Growth Performance Research Articles

Effects of naked neck and frizzle genes on growth and egg-laying performance of chickens in the tropics in an era of climate change.

In regions characterized by tropical and subtropical climates, the elevated ambient temperatures exert adverse effects on both broiler and laying chickens, impacting their growth and egg production performance. To mitigate the challenges posed by heat stress, genetic strategies aimed at reducing feather coverage have gained prominence in hot climate areas. Among these approaches, the naked neck (Na) and frizzle (F) genes have emerged as particularly noteworthy. The Na and F genes play a pivotal role in facilitating heat dissipation and temperature regulation. By decreasing feather insulation, these genes enable efficient heat dissipation through exposed areas of the chickens' bodies. This reduction in feather coverage leads to elevated body surface temperature, which, in turn, enhances the capacity for heat loss and contributes to overall body temperature reduction. A substantial body of literature underscores the well-established positive impacts of the naked neck and frizzle genes on growth and egg-laying performance. As a result, these genes hold significant potential for integration into broiler and layer production systems, especially in regions characterized by high tropical temperatures. In the context of broiler farming under challenging heat conditions, the Na and F genes have demonstrated favorable effects on crucial parameters such as feed conversion ratio, body weight gain, disease resistance, and carcass attributes. Likewise, layers exposed to elevated temperatures exhibit enhanced egg production, eggshell quality, fertility, hatchability, and resistance to diseases when these genesare incorporated. Given that the prevalence of the naked neck and frizzle genes is primarily observed in indigenous chicken populations, it becomes imperative to prioritize measures for their conservation due to their exceptional performance in heat-stressed environments. To unlock the full genetic potential of exotic poultry reared in hot and humid conditions, the integration of the Na and F genes is a strongly recommended strategy.

Supplementation of Enzymatic Hydrolysate in Low-Fishmeal and Low-Crop Diet Improves Growth, Antioxidant Capacity, and Immunity of Juvenile Sea Cucumber Apostichopus japonicus (Selenka)

As the global demand for aquafeed ingredients continues to rise, sourcing sustainable alternatives is crucial for aquaculture industries. This study aimed to explore the potential of enzymatic hydrolysate as a substitute for traditional fishmeal and soybean meal in diets for juvenile sea cucumbers (Apostichopus japonicus). Three isonitrogenous (15% crude protein) and isolipidic (2.4% crude lipid) diets were formulated: a control diet containing 10% fishmeal and 5% soybean meal and two experimental low-fishmeal (8%) and low-soybean meal (0%) diets, supplemented with either 8% enzymatically hydrolyzed fish stickwater (EFS) or 8% enzymatically hydrolyzed chicken pulp (ECP), designated as Control, EFS, and ECP, respectively. Juvenile sea cucumbers (initial body weight, 0.25 ± 0.01 g) were fed these diets for 84 days to evaluate the effects of ECP and EFS on their growth performance, antioxidant capacity, and inflammatory responses. The results revealed significantly higher final weights and specific growth rates in both experimental groups than the control (p < 0.05). The proximate chemical compositions of sea cucumber were less affected by the diets (p > 0.05). Compared with the control group, significantly elevated levels of digestive enzymes, antioxidants, and lysozyme, together with lower malondialdehyde levels, were recorded in the experimental groups (p < 0.05). ECP appeared to exhibit greater potency than EFS in enhancing growth performance and antioxidant capacity. Similar trends were observed in the mRNA expression of SOD, CAT, and inflammation-related genes across the groups. In a nutshell, both ECP and EFS supplemented in a low-fishmeal and low-soybean meal diet could effectively promote the growth and health of A. japonicus, with ECP showing a superior effect over EFS. These findings suggest that enzymatic hydrolysate demonstrates potential as a viable alternative to traditional fishmeal and soybean meal in diets for sustainable sea cucumber aquaculture. Further investigations are warranted to reveal its underlying mechanism.

Incidence of Natural Virus Infection on Selected Improved Genetic Varieties of Cassava (Manihot esculenta Crantz) in Minna, Northern Nigeria

Cassava is a major staple food source for millions of people in Africa. It is one of the most cultivated root crops and it is a sustainable source of food security and family income for the poor in the developing world. Despite its economic significance, cassava yield is significantly reduced by viral diseases which can often result in 100 % yield loss in susceptible cultivars. Through a field-based randomized complete block-designed experiment, the present study screened five cassava genotypes in three replications at Teaching and Research Farm, Federal University of Technology, Minna, Nigeria. Collected samples were scored based on disease severity scale and data were subjected to ANOVA. Research results reveal that the five genotypes (PRV A, TME 419, TMS 98/0505, TMS 98/0581, and TMS 30572) were asymptomatic throughout the growing season, suggesting that all treatments were resistant to natural virus infection. Despite all treatments being resistant to virus infection, TME 419 had a better growth and yield performance compared to other treatments. Hence, the cassava genotypes identified in this study could be used for future breeding programs as resistant varieties to virus diseases in Minna, which can enhance food security and family income. Additionally, more research is needed to better understand the effect of diseases on these selected varieties.

