Squid meal and shrimp hydrolysate as novel protein sources for dog food

Abstract

The world’s growing pet population is raising sustainability and environmental concerns for the petfood industry. Protein-rich marine by-products might contribute to mitigating negative environmental effects, decreasing waste, and improving economic efficiency. The present study evaluated two marine by-products, squid meal and shrimp hydrolysate, as novel protein sources for dog feeding. Along with the analysis of chemical composition and antioxidant activity, palatability was evaluated by comparing a commercial diet (basal diet) and diets with the inclusion of 150 g kg−1 of squid meal or shrimp hydrolysate using 12 Beagle dogs (2.2 ± 0.03 years). Two in vivo digestibility trials were conducted with six dogs, three experimental periods (10 days each) and three dietary inclusion levels (50, 100 and 150 g kg−1) of squid meal or shrimp hydrolysate in place of the basal diet to evaluate effects of inclusion level on apparent total tract digestibility (ATTD), metabolizable energy content, fecal characteristics, metabolites, and microbiota. Both protein sources presented higher protein and methionine contents than ingredients traditionally used in dog food formulation. Shrimp hydrolysate showed higher antioxidant activity than squid meal. First approach and taste were not affected by the inclusion of protein sources, but animals showed a preference for the basal diet. Effects on nutrient intake reflected the chemical composition of diets, and fecal output and characteristics were not affected by the increasing inclusion levels of both protein sources. The higher ATTD of dry matter, most nutrients and energy of diets with the inclusion of both by-products when compared to the basal diet, suggests their potential to be included in highly digestible diets for dogs. Although not affected by the inclusion level of protein sources, when compared to the basal diet, the inclusion of squid meal decreased butyrate concentration and shrimp hydrolysate increased all volatile fatty acids, except butyrate. Fecal microbiota was not affected by squid meal inclusion, whereas inclusion levels of shrimp hydrolysate significantly affected abundances of Oscillosperaceae (UCG-005), Firmicutes and Lactobacillus. Overall, results suggest that squid meal and shrimp hydrolysate constitute novel and promising protein sources for dog food, but further research is needed to fully evaluate their functional value.

Protein hydrolysate and oil from fish waste reveal potential as dog food ingredients

“…Similarly, the CP content and amino acid profile of seafood and crustacean hydrolysates might differ depending on the primary source of protein (species and part of the animal), enzyme source, and hydrolysis conditions ( 17 , 64 ). An earlier study ( 37 ) showed that in shrimp hydrolysate obtained from the enzymatic hydrolysis of heads and cephalothoraxes of Litopenaeus vannamei , as the one used in the current study, lysine and leucine were the essential amino acids found in the highest amounts, and glutamic acid plus glutamine were the main non-essential amino acids. For fish hydrolysates, the review from Chalamaiah, Kumar ( 65 ) reported aspartic acid and glutamic acid to be found in high amounts in most of the fish protein hydrolysates, and that muscle, head, skin, and visceral hydrolysates contain all the essential and non-essential amino acids, whereas in fish frame protein hydrolysates, aromatic amino acids were not reported.…”

“…Although using 20 animals over 2 or 4 days is considered to increase the test resolution ( 36 ), the number of animals used in palatability tests greatly differs in the literature, with studies reporting the use of 8 ( 66 ), 10 ( 67 ), and 16 ( 68 ) animals. In the current study, despite the sample size (12 animals) being defined according to an earlier study that evaluated the dietary supplementation with shrimp hydrolysate ( 37 ), the number of animals used was lower than the generally recommended (20 animals), so some caution should be taken when interpreting the results obtained. Animals accepted well both the control and the experimental diet, with no differences in the first approach, taste, or intake ratio.…”

“…Therefore, this current study aimed to investigate the effects of fish hydrolysate and oil from fish wastes during the processing stage on palatability, apparent total tract digestibility, fecal characteristics and metabolites, blood fatty acid profile, and coat quality of adult dogs. The experimental diet containing fish hydrolysate and oil was compared to a commercial diet including shrimp hydrolysate, commonly used in fish diets ( 55 , 56 ), but recently shown to have the potential to be included in dog diets ( 37 ), and salmon oil, a common oil source used in dog food. With shrimp hydrolysate and salmon oil mainly imported from third countries, the use of fish hydrolysate and oil locally produced might contribute to the increased sustainability of the pet food sector.…”

“…Animals ( n = 12) were given the choice between the two diets in two different bowls (45 cm apart) on both meals for two consecutive days. The sample size and the duration of the trial were defined according to an earlier study ( 37 ) that found significant differences in intake ratio among diets without or with the inclusion of shrimp hydrolysate. The position of the bowls was switched between meals to eliminate any bowl-placement bias.…”

Shrimp Waste Upcycling: Unveiling the Potential of Polysaccharides, Proteins, Carotenoids, and Fatty Acids with Emphasis on Extraction Techniques and Bioactive Properties

“…Besides the human diet, shrimp hydrolysates also have the potential to be incorporated into petfood. Guilherme-Fernandes et al [215] conducted a study with Beagle dogs to compare a commercial diet with diets incorporating 150 g/ kg of squid meal or shrimp hydrolysate. Based on the results obtained for apparent total tract digestibility, metabolizable energy content, fecal characteristics, metabolites, and microbiota, the authors concluded that squid meal and shrimp hydrolysate could constitute novel and promising protein sources for dog food.…”