The first insight into full-fat superworm (Zophobas morio) meal in guppy (Poecilia reticulata) diets: a study on multiple-choice feeding preferences and growth performance

Insect meals are sustainable alternative protein sources in animal nutrition. However, the data in the topic of their application in petfood and ornamental fish nutrition are scarce. Thus the present study was undertaken to asses their usability in guppy (Poecilia reticulata) diets. The first experiment aimed to investigate the attractiveness of select insect meals for guppies, and the second in evaluation of superworm (Zophobas morio) meal monodiet effects. The first experiment (free-choice feeding test) lasted five days. Fish were given a choice between four attractants: fish meal, black soldier fly (Hermetia illuces) meal (HI), Madagascar cockroach (Gromphadorhina portentosa) meal (MC), and superworm (Zophobas morio) meal (ZM). The preliminary part of the study showed that the most frequently chosen attractant throughout the entire free-choice feeding test period was ZM. Based on the obtained results, the second part of the study was designed as a growth test with the use of a ZM monodiet compared to commercial feed. The experiment lasted 90 days, and 150 guppy fry were used. The fish were randomly divided into two groups (CON - commercial feed, ZM - Zophobas morio meal). No effects of dietary treatment were found in terms of survival rate, fish body length, or fish body length gain. The present study shows that ZM was the most preferred attractant and that a monodiet based on insect meal can be successfully applied in guppy fry nutrition.

Prenatal Exposure to Innately Preferred D-Limonene and Trans-Anethole Does Not Overcome Innate Aversion to Eucalyptol, Affecting Growth Performance of Weanling Piglets

In the present research, two studies were performed to determine the effects of specific botanical compounds (BCs) on the innate feed preference and feed intake of piglets, as follows: Exp. 1 studied the innate feed preferences of post-weaning piglets using a double-choice feeding test. A total of 828 weaned piglets were distributed into 36 pens (23 pigs/pen) and assigned to three dietary pair choice feeding options (n = 12): unsupplemented prestarter diets (reference) versus reference plus D-limonene, trans-anethole, or eucalyptol. Piglets showed a preference for diets with D-limonene (53.8%) and trans-anethole (54.5%), and an aversion to eucalyptol (41.6%) (p < 0.05). Exp. 2 studied whether the prenatal and perinatal exposure to D-limonene, trans-anethole, and eucalyptol influences the feed intake and growth of newly-weaned piglets. Twenty-eight gestating and lactating sows were distributed into two dietary treatments (n = 14): unsupplemented Control diets or Control plus a blend of BCs (BBC; containing D-limonene, trans-anethole, and eucalyptol). D-limonene, trans-anethole, and eucalyptol were transferred into the placental fluid, and D-limonene and trans-anethole into the milk (p < 0.05). Furthermore, weanling piglets (n = 200; Control) and (n = 203; BBC) received the same treatment as their mothers in prestarter diets. The early response after weaning showed that piglets’ post-weaning BW gain was higher in the Control (p < 0.05) group than in those exposed to BBC. In conclusion, prenatal exposure to preferred D-limonene and trans-anethole, or familiarity to eucalyptol did not help to overcome the innate aversion to eucalyptol and its negative effect on weanling piglets’ BW.

Exposure to moderately elevated temperatures changes food preferences in the tropical marine herbivore Haliotis squamata

Ocean warming is affecting marine ectothermic herbivores as well as the macroalgal species they consume and this has the potential to alter their trophic interaction. However, it is currently still unknown how these two important components of benthic food webs will react to a warming environment. Consumption rates of grazers change with increasing temperatures, but it is unclear whether this is also true for feeding preferences. In this study, multiple-choice feeding assays with the tropical abalone Haliotis squamata from Western Indonesia were conducted in August 2018. After brief acclimation of either the grazer or the macroalgae to moderately elevated water temperatures (maximum 2 °C above the long-term average) in the laboratory, three species of living macroalgae were simultaneously offered to the abalone in feeding assays. Consumption rates of H. squamata were lower under elevated water temperatures, while its feeding preference switched: At 27 °C (2 °C below long-term average), abalone preferred non-acclimated Gracilaria salicornia, but switched to non-acclimated Amphiroa spp. at 31 °C. Interestingly, no such switch in preference occurred when the macroalgae, but not the grazers were acclimated. This indicates that the grazer will presumably be the driver of this potential change in interactions between H. squamata and its macroalgal food. Ocean warming may result in changes in the structure of benthic communities, mediated by changes in the feeding behaviour of herbivorous invertebrates.

Do Growing Rabbits with a High Growth Rate Require Diets with High Levels of Essential Amino Acids? A Choice-Feeding Trial