Comparative Study on Growth, Yield and Economics of Potato Production Propagated through Apical Rooted Cuttings

This study investigates the comparative growth, yield and economic performance of potato production propagated through apical rooted cuttings (ARCs) in the Northern Transitional Zone of Karnataka. Eight genotypes, including Kufri Jyoti, Kufri Lima and Kufri Sangam, were analyzed for key growth parameters such as plant height, number of primary shoots, number of compound leaves, stem diameter and tuber yield. Results showed that tuber propagation consistently outperformed ARCs, with Kufri Jyoti (tuber) recording the highest plant height (46.82 cm), number of tubers per plant (6.80) and total yield per hectare (16.45 t/ha). Among ARC-propagated genotypes, Kufri Lima performed best, with a yield of 9.56 t/ha. Economic analysis revealed that Kufri Jyoti (tuber) also achieved the highest net returns (₹256,146.72/ha) and benefit-cost ratio (2.65). While ARCs offer cost savings on seed material, they showed limitations in overall yield and profitability, particularly in genotypes like Kufri Karan. These findings provide crucial insights into optimizing potato production practices.

Effect of beta-agonist type and timing of Experior feeding on calculated cumulative ammonia gas emissions, live growth performance, and carcass outcomes, and objective tenderness outcomes of feedlot steers

Abstract Our objective was to compare beta-agonist feeding strategies and evaluate Experior (EXP) with added days on feed (DOF) for live growth performance and carcass outcomes. Steers (n = 2,517; initial BW = 336 ± 23 kg) were allocated to 36 pens in a randomized, complete-block design and assigned to 1 of 6 treatments. Treatments were negative control (no beta-ligand; CON), Optaflexx (ractopamine hydrochloride, 300 mg·head-1·day-1 for 35 d; OPT), and Experior (lubabegron fumarate, 36 mg·head-1·day-1 for 56 d + 4 d removal; 0EXP) with all three treatments fed for 198 d. Remaining treatments were fed EXP for same duration as 0EXP, but total DOF were adjusted by -14 d (-14EXP), +14 d (+14EXP) and +28 d (+28EXP). Statistical analyses were conducted using mixed models; treatment was the fixed effect, block was a random effect, means were separated with the Tukey-Kramer adjustment, and contrasts were calculated to test linear or quadratic effects of EXP across DOF. No treatment differences (P ≥ 0.72) were observed for daily dry matter intake. Calculated cumulative ammonia (NH3) gas emissions (CCAGE) expressed either as total NH3 emitted (g) or NH3 emitted per kg of BW or HCW was reduced (P < 0.01) by 5.6 – 8.5%, 5.1 – 10.7%, and 6.3 – 13.6%, respectively for 0EXP, +14EXP and +28EXP compared to CON. Carcass ADG of 0EXP steers was 6.8% greater (P < 0.01) than CON, which had similar (P ≥ 0.10) ADG to OPT, +14EXP, and +28EXP steers. Carcass G:F of 0EXP steers was improved 5.0% compared to CON (P = 0.01) and was not different (P ≥ 0.10) from OPT, -14EXP or +14EXP steers. Hot carcass weight of 0EXP, +14EXP, or +28EXP steers was 14 to 37 kg heavier (P < 0.01) than CON, which did not differ (P = 0.81) from OPT. Steers fed EXP had 1.15 to 2.5 percentage point increase (P < 0.01) in dressed yields. Longissimus muscle area was 4.03 to 6.23 cm2 larger (P < 0.01) in steers fed EXP compared to CON, which tended to differ (P = 0.08) from OPT. Marbling score was 31 to 39 points lower (P ≤ 0.02) for -14EXP compared to CON and OPT, whereas 0EXP tended (P = 0.09) to differ from CON and +14EXP and +28EXP were similar (P ≥ 0.28) to CON and OPT. Slice shear force values were 20.1% greater (P < 0.02) for +14EXP compared to CON, whereas 0EXP tended (P = 0.09) to be greater and +28EXP, -14EXP and OPT were similar (P ≥ 0.28) to CON. This study illustrates EXP decreased CCAGE and increased HCW with minimal quality changes when fed the last 56 d on feed.

