Small amounts of agro-industrial byproducts in dairy ewes diets affects milk production traits and hematological parameters

The effect of Momordica charantia extract on sheep infected with Haemonchus contortus

Bitter melon (Momordica charantia) has several biological properties including anthelmintic activity. Presented in vivo study evaluated the anthelmintic activity of the hydroalcoholic extract of M. charantia Presented in vivo study (HEMC) and its effect on animal performance, carcass characteristics and lamb meat quality in animals infected by Haemonchus contortus. The HEMC demonstrated effectiveness against the parasite. Lambs treated with HEMC showed a significant reduction in egg count per gram of faeces and in the number of parasites in the abomasum. However, nutrient intake decreased with increasing doses of HEMC, leading to reductions in final live weight and carcass weight. No significant effects were observed on meat quality. Therefore, it is concluded that HEMC presents anthelmintic action, but it also impairs animal performance, highlighting the need to assess the benefits and impacts of HEMC use for H. contortus control.

Cocoa byproduct inclusion in dairy sheep diet: Effects on sensory, volatile, and antioxidant properties of cheese

The possibility of inclusion of agro-industrial byproducts in the diet of small ruminants represents both an economic and an environmental strategy for reducing waste management by industries and costs of feeding as well as the impact of livestock farming. Large amounts of wastes from the cocoa industry are produced annually, with a considerable part represented by cocoa bean shells, considered a suitable ingredient to be included in the diet of ruminants within the limits established by European legislation. The aim of this study was to assess the effect of including cocoa bean shells in the diet of dairy sheep on the sensory, volatile, and antioxidant properties of cheese. To this purpose, 20 lactating Comisana ewes were randomly assigned to 2 experimental groups: control (CTRL) and cocoa bean shells (CBS), and received alfalfa hay ad libitum and 800 g of conventional (CTRL) or experimental (CBS) concentrate containing 11.7% CBS to partially replace corn and barley of the CTRL concentrate. Bulk milk collected from each group was used to produce a total of 15 cheeses per group, obtained in 5 different days of cheesemaking (3 cheeses a day per group). After 60 d of aging, each cheese of each experimental group was sampled for the analyses. The results on chemical composition revealed a greater content of monounsaturated fatty acids and an increase in the nutritional indices, suggesting a favorable role of cocoa bean shell dietary inclusion on the nutritive value of cheese. The cheese sensory profile was affected by the cocoa bean shell inclusion, with more pronounced appearance, odor, aroma, and taste attributes in the product. The volatile profile showed only a few significant differences, mainly related to the cheese ripening process, and no differences were found in α-tocopherol contents in cheese fat between the 2 groups. Therefore, the inclusion of coca bean shells in the diet of dairy sheep allowed us to obtain a good-quality cheese, without altering the characteristics associated with the typical profiles of sheep cheese. Furthermore, the use of this byproduct could contribute to decreasing feed costs and waste management, representing a good practice for increasing the sustainability of dairy products.

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.

Feeding of Camelina sativa Seeds to Light-Type Gentile di Puglia Lambs: Effect on Productive Performance and Muscle Fatty Acid Composition

The effect of different amounts of camelina (CAM; Camelina sativa) seeds in lambs of the Gentile di Puglia breed on growth, carcass characteristics, and meat quality was investigated. Up to 70 days of age, twenty-four male lambs (13.0 ± 0.35 kg) were randomly assigned to three isocaloric and isonitrogenous diets. Pelleted total mixed rations (TMR) were created to provide: (1) a control diet (CON), (2) an experimental corn-based diet including 5% camelina (CAM5) seeds, and (3) an experimental corn-based diet containing 10% camelina (CAM10) seeds. The presence of CAM in the diet impacted lamb performance (p < 0.05), according to the results of a growth study. Lambs were slaughtered at the conclusion of the feeding period, and none of the carcass characteristics investigated were significantly affected by dietary treatment, with the exception of brisket and rib weight and carcass lean, which were improved (p < 0.05) in lambs fed the CAM diet. The color of lamb flesh from the Longissimus lumborum muscle was affected by CAM diets (p < 0.05), but the chemical content and physical characteristics did not differ across treatments (p > 0.05). The fatty acid composition of lamb meat in muscle was somewhat regulated by the experimental diets, with CAM feeding improving (p < 0.05) the level of linolenic acid and MUFA while reducing SFA and PUFA. As a result of the current data, it can be stated that camelina seed supplementation may be included in the lamb diet because no negative impacts on productivity, as well as an enhancement in meat quality, have been found.

