Petfood Forum Guide - 2018 - 11
the mechanisms and health effects of protein oxidation has increased and currently,
there is very little information on the amount of oxidation present in these products
after the rendered process. The objective of this study was to characterize how time
and temperature can impact the amount of protein oxidation in rendered by-products.
Bovine plasma was subjected to a 3x4+2 factorial design with temperature (45
C, 65 C or 100 C) over time (24, 48, 72 or 96 hours) in addition to two control
samples with two temperatures (-20 C and -80 C). Levels of oxidation were
assessed through a carbonyl assay using 2,4-Dinitrophenylhydrazine (DNPH). After
rendering bovine plasma contained 2.70 and 3.02 nmol carbonyl/mg of protein
when temperature was maintained at -20 C or -80 C, respectively. As temperature
increased for extended periods of time, a significant increase in carbonyls/mg was
observed. Samples at 45 C, increased from 3.19 nmol/mg at 24 hours to 5.94
nmol/mg at 96 hours (p<.0001). At 65 C, carbonyl levels increased from 3.60
nmol/mg at 24 hours to 5.87 nmol/mg at 96 hours (p<.0001). When plasma
was at 100 C carbonyls increased from 7.65 nmol/mg at 24 hours to 15.23
nmol/mg at 96 hours (p<.0001).
In conclusion, exposure to increased temperatures, in addition to longer durations,
will increase protein oxidation separately, or in combination. Further investigation
should examine the level of protein oxidation in other rendered by-products. Additionally, the effects of oxidized protein from rendered by-products on overall health of the
animal should be analyzed.
Carl Frame received his Bachelor of Science degree in May of 2017 from Iowa State
University where he majored in Animal Science with a minor in Meat Science. He
is currently pursuing his Master of Science degree at Iowa State University focusing
on by-products of the meat industry as ingredients in pet food nutrition. Frame has
been involved in the meat industry through internships and collegiate activities and
has presented at extension short courses on various topics related to meat. His background in the meat industry has led him to pet food to study rendered by-products
and how processing effects these ingredients.
Protein quality evaluation of different chicken protein sources
for pet food
Megan Morts*, Greg Aldrich; Kansas State University; email@example.com
Growth of the pet food market is fueled in part by the perception that whole or less
processed protein ingredients are superior to classically produced and/or rendered
ingredients. However, there is little nutritional information to confirm if the process of
producing these proteins has a direct impact on their protein quality. The objective of
this study was to determine the protein quality of chicken dried by different methods.
All experimental protein sources were analyzed for crude protein content and
amino acid profile. Day-old male broiler chicks were acclimated for one week to
the environment, then assigned to pen by weight in a randomized complete block
design. Protein sources were added to a N-free basal ration to contribute 10 percent
crude protein. Spray-dried egg (10 percent CP to basal ration) was used as the
positive control. Chicks were fed experimental diets for 10 days before final weight
was recorded to calculate weight gain and feed intake. Protein efficiency ratio (PER)
was calculated as weight gain per unit of protein intake (g/g). Chicks fed the
spray dried egg had a PER of 4.94. The PER of chicks fed dehydrated chicken and
high-protein chicken powder were not different than those fed spray-dried egg (4.44
and 4.71, respectfully). High-fat chicken powder was lower, 4.26 (P < 0.05), with
chicken meal and chicken by-product meal even less (3.35 and 3.25). The lowest
PER value of poultry origin was poultry by-product meal at 2.55. Chicks fed corn
gluten meal had the lowest PER (0.19; P < 0.05) of all protein sources. Lysine and
methionine content were much lower in chicken meal, chicken by-product meal,
and poultry by-product meal when compared to spray-dried egg, high-fat chicken
powder, high-protein chicken powder, and dehydrated chicken breast. Chicken meal,
chicken by-product meal and poultry by-product meal also had higher amounts of
hydroxyproline, which suggest higher amounts of connective tissue.
Overall, these data were able to rank protein sources based on method of production
(drying vs. rendering) and amino acid profile.
Megan Morts is from Wichita, Kansas, USA. She graduated with her Bachelor of
Science and Master of Science degrees in Animal Science at Kansas State University.
During her master's program, Morts presented at three Animal Science meetings and
one Poultry Science meeting. Upon completion of her masters, Morts completed an
eight-month internship at Hill's Pet Nutrition in quality systems and operations. She
is currently working on her PhD in the Pet Food Processing laboratory of Dr. Greg
Aldrich. The focus of her research is quality and shelf-life in minimally processed pet
Chitin and chitosan - potential uses in the pet food industry
Charles Roe*; University of Florida, College of Veterinary Medicine;
Chitin is the second most abundant polysaccharide on the planet behind cellulose and
its annual production has been estimated at over 100 billion tons. A great deal of
interest has surrounded chitin, as it is often considered a waste product of crustacean
processing yet has a nitrogen content of 6.1-8.3%. It is biochemically similar to
cellulose, a long-chained linear polymeric polysaccharide of repeating N-acetylglucosamine units, and carries out a similar function to cellulose in biological tissues. That
is, it is a structural polymer. Chitin can be chemically treated to form chitosan, which
is a deacetylated form of chitin.
In recent years a wide array of research has surrounded chitin and chitosan as their
applications have been found to be broad, and many of these uses may have applications in veterinary medicine. Chitin has been used to create biodegradable suture
and artificial skin for burn victims, and to produce anti-bacterial bandages. Dietary
chitin has been found to act similarly to a fiber and has been shown to stimulate
the growth of Lactobacillus and Bifidobacterium species in the intestine and thus
potentially has a role as a prebiotic. Chitosan has been used as a dietary phosphorus
binder for patients in renal failure and has been found to be an effective hypolipidemic in some species. This review will focus on chitin and chitosan and the role that they
may have in the pet food industry and potential avenues for future research.
Chuck Roe is a PhD student at the University of Florida, College of Veterinary Medicine working within the Aquatic Animal Health program. His specific area of interest
is animal nutrition and has a Master of Science in Aquaculture Nutrition from Auburn
University. He is currently studying calcium oxalate urolithiasis in Asian small-clawed
otters held in zoos and aquariums.
Effect of next generation-distillers dried grains on processing
parameters of extruded dog and cat food
Spencer Smith*, Greg Aldrich, Scott Tilton; Kansas State University;
The majority of pet foods utilize traditional ingredients like corn, wheat and soy.
These ingredients, and other grains such as distillers dried grains (DDG) have been
evaluated in the past with good results. Next generation-DDG (NG-DDG) are a
nutrient density improvement to DDGs, but have not been evaluated in pet food.
2018 Petfood Forum