Probiotics in Poultry: Unlocking Productivity Through Microbiome Modulation and Gut Health

This review explores the role of probiotics in improving productivity and gut health in poultry through microbiome modulation, particularly during early life. Gut health is pivotal to poultry performance, influencing nutrient absorption, immune function, and disease resistance. Early-life interventions target the microbiome to shape long-term health and productivity. Probiotics, live microorganisms providing health benefits, improve gut health through the competitive exclusion of pathogens, immune modulation, antimicrobial compound production, and enhancing gut barrier integrity. Applying probiotics improves growth performance, feed conversion efficiency, body weight gain, and carcass quality by promoting lean muscle growth and reducing fat deposition. For laying hens, probiotics enhance egg production and quality. These benefits are linked to better nutrient utilization, a well-balanced microbiome, and reduced gastrointestinal disorders. However, the efficacy of probiotics depends on strain specificity, dosage, and administration methods. Factors like environmental conditions, storage stability, and interactions with other feed additives also influence their effectiveness. Despite these challenges, advancements in microbiome research and probiotic technologies, such as precision probiotics and synbiotics, provide promising solutions. Future research should focus on optimizing formulations, understanding host–microbiome interactions, and leveraging new technologies for targeted microbiome management.

Influence of Source of Origin and Region of Finishing on Growth Performance and Carcass Characteristics of Finishing Heifers Fed in the United States.

The objective was to evaluate growth performance and carcass traits of finishing beef heifers sourced and finished in different regions in the U.S. Heifers [n = 190; initial body weight (BW) 483 ± 0.4kg and 425 ± 1.9kg for SD and TX sourced, respectively] were used in a 2 × 2 factorial arrangement of origin state (SD vs. TX) and finishing state (SD vs. TX) was used. Heifers were allotted on d -1 to: 1) sourced from SD and finished in SD (SD-SD), 2) sourced from SD and finished in TX (SD-TX), 3) sourced from TX and finished in SD (TX-SD), and 4) sourced from TX and finished in TX (TX-TX). Heifers were weighed on d -1, 3, 15, 28, 56, 78 (TX-TX and SD-TX) and 90 (SD-SD and TX-SD). On d 0, SD-TX and TX-SD heifers were shipped to their respective finishing locations. The following morning (d 1), SD-TX and TX-SD heifers were individually weighed to determine transit shrink. To monitor transit stress effects, vaginal temperature probes were used on all SD-TX and TX-SD heifers and a portion of SD-SD and TX-TX heifers on d -1 and removed on d 3. Clinical attitude scores (CAS) were recorded on d -1, 0, 1, 2 and 3 for bovine respiratory disease symptoms. Transported heifers had decreased temperatures (P ≤ 0.01) during transit and post-transit and increased (P ≤ 0.01) vaginal temperature during loading and unloading compared to non-transported heifers. On d 0, 1, and 3 there was a shift in the distribution of heifers that had a CAS score greater than 0 for TX-TX, SD-TX and TX-SD. Heifers endured elevated ambient temperatures (temperature humidity index > 75) for 54% and 18% of the feeding period for TX and SD. Growth performance and carcass trait interactions were significant (P < 0.01) except for d -1 BW, percent shrink during transit, average daily gain, dressing percent, ribeye area and liver abscess severity, which did not differ (P > 0.30). A shift in the distribution (P < 0.02) towards a greater proportion of Yield Grade 1 and Select carcasses for was observed for TX versus SD. Overall, heifers transported to higher ambient temperatures had improved overall yield grades, but decreased dry matter intake, quality grades (QG) and limited growth recovery (45kg lighter) following transit than non-transported heifers. Heifers transported to lower ambient temperatures recovered growth and had improved QG (P < 0.02) at the same thickness of rib fat compared to non-transported heifers but had decreased overall yield and yield grades.

