Effect of Olive Cake and Cactus Cladodes Incorporation in Goat Kids’ Diet on the Rumen Microbial Community Profile and Meat Fatty Acid Composition

The olive cake (OC) and the cactus cladodes (CC) are two alternative feed resources widely available in the southern Mediterranean region that could be used in ruminants’ diet. Their impact on the rumen bacterial ecosystem is unknown. This work aims to evaluate their effects on the microbial community and meat fatty acids of goat’s kids. Forty-four goat kids were divided into four groups receiving diets with conventional concentrate, or 35% OC, or 30% CC, or 15% OC, and 15% CC. After 3 months, these animals were slaughtered, and the rumen liquor and longissimus dorsi and semimembranosus muscles samples were collected. Animals receiving a control diet had rumen liquor with high acidity than test groups (p < 0.001). Test rumen liquor was more adapted to digest efficiently their matching diet than control liquor (p < 0.05). These feedstuffs did not affect rumen bacteria abundance and alpha diversity (richness, evenness, and reciprocal Simpson indexes), and these results were confirmed by beta-diversity tests (NMDS plot, HOMOVA, PERMANOVA). The test diets slightly affected the individual fatty acids of meat (p < 0.05) without effect on fatty acids summaries, indexes, and ratios. Thus, these alternative feed resources could take place in goat kids’ diet to diversify their feed and to reduce feed costs.

Rumen bacterial community profile and fermentation in Barki sheep fed olive cake and date palm byproducts

Rumen bacteria make the greatest contribution to rumen fermentation that enables the host animal to utilize the ingested feeds. Agro-industrial byproducts (AIP) such as olive cake (OC) and date palm byproducts (discarded dates (DD), and date palm fronds (DPF)) represent a practical solution to the deficiency in common feed resources. In this study, thirty-six growing Barki lambs were divided into three groups to evaluate the effect of untraditional diets including the AIP on the growth performance. Subsequently, nine adult Barki rams were used to evaluate the effect of experimental diets on rumen fermentation and rumen bacteria. Three rations were used: common concentrate mixture (S1), common untraditional concentrate mixture including OC and DD (S2), and the same concentrate mixture in S2 supplemented with roughage as DPF enriched with 15% molasses (S3). The animals in S2 group showed higher dry matter intake (DMI) and lower relative growth rate (RGR) as compared to the animals in S1 group. However, the animals in S3 group were the lowest in DMI but achieved RGR by about 87.6% of that in the S1 group. Rumen pH, acetic and butyric acids were more prevalent in animals of S3 group and rumen ammonia (NH3-N), total volatile fatty acids (TVFA), propionic acid were higher in S1. Rumen enzymes activities were higher in S1 group followed by S3 and S2. The bacterial population was more prevalent in S1 and microbial diversity was higher in the S3 group. Principal coordinate analysis revealed clusters associated with diet type and the relative abundance of bacteria varied between sheep groups. The bacterial community was dominated by phylum Bacteroidetes and Firmicutes; whereas, Prevotella, Ruminococcus, and Butyrivibrio were the dominant genera. Results indicate that diet S3 supplemented by OC, DD, and DPF could replace the conventional feed mixture.

Preparation of Activated Carbon Derived from Jordanian Olive Cake and Functionalized with Cu/Cu2O/CuO for Adsorption of Phenolic Compounds from Olive Mill Wastewater

Olive oil production generates solid and liquid wastes that cause various environmental problems due to their high phenols and polyphenols load. Although many treatment methods were investigated to manage these wastes, more research is still needed to identify simple and cost-effective approaches. In this study, activated carbon (AC) was prepared from olive cake waste and functionalized with Cu/Cu2O/CuO for efficient and selective removal of phenolic content from olive mill wastewater (OMW). AC media were characterized by scanning electron/dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectrometry, and Brunauer–Emmett–Teller (BET) surface area analysis. The optimum adsorption parameters were investigated, and the adsorption isotherms, thermodynamics, and kinetics were determined. The adsorption of phenols onto copper oxide AC was best described by the Langmuir adsorption with maximum adsorption capacity of 13.9, 12.7, and 9.9 mg/g at 311, 302, and 293 K, respectively. The adsorption reaction was found to be spontaneous and endothermic where ∆H° and ∆G° were found to be 30.104 kJ/mol and −1.765, −2.839, and −3.723 (kJ/mol) at 311, 302, and 293 K, respectively. In addition, the kinetics data were perfectly fit by the pseudo-second-order model. The activated product derived from recyclable olive cake and enriched with inorganic functionality can offer a cost-effective treatment solution for OMW; thus, reducing both the liquid and solid waste generated from the olive mill industry.