Effects of increasing levels of orange peel extract on kit growth, feed utilization, and some blood metabolites in the doe rabbits under heat stress conditions

One of the most severe consequences of climate change on the rabbit production sector is heat stress. Dietary supplementation of phytochemicals could alleviate the negative impact of heat stress on rabbits. Thirty-six V-line rabbit does with average live body weight (LBW) of 2.672 ± 0.031 kg were randomly allocated into three experimental groups as follows: the control group (OPE0) and the OPE2.5 and OPE5 groups were orally administered orange peel extract (OPE) at doses of 2.5 and 5 mL/doe. The increasing OPE levels significantly improved LBW at partum (p = 0.002) and weaning (p = 0.004), daily and total feed intake from pregnancy until weaning (p = 0.007), daily milk yield per doe at 7th and 14th days (p ≤ 0.05), and milk efficiency (p = 0.001). Litter size at 1st-28th days, litter weight gain, survival rate, and kit weight gain at 21st-28th days of heat-stressed doe rabbits were significantly improved with OPE treatments. The treatment of OPE5 significantly decreased serum glucose, triglycerides, and very-low-density lipoprotein-cholesterol levels of rabbits. The increasing OPE levels decreased significantly total lipid and low-density lipoprotein-cholesterol levels and increased (p = 0.001) high-density lipoprotein-cholesterol concentration in heat-stressed rabbits. In conclusion, the treatment of OPE improved feed utilization, milk efficiency, and reproductive performance and alleviated the drastic impacts of heat stress on rabbits.

Measuring the Phytochemical Richness of Meat: Effects of Grass/Grain Finishing Systems and Grapeseed Extract Supplementation on the Fatty Acid and Phytochemical Content of Beef

Grass-finished beef (GFB) can provide beneficial bioactive compounds to healthy diets, including omega-3 polyunsaturated fatty acids (n-3 PUFAs), conjugated linoleic acid (CLA), and secondary bioactive compounds, such as phytochemicals. The objective of this study was to compare fatty acids (FAs), micronutrients, and phytochemicals of beef fed a biodiverse pasture (GRASS), a total mixed ration (GRAIN), or a total mixed ration with 5% grapeseed extract (GRAPE). This was a two-year study involving fifty-four Red Angus steers (n = 54). GFB contained higher levels of n-3 PUFAs, vitamin E, iron, zinc, stachydrine, hippuric acid, citric acid, and succinic acid than beef from GRAIN and GRAPE (p < 0.001 for all). No differences were observed in quantified phytochemicals between beef from GRAIN and GRAPE (p > 0.05). Random forest analysis indicated that phytochemical and FA composition of meat can predict cattle diets with a degree of certainty, especially for GFB (5.6% class error). In conclusion, these results indicate that GFB contains higher levels of potentially beneficial bioactive compounds, such as n-3 PUFAs, micronutrients, and phytochemicals, compared to grain-finished beef. Additionally, the n-6:n-3 ratio was the most crucial factor capable of separating beef based on finishing diets.

Valorization of Olive Mill Byproducts: Recovery of Biophenol Compounds and Application in Animal Feed

This study aimed to recover the phenols from olive oil mill wastewater, a major pollutant of the oil industry, by using spray-drying technology to produce a new feed with a nutraceutical value for animal feed supplementation and to evaluate its effect on the productivity and nutritional quality of ewe milk. Forty-five Sarda ewes in late lactation (150 ± 2 d) and with homogeneous live weight (52 ± 1.5 kg) were randomly allotted into three groups and fed with three dietary treatments containing increasing levels of polyphenols: 0% (C), 0.1% (T0.1), and 0.2% (T0.2) of dry matter. No effect of the dietary treatments was found on the milk yield and composition. Interestingly, milk urea content (p < 0.0001) and somatic cell counts (p < 0.001) decreased as the level of polyphenols inclusion in the diet increased. The inclusion of phenols (0.2% of dry matter) in the diet of sheep was effective in increasing the vaccenic (C18:1 trans-11) and rumenic acid (C18: cis-9 trans-11) levels, which are beneficial for human health. Finally, the recovery of polyphenols via spray-drying technology and their incorporation into a new fortified feed can be a valid strategy for naturally improving the nutritional value of milk while valorizing an oil industry byproduct, reducing environmental impact, and promoting waste reuse that is in line with circular economy principles.

