Grape, Pomegranate, Olive, and Tomato By-Products Fed to Dairy Ruminants Improve Milk Fatty Acid Profile without Depressing Milk Production

Recycling Agricultural Waste: Sustainable Solutions for Enhancing Livestock Nutrition

The increasing demand for sustainable agricultural practices prompts a reevaluation of feeding strategies in ruminant nutrition. Agricultural waste, often viewed as a by-product (BP), presents a promising opportunity to enhance the sustainability of livestock production systems. This review explores the potential of incorporating various agricultural BPs into ruminant diets. Utilizing these BPs reduces the environmental impact of livestock farming and contributes to the circular economy by recycling nutrients back into the food system. The nutritional composition of these wastes varies widely, and their inclusion in ruminant diets improves feed efficiency, animal performance and overall health. Research indicates that specific treatments, such as fermentation and ensiling, enhance the digestibility and nutrient availability of these materials. Moreover, incorporating agricultural waste into ruminant nutrition leads to financial benefits for farmers by reducing reliance on conventional feed sources. However, key challenges remain, particularly the need for further research to optimize inclusion rates and address potential anti-nutritional factors found in some agricultural wastes. Notably, adding these materials to ruminant diets results in 10%-30% reductions in feed costs and improvements of 5%-20% in key performance metrics, such as weight gain and milk production. These findings highlight the economic and sustainability benefits of utilizing agricultural BPs in livestock feeding practices. This review emphasizes the necessity of developing innovative and sustainable feeding strategies that leverage agricultural waste, calling for interdisciplinary approaches that combine animal nutrition, agronomy and environmental science. By adopting these practices, the livestock sector contributes to food security while minimizing its ecological footprint. Future research focuses on innovative processing techniques, effective management of anti-nutritional factors, and assessing long-term impacts on animal health and productivity. Additionally, examining the nutritional and health aspects of commonly used BPs, such as pomegranate, grape, pistachio, saffron, raisin, olive and tomato, is essential for fully understanding their potential in ruminant nutrition and guiding the development of targeted feeding strategies.

Assessment of the effect of agro-industrial by-products rich in polyphenols on in vitro fermentation and methane reduction in sheep

Introduction

This study aimed to evaluate, using the in vitro gas production technique, the effect of including eight agro-industrial by-products (carob, grape, two types of olive pomace, citrus pulp, tomato, and hazelnut skin) on fermentation end-products, ruminal degradability, and methane production in sheep diets.

Methods

The by-products were included at 10% dry matter in the control (CTR) diet, commonly adopted for adult sheep (80% natural grassland and 20% concentrate), and incubated at 39°C under anaerobic conditions.

Result and discussion

After 24 h of the incubation, the organic matter degradability (OMD24h) and methane production were assessed. After 120 h of the incubation, the organic matter degradability (OMD120h), volume of gas produced (OMCV), fermentation kinetics, pH, volatile fatty acids (VFAs), and ammonia were evaluated. Dunnett's test was used to compare the differences between the control and experimental diets, and multivariate analysis was performed to highlight the differences among the diets based on their in vitro characteristics. The results indicated that the inclusion of the by-products decreased the degradability and increased gas production after 120 h of the incubation. The by-products from the hazelnuts, citrus, grapes, and tomatoes significantly (p < 0.001) reduced the methane production, whereas the pomegranate, grape, 3-phase olive cake, tomato, and hazelnut by-products significantly (p < 0.001) increased the acetate production. The multivariate analysis showed that the butyrate concentration was a determining factor in the differences between the diets. The concentration of polyphenols in the selected agro-industrial by-products could modify fermentation parameters and metabolic pathways, leading to reduced methane production.

The Beneficial Dietary Effect of Dried Olive Pulp on Some Nutritional Characteristics of Eggs Produced by Mid- and Late-Laying Hens

This research evaluated the impact of incorporating dried olive pulp (OP) into the feed of laying hens on the fatty acid profile, cholesterol, triglyceride, total phenolic, oleuropein and hydroxytyrosol content, and health lipid indices of eggs produced by mid- (39 weeks) and late-laying (59 weeks) birds. Over a 36-week trial, 300 eggs from 180 Isa-Brown hens, assigned to three dietary groups with different OP levels (CON, OP4 and OP6), were analyzed. OP reduced egg cholesterol, with significant effects in late-age eggs (p < 0.05). In mid-age hens, the OP6 eggs had higher total phenolics than the controls (p < 0.05) and more PUFAs than the other groups (p < 0.05). The concentration of total phenolics, cholesterol, n3 PUFAs and % fat increased with hen age (p < 0.05), while triglycerides and oleuropein decreased (p < 0.05). With increasing hen age, the SFAs in the OP eggs decreased (p < 0.05) and the MUFAs increased (p < 0.05). Eggs from older hens had higher nutritional value, as indicated by the lower n6/n3 PUFA ratio, lower AI and TI indices, and higher h/H ratio (p < 0.05). Overall, dietary OP supplementation improved the nutritional quality of eggs, suggesting potential health benefits. Our results also highlighted eggs from older hens as a valuable source of high-quality fats.

