Growth Performance Variables Research Articles

Comparative analysis of genetic diversity, growth performance, disease resistance and expression of growth and immune related genes among five different stocks of Labeo rohita (Hamilton, 1822)

For the initiation of a genetic improvement program of any culturable fish species, the assessment of the genetic quality of different stocks is prerequisite. However, in Pakistan, such data of all culturable fish species including an indigenous Labeo rohita are lacking. Here, an attempt has been made to determine the genetic diversity among five different stocks of L. rohita using DNA barcoding with cytochrome oxidase subunit I (COI) and cytochrome b genes and then compared their growth performance, immune response, and disease resistance. For the evaluation of growth performance, fingerlings of five different stocks; TH-S (Tawakkal Fish Hatchery Muzaffargarh), MCH-S (Government Fish Hatchery Mian Channu), RH-S (Rawal Fish hatchery Islamabad), SH-S (Farooqabad Fish Hatchery Sheikhupura), and MRH-S (Char Banda Fish Hatchery Mardan) across Pakistan were collected, PIT tagged, and reared in communal earthen ponds for 3 months under semi-intensive culture conditions. Similarly, for the evaluation of immunity and disease resistance, the environmental influence was minimized by conducting experiments under control conditions and challenging with Staphylococcus aureus. The results of both DNA barcoding markers indicated the significant level of genetic difference among different stocks, as clades in the phylogenetic trees clearly separated five stocks. The growth performance, immunity, and disease resistance data also revealed significant (p < 0.05) differences among them, as TH-S followed by MCH-S showed the highest growth performance in term of weight gain, specific growth rate, and the expression of Insulin like growth factor II (IGF II) and Preproghrelin genes in muscle and liver tissues compared to other strains. The post-challenge survival (%), and the expression of immune-related genes, i.e., Natural killer enhancing factor (NKEF), Complement component (C9), Hepcidin, and Transferrin genes also showed a similar trend among strains. The overall results indicated the genetic variability and variation in growth performance and disease resistance among different stocks of L. rohita collected from different hatcheries. Based on the results, it seems that TH-S has more vigor in terms of growth rate and disease resistance.

Evaluating differences between formulated dietary net energy values and net energy values determined from growth performance in finishing beef steers.

Based on principles of the California Net Energy System, the dry matter intake (DMI) by feedlot cattle can be subdivided into DMI required for maintenance and DMI required for gain. Thus, if DMI along with body weight at a compositional endpoint and shrunk weight gain are known, dietary concentrations of net energy for maintenance and gain (NEm and NEg, respectively) can be calculated from growth performance data. Close agreement between growth performance-predicted and tabular NEm and NEg values implies the system can be used to accurately predict growth performance and be used to evaluate marketing and management decisions. We used 747 pen means from 21 research studies conducted at Texas Tech University and South Dakota State University to assess the agreement between growth performance-predicted NEm and NEg values and those calculated from tabular energy values for feeds reported by the 2016 National Academies of Science, Engineering, and Medicine publication on beef cattle nutrient requirements. Regression of growth performance-predicted values on tabular values with adjustment for random effects of study indicated that the intercepts of the two regressions did not differ from zero, and the slopes did not differ from one. Residuals (tabular minus growth performance-predicted values) for NEm and NEg averaged -0.003 and -0.005, respectively. Nonetheless, the precision of growth performance-predicted values was low, with approximately 40.3% of performance-predicted NEm values and 30.9% of NEg values falling within 2.5% of the corresponding tabular value. Residuals for NEm were divided into quintiles to evaluate dietary, growth performance, carcass, and energetics variables that might help explain lack of precision in growth performance-predicted values. Among the variables considered, gain:feed ratio was the most discriminating, with differences (P < 0.05) among each of the quintiles. Despite these differences, however, gain:feed ratio did not explain important percentages of variation in components of growth performance-predicted NEm values like maintenance energy requirements (r2 = 0.112) and retained energy (r2 = 0.003). Further research with large datasets that include dietary composition, growth performance and carcass data, and environmental variables, along with fundamental research on maintenance requirements and energy retention, will be required to identify ways to improve the precision of growth performance-predicted NE values.

