The feasibility of partial replacement of berseem hay by spent mushroom (Pleurotus osteratus) substrate in rabbit diets on growth performance, digestibility, caecum fermentation, and economic efficiency.

Nowadays, agricultural by-product disposal is a major concern. The mushroom by-products could be used as an alternative feed source in rabbit diets. Therefore, partial replacement of berseem hay (BH) with spent mushroom substrate (SMS) was conducted in four experimental groups as follows: 0, 20, 40, and 60% of SMS. Forty weaned New Zealand White (NZW) rabbits at 6th weeks of age with an initial body weight of 520.25 ± 70.01 g were fed the experimental diet for 8 weeks. The results showed that ash content and cell wall constituents in SMS were higher than in BH, while the other nutrient compounds in SMS were lower than in BH. Dietary SMS at a level of 60% increased the final body weight (p = 0.05) and feed conversion ratio (p ≤ 0.05). However, average daily gain and total feed intake were not affected by treatments. The replacement of SMS at levels of 40 and 60% significantly improved nutrient digestibility and total digestible nutrient value. SMS 60% decreased (p = 0.040) faecal N and improved (p = 0.006) retained nitrogen. The SMS replacement increased caecum length (p = 0.001), and full and empty caecum weight (p = 0.001 and 0.021, respectively) compared to the control. The SMS inclusion caused a decrease (p = 0.021 and 0.007) in the pH and NH3-N concentrations, respectively. Total VFA, acetic acid, butyric acid, and propionic acid proportions increased with the dietary inclusion of SMS in a level-dependent manner. Using SMS as a replacement for BH in growing rabbit diets reduced the total feed cost, and consequently improved net revenue, economic efficiency, and relative economic efficiency.

Counteract severe heat stress by including different forms of zinc in the rabbit bucks' diet.

The harmful influences of global warming on rabbit reproduction and industry attract global attention. Zinc (Zn) is an important trace element with a wide list of functions in the male reproductive system. The aim of this study was to estimate the effects of different forms of zinc supplementation, as organic (Zn methionine), nano (nano Zn oxide) as indirect way to minimized it impact on environment, and inorganic (Zn sulphate) on physiological parameters, semen quality, anti-oxidative status, hormonal profiles of male rabbits subjected to server heat stress. Thirty-six V-line bucks (6-7 months old, 2842.29 ± 34.46 g weight) were randomly distributed to 4 groups, bucks in 1st group (control group, Con) fed basal diet without Zn supplementation, the 2nd, 3rd and 4th groups fed basial diet with 30 mg/kg of zinc methionine (Zn-Met), nano zinc oxide (ZnO-NPs), and zinc sulphate (Zn-S), respectively for a period of 10 weeks suffered from severe heat stress of environmental ambient temperature (over 32 of temperature humidity index, THI). Semen samples were collected and evaluated for volume, pH, motility, concentration, viability, initial fructose, and seminal plasma antioxidant concentration. Liver, kidney function, hormonal and antioxidant profile were measured in blood serum. The results revealed that, compared to control, all forms of Zn supplementation used significantly improved kidney function (creatinine), serum antioxidant (SOD and CAT), physiological parameters, especially on 1st month of the experiment, and seminal plasma antioxidant (SOD and CAT) of heat stressed bucks. Likewise, semen quality in terms of sperm concentration, sperm viability, and initial fructose enhanced significantly (P ≤ 0.05) by ZnO-NPs supplementation. Zinc methionine supplementation significantly improved liver function and decreased seminal plasma TBARs. Treatments with Zn-Met and ZnO-NPs increased seminal TAC and blood testosterone levels with reduced blood cortisol levels compared to other groups. Severe heat stress could be counteract by inclusion Zn with studied forms Zn-Met and ZnO-NPs at recommended dose (30 mg/kg diet) to improve semen quality and antioxidant status.

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.

Identification, Biochemical Characterization, and Safety Attributes of Locally Isolated Lactobacillus fermentum from Bubalus bubalis (buffalo) Milk as a Probiotic.