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.

Determining the Effects of Pelleted Cranberry Vine Grains on the Ewe and Offspring during Pregnancy and Lactation

When creating any new anti-parasitic interventions, it is important to evaluate their effects across all life stages. This study had three objectives, which were to evaluate the effect of feeding cranberry vine pellet (CVP) on (1) ewes' body weights and BCS during late gestation and lactation; (2) ewes' milk quality during lactation; and (3) lambs' body weight and growth parameters from birth to 65 days of age. Across two years, 41 Dorset ewes were fed either a 50% CVP or a matching control pellet (CON) from 104 ± 1.60 days of gestation for 62.8 ± 0.68 days of lactation. Measurements were collected from ewes (BW, BCS, and milk) and lambs (BW and body size). Milk from CVP ewes exhibited reduced milk fat and solids (p < 0.01) and increased concentrations of milk urea nitrogen (p = 0.02) when evaluated for the treatment-time. There was no significant difference in the BCS, protein, lamb BW, or growth measurements for treatment-time (p ≥ 0.05). Additional research that targets blood biochemistry and metabolic assessments is needed to fully determine the impact of this pellet on ewes and lambs.

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

The continuous increase in the cost of feeds and the need to improve the sustainability of animal production require the identification of alternative feeds, such as those derived from the agro-industrial sector, that can be effectively used for animal nutrition. Since these by-products (BP) are sources of bioactive substances, especially polyphenols, they may play an important role as a new resource for improving the nutritional value of animal-derived products, being effective in the modulation of the biohydrogenation process in the rumen, and, hence, in the composition of milk fatty acids (FA). The main objective of this work was to evaluate if the inclusion of BP in the diets of dairy ruminants, as a partial replacement of concentrates, could improve the nutritional quality of dairy products without having negative effects on animal production traits. To meet this goal, we summarized the effects of widespread agro-industrial by-products such as grape pomace or grape marc, pomegranate, olive cake, and tomato pomace on milk production, milk composition, and FA profile in dairy cows, sheep, and goats. The results evidenced that substitution of part of the ratio ingredients, mainly concentrates, in general, does not affect milk production and its main components, but at the highest tested doses, it can depress the yield within the range of 10-12%. However, the general positive effect on milk FA profile was evident by using almost all BP at different tested doses. The inclusion of these BP in the ration, from 5% up to 40% of dry matter (DM), did not depress milk yield, fat, or protein production, demonstrating positive features in terms of both economic and environmental sustainability and the reduction of human-animal competition for food. The general improvement of the nutritional quality of milk fat related to the inclusion of these BP in dairy ruminant diets is an important advantage for the commercial promotion of dairy products resulting from the recycling of agro-industrial by-products.

The protective effect of aqueous orange peel extract against severe heat stress on reproductive efficiency, milk yield, and antioxidant status of female rabbits

Heat stress in rabbits negatively affects their reproductive ability and milk yield. Aqueous orange peel extract (AOPE) is high in potential natural antioxidants that help avoid free radical damage and is a good source of phytochemicals. Based on these benefits, it was hypothesized that oral administration of AOPE could overcome the negative impacts of severe heat stress on reproductive and lactation performance, physiological parameters, and antioxidant status. To determine the protective effect of AOPE, 36 female rabbits (six-months-old, average body weight of 2.67 ± 0.03 kg) were given 1.50 mL water (control), and 2.50 or 5.00 mL AOPE every two days for four months. Oral AOPE administration significantly reduced the respiration rate (RR) and rectal temperature (RT) during pregnancy and lactation. The reproductive performance (litter size) and productive performance (litter weight and litter weight gain) were significantly increased by AOPE treatment, compared with the control. The highest milk yield was recorded in 5.00 mL AOPE treatment (5.00 mL). AOPE treatments significantly increased serum superoxide dismutase (SOD) and catalase (CAT), and AOPE treatment (5.00 mL) lowered serum thiobarbituric acid reactive substances (TBARs) of heat-stressed rabbits. Serum total antioxidant capacity (TAC) was not affected by AOPE treatment. The addition of AOPE improved reproductive performance, physiological parameters, and antioxidant status, but did not have a beneficial effect on conception rate of female rabbits under severe heat stress.