Effect of dietary supplementation of organic and inorganic Se on performance and antioxidant response in commercial broiler chickens

ABSTRACT 1. The study was carried out to determine the effects of supplementing organic (OG) or inorganic (IOG) Se to record the performance, immune and anti-oxidant response in broiler chickens. 2. One-day-old Vencobb-400 (50.1 ± 0.84 g; n = 280) male broiler chicks were allocated randomly into seven treatments to give eight replicates containing five chicks each and housed in deep littered floor pens (76 cm × 91 cm) for a period of 42 d. 3. The control diet (CD) was formulated without any Se supplementation (diet I), CD plus 0.15, 0.30 or 0.45 mg/kg OG Se (diets II, III and IV, respectively) and CD plus 0.15, 0.30 or 0.45 mg/kg IOG Se (diets V, VI and VII, respectively). 4. Feed intake (FI), body weight gain (BWG), immune variables and mRNA expression profile of hepatic selenoproteins (SepW, GSHPx1, TrxR and GSHPx3) genes were determined. The BWG, FI and feed conversion ratio did not differ among various dietary treatments. 5. The lipid peroxidation and activity of RBC catalase were lower (P < 0.05) in groups fed diets supplemented OG Se compared to those fed IOG Se and CD. The activity of GSH Px was higher among the groups fed diet supplemented OG Se compared to those groups fed OG Se and CD. However, supplementing diets with OG or IOG Se did not affect humoral or cell mediated immune responses. 6. The expression levels of SepW were higher (P < 0.01) among the groups supplemented with OG Se. Expression levels of GSH-Px1, TrxR and GSHPx3 were higher (P < 0.01) among the groups supplemented with OG Se compared to those groups fed IOG Se or CD. 7. Supplementing OG Se improved the activities of anti-oxidant enzymes and hepatic expression of selenoproteins genes in the present study. However, supplementing OG or IOG Se did not affect growth performance and immune variables in broiler chickens.

The effects of a nutritional packet (live yeast, vitamins C and B1, and electrolytes) offered to steers in a calf-fed system on growth performance, nutrient digestion, feeding behavior, carcass characteristics, and ruminal variables.

Effects of a nutritional packet strategically offered to calf-fed system steers on growth performance, nutrient digestibility, feeding behavior, ruminal variables, and carcass characteristics were evaluated. Angus crossbred steer-calves (N = 60; body weight [BW] = 234 ± 4 kg) were used in a randomized complete block design (block = BW) and stratified into two treatments: 1) control; and 2) 30 g/steer-daily (dry matter [DM] basis) of a nutritional packet containing (steer-daily basis): Live yeast (Saccharomyces cerevisiae; 1.7 × 1010 CFU), vitamin C (Ascorbic acid, 162 mg), vitamin B1 (thiamin hydrochloride, 400 mg), sodium chloride (2.4 g), and potassium chloride (2.4 g). Animals were offered (electronic feed-bunks [SmartFeed, C-Lock Inc., Rapid City, SD]), a steam-flaked corn-based finishing diet to ad libitum (individual intake), once daily for 233 d. Treatments were offered during the first and last 60 days on feed (DOF). The GLIMMIX procedure of SAS was used, with steer as the experimental unit, treatment and phase (for feeding behavior and digestibility) as fixed effects, and BW-block as a random effect. Steers offered the nutritional packet had 14% less (P < 0.01) intake and 18% greater (P = 0.01) feed efficiency during the initial 30 DOF. Intake (days 0 to 233) was 6% greater (P = 0.02) for steers offered the nutritional packet, while BW gain was not different (P ≥ 0.44). Greater (P = 0.02) dressing percent (61.1% vs. 62%) for steers offered the packet was observed, while other carcass variables were not different (P ≥ 0.33). Digestibility of DM, organic matter, and fiber were greater (P < 0.01) for steers offered the packet. Steers offered the packet spent 13% less time eating during the first 60 DOF, while during the last 60 DOF a 14% greater meal frequency and 12.3% smaller mean meal size (treatment × phase interaction, P < 0.02) were observed. Steers offered the packet had a reduced (P ≤ 0.01) mean meal duration during both phases. Regardless of treatment, a decreased rumination (P ≤ 0.03) and chewing (P ≤ 0.01) activities were observed for the last 60 DOF compared to the first 60 DOF. Ruminal papillae area was 30% greater (P = 0.02) and the total volatile fatty acid (VFA) tended (P = 0.09) to be greater for steers offered the nutritional packet. The nutritional packet offered to calf-fed steers improved feed efficiency during the initial 30 d after arrival, while inducing superior overall intake, nutrient digestibility, dressing percentage, ruminal papillae area, and total ruminal VFA.

Investigations on modulating effect of three tropical red seaweed by-products on growth performance, immune response, antioxidant status and endocrine variables in crossbred calves

Investigations on modulating effect of three tropical red seaweed by-products on growth performance, immune response, antioxidant status and endocrine variables in crossbred calves

Assessing essentiality of nickel in growing Hariana heifers by determining its effect on performance, nitrogen and mineral metabolism, urease activity, and endocrine biomarkers