Slowly digestible starch impairs growth performance of broiler chickens offered low-protein diet supplemental higher amino acid densities by inhibiting the utilization of intestinal amino acid

BackgroundThe synchronized absorption of amino acids (AAs) and glucose in the gut is crucial for effective AA utilization and protein synthesis in the body. The study investigated how the starch digestion rate and AA levels impact intestinal AA digestion, transport and metabolism, breast muscle protein metabolism, and growth in grower broilers. A total of 720 21-day-old healthy male Arbor Acres Plus broilers were randomly assigned to 12 treatments, each with 6 replicates of 10 birds. The treatments comprised 3 different starch [corn: control, cassava: rapidly digestible starch (RDS), and pea: slowly digestible starch (SDS)] with 4 different AA levels [based on standardized ileal digestible lysine (SID Lys), 0.92%, 1.02% (as the standard), 1.12% and 1.22%].ResultsAn interaction between dietary starch sources and SID Lys levels significantly affected breast muscle yield (P = 0.033). RDS and SDS diets, or SID Lys levels of 0.92%, 1.02%, or 1.22%, significantly decreased the breast muscle yield of broilers in contrast to the corn starch diet with 1.12% SID Lys (P = 0.033). The SID Lys levels of 1.12% and 1.22% markedly improved body weight (BW), body weight gain (BWG) from 22 to 42 days of age, and mRNA expression of y+LAT1 and mTOR while reducing feed intake (FI) and feed/gain ratio (F/G) compared to the 0.92% SID Lys level (P < 0.05). The SDS diet significantly decreased BW and BWG of broilers from 22 to 42 days of age, distal ileal starch digestibility, jejunal amylase and chymotrypsin activities, and mRNA expression of GLUT2 and y+LAT1 compared to the corn starch diet (P < 0.05). The RDS diet suppressed the breast muscle mass by down-regulating expression of mTOR, S6K1, and eIF4E and up-regulating expression of MuRF, CathepsinB, Atrogin-1, and M-calpain compared to the corn starch diet (P < 0.05). Targeted metabolomics analysis revealed that the SDS diet significantly increased acetyl-CoA and α-ketoglutaric acid levels in the tricarboxylic acid (TCA) cycle (P < 0.05) but decreased the ileal digestibility of Lys, Tyr, Leu, Asp, Ser, Gly, Pro, Arg, Ile, and Val compared to the corn starch group (P < 0.05).ConclusionThe SDS diet impaired broiler growth by reducing intestinal starch digestibility, which inhibited intestinal AA and glucose absorption and utilization, increased AA oxidation for energy supply, and lowered the efficiency of protein synthesis. Although the RDS diet resulted in growth performance similar to the corn starch diet, it reduced breast muscle mass by inhibiting protein synthesis and promoting degradation.Graphical

Fermented Bamboo Powder Affects Dwarf Yellow-Feathered Broiler Growth, Blood Biochemistry, Antioxidant Status, Intestinal Morphology, and Nutrient Transporter Gene Expression

This study explores the effects of fermented bamboo powder (FBP) on the growth performance, antioxidant status, intestinal morphology, and expression of nutrient transporter genes in broiler chickens. Two groups were formed from 600 healthy 1-day-old chicks; each group included 30 chicks, repeated 10 times. The control group was fed a basal diet and supplemented the experimental group’s diet with 1.0 g/kg FBP during phase I (days 1–22) and 2.0 g/kg FBP during phase II (days 23–45). The findings revealed a significant enhancement in the growth performance for the group that received fermented bamboo powder in contrast to the control group (p &lt; 0.05). The levels of triglycerides exhibited a significant reduction (p &lt; 0.05), alongside a significant decrease in urea and creatinine levels (p &lt; 0.05). The levels of malondialdehyde (MDA), a marker of oxidative stress, exhibited a significant reduction in the FBP group compared to the control group (p &lt; 0.01). It was found that the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) worked much better in the FBP group than in the control group (p &lt; 0.01). On the other hand, fermented bamboo powder greatly increased the surface area that could absorb nutrients in the intestines (duodenum, jejunum, and ileum) by increasing the villus height, intestinal lumen depth, and villus area (p &lt; 0.01). Compared to the control, FBP increased the expression levels of genes involved in the transport of nutrients from the intestinal regions (duodenum, jejunum, and ileum), including GLUT1, GLUT2, CAT1, CAT2, PEPT1, PEPT2, and LAT1. The upregulation of nutrient transporter genes further facilitated nutrient absorption, contributing to the observed improvements in growth and body weight. These findings endorse FBP as a viable feed additive in broiler diets to enhance health and performance.

Assessment of commercial fish feeds on the growth performance and biochemical condition of African Catfish (&lt;i&gt;Clarias gariepinus&lt;/i&gt;)

Assessment of commercial fish feeds on the growth performance and biochemical condition of African Catfish (&lt;i&gt;Clarias gariepinus&lt;/i&gt;)

Growth Rate Prediction, Performance, and Biochemical Enhancement of Black Soldier Fly (Hermetia illucens) Fed with Marine By-Products and Co-Products: A Potential Value-Added Resource for Marine Aquafeeds

Growth Rate Prediction, Performance, and Biochemical Enhancement of Black Soldier Fly (Hermetia illucens) Fed with Marine By-Products and Co-Products: A Potential Value-Added Resource for Marine Aquafeeds

Weaning impact: Evaluating growth, behavior, and production performance in Sahiwal cows and their calves.