Grape Pomace for Feed Enrichment to Improve the Quality of Animal-Based Foods

In this review, the potential role of grape pomace (GP) as a tool for improving feed has been critically summarized, considering the findings of the literature of the last five years (2020-2024). The main applications of GP to the nutrition of different animals and the impact on derived foods (meat, milk and dairy products, eggs, fish) are discussed along with the major advantages and limits. Emphasis was placed on the phenols and fatty acids of GP, which are considered phytochemicals with health-promoting effects. Phenolic compounds increase the antioxidant potential of animal-based foods even if their content and profile are strongly related to grape cultivar and geographical origin. Unsaturated fatty acids, including linoleic and oleic acids, contributed to extending the shelf life of new products. Few approaches exploited chemometrics tools. Generally, GP showed a promising role in feed fortification, even if, in most cases, GP was key only if used in a correct percentage within a balanced diet and for an adequate administration time. From a multidisciplinary perspective, future research endeavors should prioritize a larger sampling, a deep phenol fraction characterization, and an appropriate chemometric approach.

Potential use of dried persimmon (Diospyros kaki) byproducts as feed sources for ruminants

The aim of this study was to evaluate the chemical composition, in vitro digestibility, and palatability of dried persimmon byproducts (persimmon peel [PP] and damaged whole persimmons [WP]) ensiled with rice straw in different mixing ratios. PP and WP were ensiled with rice straw at ratios of 3:7 (PP3R7, WP3R7), 5:5 (PP5R5, WP5R5), 7:3 (PP7R3, WP7R3), and 8:2 (PP8R2, WP8R2) for 70 d. WP3R7 had the highest (p < 0.05) crude protein and lactate contents compared to the other combinations. On the other hand, PP3R7 and PP8R2 had lower concentrations of neutral and acid-detergent fibers (p < 0.05) and produced lower amounts of ammonia-N (p < 0.05). The silages were compared to rice straw silage (RS), maize silage (MS), whole-crop rye silage (WCRS), and sorghum-sudangrass silage (SSGS) during an in vitro study. The results showed that PP8R2 and WP7R3 had higher (p < 0.05) dry matter digestibility values than RS, MS, WCRS, and SSGS in a 6 h incubation period. In addition, a palatability test of the silages was conducted on Hanwoo cattle, goats, and deer, using the cafeteria method. The palatability index rate of PP7R3 was the highest (p < 0.05) for the goats and the Hanwoo cattle, whereas PP8R2 had the highest (p < 0.05) rate for the deer and the Hanwoo cattle. In conclusion, dried persimmon byproducts in the form of PP and WPs can be used as ruminant feed when ensiled with RS at ratios of 7:3 and 8:2.

The quality of meat in milk fed lambs is affected by the ewe diet: A review

Several scientific publications have highlighted the importance of feeding management practices in improving the nutritional properties of milk from dairy ewes. Meat production quality from suckling lambs is based on the use of milk as exclusive or near exclusive dietary component. There is considerable evidence that lamb meat contains many important nutrients and bioactive compounds that play an important role in consumer health. This paper examines the different quality characteristics of lamb meat from ewes fed different diets to improve milk quality. To conduct this research, we consulted different scientific databases and acquired relevant documents that studied the relationships between the dietary treatment of lactating ewes and the performance of their suckling lambs (growth and carcass traits) as well as the meat quality in terms of nutrient content (fat and protein in particular), bioactive compounds content (fatty acids, vitamins, and antioxidant molecules), color, odor and flavor. The extent of change in meat carcass traits and meat quality of suckling lambs due to different feeding strategies applied to ewes was evaluated and discussed. This overview of the knowledge on the relationship between the milk quality and suckling lamb quality can be useful for production and communication strategies development for the lamb meat industry.

Exploring the environmental and economic impact of fruits and vegetable loss quantification in the food industry

Population growth has stimulated rising demand for agro-food products and economic activity for many years, negatively impacting the ecosystem and non-renewable resource consumption. Algeria confronts the monumental challenge of effectively choosing how to nourish everyone on a more congested globe. However, food loss is a significant issue that worsens as Algerians' population expands and food consumption increases. In Algeria, food production and processing of food items, which include fruits, vegetables, and cereals, generate a considerable amount of by-products, with no commercial exploitation and a negative environmental impact, generating enormous socioeconomic problems. These by-products are essential sources of products with high levels of added value that can be applied in different sectors. They have no studies to measure the scope of food loss in the Algerian food industry. In this background, our research aims to quantify the loss in the Algerian food industry generated by the transformation of various agricultural products, directly affecting the economy and food availability for the population. The research utilizes a mixed methods approach, including coefficients, production statistics transformed, and data analysis; the findings reveal that a significant portion of fruits and vegetables are lost in the Algerian food industry, suggesting that minimizing food loss can help companies minimize costs and mitigate the adverse environmental effects of food production. Finally, the study proposes practical options to minimize food loss to create a long-term food system in Algeria.

Feeding and Nutritional Factors That Affect Somatic Cell Counts in Milk of Sheep and Goats

The purpose of this quantitative review is to highlight the effects of feeding strategies using some mineral, vitamin, marine oil, and vegetable essential oil supplements and some agri-food by-products to reduce SCCs in the milk of sheep and goats. According to the results, only specific dietary factors at specific doses could reduce SCCs in the milk of dairy sheep and goats. The combination of Se and vitamin E in the diet was more effective in sheep than in goats, while the inclusion of polyphenols, which are also present in food matrices such as agro-industrial by-products, led to better results. Some essential oils can be conveniently used to modulate SCCs, although they can precipitate an off-flavoring problem. This work shows that SCCs are complex and cannot be determined using a single experimental factor, as intramammary inflammation, which is the main source of SC in milk, can manifest in a subclinical form without clinical signs. However, attention to mineral and vitamin supplementation, even in the most difficult cases, such as those of grazing animals, and the use of anti-inflammatory substances directly or through by-products, can improve the nutritional condition of animals and reduce their SCCs, offering undeniable benefits for the milk-processing sector as well.