4 Engineered Resilience in Livestock for Improved Animal Welfare

Welfare status for any species is dependent upon an animal’s ability to cope with its environment. Environmental conditions, animal husbandry, and overall health are major components that contribute to managing livestock species with quality animal welfare. Previous approaches intending to create more robust animals have applied genetic selection, nutritional programming, or advancements in facilities. Engineered resilience, the approach explored here, represents: (a) the ability to identify certain physiological biomarkers, behaviors, and environmental stressors that contribute to the individual’s response to a challenge; and (b) manipulate them in a targeted way with well-timed and controlled exposure to improve outcomes of a challenge to homeostasis (i.e. improve fitness with prior conditioning). Foundational understanding of natural adaptation in response to challenge reveals that some animals emerge from a challenge with greater coping abilities and others fail to thrive. By determining which animals have natural resilience and exploring the factors that created desired outcomes, scenarios can be identified to initiate resilience in susceptible animals. Such responses can then be stimulated through the development of managerial techniques. This project was conducted by reviewing published literature with the goal of identifying more refined areas of study for future research in engineered resilience in livestock species. Potential for application of this concept includes building thermal resilience, social resilience, and disease resilience.

Analysis of Both Lipid Metabolism and Endocannabinoid Signaling Reveals a New Role for Hypothalamic Astrocytes in Maternal Caloric Restriction-Induced Perinatal Programming

Maternal malnutrition in critical periods of development increases the risk of developing short- and long-term diseases in the offspring. The alterations induced by this nutritional programming in the hypothalamus of the offspring are of special relevance due to its role in energy homeostasis, especially in the endocannabinoid system (ECS), which is involved in metabolic functions. Since astrocytes are essential for neuronal energy efficiency and are implicated in brain endocannabinoid signaling, here we have used a rat model to investigate whether a moderate caloric restriction (R) spanning from two weeks prior to the start of gestation to its end induced changes in offspring hypothalamic (a) ECS, (b) lipid metabolism (LM) and/or (c) hypothalamic astrocytes. Monitorization was performed by analyzing both the gene and protein expression of proteins involved in LM and ECS signaling. Offspring born from caloric-restricted mothers presented hypothalamic alterations in both the main enzymes involved in LM and endocannabinoids synthesis/degradation. Furthermore, most of these changes were similar to those observed in hypothalamic offspring astrocytes in culture. In conclusion, a maternal low caloric intake altered LM and ECS in both the hypothalamus and its astrocytes, pointing to these glial cells as responsible for a large part of the alterations seen in the total hypothalamus and suggesting a high degree of involvement of astrocytes in nutritional programming.

The use of live food as a vehicle of soybean meal for nutritional programming of largemouth bass Micropterus salmoides

Nutritional Programming (NP) has been studied as a means of improving dietary plant protein (PP) utilization in different fish species. This study investigated the use of enriched live feed as a vehicle for NP in larval fish. The objective of this study was to determine the effect of NP induced during the larval stage via PP-enriched live feed on: (1) growth performance; (2) expression of genes associated with inflammation and any morphological changes in the intestine; and (3) muscle free amino acid composition in largemouth bass (Micropterus salmoides) during its later life stages. Two diets were used in this study, a fish meal (FM)-based diet, and a soybean mean (SBM)-based diet, serving as the PP diet. There were 4 groups in this study. The two control groups, ( +) Control and (−) Control, were not programmed and received the FM-diet and SBM-diet, respectively throughout the whole trial after the live feed stage (27–122 days post hatch (dph). The next group, programmed, was programmed with SBM-enriched Artemia nauplii during the live feed stage (4–26 dph) and challenged with the SBM-diet during the final stage of the study (79–122 dph). The final group, non-programmed, did not receive any programming and, was challenged with the SBM-diet during the final stage of the study. The programmed group experienced a significantly higher (%) weight gain during the PP-Challenge than the non-programmed group. In addition, the live feed programming resulted in significantly longer distal villi, and a higher villi length to width ratio, compared to the non-programmed group. No significant effects on free amino acid composition and gene expression were observed between the programmed and non-programmed group, except for an increased post-prandial concentration of free proline in the programmed group. The results of this study support use of live feed as a vehicle for nutritional programming and improving the growth performance of largemouth bass fed with a SBM-based diet.

