Effects of Restricted Feeding on Growth Performance, Intestinal Immunity, and Skeletal Muscle Development in New Zealand Rabbits

This study aimed to explore the effects of different feeding restriction levels on the growth performance, intestinal immunity, and skeletal muscle development of meat rabbits. Additionally, we studied whether complete compensatory growth could be obtained post 2 weeks of restricted feeding, in order to seek a scientific mode of feeding restriction. Each of three groups was exposed to 3 weeks of feeding restriction and 2 weeks of compensatory growth. The 15% feeding restriction showed a negligible effect on the final body-weight of the rabbits (p > 0.05), but significantly reduced the feed-to-weight ratio (p < 0.05); reduced diarrhea and mortality; and increased digestive enzyme activity and antioxidant capacity. However, a 30% feeding-restriction level substantially reduced the growth rate of the rabbits (p < 0.05), impaired skeletal muscle development, and showed no compensatory growth after 2 weeks of nutritional recovery. Additionally, immunoglobulin and antioxidant enzyme synthesis were impaired due to reduced nutritional levels, and levels of pro-inflammatory factors were increased during the compensation period. The IGF1 mRNA expression decreased significantly (p < 0.05), whereas MSTN and FOXO1 expression increased noticeably (p < 0.05). Moreover, protein levels of p-Akt and p-p70 decreased significantly in the 15% feeding restriction group. Overall, the 15% feeding limit unaffected the weight and skeletal muscle development of rabbits, whereas the 30% feeding limit affected the growth and development of skeletal muscle in growing rabbits. The PI3K/Akt signaling pathway is plausibly a mediator of this process.

Protein-energy supplementation on productive and nutritional performance of grazing beef heifers

This study was conducted with the aim of evaluating the effect of protein-energy supplementation on productive performance, intake, digestibility, and microbial protein synthesis in heifers fed tropical forage. Twelve Nellore heifers at 11 months of age, with a mean initial body weight of 248.8 ± 11.40 kg were used. The animals were distributed in a completely randomized design with two treatments and six replicates. The treatments evaluated were: control (without supplementation); and supplementation in the amount of 1.5 kg animal-1 day-1. Forage samples were collected to evaluate the chemical composition and the total availability of dry matter of the pasture consumed by the animals. To evaluate the intake and forage digestibility, a trial was performed using internal and external markers. In this study no effect of supplementation was observed on the intakes of dry matter (DM), organic matter (OM), forage DM, or neutral detergent fiber corrected for ash and protein (NDFap; P > 0.10). However, supplementation increased (P < 0.01) the intakes of crude protein (CP), ether extract (EE), and non-fibrous carbohydrates (NFC). Additionally, an upward trend (P=0.076) was observed in the intake of digested OM (DOM) with supplementation. On the other hand, supplementation increased (P < 0.01) the digestibility coefficients of OM, CP, EE, and NFC, although supplementation did not affect the ruminal synthesis of nitrogen compounds (MICN), efficiency of protein microbial synthesis (EMS), relative microbial nitrogen (RMICN) or urine urea nitrogen (UUN) excretion (P > 0.57). Lastly, supplementation increased (P=0.050) the average daily gain of the animals, although no effect (P > 0.10) was observed on their final body weight. These results suggested that protein-energy supplementation improves the productive performance and nutritional characteristics of grazing beef heifers.

Different Fish Meal and Fish Oil Dietary Levels in European Sea Bass: Welfare Implications After Acute Confinement Stress