The demand of functional foods is on the rise, and researchers are trying to develop nutritious dairy products by using well-characterized strains of bacteria. In this study, we identified locally isolated strains of Lactobacillus fermentum from Bubalus bubalis (Nilli Ravi buffalo) milk and evaluated their potential as probiotics in food products like fermented milk. Fifteen Lactobacillus strains were initially isolated, and only four strains (NMCC-2, NMCC-14, NMCC-17, and NMCC-27) were examined for morphological and biochemical characterizations due to their ability of gas production in Durham tubes. Moreover, these strains were selected for further probiotic characterizations due to their extreme morphological resemblance with lactic acid bacteria for their antimicrobial activity, enzymatic potential, autoaggregation capability, hydrophobicity, and acid and bile tolerance. All selected isolates showed significant probiotic potential. However, NMCC-14 and NMCC-17 strains showed maximum probiotic potential. The isolates (NMCC-2, NMCC-14, NMCC-17, and NMCC-27) were identified as Lactobacillus fermentum utilizing 16S rRNA gene sequencing. The in vivo safety study of NMCC-14 (dose: 1010 CFU/day/mice; 21 days, orally) showed no histological dysfunctions in a mouse model. Pathogenic bacterial enzymes reduced the beneficial bacterial load in the host gastrointestinal tract. These results suggest that the NMCC-14 strain is safe and can be potentially used as a probiotic. Moreover, fermented milk was prepared by using the NMCC-14 strain. The results revealed that NMCC-14 strain-based fermented milk had significantly (p < 0.05) higher protein content (4.4 ± 0.06), water-holding capacity (WHC), and dynamic viscosity as compared to non-fermented milk. The results suggest that L. fermentum NMCC-14 is safe and nontoxic; hence, it can be a beneficial supplement to be used for the development of dairy products to be subjected to further clinical testing.

Effect of Dietary Rosemary and Ginger Essential Oils on the Growth Performance, Feed Utilization, Meat Nutritive Value, Blood Biochemicals, and Redox Status of Growing NZW Rabbits.

This study was conducted to assess the impacts of using two essential oils, rosemary and ginger, on growing rabbits' performance, carcass traits, meat composition, blood biochemicals, and the redox status of growing New Zealand White (NZW) rabbits. A total of 120 unsexed NZW rabbits, 42-days-old, were assigned randomly to five experimental groups (n = 24, 6 replicates with 4 rabbits each). The first group received a basal diet (control), the second to fifth groups were dietary supplemented daily with rosemary essential oil (REO) and ginger essential oil (GEO) at doses of 0.25 and 0.5% for each supplementation (REO-0.25, REO-0.5, GEO-0.25, and GEO-0.5), respectively. The growth traits were studied for 7 weeks, from the 7th to the 13th week of the rabbits' age. The results revealed that final body weight, weight gain, and average daily gain increased significantly (p < 0.01) in the REO-0.5 and GEO-0.5 treatments compared to the control group. Daily feed intake decreased (p = 0.005) in essential oil treatments. Meanwhile, the feed conversion ratio improved significantly (p = 0.001) in REO and GEO at the high doses compared to the control group. The weight percentages of liver and giblets increased (p < 0.001) with both treatments of REO and GEO compared to the control group. The dietary supplementation with REO and GEO did not affect (p > 0.05) the meat composition of Longissimus dorsi and hind leg muscles. Meanwhile, REO and GEO supplementation significantly decreased cholesterol levels in the rabbit meat. Thiobarbituric acid reactive substance concentrations decreased by 10 and 15% in the meat of REO-0.5 and GEO-0.5 treatments, respectively, compared to the other groups. In the same trend, REO and GEO treatments induced a significant (p = 0.001) reduction in the plasma cholesterol concentrations and triglycerides compared to the control. The total antioxidant capacity increased by 7.60% and the malondialdehyde decreased by 11.64% in the plasma of GEO-0.5 treatment than the control. Thus, the dietary supplementation of REO and GEO have a beneficial effect in improving the productivity and meat quality of growing rabbits.