Effect of different dietary inclusion levels of whole plant green tomato (Physalis philadelphica) silage on nutrient intake and digestibility, and in vitro rumen fermentation kinetics in sheep

Mexico has many agricultural by-products that can be used for animal feed, and green tomatoes are produced throughout the country and can be an alternative to overcome the high prices of cereal-based feeds. This study determined in vitro fermentation kinetics, production performance, nutrient intake, digestibility, and nitrogen balance from sheep supplemented with whole plant green tomato (GT) on corn silage (CS) based diets. For 21 days, eighteen Suffolk lambs (38 ± 4 kg of live weight) were grouped into three dietary GT inclusion levels to replace CS: a control diet based on 100% CS (GT0, 570 g /kg dry matter, DM), while 100 g/kg DM (GT100) and 200 g/kg DM (GT200) of GT were included as a replacement for CS. A completely randomized design was used to measure in vitro gas production, in vitro rumen fermentation, chemical composition, and in vivo parameters. In vitro gas production, “A” (ml/g DM), fermentation rates “B,” (h⁻¹), and “C” (h^−½), were lower for GT200, while DM disappearance (mg/100mg) was lower for GT100 compared with GT0. Compared to GT0, GT100 and GT200 did not affect (P > 0.05) DM and organic matter (OM) intake (g/kg^LW0.75). Ether extract intake was higher for GT0 and GT100 (P < 0.001) compared to GT200. Neutral detergent fiber (NDF) intake was higher (P < 0.05) for GT200 compared with GT0. Intake of lignin was higher (P < 0.001) for GT200 than that of GT0 and GT100. Digestibility coefficients for DM, OM, NDF, and Acid detergent fiber (ADF) were lower (P < 0.05) in GT100 than in the rest of the treatments. Nitrogen intake and N excreted in feces and urine were lower (P < 0.001) for GT0. N balance was negative for all treatments, being higher for GT200 (P < 0.05). Overall, the addition of GT at 100 or 200 g/kg DM in sheep diets negatively affects nutrient digestibility and N balance, so their dietary inclusion is not recommended.

Combining Grape Byproducts to Maximise Biological Activity of Polyphenols in Chickens

Simple Summary

Grape byproducts (grape pomace, seeds and skins) contain a wide range of phenolic compounds with antioxidant properties and thus can become functional ingredients in animal feeds. The dietary inclusion of grape pomace in chicken diets has been shown to increase plasma and meat α-tocopherol content and to mitigate meat lipid oxidation. However, the separate inclusion of the main components of grape pomace (grape seeds and skins) in the diet of chickens has been less studied. In the present research work, the dietary inclusion of grape byproducts did not compromise the growth of chickens nor did it affect ileal protein digestibility. Concerning plasma and meat α-tocopherol concentrations and meat lipid oxidation, the dietary combination of grape seeds and skins provided better results than the individual inclusion of these grape byproducts. Actually, combinations with a proportion of at least 50% of grape skins enabled optimal results of meat oxidative stability.