To provide practical feeding management guidelines preceding a stressful episode during farming practices, European sea bass juveniles (initial weight: 72.3 g) were fed for 60-days different fish meal (FM) and fish oil (FO) dietary levels [high (30% FM, 15% FO, FM30/FO15), intermediate (20% FM, 7% FO, FM20/FO7), and low (10% FM, 3% FO, FM10/FO3)] in triplicate conditions. Fish were then fasted for 36 h and exposed to a 2-h acute crowding (80 kg m–3 biomass). Plasma biochemistry, skin mucus parameters and gene expression of stress and immune-related genes were performed before, at 2 and 24 h after crowding. At the end of the trial, the FM10/FO3 group showed lower final body weight, weight gain, and specific growth rate compared to the other treatments. Most of the plasma parameters were mainly affected by crowding condition rather than diet; however, after stress, lactate was higher in the FM30/FO15 group compared to the other treatments. Similarly, protease, antiprotease, peroxidase and lysozyme in skin mucus were mostly affected by crowding conditions, while fish fed FM10/FO3 displayed higher skin mucosal IgM and bactericidal activity against Vibrio anguillarum and V. harveyi. Most of the stress-related genes considered (hsp70 and gr-1 in the brain; hsp70, gr-1 and gr-2 in the head kidney), showed an overall expression pattern that increased over time after stress, in addition, hsp70 in the head kidney was also up-regulated in fish fed FM30/FO15 after stress. Higher plasmatic lactate together with the up-regulation of some stress-related transcripts suggest a higher reactivity to acute crowding of the stress-response mechanism in fish fed high FM and FO dietary levels. Otherwise, the higher skin mucosal IgM and bactericidal activity observed in fish fed FM10/FO3 dietary levels seems to indicate that acute crowding was able to activate a higher pro-inflammatory response in this treatment. Overall, the results of the present study seem to indicate that 10% FM and 3% FO dietary levels might affect stress and immune responses.

Productive Performance of Mexican Creole Pullets and Immature Males Fed Different Levels of Metabolizable Energy and Crude Protein

Mexican Creole birds are a poorly researched genetic resource whose nutritional requirements are unknown. The objective was to evaluate the productive performance and nutrient use efficiency of Mexican Creole birds, using four diets with different concentrations of metabolizable energy (EM, MJ/kg) and crude protein (PC, g/kg). The experimental diets with constant ME/CP ratios equal to 0.06, were: 12.55/200, 11.92/190, 11.30/180 and 10.67/170. One hundred and ninety-two 12-week-old creole birds (96 males and 96 females) were randomly distributed amongst the diets (24 males and 24 females each). Due to the diet × sex interaction, males fed the 10.67/170 diet had higher feed intake, and males under 10.67/170, 11.92/190 and 11.30/180 had higher final body weight and weight gain than the other birds. Feed conversion ratio was lower in birds with diets 12.55/200 and 11.92/190. Total body fat retention was higher in females with the diet 12.55/200, 11.92/190 and 11.30/180. In conclusion, males with the 10.67/170 (lowest ME and CP) diet showed a high productive performance, without compromising carcase yield and body composition, while females with all diets did not show differences in productive performance, carcass yield and body composition.

Micro-Aid Liquid 10 Promotes Growth Performance and Health Status of White Shrimp, Litopenaeus vannamei

An experiment was conducted to evaluate the effects of the Micro-Aid Liquid 10 (MAL10) (DPI Global, Porterville, CA, USA), a product made from yucca extract, on growth performance, gut microbiota, and resistance of white shrimp, Litopenaeus vannamei against infectious disease caused by Vibrio alginolyticus. MAL10 was added to shrimp rearing water at different levels of 0 (control), 0.25 mL m3−1 (W0.25), 0.5 mL m3−1 (W0.5), 1 mL m3−1 (W1), and 5 mL m3−1 (W5), respectively, once per week for 70 days. Growth performances, including final body weight, specific growth rate, average daily growth and percentage of weight gain, were significantly improved by adding the MAL10 at levels up to 5 mL m3−1, which may be due to the proliferation of B cells in hepatopancreas of MAL10-treated shrimp. No significant differences in the total viable count and Vibrio-like count in the gut of shrimp were recorded by spread plate method. In the challenge test, shrimp reared in the water supplemented with MAL10 at levels of 1–5 mL m3−1 had significantly lower cumulative mortality after a challenge test with V. alginolyticus compared to shrimp reared in the control, W0.25 and W0.5 groups. Next-generation sequencing indicated that the relative distribution of phylum Proteobacteria in control (80.4%) was higher than the W (77.4%). The proportion of Vibrio was primarily dominant genera in the shrimp intestine and highest in the control group compared to the W group, followed by Spongiimonas, Motilimonas, Demequina, and Shewanella genera. Although there was no statistically significant difference, higher α-diversity indices were recorded in the W5-treated group than in the control group. Therefore, it is considered that MAL10 could be used as a natural alternative in shrimp aquaculture to reduce the risk of infectious disease caused by pathogenic Vibrio and improve the growth performance of white shrimp.