Possible Dietary Effects of Insect-Based Diets across Zebrafish (Danio rerio) Generations: A Multidisciplinary Study on the Larval Phase

Insects represent a valuable and sustainable alternative ingredient for aquafeed formulation. However, insect-based diets have often highlighted controversial results in different fish species, especially when high inclusion levels were used. Several studies have demonstrated that nutritional programming through parental feeding may allow the production of fish better adapted to use sub-optimal aquafeed ingredients. To date, this approach has never been explored on insect-based diets. In the present study, five experimental diets characterized by increasing fish meal substitution levels with full-fat Black Soldier Fly (Hermetia illucens; BSF) prepupae meal (0%, 25%, 50%, 75% and 100%) were used to investigate the effects of programming via broodstock nutrition on F1 zebrafish larvae development. The responses of offspring were assayed through biometric, gas chromatographic, histological, and molecular analyses. The results evidenced that the same BSF-based diets provided to adults were able to affect F1 zebrafish larvae fatty acid composition without impairing growth performances, hepatic lipid accumulation and gut health. Groups challenged with higher BSF inclusion with respect to fish meal (50%, 75% and 100%) showed a significant downregulation of stress response markers and a positive modulation of inflammatory cytokines gene expression. The present study evidences that nutritional programming through parental feeding may make it possible to extend the fish meal substitution level with BSF prepupae meal in the diet up to almost 100% without incurring the well-known negative side effects of BSF-based diets.

Analyzing the Impact of Long-Lasting Changes in Energy Homeostasis and Nutrient Sensing on Nutritional Programming of Hypothalamus in Rats

Background: The diseases due to nutritional deficiencies or imbalanced diet can be due to different factors. These factors can be biological or environmental. The study indicated that there will be increase risks of acquiring diseases as a result of irregular intake of diet. These risks include the increased risk of diseases such as liver abnormality, hypertension, lipids deposition, and other diseases. Methodology: The databases used for the collection of secondary information include Science Direct, PubMed, and Google Scholar. Besides, the keywords used for the searching of relevant research articles include “experimental rats, nutritional deficiencies. Hypothalamus, mechanisms studies, gene ontology, metabolic syndromes”. There were the use of female rats (n=8) and the weight was ranged between 200 to 250 grams. The experimental rats were placed in a cycle of 12 h light/dark. An adequate amount of water and food was provided for about one week to the rats before starting the experiment. Enzymatic procedures were used for the analysis of cholesterol, fatty acids, and triglycerides. Glucose concentrations in the blood samples were also assessed using the glucose meter. The insulin levels were also measured by using the assay kits. The hybridisation, scanning, and normalization of the data were also done. The extracted RNA from the hypothalamus was transcribed by using the “Superscript II RNAseH- Reverse-Transcriptase”. The t-test was also performed using statistical software. The groups of genes and their altered expressions were studied after the malnutrition conditions. The results obtained through PCR were expressed in the form of average and standard deviation values [1]. The mRNA expression levels in the samples of the hypothalamus were also assessed. The data were compared using the student test. The significance levels were measured at p < 0.05. Findings: The findings of the study also indicated that the transcription of co-regulators is also link with the nutritional and temporal cues to the metabolism process by means of their association with circadian clock. The findings revealed that the hypothalamic circuits and its nutritional programming plays significant role in the regulation of energy homeostasis which is a major factor of obesity development in association with malnutrition in early life development. Conclusion: Conclusively, it has been identified that the deficiency of nutrients during developmental period such as prenatal and postnatal is linked with the enhanced risk of different types of diseases in childhood as well as in adulthood.