The objective of this study was to determine the effect of nickel (Ni) on growth performance, nutrient utilization, urease activity, and endocrine variables in growing cattle. Growing Hariana heifers (18) were randomly assigned into three groups (n=6), i.e. groups either without Ni supplementation (Ni0.0; control) or supplemented with 1.5 mg of Ni/kg DM (Ni1.5), and 3.0 mg of Ni/kg DM (Ni3.0). The experiment lasted for 90 days. Heifers supplemented with Ni showed higher nutrient intake and average daily gain (ADG) than control group. The nutrient digestibility was not affected by treatment, while the Ni supplemented animals showed higher intake, excretion, and nitrogen balance. The urease activity was comparable and higher in the Ni1.5 and Ni3.0 groups than in the control group. There was no effect of treatment on the metabolism of calcium (Ca), phosphorus (P), zinc (Zn), copper (Cu), and chromium (Cr). However, iron (Fe) retention showed a negative association with Ni levels. Plasma cortisol concentration was lower while the insulin like growth factor-1 (IGF-1) and tetraiodothyronine (T4) were higher in the Ni3.0 group compared to the Ni0.0 group, with Ni1.5 being intermediate. The plasma concentrations of triiodothyronine (T3) and thyroid stimulating hormone (TSH) were not affected by dietary treatment. Plasma Ni concentration showed a dose dependent increase whereas, plasma levels of other minerals were not affected by treatment. In conclusion, dietary Ni supplementation in growing Hariana heifers improves performance and nutrient utilization by modulating urease activity and endocrine growth biomarkers.

The effects of administering different metaphylactic antimicrobials on growth performance and health outcomes of high-risk, newly received feedlot steers.

Bovine respiratory disease (BRD) is the primary animal health concern facing feedlot producers. Many antimicrobial mitigation strategies are available, but few studies have compared feedlot performance during both the receiving and finishing periods following application of different antimicrobials used as metaphylaxis at arrival. The objective of this study was to compare antimicrobial metaphylaxis methods on clinical health and growth performance across both the receiving and finishing periods. A total of 238 multiple-sourced steers in two source blocks were used in a generalized complete block design. The four treatments included: 1) a negative control, 5 mL of sterile saline injected subcutaneously (CON); 2) subcutaneous administration of florfenicol at 40 mg/kg of BW (NUF); 3) subcutaneous administration of ceftiofur in the posterior aspect of the ear at 6.6 mg/kg of BW (EXC); and 4) subcutaneous administration of tulathromycin at 2.5 mg/kg of BW (DRA). The morbidity rate for the first treatment of BRD was decreased for the DRA and EXC treatments compared to CON and NUF (P < 0.01). Additionally, average daily gain (ADG), dry matter intake (DMI), and gain-to-feed (G:F) were greater (P ≤ 0.02) in the DRA treatment during the receiving period compared to all other treatments. The ADG was also greater (P < 0.05) for EXC than the CON treatment throughout the finishing period. Nonetheless, other growth performance variables did not differ among metaphylactic treatments during the finishing period (P ≥ 0.14). Likewise, no differences in carcass characteristics or liver abscess score were observed (P ≥ 0.18). All complete blood count (CBC) variables were affected by day (P ≤ 0.01) except mean corpuscular hemoglobin concentration (P = 0.29). Treatment × time interactions were observed for platelet count, white blood cell (WBC) count, monocyte count and percentage, and lymphocyte percentage (P ≤ 0.03). However, there were no observed hematological variables that differed among treatment (P ≥ 0.10). The results indicate that some commercially available antimicrobials labeled for metaphylactic use are more efficacious than others in decreasing morbidity rate.

Growth Performance of Kuroiler (Rhode Island x White Leghorn) Chickens Fed Aflatoxin Contaminated Maize- Based Diets Treated with Different Amounts of Lemon (Limon citrus) Juice

Aflatoxin contamination in feed and feed ingredients is prevalent worldwide, and poses serious risks to both livestock and humans. This study was conducted to assess the effects of feeding Aflatoxin (AF) contaminated maize-based diets treated with varying levels of Lemon juice, to Kuroiler chickens on their growth performance. Lemon juice was extracted from fruits purchased from the local market and mixed with isocaloric and Isonitrogenic diets (starter, grower and finisher) containing AF-contaminated maize, at 0, 250, 500 and 750ml Lemon juice/Kg of feed. The diets were left to dry for 24hrs, after which 100g samples were collected from each diet to measure and compare the residual AF levels. Then, 100 day-old Kuroiler chicks were sourced from a local hatchery, and divided into four treatment groups (n = 25). Each group was replicated four times. The treatment groups were randomly assigned to 0, 250, 500, and 750ml Lemon juice/Kg feed –treated diets. These feeds and clean drinking water, were supplied to the birds ad libitum for 49 days. Feed intake was monitored every day, and body weights, weight gains, and feed conversion ratios were assessed every week. It was observed that the amount of residual AF in each diet depended on the amount of lemon juice used to treat it. Untreated diet had the highest AF levels at 36 ppb, followed by that which was treated with 250, 500, 750 ml Lemon juice/Kg feed at 28.1, 21.3, and 7.4 ppb, respectively. Growth performance variables assessed were also influenced by the amounts of residual AF levels in the diet. Birds fed diets with the lowest residual AF levels at 7.4 ppb had the best (p &lt; 0.05) growth performance in all the variables, while the least (p &lt; 0.05) was observed in birds fed untreated diet, followed by those that were fed diets treated with 250 and 500ml Lemon juice/Kg feed. It was concluded that Lemon juice was able to degrade AF in diets that had maize contaminated with AF, but the extent to which it inactivated it, depended on the amount of juiced used. Similarly, growth performance of birds fed diets with AF-contaminated maize treated with lemon juice was also dependent on the levels of residual AF in feeds after treatment, with the best performance observed in chickens fed diets treated with 750ml Lemon juice per Kg feed.