Dietary net energy levels for growing barrows from 30 to 70 kg

ABSTRACT: This study evaluated the effect of dietary net energy (NE) levels on growth performance and carcass characteristics of barrows from 30 to 70 kg of body weight (BW). Sixty barrows with initial body weight (IBW) of 31.94 ± 3.54 kg and final body weight (FBW) of 71.98 ± 5.99 kg were allotted to one of five dietary NE levels (2.40, 2.45, 2.50, 2.55, and 2.60 Mcal kg-1), using a completely randomized block design with six replicates and two barrows per replicate. The experimental period was divided into phase I: 30 to 50 kg and phase II: 50 to 70 kg. The variables analyzed were average daily feed intake (ADFI), net energy intake (NEI), digestible lysine intake (LysI), average daily gain (ADG), feed conversion (FC), FBW, digestible lysine conversion:gain (LysI:G), Cost:Gain (C:G), loin eye area (LEA), muscle depth (MD), first backfat layer (BF1), second backfat layer (BF2), total backfat (BFt), lean meat percentage, and carcass bonus index (BI). In phase I, there was a linear increase (P < 0.05) in FBW, ADG, NEI, and LysI with increasing NE levels in the diet. In phase II, increasing dietary NE levels also increased (P < 0.05) FBW, ADG, NEI, LysI, and FC linearly. Overall, there was a linear increase (P < 0.05) in ADG, NEI, LysI, and FC with increasing NE levels in the diet. The other performance variables were not affected (P > 0.05) by the NE levels. There was an increase (P < 0.05) in BF2 with increasing NE levels, but the other carcass characteristics were not altered (P > 0.05). We recommended 2.60 Mcal of NE kg-1 in the diet for growing barrows from 30 to 70 kg.

The growth performance of Peking ducks fed with rations containing probiotic agents and waste products of leubiem fish (Chanthidermis maculatus)

The purpose of this study was to evaluate the growth performance of Peking ducks fed with rations containing waste products of leubiem fish (Chanthidermis maculatus) and probiotic agents. The study was conducted experimentally using 96 Peking ducks, within an age range of about 1 to 8 weeks, and a Completely Randomized Design (CRD), which consisted of four treatment rations and four replications. The treatment rations used in this research included treatment R0, which was the basal diet, serving as the control ration, and also treatment R1, R2, and R3, which consisted of 10% concentration of leubiem fish skin, head, and bone, respectively, as well as 1% of a probiotic agent. The observed variables included the rate of feed consumption, body weight gain, final body weight, feed conversion ratio, and mortality were then analysed using Analysis of Variance (ANOVA). The results showed that the use of leubiem fish components and probiotic agents in rations at 10% and 1%, respectively, had a significant effect (p<0.05) on the rate of feed consumption, body weight gain, feed conversion ratio and final body weight. However, there was no significant effect on the mortality of Peking ducks. Therefore, this study concluded that the use of rations containing leubiem fishbone and probiotic agents at 10% and 1%, respectively, were able to accelerate the growth performance of Peking ducks.