Abstract

Grape seeds (GS) and grape skins (GK) are natural sources of polyphenols with antioxidant capacity. An experiment was conducted to investigate in chickens the effect of including GS and GK (40 g/kg), individually or combined in different proportions (20 g/kg GS–20 g/kg GK; 30 g/kg GS–10 g/kg GK; 10 g/kg GS–30 g/kg GK), in a corn-soybean diet on growth performance, ileal and excreta contents of total extractable polyphenols (TEP) and tannins, ileal digestibility of protein, plasma and meat α-tocopherol concentration and lipid oxidation (assessed by measuring the thiobarbituric acid reactive substances, TBARS) of stored thigh meat. Neither growth performance parameters nor ileal digestibility of protein were affected by dietary treatments. As compared with control birds, chickens fed the grape byproduct diets showed higher ileal (p < 0.001) and excreta (p < 0.001) TEP and tannins contents. Dietary inclusion of grape byproducts increased α-tocopherol concentration both in plasma (p < 0.001) and in thigh meat (p < 0.01 at 1 d; p < 0.001 at 7 d), as compared with the control group. The highest plasma α-tocopherol concentrations were reached with the 30 g/kg GS–10 g/kg GK and 20 g/kg GS–20 g/kg GK combinations. On day 1 of meat storage, no differences on meat α-tocopherol concentration were found among the grape byproducts treatments but on day 7 of storage, the 20 g/kg GS–20 g/kg GK and 10 g/kg GS–30 g/kg GK combinations led to the highest α-tocopherol concentrations in chicken thigh meat. After seven days of refrigerated storage of meat, the TBARS value was lower in chickens fed the grape byproducts diets than in control birds (1.27 vs. 2.49 mg MDA/kg, p < 0.001). Moreover, among the different grape byproduct treatments, the lowest MDA values were reached with the diets containing GK at rates from 20 to 40 g/kg. In conclusion, dietary incorporation of 40 g/kg of GS and GK added separately or combined increased the plasma and meat α-tocopherol content. Furthermore, the combinations of GS and GK with a proportion of GK of at least 50% optimised α-tocopherol concentration both in plasma and in thigh meat and mitigated lipid oxidation in 7-day stored meat.

Replacing Soybean Meal with Distillers Dried Grains with Solubles plus Rumen-Protected Lysine and Methionine: Effects on Growth Performance, Nutrients Digestion, Rumen Fermentation, and Serum Parameters in Hu Sheep

Simple Summary

Improving the economic benefits and precise nutrient supply are hotspots of the sheep breeding industry. Evaluation of the production performance, the rumen fermentation, and blood metabolism indexes found that replacement of soybean meal with distillers dried grains with solubles in a diet with adequate metabolizable protein and amino acids (lysine and methionine) could maintain the normal growth performance of Hu sheep. The comprehensive evaluation results provide a reference for reducing production costs, improving production efficiency, and decreasing the nitrogen excretion of the sheep breeding industry. Besides, the study will help in the development of low-protein diets with amino acid balance for sheep.

Abstract

(1) Background: we investigated the influence of dietary soybean meal (SBM) replaced with distillers dried grains with solubles (DDGS) plus rumen-protected (RP) lysine and methionine on the growth performance, nutrients digestion, rumen fermentation, and serum parameters of Hu sheep. (2) Methods: ninety Hu sheep were allocated to five groups: the control group (CON) which received the SBM diet, the DDGS group (NSM), the DDGS diet with RP lysine group (DRPL), the DDGS diet with RP methionine group (DRPM), and the DDGS diet with a mixture of RP lysine and methionine group (DRPLM). (3) Results: Final BW and carcass weight of the DRPLM and CON groups were greater (p ≤ 0.05) compared to NSM, DRPL, and DRPM groups. The DRPLM group tended to increase the dry matter intake (DMI, p = 0.06), average daily gain (ADG, p = 0.06), dressing percentage (p = 0.07), and tail fat weight (p = 0.09). The DRPLM group had increased (p ≤ 0.05) apparent digestibility and had altered ruminal fermentation characteristics. (4) Conclusions: replacement of SBM with DDGS in a diet with adequate metabolizable protein and by-pass amino acids (lysine and methionine) could maintain the growth performance of Hu sheep.

Dietary Supplementation of Two-Stage Fermented Feather-Soybean Meal Product on Growth Performance and Immunity in Finishing Pigs

Simple Summary

Feathers contain around 90% of keratin which compose of unbalanced amino acids with low digestibility and limiting the usage in monogastric animal diets. To improve the nutrient value of feather through fermentation using keratinase-producing microbes pose a high economic potential. This study investigates the effects of two-stage fermented feather-soybean meal product (TSFP) on growth performance, blood characteristics, and immunity of finishing pigs. In growth performance, 2.5–5% TSFP promotes the average daily feed intake and feed conversion rate with a best performance of 5%. In blood characteristics, 5% TSFP increased HDL-C, and decreased LDL-C and blood urea nitrogen content. In immunity, 5% TSFP increased lymphoblastogenesis stimulated by lipopolysaccharide and concanavalin A, and promoting IFN-γ, IgA productions, and phagocytic cells oxygen burst capacity. It appears that TSFP improves the growth performance and immunity of finishing pigs.