Effects of dietary palygorskite supplementation on the growth performance, oxidative status, immune function, intestinal barrier and cecal microbial community of broilers

The present study aimed to investigate the effects of palygorskite (PAL) as an alternative to antibiotic on the growth performance, oxidative status, immune function, intestinal barrier and cecal microbial community of broilers. A total of 360 1-day-old male Ross-308 broilers were randomly allotted to three treatments with eight replicates. Broilers in the three groups were designated as follows: basal diet (CON group), basal diet+50 mg/kg chlorotetracycline (ANT group), and basal diet+ 10 g/kg PAL (PAL group). Supplementing PAL reduced feed to gain ratio in broilers during 22 to 42 days of age (P < 0.05), with its value being similar to that of the ANT group (P > 0.05). Broilers fed a PAL-supplemented diet exerted decreased contents of interferon-γ (IFN-γ) and interleukin-1β in serum, and the same reduction was found in jejunal IFN-γ level, when compared to the CON group (P < 0.05). Moreover, compared with the CON group, broilers after PAL treatment had a lower malondialdehyde content in jejunal mucosa (P < 0.05). Supplementing PAL elevated jejunal villus height (VH) and ratio of VH to crypt depth compared with the ANT group (P < 0.05). Cecal microbiota communities among the three groups were significant different, as demonstrated by distinct clusters from partial least squares discriminant analysis, although dietary treatments had no significant effects on the bacterial richness and diversity indices (P > 0.05). At genus level, the addition of PAL increased the relative abundance of norank_f__Barnesiellaceae and decreased that of unclassified_f__Oscillospiraceae in cecal digesta compared with those in the CON group (P < 0.05); the proportion of genus norank_f__Barnesiellaceae was increased by PAL treatment when compared with the ANT group (P < 0.05). Moreover, spearman's correlations showed that the modulation of cecal microflora composition by PAL supplementation was closely correlated with the promotion of growth performance (feed to gain ratio) and intestinal health-related (contents of malondialdehyde and IFN-γ, and VH value in jejunum) variables of broilers (P < 0.05). Taken together, dietary PAL could improve the growth performance, antioxidant capacity, and immune status, as well as intestinal barrier function in broilers, which might be partially associated with the alteration of cecal microbiota. Moreover, dietary PAL may be a promising alternative to antibiotic growth promoter for broilers.

Addition of essential oil from Lippia sidoides to the diet of tambaqui: An analysis of growth, metabolic and blood parameters, and intestinal enzymes

Plant essential oils can benefit fish growth and health when incorporated into fish diets. This study aimed to evaluate the effect of dietary supplementation of essential oil from Lippia sidoides (EOLS) on growth performance, hematological and biochemical variables, and digestive enzymes in tambaqui (Colossoma macropomum) juveniles. Five diets with different levels of EOLS—0.0 (control), 0.25, 0.50, 1.00, and 1.50 mL kg diet−1— were evaluated for 60 days. Carvacrol was the major chemical compound (44.50%) of EOLS. Supplementation of 0.50 mL EOLS kg diet−1 improved growth performance and increased hematocrit, hemoglobin rate, mean corpuscular hemoglobin concentration, plasma glucose, liver, and muscle glycogen values in juveniles. The tambaqui fed a diet supplemented with 1.00 or 1.50 mL EOLS kg−1 increased plasma triglycerides, albumin, lysozyme, and alanine aminotransferase levels, in addition to intestinal amylase and lipase activity. As the EOLS concentration in the diet increased, intestinal alkaline protease activity was reduced. In conclusion, the addition of 0.50 to 1.00 mL EOLS kg diet−1 is a promising alternative for tambaqui juveniles, as it has been shown to improve growth, metabolism, hematological parameters, and plasma lysozyme and intestinal amylase and lipase activity.

Recommended levels of calcium and non-phytate phosphorus for yellow-feathered broilers (finisher phase).