Enhancement of growth, antioxidative status, nonspecific immunity, and disease resistance in gibel carp (Carassius auratus) in response to dietary Flos populi extract

This study investigated the effects of dietary Flos populi extract (FPE) on the growth, antioxidation capability, innate immune response, and disease resistance in gibel carp. A total of 480 fish were fed with five different diets containing 0, 0.5, 1.0, 1.5, or 2.0 g kg−1 FPE (designated as control, D0.5, D1.0, D1.5, or D2.0 groups) for 45 days. The fish were challenged with A. hydrophila after the feeding trial. Compared with the control, the feed efficiency (FE), weight gain (WG), final body weight (FBW), and specific growth rate (SGR) were significantly improved in groups D1.0 and D1.5. Dietary FPE significantly increased serum superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, as well as glutathione (GSH) content. The contents of protein carbonyl (PCC) and malondialdehyde (MDA) in serum decreased significantly. Additionally, FPE supplementation in diets resulted in significant improvement in serum lysozyme (LZM) and myeloperoxidase (MPO) activities, as well as immunoglobulin M (IgM) and complement 3 (C3) concentrations. The hepatic antioxidant enzymes (CAT and SOD) activities increased, whereas content of MDA decreased in fish treated with dietary FPE than those of control both pre- and post-challenged. After 12 h-challenge, an obvious downregulation of hepatic Kelch-like-ECH-associated protein 1 (Keap1), splenic tumor necrosis factor-α (TNF-α), interleukin (IL)-8, IL-1β, and toll-like receptor 2 (TLR2) mRNA levels was observed in fish treated with dietary FPE, whereas hepatic Nrf2 transcription level was upregulated compared to the control. Furthermore, compared to group D0.5, higher relative percent survival (RPS) was observed in gibel carp fed dietary 1.0–2.0 g/kg FPE. Our results reveal that FPE supplemented diet has a stimulatory effect on antioxidant capacity and nonspecific immune response, along with improved growth performance and enhanced resistance against A. hydrophila infection in juvenile gibel carp.

Increase in body weight and protein retention on meat chicken due to the addition of probiotics and digestive enzymes in fermented diet containing maggot flour and local materials

The purpose of this study was to determine the growth response of meat chickens due to the addition of probiotics and digestive enzymes in the fermented diet containing maggot flour and local materials. The research was carried out at Field Laboratory of Animal Science, University of Syiah Kuala-Banda Aceh, Indonesia for 66 days. A total of 100 meat chickens were designed using a completely randomized design (CRD) consisting of 5 treatments, namely P0 = 100% fermented ration (control), P1 = 0.5% probiotic + 0% digestive enzymes + 100% fermented diet, P2 = 0% probiotic + 0.5% digestive enzymes + 100% fermented diet, P3 = 0.5% probiotic + 1% digestive enzymes + 100% fermented diet, P4 = 1% probiotic + 0.5% digestive enzymes + 100% fermented diet with 4 replications. The data obtained were analyzed using ANOVA (Analysis of variance) and significant difference of data was analyzed by Duncan’s multiple distance test. The results showed that the addition of probiotics and digestive enzymes with different levels of administration in the fermented diet had a significant effect (P<0.05) on the increase in final body weight and percentage of protein retention. The best results were obtained on chicken fed on fermented diet contained 0, 5% digestive enzymes by increasing on final body weight, protein retention, feed conversion and feed efficiency which were higher than fermented feed containing probiotics. In conclusion, it was well known that digestive enzyme effected synergistically on fermented diet in increasing protein retention resulted a higher final body weight of meat chicken.

EFECTO DE LA SUPLEMENTACIÓN ENZIMÁTICA EN PARÁMETROS PRODUCTIVOS DE CUYES (LÍNEA SINTÉTICA P 0.625)

The aim of this study was to evaluate the effect of the supplementation of an enzymatic complex in integral diets for guinea pigs in the growing phase on productive performance. In total, 54 male guinea pigs (Synthetic line P 0.625) were used and submitted to a diet free of the enzyme complex (T1), and two experimental ones, one with 0.1% (T2) and the other with 0.2% (T3) of enzyme complex evaluated between two weeks of age (weaning) and after rearing (nine weeks old). It was statically evaluated and there were found no significant difference between treatments in relation to final body weight, weight gain, feed intake and feed conversion; and it was reported the weekly average of percentage of dairy dry matter intake by body weight.