digestibility and bioavailability. Conversely, digestibility and nutrient bioavailability can be significantly reduced by improper processing or excessive heat treatment. For example, excessive heat damages protein, resulting in decreased digestibility of the protein and reduced bioavailability of certain amino acids. This means that a smaller proportion of the protein is digested and absorbed. Some of the amino acids that are absorbed are also altered in structure (called a “Maillard Reaction” leading to a reduced ability of target tissues to use them efficiently.
What is palatability and how is it measured?
Palatability refers to perceptions of a food’s taste, smell, and texture. It is an important food characteristic because, simply put, pets must be willing to eat adequate amounts of the food to meet their calorie and nutrient needs. Unpalatable foods will be rejected, regardless of the quality of their ingredients or balance of essential nutrients. Dogs and cats differ somewhat in the food characteristics that they find desirable. Cats are strongly affected by the aroma of a food and will carefully smell a new food before tasting it. Dogs often prefer foods that are high in fat and include protein from animal sources. For both dogs and cats, the texture, size, and shape of food pieces are important; scientists who study palatability refer to this as “mouth feel”. Finally, in addition to animals’ sensory preferences, scientists who study palatability also consider the pet’s environment and the owner’s reactions to different types and flavors of food.
Similar to digestibility, there are a number of ways that pet food companies assess a food’s palatability. Tests that measure the animal’s preference when initially presented with a new food provide information about the immediate appeal of the food’s smell, appearance and texture. Long-term interest is measured using food preference studies. Each dog or cat is offered a choice of two diets that are presented in identical bowls to the left and right. Surplus food is offered in each bowl and the positions of the bowls are switched daily to account for dogs or cats with right- or left-side preferences. The amount of each food that is consumed at each meal is measured over a period of several days. These tests provide information about a food’s acceptability to dogs and cats over time and its relative palatability when compared with other foods. And, finally, the ultimate test of palatability involves presenting the food to pets in homes, where both the pet’s and the owner’s perceptions of the food are considered.
Selecting a Digestible (and Desirable) Food for Your Pet
Some pet food companies provide digestibility data with product literature or through the company’s customer service web site. However, neither digestibility nor palatability is explicitly reported on pet food labels. Here are a few helpful tips for selecting a food that is both highly digestible and palatable for your dog or cat:
• High quality ingredients that are correctly processed produce highly digestible foods. When digestibility information is available, select a food from a reputable manufacturer that has a dry matter digestibility of 80% or greater. Reject maintenance diets that have digestibilities that are lower than 75%.
• A product that is highly digestible will produce normal stool volumes and well formed and firm feces. In addition, the fecal matter will not contain mucous, blood, or any recognizable components of the food.
• Highly digestible foods result in relatively low defecation frequencies, and bowel movements that are regular and consistent. Foods that are not highly digestible may cause excessive gas (flatulence), loose stools, or diarrhea.
• Your dog or cat should readily consume and enjoy the food, in a quantity that promotes normal growth rate and optimal body weight. There should be no need to entice your pet to eat the food by adding treats, table scraps, or other human foods. An excessive quantity of food should not be needed to maintain your pet’s normal body condition.
Last edited by BEES4U; 09-01-2011 at 09:46 AM.
Reason: Added credits to the author and date.
Re: Testing pollen sub
I understand TDN and what it means. I understand what Bees4U is saying. I get it. I also understand that high TDN and high fibre or rather high undigestable fibre makes the TDN irrelevant because it make the product like the nutrition of straw. I get that. I get feed tested every year so we can ration our cows. I do not always understand the formula, but i then i get our ag reps to interpret the data...its a free service and its what they went to school for and what they get paid to do. Most of these ag reps are seasoned farmers and ranchers, not just schooled in the technical data.
What i am asking is are there times in the year when we do not need so much protien or TDN. Are we over conditioning the bees, making them too fat, and by the same token not as productive. Remember, too fat = low production. Is our need to feed such high concentrates costing us more in unproductive bees or them pooping the excess out? $ not spent wisely
I also understand the nutrition needs are high in the spring. This is to encourage hive growth and this costs energy. So protien should be up, quality should be up, TDN should be good and high fibre should be good quality which can be digested.