Abstract

This study investigates the effects of two-stage fermented feather meal-soybean meal product (TSFP) on growth performance, blood characteristics, and immunity of finishing pigs. Firstly, feather meal-soybean meal is subjected to aerobic fermentation with Bacillus subtilis var. natto N21, B. subtilis Da2 and Da15, B. amyloliquefaciens Da6, Da16 for two days, and anaerobic fermentation with B. coagulans L12 for three days. Then, the fermented product is air-dried into an end product—TSFP. Eighty hybrid pigs (Duroc x KHAPS) with equal numbers of both sexes are randomly assigned into 3% fish meal, 0%, 2.5%, or 5.0% TSFP groups with five replicates per group. Our results show that the average daily feed intake and feed conversion rate of TSFP groups are significantly better than the other groups at 0–3 weeks (p < 0.05). The 5% TSFP group significantly increased HDL-C in the blood (p < 0.05), and decreased LDL-C and blood urea nitrogen content (p < 0.05). The lipopolysaccharide (LPS) and concanavalin A (ConA) in 5% TSFP group and interferon-γ (IFN-γ) content in 2.5% and 5% TSFP groups are significantly higher than the other groups (p < 0.05). The phagocytic oxygen burst capacity and serum IgA content of the 5% TSFP group are significantly higher than those of the fishmeal group (p < 0.05). The CD3, CD4, and CD4 + CD8 + T cells subsets in 2.5% and 5% TSFP groups are significantly higher than the control group (p < 0.05). In conclusion, TSFP has a positive effect on the growth performance and immunity of finishing pigs with the best performance on 5% TSFP.

Dietary Polyphenol Supplementation in Food Producing Animals: Effects on the Quality of Derived Products

Simple Summary

Polyphenols are secondary plant metabolites mainly known for their antioxidant properties. Their use as feed additives in the nutrition of farm animals is becoming increasingly popular as they are particularly exposed to oxidative stress which is reflected in a lipoperoxidation of the final product. For this reason, it is essential to preserve the quality and the safety of meat and milk products by attenuating oxidative deterioration. Moreover, polyphenols present the advantage of being more acceptable to the consumers than synthetic counterparts, as they are considered to be “non-toxic”. The present review presents an overview of several studies focused on the dietary supplementation of polyphenols to monogastric and ruminants, as well as their direct addition to meat and dairy products, with particular emphasis on their antioxidant effects on the final product.

Abstract

The growing interest in producing healthier animal products with a higher ratio of polyunsaturated to saturated fatty acids, is associated with an increase in lipoperoxidation. For this reason, it is essential to attenuate oxidative deterioration in the derived products. Natural antioxidants such as polyphenols represent a good candidate in this respect. The first part of the review highlights the occurrence, bioavailability, and the role of polyphenols in food-producing animals that, especially in intensive systems, are exposed to stressful situations in which oxidation plays a crucial role. The second part offers an overview of the effects of polyphenols either supplemented to the diet of monogastric and ruminants or added directly to meat and dairy products on the physicochemical and sensorial properties of the product. From this review emerges that polyphenols play an important, though not always clear, role in the quality of meat and meat products, milk and dairy products. It cannot be ruled out that different compounds or amounts of polyphenols may lead to different results. However, the inclusion of agro-industrial by-products rich in polyphenols, in animal feed, represents an innovative and alternative source of antioxidants as well as being useful in reducing environmental and economic impact.

Polyphenols in Farm Animals: Source of Reproductive Gain or Waste?