Initial periods of life, beginning before birth and lasting until weaning are characterised by the greatest neural plasticity. Early postnatal stress causes lasting changes in a variety of behaviours as well as stress reactivity. Cow-calf contact for an extended period is believed to improve the social skills of calves and has also been linked to improved productivity of mothers. This research was carried out to investigate the impact of weaning stress on the growth, behaviour and performance of Sahiwal cows and their calves. For this, 32 healthy cows and their calves were selected from the Sahiwal herd of the Livestock Research Centre, ICAR-National Dairy Research Institute. They were grouped equally into two groups of 16 cow-calf pairs, which became the treatment groups (i.e., 'Fenceline' contact and 'Separated' groups). Calves in the fenceline contact group were allowed to suckle during the morning and evening milking and were housed together with fenceline separation. In the separated group, calves were separated from their mothers immediately after birth and fed colostrum and milk with a bottle throughout the experiment. Each calf was monitored for its growth and behavioural responses while cows were monitored for their production performance and behaviour. The results showed that growth and behaviour responses were better for fenceline calves compared to separated calves and also production performance and behaviour of Sahiwal cows provided with fenceline contact were better when compared to separated cows. From this study, it was concluded that fenceline cow-calf contact improved growth, behavioural response of calves; and production performance and behaviour of cows compared to separated cows and calves.

The Enhanced Growth Performance and Antioxidant Capacity of Juvenile Procambarus clarkii Fed with Microbial Antioxidants

Given the economic significance of Procambarus clarkii in freshwater aquaculture and the lack of microbial antioxidants in Procambarus clarkii diet research, this study aimed to investigate the optimal supplementation level and feeding duration of microbial antioxidants in Procambarus clarkii diets. A series of three experiments were conducted to assess the long-term effects of different MA levels on crayfish and evaluate the palatability of the diets by observing feeding behavior and examining the short-term effects of high levels of MA. Our results indicate that long-term feeding using 1.5% MAs markedly increased the activities of antioxidant enzymes (T-AOC, T-SOD, and GSH-PX) and decreased the malondialdehyde (MDA) content in the hepatopancreas and hemolymph, with the crayfish showing significantly higher survival rates due to better antioxidant capacity after 24 h of air exposure stress. Under the condition of long-term feeding, the appropriate level of addition of MAs that can promote the growth of crayfish is 0.62–0.66%. The feeding behavior results indicate that the lower willingness and food intake of the crayfish in the high MA group may be the main reason affecting their growth. Conversely, short-term feeding using MAs alleviated the adverse effects on growth associated with the reduced palatability of the diet. The results indicate that the inclusion of 1.5% MAs in the diet for a period of 21 d optimized crayfish growth, accompanied by an improvement in antioxidant capacity and survival during transportation. This study demonstrates that diets supplemented with microbial antioxidants (MAs) can improve growth performance, antioxidant capacity, and resistance to air exposure stress in Procambarus clarkii. These results provide valuable insights into the potential benefits of MA supplementation in crayfish aquaculture.

Cost Benefits and Growth Promoting Ability of Dietary Bambara Nut (Vigna subterranean) Powder on the Rearing of Catfish (Clarias gariepinus)