Effect of Exhausted Olive Cake Contamination on Fly and Bottom Ash in Power Plants

With the aim to prevent possible power plant malfunction due to the feedstock properties and suggest possible ash applications, feedstock samples and bottom and fly ash samples collected along more than a year in a 16 MW suspension-fired boiler power plant, fed mainly with pulverized exhausted olive cake (orujillo), were studied. A detailed characterization of fly and bottom ash has been done, as well as a seasonal evolution study. Altogether in order to find any trend on the ash composition changes and to study the relationship between ash (both fly and bottom fractions) and, on the one hand, the feedstock composition, and on the other hand, the troublesome deposit formation. A relationship between deposit growth and higher Cl and Na content in the feedstock has been noticed, showing the need for some control on these feedstock’s components. The high Cl and Na content is attributed to external contamination. Furthermore, the high Al content in the feedstock and the strong relationship between Al, Fe and Si (indicating a common origin) suggest some biomass soil contamination. However, no relationship was observed between troublesome deposit formation and the hypothesized biomass soil contamination. Graphic Abstract

Effects of Replacing Yellow Corn with Olive Cake Meal on Growth Performance, Plasma Lipid Profile, and Muscle Fatty Acid Content in Broilers

The current study focused exclusively on evaluating the effects of replacing corn with olive cake meal (OCM) in the diet of broilers on their growth performance, abdominal fat, selected plasma parameters, and muscle fatty acid (FA) content. A total of 480 one-day-old male broiler chickens (Ross 308) were divided into four treatment groups with 12 replicates/treatment. The control group was fed the base diet, whereas the second to fourth groups were fed diets of corn with 5%, 10%, and 20% contents of OCM, respectively. Broilers fed with the 5% and 10% OCM diets showed better body weight (p = 0.04) and feed conversion ratio than the 20% OCM group (p < 0.048). Both nitrogen retention and ether extract digestibility were not improved by replaced corn with OCM. Replacing corn with OCM led to a decreased abdominal fat percentage (p = 0.023) compared with the control group. Birds in the OCM groups showed the lowest total cholesterol values (p = 0.038). The breast muscle (musculus pectoralis superficialis) content of oleic and linoleic, linolenic, and arachidonic acids was significantly high in birds fed with OCM diets. However, their palmitic acid level was significantly decreased. Vitamin E was increased by increasing the OCM level. Thus, we concluded that replacing corn with OCM, especially at a 10% level, is more effective than other replacement levels in improving growth performance, plasma lipid profile, and muscle FA content, as well as in causing a reduction in abdominal fat in broilers.

The Effects of Dietary Olive Cake Meal on Fattening Performance, Carcass and Slaughter Traits in Japanese Quails (Coturnix coturnix japonica)

This study was aimed at investigating the effects of dietary supplementation with different levels of olive cake meal (0%, 2.5%, 5% and 7.5%) on the fattening performance and slaughter and carcass traits of quails. For this purpose, 400 one-day-old Japanese quail chicks were randomly assigned to 4 groups, each with 5 replicates. The quails were fed on either a basal diet alone (Control Group) or a basal diet supplemented with olive cake meal at rates of 2.5% (Group I), 5% (Group II) and 7.5% (Group III) for a period of 42 days. At the end of the fattening period, dietary olive cake meal was observed not to have caused any adverse effect on body weight, feed intake and feed conversion rate. Eviscerated hot carcass weight, eviscerated cold carcass weight, wing weight, breast weight, thigh weight and edible visceral organ weights were determined to have improved in the treatment groups that received dietary olive cake meal, when compared to the control group. In conclusion, dietary supplementation with olive cake meal, a waste product of the olive oil industry, at a level of 5%, was observed to produce the closest and most similar results to those of feeding on the basal diet. Thus, it is suggested that olive cake meal could be used as an alternative feedstuff for poultry. Furthermore, the use of olive cake meal as an alternative feedstuff would contribute to reducing both feed costs and environmental pollution.