Reproduction is a complex process that is substantially affected by environmental cues, specifically feed/diet and its components. Farm animals as herbivorous animals are exposed to a large amount of polyphenols present in their natural feeding system, in alternative feed resources (shrubs, trees, and agro-industrial byproducts), and in polyphenol-enriched additives. Such exposure has increased because of the well-known antioxidant properties of polyphenols. However, to date, the argumentation around the impacts of polyphenols on reproductive events is debatable. Accordingly, the intensive inclusion of polyphenols in the diets of breeding animals and in media for assisted reproductive techniques needs further investigation, avoiding any source of reproductive waste and achieving maximum benefits. This review illustrates recent findings connecting dietary polyphenols consumption from different sources (conventional and unconventional feeds) with the reproductive performance of farm animals, underpinned by the findings of in vitro studies in this field. This update will help in formulating proper diets, optimizing the introduction of new plant species, and feed additives for improving reproductive function, avoiding possible reproductive wastes and maximizing possible benefits.

Composition, Mineral and Fatty Acid Profiles of Milk from Goats Fed with Different Proportions of Broccoli and Artichoke Plant By-Products

In the Mediterranean region, artichoke and broccoli are major crops with a high amount of by-products that can be used as alternative feedstuffs for ruminants, lowering feed costs and enhancing milk sustainability while reducing the environmental impact of dairy production. However, nutritional quality of milk needs to be assured under these production conditions and an optimal inclusion ratio of silages should be determined. This work aimed to evaluate the effect of three inclusion levels (25%, 40%, and 60%) of these silages (artichoke plant, AP, and broccoli by-product, BB) in goat diets on milk yield, composition, and mineral and fatty profiles. Treatments with 60% inclusion of AP and BB presented the lowest milk yield. No differences were found on the milk mineral profile. Inclusion of AP in the animals' diet improved the milk lipid profile from the point of view of human health (AI, TI) compared to BB due to a lower saturated fatty acid content (C12:0, C14:0, and C16:0) and a higher concentration of polyunsaturated fatty acids (PUFA), especially vaccenic acid (C18:1 trans11) and rumenic acid (CLA cis9, trans11), without any differences with the control treatment.

Short-Term Effect of the Inclusion of Silage Artichoke By-Products in Diets of Dairy Goats on Milk Quality

Simple Summary

The use of artichoke by-products, both from the canning industry or from the stubble that remains in the field, provides a cheaper source of nutrients, suitable for ruminant feeding due to their ability to digest fibre-rich foods. The use of these by-products for animal feed is also a way to reduce waste caused by the canning industry and disposal costs, as well as the area and resources allocated to the production of food for livestock, contributing to the circular economy. Evaluating the effect of the inclusion of silage artichoke by-products (bracts and rest of crop plant) in dairy goat rations on the milk yield and composition, animal health status, mineral and lipid profile is an effective way to explore the suitability of these alternative feedstuffs for goat cattle. The use of artichoke bracts and whole plant silage in dairy goat diets does not lead to marked differences in the milk yield and quality or the animals’ health status. From a nutritional point of view for human health, slightly better mineral and lipid profiles are observed in milk from goats fed artichoke plant silage, due to its higher polyunsaturated fatty acids and conjugated linoleic acid contents.

Abstract

Artichoke by-products represent a high amount of waste whose removal entails several costs. Moreover, feed is the main cost in a farm. So, including these by-products in ruminant diets would lower feed costs. Two experiments were conducted to evaluate the effect of two levels of inclusion, 12.5% and 25.0%, of two silages of artichoke by-products (artichoke bracts, AB and artichoke plant, AP) in the diet of goats on the milk yield, composition and quality and on the metabolic profile of the animals. AB presented the lowest blood urea content and there were no differences in milk yield in the two experiments. However, with 25.0% of silage by-product in the diet, a higher fat content was observed in AB and of protein in AP, as well as this treatment showing a slightly higher Se content. Regarding the milk lipid profile, milk from 12.5% of AP treatment presented a higher PUFA content. In conclusion, the use of silage artichoke by-products in dairy goat diets does not jeopardise milk yield and quality and health status of animals and, from a nutritional point of view for human health, a slightly better mineral and lipid profile is observed in milk from AP treatments.