The efficacy of dietary Bambara nut (Vigna subterranean) in the growth performance and cost benefit of Clarias gariepinus culture was evaluated. To this end 35% CP diet was formulated using locally available ingredients. Five different diets were prepared from the 35% CP diet, replacing Soybean with Bambara nuts at different percentage as follows: T1 (0% BN: 100 SB), T2 (25% BN: 75% SB) T3 (50% BN: 50% SB), T4 (75% BN: 25% SB) and T5 (100% BN: 0% SB), and organoleptic assessment was conducted on the diets to determine texture, aroma and color, while chemical assessment was conducted to determine the nutritional qualities of the diets. One hundred and fifty (150) sub-adult Clarias gariepinus were distributed into five (5) groups in triplicates of ten (10) using fifteen aquaria, and were fed T1 – T5, for eight (8) weeks. Length and weight of fish were evaluated fortnightly to determine: weight gain, percentage weight gain, specific growth rate, performance index and condition factor. And the cost of feed and fish were determined to evaluate the cost benefits of the various diets. At the end of the feeding trials, data were collected and analysed using ANOVA followed by a Turkey multi-companism test with SPSS 170 package software and the following results were obtained: (1) the experimental diets T1-T5 had no effects on the physico-chemical properties of the experimental waters (2) the aroma of the experimental diets were less fishy, their texture ranges from fibrous to less fibrous and the colour from dark brown to light brown as the quantity of the Bambara nut in the diets increases (T1-T5). (3) The % lipid, % proteins and % fibre decreased as the quantity of Bambara nut increased in the experimental diets (T1-T5). (4) All the growth parameters and performance index increased significantly (P&lt;0.05) as the quantity of Bambara nuts increased in the various diets (T1-T5):- Weight gain (WG): T1 (54.61+2.11), T2 (70.96+8.47), T3 (67.82+0.63), T4 (70.90+5.90) and T5 (77.35+3.81), Percentage weight gain (PWG): T1 (30.76+0.77), T2 (40.66+1.46), T3 (35.64+1.64), T4 (37.46+1.13) and T5 (44.84+10.30); Condition factor (CF): T1 (0.55+0.13), T2 (0.62+1.02), T3 (0.70+0.41), T4 (0.64+11.4) and T5 (0.64+4.30); Specific growth rate (SGR): T1 (0.34+0.02), T2 (0.43+0.05), T3 (0.42+0.01), T4 (0.43+0.02) and T5 (0.49+0.02); Performance index (PI): T1 (158.99+2.76), T2 (208.99+25.84), T3 (210.98+2.28), T4 (203.85+11.87) and T5 (213.13+4.30). The fish fed the Bambara nut diets (T2-T5) had enhanced net profit, profit index and benefit cost ratio, but lower economic weight gain. Bambara nut is unarguably a better feed ingredient than Soybean in the culture of Clarias gariepinus.

Co-Supplementation of Diet with Saccharomyces cerevisiae and Thymol: Effects on Growth Performance, Antioxidant and Immunological Responses of Rainbow Trout, Oncorhynchus mykiss

This study assessed the effects of thymol and yeast Saccharomyces cerevisiae on the growth performance, antioxidant capacity and immunological responses and gut immunological transcripts in rainbow trout, Oncorhynchus mykiss. Two hundred and seventy fish (6.62 ± 0.18 g) were distributed in 18 aquaria (15 fish per aquarium) as a 2 × 3 factorial design. The fish were fed on diets containing 0 and 1 × 108 cfu/g of yeast and 0, 250 and 500 mg/kg of thymol for 60 days. The results showed that dietary yeast supplementation led to significantly improved fish weight gain and feed efficiency (p &lt; 0.05). Thymol and yeast supplementation affected the hepatic antioxidant status, leading to lower lipid peroxidation and higher glutathione reserves (p &lt; 0.05). Thymol and yeast supplementation led to significantly lowered plasma aspartate aminotransferase levels (p &lt; 0.05). Dietary yeast supplementation led to significantly elevated plasma and mucus lysozyme, plasma alternative complement, immunoglobulin and mucus alkaline phosphatase levels. In contrast, thymol supplementation led to significantly increased plasma lysozyme and mucus alkaline phosphatase levels (p &lt; 0.05), whereas it had no significant effects on other immunological parameters. The mucus bactericidal activities were improved by dietary yeast but both supplements enhanced the plasma bactericidal activity (p &lt; 0.05). Thymol and yeast supplementation significantly up-regulated the expression of tumor necrosis factor-alpha, interleukin-1 beta, transforming growth factor-beta, beta-defensin and heat shock protein-70 in the hindgut (p &lt; 0.05). In conclusion, dietary yeast supplementation was particularly effective in enhancing fish growth performance and non-specific immunity, while thymol supplementation primarily led to improved antioxidant capacity. Notably, a dietary dose of 250 mg/kg of thymol alone failed to affect the gut transcription as much as 500 mg/kg; however, the co-supplementation of 250 mg/kg of thymol and yeast led to comparable results.