This study examined the effects of dietary calcium (Ca) and non-phytate phosphorus (NPP) on performance, tibial characteristics, meat quality and plasma biochemical variables in yellow-feathered broilers during 85 to 105 d of age. A total of 720 heads of 85-d broilers were allocated into 9 groups and provided with three levels of Ca (0.65%, 0.75%, 0.85%), and NPP (0.25%, 0.30%, 0.35%) in diets for 21 d. The final body weight (FW), average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F:G) were affected (p<0.05) by dietary Ca. From the quadratic regressions, the optimal level of Ca in diet were 0.71% for FW and ADG, and 0.67% for ADFI. Dietary Ca and NPP both significantly affected tibial breaking strength and density. From the quadratic regressions, the optimal level of Ca and NPP in diet were 0.81% and 0.37% for tibial density. The shear force of breast muscle of broilers given 0.75% or 0.85% Ca were lower than that in birds with 0.65% Ca and drip loss of birds given 0.65% or 0.75% Ca was lower than that in birds with 0.85% Ca (p<0.05). The drip loss of birds given 0.25% NPP was lowest among all NPP treatments (p<0.05). Calcium affected (p<0.05) the plasmal contents of phosphorus, osteocalcin (OC), parathyroid hormone (PTH) and calcitonin and the contents of OC and PTH were also influenced by dietary NPP. Dietary Ca and NPP level affected tibial characteristics, meat quality and biochemical variables in plasma of finisher-phase yellow-feathered broilers (85 to 105 d) and Ca also affected growth performance. Dietary 0.71% Ca and 0.30% NPP were enough for growth performance, while considering the growth performance, tibial characteristics, meat quality and biochemical variables together, 0.75% Ca and 0.37% NPP were recommended.

Uso de óleos essenciais em dietas de frangos de corte de crescimento lento e seus efeitos sobre o desempenho

ABSTRACT This study proposes to examine the effect of supplementing the diet of slow-growing broilers with essential oils. A total of 270 one-day-old female chicks of the Pesadão Vermelho line, reared in an intensive system, were allocated to one of three treatments (1: Control, without addition of essential oils; 2: Feed supplemented with cinnamon essential oil; and 3: Feed supplemented with lemongrass essential oil) in a completely randomized design with nine replicates of 10 birds each. Growth performance variables were evaluated at 14, 28, 42, 56, and 70 days, whereas carcass yield, primal cuts, and internal organs were analyzed at 71 days of age. Data were subjected to analysis of variance and differences between means were compared using the Scott-Knott test at 5% probability. Supplementation with lemongrass essential oil improved the live weight of birds at 14, 28, and 42 days, as well as feed conversion and feed efficiency at 42 and 56 days of rearing (P&lt;0.05). The treatments with cinnamon and lemongrass essential oils provided the highest thigh yields (P&lt;0.05). The other evaluated variables did not show statistically significant differences (P&gt;0.05) between treatments.

Variability in growth-determining hydraulic wood and leaf traits in Melia dubia across a steep water availability gradient in southern India

In India, short-rotation plantations have increasingly been promoted over the last decades in response to altered forest management policy and increased wood demand. Understanding how short-rotation forest species coordinate fast growth with water demand and carbon investment will help improving management decisions.We investigated the intra-specific variability in growth performance, leaf traits, and wood anatomical and derived hydraulic properties in 31 Melia dubia (Meliaceae) plantations along a steep rainfall gradient from 450 to 1,700 mm yr−1, and addressed the role of different irrigation practices and soil nutrient availability.We found water supply and soil nutrient status to have a dominant influence on the aboveground biomass increment (AGBI) of M.dubia. AGBI was higher at irrigated sites with a less negative climatological water balance (i.e. with lower rainfall) and at sites with higher soil phosphorus availability. Stem wood anatomical traits associated with the water transport capacity mirrored the patterns in AGBI. At sites with higher water and soil phosphorus availability, the xylem was composed of larger vessel diameters and lower vessel densities. However, both branch wood anatomical traits and leaf traits including the leaf-to-sapwood area ratio were largely independent of water availability and soil conditions.We conclude that a high stem hydraulic efficiency determined by large xylem vessels is a prerequisite for high aboveground productivity, and that the growth of M. dubia may often be phosphorus-limited. Short-rotation plantations with M.dubia will therefore clearly benefits from continuous irrigation in regions that receive annual precipitations substantially below 1,000 mm yr−1. This highlights the potential to increase yields in this important short-rotation forest species by improving irrigation and fertilization protocols.

Effect of Nanoencapsulated Alginate-Synbiotic on Gut Microflora Balance, Immunity, and Growth Performance of Growing Rabbits.