Supplementation of by-products from grape, tomato and myrtle affects antioxidant status of dairy ewes and milk fatty acid profile

The aim of this study was to evaluate the effect of diets containing different dried by-products on milk and blood plasma antioxidant capacity of dairy ewes. Thirty-six Sarda ewes were assigned to four treatments: control (CON; no by-product), 100 g/day of grape marc (GM), 100 g/day tomato pomace (TP) and 75 g/day of exhausted myrtle berries (EMBs). The superoxide dismutase (SOD), glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GSH-Px) in blood, and SOD, GR and lactoperoxidase (LPO) in milk were determined. Total antioxidant capacity (FRAP and ABTS assays), malondialdehyde (MDA) and protein carbonyls (PCs) were also measured. Milk fatty acid profile was investigated by gas chromatography. The results showed higher antioxidant capacity measured by FRAP or ABTS assays and a reduction in MDA in GM plasma than CON. All by-products enhanced the protection of milk proteins by oxidation, as evidenced by lower values of PCs compared with CON. GM supplementation increased PUFAn-6, due to increase in C18:2n-6, the main component of GM compared with CON. All by-products did not modify the nutritional indexes of milk fat. In conclusion, dietary GM may enhance protection against oxidative condition of dairy ewes, whereas TP and EMB need further research to define the optimum inclusion level in sheep diet.

Can Agro-Industrial By-Products Rich in Polyphenols be Advantageously Used in the Feeding and Nutrition of Dairy Small Ruminants?

Simple Summary

In the Mediterranean area, where dairy sheep and goats are widespread, the use of by-products in the diet of small ruminants is an ancient practice. Today the great availability of industrial by-products produced at the local level (e.g., grape, olive, tomato and myrtle residues), appears to be a promising strategy for reducing competition with human edible foods and the cost of off-farm produced feeds since they are imported worldwide. Moreover, these co-feeds can contribute to reducing the ecological and water footprint associated with crop cultivation. The presence of bioactive compounds, such as polyphenols, confers added value to these materials. Several positive aspects are apparent when such by-products are included in the diets of small dairy ruminants, in particular on ruminal metabolism, animal health, and the quality of derived products.

Abstract

Recently, the interest in industrial by-products produced at the local level in Mediterranean areas, resulting from fruit and vegetable processes, has increased because of their considerable amounts of bioactive compounds, including polyphenols. In this review, we analyze the most recent scientific results concerning the use of agro-industrial by-products, naturally rich in polyphenols (BPRP), in the diets of small dairy ruminants. Effects on milk production, milk and rumen liquor fatty acid profile, metabolic parameters, and methane production are reviewed. The feed intake and digestibility coefficients were generally depressed by BPRP, even though they were not always reflected in the milk yield. The main observed positive effects of BPRP were on quality of the milk’s FA profile, antioxidant activity in milk and blood, a reduction of rumen ammonia, and, consequently, a reduction of milk and blood urea. The expected beneficial effects of dietary polyphenols in small ruminants were not always observed because of their complex and variable matrices. However, owing to the large quantities of these products available at low prices, the use of BPRB in small ruminant nutrition offers a convenient solution to the valorization of residues arising from agricultural activities, reducing feed costs for farmers and conferring added value to dairy products at the local level, in a sustainable way.

Myrtus communis Liquor Byproduct as a Source of Bioactive Compounds

The fatty acid (FA), polyphenol content and evaluation of the antioxidant capacity of exhausted Myrtus communis berries (EMB) resulting from the production of myrtle liqueur were assessed. All parts of the exhausted berries exhibited high concentrations of carbohydrates, proteins, lipids and phenolic compounds. The lipid fraction contained a high amount of poly unsaturated fatty acids (PUFA), mainly represented by linoleic acid (>70%). Of the phenolic acids evaluated by liquid chromatography/mass spectrometry, ellagic acid was the most predominant (>50%), followed by gallic and quinic acids. Quercetin and quercetin3-O-rhamnoside were the most abundant flavonoids. The seed extracts showed a higher antioxidant potential than the pericarp extracts; the same trend was observed for total phenolic compounds evaluated by spectrophotometric assay. The overall high content of bioactive compounds and the high antioxidant potential of this byproduct sustain its suitability for a number of industrial applications, such as a food ingredient in novel foods, an additive in cosmetic formulations or a component of animal feed formulations.