Partial replacement of soybean meal with mixed plant proteins yields comparable growth and carcass quality in growing-finishing pigs

ObjectiveThis study evaluated the impacts of partial replacement of soybean meal with different concentrations of mixed plant protein products (rapeseed meal (RSM) - palm kernel meal (PKM) -distillers dried grains with soluble (DDGS)) on growth performance and carcass quality of growing-finishing pigs.MethodsA total of 180 crossbred [Yorkshire x Landrace] pigs with average initial weight of 29.72 + 1.65 Kg were randomly assigned to one of five dietary treatment groups on the basis of weight and sex, and the experimental duration was 105 days. The basal diet (C23ON) of growing and finishing pigs were partially replaced with increasing level of RSM-PKM-DDGS (1 to 5% for growing pigs, and 2 to 6% for finishers). Each treatment group had 9 replicate pens, each containing 2 barrows and 2 gilts. During the 15-week trial, body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were calculated for the periods of weeks 0–5, weeks 5–10, week 10–15, and for the entire experimental period.ResultsThe partial replacement of soybean meal with mixed plant protein products (RSM, PKM-DDGS) showed no significant effect on the growth performance of pigs during the entire experimental period (p &amp;gt; 0.05). However, a decreasing ADG (p = 0.0837) and ADFI (p = 0.0779) were observed during weeks 0–5, while an increasing FCR was noted during weeks 10–15 (p = 0.0835) and the overall period. Furthermore, the replacement of soybean meal with mixed plant protein products (RSM-PKM-DDGS) showed no linear or quadratic effects on the digestibility of dry matter (DM), nitrogen (N), energy (E), fecal scores, or meat quality.ConclusionThis suggests that mixed plant protein products (RSM, PKM, and DDGS) can effectively replace soybean meal as the primary protein source, providing comparable outcomes while potentially reducing feed costs.

Effects of dietary l-carnosine supplementation on the growth, intestinal microbiota, and serum metabolome of fattening lambs

Dietary l-carnosine supplementation has been shown to enhance animal performance and improve meat quality. However, the mechanisms underlying the effects of l-carnosine on the physiological functions of animals have not been fully elucidated. We investigated the effects of dietary l-carnosine supplementation on growth performance, intestinal microbiota diversity, and the serum metabolome in fattening lambs to reveal the molecular mechanism underlying the effect of l-carnosine on the growth performance of sheep. Sixty 3-month-old male crossbred lambs (Dorper ♂ × Small Tail Han ♀) with an average body weight of 30 ± 5 kg were randomly divided into two groups: a control group (group C) fed a basal diet, and an experimental group (group L) fed a basal diet supplemented with 400 mg/kg of l-carnosine. At the end of the 60-day experiment, all sheep were weighed, and fecal and blood samples were collected from 12 random sheep. The fecal microbiota was analyzed using 16S rRNA sequencing, and serum metabolites were analyzed using liquid chromatography–tandem mass spectrometry. Spearman correlation analysis was employed to assess the associations between intestinal microbiota and serum metabolite biomarkers. The results showed that weight gain and daily weight gain were significantly increased in group L compared to group C (p &amp;lt; 0.01). The dominant phyla in the intestinal microbiota (Firmicutes and Bacteroidetes) did not significantly differ between the two groups (p &amp;gt; 0.05). At the genus level, the abundances of Syntrophococcus (p &amp;lt; 0.01) and Butyricimonas (p &amp;lt; 0.001) were higher, whereas those of Escherichia-Shigella and Candidatus Saccharimonas were significantly lower in group L than in group C (p &amp;lt; 0.05). Non-targeted metabolomics identified 68 differentially abundant biomarkers (VIP &amp;gt; 1, p &amp;lt; 0.05). The content of pyridine N-oxide glucuronide was significantly downregulated (p &amp;lt; 0.01), whereas those of l-histidinol, d-apiose, and isodomedin were significantly upregulated in group L versus group C (p &amp;lt; 0.001). Holdemania and Butyricimonas were positively correlated with l-histidine, d-apiose, and l-erythrulose (p &amp;lt; 0.001), whereas Butyricimonas was negatively correlated with pyridine N-oxide glucuronide (p &amp;lt; 0.001). This study provided new insights into the effects of l-carnosine on the intestinal microbiota and nutrient metabolism in fattening sheep that will be helpful for the future application of l-carnosine in ruminants.