A synbiotic comprising Saccharomyces cerevisiae yeast (SCY) and Moringa oleifera leaf extract (MOLE) has been encapsulated using nanotechnology. This duo is used as a dietary supplement for growing rabbits. Physicochemical analyses, in vitro antimicrobial activity, and gastrointestinal system evaluation were used to evaluate the quality of the nanofabricated synbiotic. The in vivo study was conducted using 40-day-old male growing rabbits (n = 16 rabbits/group) to evaluate the effect of the nanofabricated synbiotic on the health and growth performance of examined rabbits. Rabbits were equally allocated into four groups; (a) NCS, which received a basal diet supplemented with a noncapsulated 11 × 1012 CFU SCY + 0.15 g MOLE/kg diet, (b) LCS: those receiving a nanoencapsulated 5.5 × 1012 CFU SCY + 0.075 g MOLE/kg diet, (c) HCS: those receiving an 11 × 1012 CFU SCY + 0.15 g MOLE/kg diet, and (d) CON: those receiving a basal diet without treatment (control). The treatments continued from day 40 to day 89 of age. During the experimental period, growth performance variables, including body weight (BW), feed consumption, BW gain, and feed conversion ratio were recorded weekly. Blood samples were collected on day 40 of age and immediately before the start of the treatments to confirm the homogeneity of rabbits among groups. On day 89 of age, blood samples, intestinal, and cecal samples were individually collected from eight randomly selected rabbits. The size and polydispersity index of the nanofabricated synbiotic were 51.38 nm and 0.177, respectively. Results revealed that the encapsulation process significantly improved yeast survival through the gastrointestinal tract, specifically in stomach acidic conditions, and significantly increased in vitro inhibitory activities against tested pathogens. Furthermore, treatments had no negative effects on hematobiochemical variables but significantly improved levels of blood plasma, total protein, and insulin-like growth factor-l. Compared to the CON, NCS, and LCS treatments, the HCS treatment increased the amount of intestinal and cecal yeast cells (p < 0.05) and Lactobacillus bacteria (p < 0.05) and decreased number of Salmonella (p < 0.05) and Coliform (p = 0.08) bacteria. Likewise, both LCS and HCS significantly improved the small intestine and cecum lengths compared to CON and NCS. The HCS treatment also significantly improved BW gain and feed conversion compared to CON treatment, whereas the NCS and LCS treatments showed intermediate values. Conclusively, the nanoencapsulation process improved the biological efficiency of the innovative synbiotic used in this study. A high dose of encapsulated synbiotic balanced the gut microflora, resulting in the growth of rabbits during the fattening period.

PSIV-2 A comparison of feedlot growth and performance of beef x Holstein crossbred steers and Holstein steers

Abstract Objectives were to compare feedlot performance and carcass traits of F1 beef × Holstein steers and Holstein steers. Angus or Limousin × Holstein crossbred [n = 27; age = 12 ± 3 months; body weight (BW) = 435 ± 8 kg] and Holstein (n = 20; age = 11 ± 2 months; BW = 400 ± 9 kg) steers were fed at the Pennsylvania Department of Agriculture Livestock Evaluation Center for 111 days. Feed intake was recorded using the GrowSafe Feed Intake Monitoring System (Model 4000E, GrowSafe Systems Ltd., Calgary AB, Canada). The diet contained corn silage, dried distillers grains, soybean meal, and cracked corn and was formulated to meet or exceed the requirements of beef cattle (NASEM, 2016). Growth performance variables of interest and carcass measurements were analyzed with the Mixed procedure of SAS (SAS 9.4; SAS Institute Inc., Cary, NC). USDA assigned quality grades (QG) and yield grades (YG) were analyzed the with GLIMMIX procedure of SAS. Breed was a fixed effect in all models. There were no differences (P &amp;gt; 0.05) between breeds in average daily gain or feed efficiency. Crossbreds exceeded Holsteins in initial (P &amp;lt; 0.01) and final BW (P = 0.01), dry matter intake (P = 0.03), hot carcass weight (P &amp;lt; 0.01), backfat (P = 0.03), and ribeye area (REA; P &amp;lt; 0.01). Thirty-five percent (35%) of the Holsteins received a QG of Choice or above while 74% of crossbreds graded USDA Choice or above (P = 0.01). However, 75% of Holsteins were YG 2 or lower while only 45% of crossbreds achieved YG 2 or less (P = 0.05). There was no improvement in efficiency when crossbreds were compared to Holsteins; however, carcasses from crossbreds were more likely to grade USDA Choice or above while yielding greater REA and backfat than Holsteins.

Factors affecting performance response of pigs exposed to different challenge models: a multivariate approach.