As a consequence of the genetic selection process in growing rabbits, there are currently fast-growing animals exhibiting an average daily gain that may exceed 45 g/d. The protein requirements of these animals, namely amino acid requirements, may differ from animals with low growth rates. The objective of this work was to evaluate growth performance, the coefficient of total tract apparent digestibility (CTTAD), the apparent ileal digestibility (AID) of amino acids and nutrient retention of fast-growing rabbits when they had access to a diet with high levels of amino acids and/or a diet formulated with current nutritional recommendations in a choice-feeding trial. To this end, two diets were formulated: the M diet following current nutritional recommendations for growing rabbits (including 8.1, 5.8 and 6.9 g/kg dry matter (DM) of total lysine, sulphur amino acids and threonine, respectively) and the H diet with higher levels of total lysine, sulphur amino acids and threonine (9.4, 6.6 and 7.8 g/kg DM, respectively). A total of 220 weaned rabbits, from a paternal line selected for the growth rate, had free access to the M diet, the H diet or both (MH) diets from 28 to 63 days of age. The CTTAD of DM, crude protein and gross energy from 49 to 53 days of age as well as the AID of amino acids of the diets at 63 days of age were determined. Protein, amino acids and energy retained in the empty body from 28 to 63 days of age were also registered. No significant differences in growth performance, CTTAD, AID and nutrient retention between dietary treatments were observed. However, animals fed the H diet showed a higher AID of cysteine (p < 0.05) and higher threonine retention (p < 0.05) compared to the M diet. As regards the choice-feeding trial, MH animals showed a higher feed intake of the M diet compared to the H diet (+8.61%; p < 0.001), and furthermore, more than 50% of the animals preferred the M diet throughout the experimental period (p < 0.05). Our results suggest that animals with high growth rates do not show significantly higher productive traits when fed the H diet compared to the M diet. As regards choice feeding, MH animals were capable of choosing their preferred diet, showing high intra-individual repeatability in preference for the M diet. It would be interesting to continue studying this behaviour of choice based on amino acid levels.

DIETS AND DIETARY INGREDIENTS SELECTION BY BROILER CHICKEN: EFFECTS ON GROWTH PERFORMANCE, CARCASS QUALITY AND ECONOMICS OF PRODUCTION

A total of 90day – old Hypeco broiler chicks were used in a choice-feeding trial to investigate whether meat-type chicken could select adequate nutrients that would support fast growth rate from a choice of imbalanced diet and feed ingredients. Three diets were used: a control diet (diet A= 200g/kg CP, 3031 kcal/kg ME) and two test diets; a low protein, high-energy diet (diet B=166g/kgCP, 3021 kcal/kg ME) and a low-protein, low-energy diet (diet C=168g/kgCP, 2838 kcal/kg ME). The diets were fed singly. The test diets were also used in a choice-feeding with ground maize and soya-bean meal (SBM). The study lasted for 5weeks and the response criteria included growth performance, carcass and organ characteristics, and economics of production. Weight gain and feed conversion ratio were significantly (P < 0.01) and (P < 0.001 respectively) influenced. Birds on the control diets had the highest weight gain and best feed conversion ratio. Birds on the low-protein, high-energy diet had performances not significantly (P > 0.05) lower than the control. The low-protein, low-energy diet depressed performance. Feeding the imbalanced diets (diets B and C) singly produced better performances than feeding them with a choice of dietary ingredients. Birds exhibited selection potentials by selecting the ground maize and SBM to compensate for deficiencies in the imbalanced diets but not at a level adequate enough to improve performances. Only the relative chest weight was significantly (P < 0.05) influenced amongst the carcass and organ weights measured. It decreased with decreasing feed quality. Economics of production showed that low quality and cheaper priced feeds do not necessarily give higher income and profit. The benefits of feeding single balanced diets and the possibility of decreasing the protein content of broiler finisher diets without compromising profits were revealed. It was suggested that broiler chicken appeared to select nutrients for maximize economic performance and that feed quality control should be enforced.

Using phosphate to increase feeding consumption in termite Coptotermes formosanus

Termites are ecologically significant in positive and negative ways; their role in breaking down debris greatly benefits forest environments, but this activity renders them a pest in domestic environments. This study examines the effect of nutrition on the feeding preference of termite Coptotermes formosanus Shiraki. Among 11 nutrition options tested, dipotassium phosphate (DKP) most significantly increased feeding consumption in the multiple feeding choice test. The mean feeding amount of the DKP-treated sample was 2.5-fold higher than that of the deionized water-treated control. This result suggests that termite colonies are deficient in phosphorus, and an additional supply of phosphate can promote feeding. The result of a no-choice feeding test using DKP shows that DKP does not promote feeding in a small number of termites. The results obtained in this study suggest that phosphorus is needed in termite colonies, making DKP especially effective. DKP will help to improve bait technology, because it is inexpensive and safe for both humans and the environment.

23 Protein Source Selection During Choice-Feeding in Nursery Pigs

Animal by-product feeding practices decrease waste from animal processing and create feedstuffs with favorable nutrient profiles. Including animal proteins has decreased recently due to consumer push to increase vegetarian fed animals. Pigs have demonstrated abilities to choose diets meeting their nutritional requirements when presented with a choice-feeding system (Rose and Kyriazakis, 1991). The objective of this study was to observe nursery pig behaviors in selecting animal and plant protein sources given a choice-feeding system. Pigs (n=72) were housed in groups of nine and given ad libitum access to ground corn, soybean meal (SBM), vitamin premix, ruminant blood meal (RBM), bovine meat and bone meal (BMB), and chicken by-product meal (CBP). Feedstuffs were randomly assigned to feeders and weighed daily. The study was repeated with individually housed pigs (n=8) to compare feeding behaviors. Pigs were weighed at the beginning of the trial with mean weights of 16.83 kg for group and 24.71 kg for individual and end of the trial with mean weights of 24.25 kg for group and 34.90 kg for individual. No intake differences were seen between housing treatment (P &gt;0.05). Protein source intake differed (P&lt; 0.0001), with CBP having the greatest consumption followed by SBM. A second trial (n=30) was conducted to determine preference when protein sources were mixed into corn-soy based diets and given ad libitum in a choice-feeding system for both groups of four (n=24) and individually housed pigs (n=6); starting mean weights of 14.83 kg and ending weights of 21.14 kg. Preference did not differ between housing or pen (P &gt;0.05) showing no feeder preferences or diet preference (P=0.9997). Data concludes that pigs preferentially select animal by-products as part of their diet when presented with a choice-feeding system. Nursery pigs do not have a preference when choosing from diets.