Effects of probiotic supplementation in rearing mud crab larvae (Scylla paramamosain estampador, 1949)

The research was conducted to evaluate effects of probiotics supplementation on growth performance and survival rate of mud crab (Scylla paramamosain) larvae. The experiment was arranged in a completely randomized design with 4 diets supplemented with various probiotics: (i) Control (w/o supplementation), (ii) L. acidophilus, (iii) B. subtilis, and (iv) a mixture of L. acidophilus and B. subtilis. A total of 12 composite tanks were filled with 60 L sterilized saline water (salinity 26 ppt) with a stocking density of 200 larvae/L and water exchange was controlled every 3 days (25% of the water volume). The probiotics (104 CFU/mL) were added separately to the experimental tanks every 3 days over a culture period. The L. acidophilus supplementation resulted in significantly higher total probiotics density (16.38 x 104 CFU/mL) compared with the control (6.37 x 104 CFU/mL) (P &lt; 0.05). Furthermore, the control showed the highest Vibrio spp. density (6.67 x 103 CFU/mL) which differed significantly (P &lt; 0.05) from remaining treatments with probiotics supplementation. The larval stage index (LSI) of mud crab larvae in probiotic supplemented treatments did not differ significantly (P &gt; 0.05). The control had the lowest Crablet 1 ’s survival rate (7.51%) which differed significantly from remaining treatments (P &lt; 0.05). In contrast, the L. acidophilus-supplemented treatment achieved the highest survival rate (10.04%). In conclusion, the obtained results suggested that L. acidophilus supplementation was considered the most potential approach to mud crab larvae production.

Effect of Dietary Lactobacillus plantarum Supplementation on the Growth Performance, Intestinal Health, Antioxidant Capacity, and mTOR Signaling Pathway of Juvenile Coho Salmon (Oncorhynchus kisutch)

This study investigates the effect of dietary Lactobacillus plantarum supplementation on juvenile coho salmon (Oncorhynchus kisutch). Four groups of the juveniles (initial weight 103.87 ± 2.65 g) were fed for 10 weeks with four diets containing 0 (control diet), 105 (T1), 107 (T2), and 109 (T3) cfu/g of L. plantarum. The main results are as follows: Compared with the control diet, the final weight, specific growth rate (SGR), and weight gain rate (WGR) of the juveniles fed the T1, T2, and T3 diet significantly (p &lt; 0.05) increased, while the feed coefficient ratio (FCR) expressed an opposite trend. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) in the serum of the juveniles fed the T2 diet significantly (p &lt; 0.05) increased, while the malondialdehyde (MDA) expressed an opposite trend. The expression of phosphatidylinositol 4,5-bisphosphate 3-kinase (pi3k), AKT-interacting protein (akt), mechanistic target of rapamycin kinase (mtor), glucose-6-phosphate dehydrogenase (g6pd), sod, cat, and gsh-px genes in the liver of the juveniles fed the T2 diet significantly (p &lt; 0.05) increased. In conclusion, the T2 diet significantly improved the growth performance, antioxidant capacity, and upregulated key mTOR pathway genes in juvenile coho salmon.

Mutation of Genes Associated with Body Color, Growth, Intermuscular Bone, and Sex Differentiation in Onychostoma macrolepis Using CRISPR/Cas9

Onychostoma macrolepis is not only a protected Cyprinid species in the wild but also an emerging commercial aquaculture fish in China. The objective of this research was to genetically modify the genes associated with commercial traits by CRISPR/Cas9 for the protection and utilization of the germplasm resources of O. macrolepis. To that end, one-cell stage embryos were obtained via hormone-induced ovulation and artificial insemination in O. macrolepis. Eight genes related to body color, growth, intermuscular bone, and sex differentiation were mutated in O. macrolepis using the CRISPR/Cas9 system by microinjection of gRNA/Cas9 mRNA. The optimal dose of gRNA/Cas9 mRNA was determined by injection of different concentrations of tyr (tyrosinase)-gRNA/Cas9 and examination of the mutation rate and hatching rate of embryos. Indels were detected by T7 endonuclease I digestion and Sanger sequencing. F0 mutants with high mutation rates were selected for phenotype analyses. Disruption of body color gene tyr, mpv17 (mitochondrial inner membrane protein MPV17), and csf1ra (colony-stimulating factor 1 receptor, a) resulted in obvious phenotype with decreased or even absence of melanophores, iridophores, and xanthophores, respectively. Mutation of mstnb (myostatin b) led to improved growth performance. Mutation of mc4r (melanocortin 4 receptor) led to no obvious phenotype. Mutation of runx2b (RUNX family transcription factor 2b) and bmp6 (bone morphogenetic protein 6) resulted in decreased or absence of intermuscular bones, as revealed by alizarin red S staining. Mutation of cyp19a1a (cytochrome P450, family 19, subfamily A, polypeptide 1a) resulted in ovarian degeneration as revealed by gonadal histological examination. Therefore, this study successfully obtained mutants with obvious phenotypes of genes associated with body color, growth, intermuscular bone, and sex differentiation by CRISPR/Cas9 in O. macrolepis.