Factors associated with the severity with which different challenge models (CMs) compromise growth performance in pigs were investigated using hierarchical clustering on principal components (HCPC) analysis. One hundred seventy-eight studies reporting growth performance variables (average daily gain [ADG], average daily feed intake [ADFI], gain:feed [GF], and final body weight [FBW]) of a Control (Ct) vs. a Challenged (Ch) group of pigs using different CMs (enteric [ENT], environmental [ENV], lipopolysaccharide [LPS], respiratory [RES], or sanitary condition [SAN] challenges) were included. Studies were grouped by similarity in performance in three clusters (C1, C2, and C3) by HCPC. The effects of CM, cluster, and sex (males [M], females [F], mixed [Mi]) were investigated. Linear (LRP) and quadratic (QRP) response plateau models were fitted to assess the interrelationships between the change in ADG (∆ADG) and ADFI (∆ADFI) and the duration of challenge. All variables increased from C1 through C3, except for GF, which decreased (P < 0.05). LPS was more detrimental to ADG than ENV, RES, and SAN models (P < 0.05). Furthermore, LPS also lowered GF more than all the other CMs (P < 0.05). The ∆ADG independent of ∆ADFI was significant in LPS and SAN (P < 0.05), showed a trend toward the significance in ENT and RES (P < 0.10), and was not significant in ENV (P > 0.10), while the ∆ADG dependent on ∆ADFI was significant in ENT, ENV, and LPS only (P < 0.05). The critical value of ∆ADFI influencing the ∆ADG was significant in pigs belonging to C1 (P < 0.05) but not C2 or C3 (P > 0.10). The ∆ADG independent of duration post-Ch (irreparable portion of growth) was significant in C1 and C2 pigs, whereas the ∆ADFI independent of duration post-Ch (irreparable portion of feed intake) was significant in C1 pigs only (P < 0.05). Moreover, the time for recovery of ADG and ADFI after Ch was significant in pigs belonging to C1 and C2 (P < 0.05). Control F showed reduced ADG compared with Ct-M, and Ch-F showed reduced ADFI compared with Ch-M (P < 0.05). Moreover, the irreparable portion of ΔADG was 4.8 higher in F (-187.7; P < 0.05) compared with M (-39.1; P < 0.05). There are significant differences in growth performance response to CM based on cluster and sex. Furthermore, bacterial lipopolysaccharide appears to be an appropriate noninfectious model for immune stimulation and growth impairment in pigs.

Effects and interaction of dietary calcium and non-phytate phosphorus for slow-growing yellow-feathered broilers during the starter phase

Calcium (Ca) and non-phytate phosphorus (NPP) are fundamental minerals for bone formation and growth, and optimizing their level is required in broiler production. This experiment was conducted to investigate the effect and interaction of dietary Ca and NPP on growth performance, tibial characteristics and biochemical variables for slow-growing yellow-feathered broilers during 1–28 d (the starter phase). Seven hundred and twenty hatchling female broilers were randomly divided into nine groups, which received three levels of Ca (0.80%, 0.90%, 1.00%) each with three levels of NPP (0.40%, 0.45%, 0.50%). The results showed: (1) Dietary Ca level influenced (P < 0.05) the feed to gain ratio (F:G) and average daily feed intake (ADFI). Compared with broilers provided 1.00% Ca, ADFI of birds provided with 0.80% or 0.90% Ca and F:G of those with 0.90% Ca were decreased (P < 0.05). Dietary NPP level did not affect (P > 0.05) growth performance of broilers. (2) Dietary Ca affected (P < 0.05) tibial length. Compared with birds provided with 0.80% Ca, the length of tibia was decreased (P < 0.05) in birds received 1.00% Ca. Interactions between dietary Ca and NPP were observed (P < 0.05) on ash content, breaking strength and bone density of tibia. These three characteristics were better when birds received 0.90% Ca and 0.40% NPP or 1.00% Ca and 0.45% NPP. (3) Dietary Ca significantly affected (P < 0.05) the activity of alkaline phosphatase (ALP) in serum with decreased activity in birds fed 0.80% or 0.90% Ca. The dietary NPP influenced (P < 0.05) the contents of Ca in serum. Serum Ca was increased when birds were provided 0.40% NPP compared with other levels (P < 0.05). Again, there was interaction between Ca and NPP in diet on the contents of phosphorus (P) in serum (P < 0.05). In conclusion, interactions occurred between dietary Ca and NPP level on tibial breaking strength, density, ash content, and the content of P in the serum of young yellow-feathered broilers. Furthermore, dietary Ca affected ADFI, F:G and serum ALP activity, and dietary NPP also affected the P content in serum. Considering all indicators, 0.90% Ca and 0.40% NPP are optimal for slow-growing yellow-feathered broilers during 1–28 d of age.

Different soybean meal particle sizes on growth performance, nutrient ileal digestibility, digestible energy, and carcass yield of broiler chickens

An experiment was conducted to investigate the effect of soybean meal (SBM) with different particle sizes included in mash diets on digestible energy, nutrient digestibility, and growth performance of broiler chickens. A total of 720 one-d-old male broiler chickens were assigned to 4 treatments with 9 replicates of 20 broiler chickens each in a completely randomized design and reared from d 0 to 42. The treatments consisted of the dietary inclusion of SBM with different particle sizes of 625, 775, 1,053, and 1,406 μm. Coefficients of apparent ileal digestibility, growth performance variables, and carcass yield, and relative yield of parts were evaluated. The SBM particle size had a quadratic effect on crude protein digestibility and ileal digestible energy (P < 0.05). From d 0 to 21, feed intake was linearly reduced as SBM particle size increased, whereas WG increased and FCR improved quadratically (P < 0.05). From d 22 to 35, WG and FCR linearly improved (P < 0.05) as SBM particle size increased, but from d 36 to 42, growth performance was not affected. During the total experimental period (d 0 to 42), WG tended to increase (P = 0.06), and FCR decreased linearly (P < 0.05) as dietary SBM particle size increased, but feed intake was not affected. Carcass yield variables were not influenced by SBM particle size. As a conclusion, diets containing SBM with large particles fed to broiler chickens from d 0 to 42 result in similar crude protein digestibility and digestible energy as smaller SBM particles, but greater WG and better FCR can be obtained with large SBM particles.