But are the nutrition needs as high in the fall when the queen shuts down? Are they as high when they are foraging in the summer months? When the winter comes and they are maintaining just them selves and not brood or foraging, do they need all that pollen in the hives or would syrup be more what they need to provide clean energy in the heart of the winter? If we are to get the needed high protien pollen on early in the spring, would feeding heavy pollen in the fall be necessary. Could the protien level be lower still allowing them to put the fat on but not large amounts of fat. When you answer, remember, I am in Canada. Cleansing flights are not always possible all the time. Some times they go weeks on end without cleansing.
I understand the concepts of TDN (total digestable nutrients) and protien, crude protien crude fat, and how high and low moister plays a part in the digestable nutrition. I also understand that Vitamins like A, D and E break down in light and have a short shelf life. Selenium is necessary for good reproduction and breed back. Good iron and copper levels play a huge role in cattle health relieving some disease stressors.
My questions earlier were not based because i did not read post 26 or not understand it. It was from a business perspective of seeing a need for pollen patties, seeing the cost for pollen patties, but wondering are we wisely spending our money feeding such hot feeds all the time during the feeding season. Would a lighter feed be more relevant in the fall and pick up the pace in the early spring for breeding when the needs are greater?
Just because they eat it or store it in the fall, does that mean they "need" it. Alot of animals eat it because it is there and they like the taste of it. Then the farmer is wondering why they are not producing like they should cause the BCS is too high or on the other end of the scale too low (BCS = body condition score)
Re: Testing pollen sub
Reading Bees4U post, and noting on the poop of dogs and cats, same can be said of cows. When the feed tests have not come back yet, the poop tells the story,
A poop pattie which mounds, dry, fiberous, is high TDN but also high undigestable fibre. This type of poop you can pick up with your hand...gloved preferably and throw it and it holds its form. This type of poop means the cows are eating and getting nothing out of it
A poop pattie which is runny and shoots out the back end and you are glad you are not behind the cow when she lets fly shows a feed ration which is too hot. NO matter how you pick it up, you can not. It is too watery. Too high in protien not enough fibre.
A poop pattie which is round, flat, somewhat solid but somewhat watery, when the final plop spits out a single drop spray, it is perfect. To pick it up you need a fork with some straw. It shows they are getting the needs of protien, fat, the TDN is good.
Now for some bee poop.
In our honey house we had some bees in the hot room. We also had this white fridge hubby was fixing. the bees took a liking to the fridge. This white fridge was no longer white in a couple of weeks. The poop on the fridge gave a wealth of information. Some of it was long and stringy, the appearance of possilby being runny. Thin. Some was in shorter chunks, some what thicker. And some was for lack of a better term, blobby. Heavy like.
I do not have enough hobbies....i examine our animals poop to find out what they need or do not need.
Poop is a poor mans nutrition test!
Re: Testing pollen sub
Friday, September 02, 2011
This may help to answer your question about honeybee nutritional needs.
I will use this beef cattle nutitional information:
Example. Assume that a group of cows
should weigh 1,200 pounds at a body condition
score of 5. This herd is within 60 to 70
days of the beginning of the calving season,
and they have an average condition score of 4.
The herd records indicate that the average 205-
day weight for the male calves is approximately
560 pounds. From Table 5, we determine
that the cows will consume
approximately 24 pounds of dry matter per
day and that they require 52.3 percent TDN
and 7.7 percent CP. Because we want to push
these cows from a condition score 4 to a score
of 5 in the 60 days before calving, we need to
provide an additional 2.6 pounds of TDN per
day. Based on the above requirements the
cows need 12.55 pounds of TDN (24 x .523)
plus the additional 2.6 for a total of 15.15
pounds per day. As a percentage, this group of
cows would require 63.1 percent TDN during
this initial 30 days of the 60-day precalving
The above information is provided for an adjustment in the nutrition for cattle which is not very different from honeybees going into winter!
Therefor, you want your pollen supplement to be high in nutrition in mid to late summer because you have a target date of 60 days to get the bees fed up to their level, #5, for wintering.
You goal is to get your herd of bees up to a score of 5 because scores below that will cause unneeded stress which results in colony failure.
You can use the same information for spring management.
If you knew the pollen anaysis between spring and fall you could make adjustments to your pollen sublement formulations.