Effect of fennel essential oil on performance, serum biochemistry, immunity, ileum morphology and microbial population, and meat quality of broiler chickens fed corn or wheat-based diet

ABSTRACT 1. The effect of Foeniculi aetheroleum essential oil (EO) on growth performance, nutrient utilisation, serum biochemistry, immune response, ileum morphology, microbial population and meat quality of broiler chickens fed a corn- or wheat-based diet were determined. 2. A total of 360 broiler chickens were arranged in a 2 × 2 factorial assay in a completely randomised design with six replicates and 15 birds per experimental unit. Birds were fed corn- or wheat-based diets supplemented with (200 mg/kg) or without fennel EO. 3. Birds fed wheat-based diets had lower BWG and FCR during grower period and lower FI during finisher period as compared to those fed corn-based diet (P < 0.05) whereas addition of fennel EO decreased chickens BWG during finisher period and EPEF, both in wheat or in corn-based diets. Dietary treatments had no effect on serum glucose, triglyceride, cholesterol, LDL-cholesterol, AST, ALT, ALP, and MDA concentrations (P < 0.05). 4. Antibody titres against avian influenza and sheep red blood cell antibody titres, crude protein and crude fat utilisation, villus height, crypt depth and epithelium thickness were not influenced by dietary treatments (P > 0.05). Inclusion of Fennel EO to the corn-based diet resulted in greater villus width and villus surface area while it reduced lamina propria thickness (P < 0.05). Fennel EO reduced ileal E. coli and Lactobacillus spp. populations (P < 0.05). Dietary treatments had no significant effect on meat pH, cooking loss, drip loss, crude protein, crude fat content and cholesterol concentration of breast and thigh meat, total phenolic and MDA concentrations, and breast meat sensory parameters (P > 0.05). 5. These results showed that addition of fennel EO to wheat-based diets had a negative effect on chicken growth performance variables and decreased gut E. coli populations. However, immunity, meat quality and nutrient utilisation were not affected by dietary treatments.

High feeding level alters physiological status but does not improve feed conversion efficiency and growth performance of juvenile red swamp crayfish Procambarus clarkii (Girard, 1852)

Red swamp crayfish, Procambarus clarkii (Girard, 1852), aquaculture has developed rapidly in recent years. However, limited knowledge about the response of physiological processes to different feeding levels has hindered the expansion of scientific feeding strategies. The present study was conducted to evaluate the growth performance (specific growth rate: SGRw, survival, and moulting frequency), feed utilisation (feeding rates, feed conversion ratio: FCR, waste production ratio: WPR), and physiological response variables to different feeding levels (1%, 2%, 3%, 4%, 5%, and 6% body weight per day, BW day−1) of juvenile P. clarkii for 60 days. Each treatment was replicated ten times, with 40 juveniles per treatment. No significant differences were observed in the growth performance of P. clarkii fed at 3%, 4%, 5%, and 6% BW day−1. However, they exhibited a significantly higher feeding rate, and FCR and WPR values when fed at 6% BW day−1. Among the physiological variables, activities of digestive enzymes (trypsin, lipase, and AKP) and antioxidant enzymes (SOD, CAT, and MDA) were significantly correlated with feeding levels; the Pearson correlation coefficients of these enzymes were 0.82, 0.57, 0.39, 0.66, 0.70, and −0.38, respectively. The biochemical indicators of nutrient status (total protein, total cholesterol, triglyceride, and GOT and PK activities) increased with increasing feeding levels, as revealed by the Self-Organizing Map. The two-way ANOVA revealed that P. clarkii fed at 5% and 6% BW day−1 had significantly higher trypsin and PK activities, and total protein and total cholesterol contents, whereas when fed at 6% BW day−1, it was exposed to oxidative stress. When the physiological variables were grouped by principal component analysis (PCA), they varied over experimental dates. P. clarkii exhibited higher trypsin, lipase, and MDA activities on the 20th day, but lower triglyceride content and GOT activity than on the 40th day. This study indicated that P. clarkii did not benefit from high feeding level (6% BW day−1), providing an incentive for farmers to reduce dietary input and production costs, thus promoting the sustainability of P. clarkii aquaculture.