Productive Performance Traits Research Articles

PSVI-16 Inclusion of dietary micelle silymarin on production performance, egg quality, storage capacity, and blood profile Sin Hy-line brown laying hens

Abstract Silymarin is known to have immunomodulating, anti-inflammatory and antioxidant effects. This study aimed to investigate the effects of micelle silymarin (MS) supplementation on production performance, egg quality, egg water loss, and blood profile in Hy-line brown laying hens. For 12 wk, a total of 288, 28-wk-old laying hens were randomly allocated into one of three treatment groups. The dietary treatments were control (CON) a basal diet and a basal diet supplemented with 0.03, and 0.06% of MS. All hens were housed in an individual cage with 38 cm width × 50 cm length × 40 cm height. Growth performance was recorded at d 1, wk 6, and wk 12. The egg production and feed conversion ratio were recorded at the end of every week. The egg quality and water loss were measured at the end of wk 4, 8, and 12. At initial and at the end of wk 12, 5 mL of blood was collected to analyze aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), triglycerides, albumin, and cholesterol concentrations. All data were analyzed by the GLM procedure of SAS. The polynomial orthogonal contrasts of increasing dietary MS supplementation were examined by linear and quadratic effects. The inclusion of MS supplement in laying hen diet did not exhibit significant impact on growth performance. However, MS group showed linear improvement in egg weight, Haugh Units, and eggshell strength throughout the trial period (P < 0.05). Additionally, egg yolk color and eggshell thickness indicated linear improvements particularly at wk 4 and 8 (P < 0.05). While albumen height and egg water in MS group were linearly increased at wk 12 (P < 0.05). Compared with CON, laying hens fed MS supplement has linearly decreased the ALP and cholesterol concentrations in the serum (P < 0.05). Based on the findings, we inferred that the inclusion of 0.04 to 0.06% MS in the laying hen diet would not only increase the production performance, egg quality, and egg water loss traits but also to improve laying hens’ health.

Performance, blood and antioxidant status in dual-purpose laying hens supplemented with aqueous extract of Christ's thorn jujube (Ziziphus spina-christi L.) leaves as phytogenic agent in subtropical conditions.

The potential of aqueous extract of Christ's thorn jujube (Ziziphus spina-christi) leaves (SLAE) to reduce the negative impacts of heat stress on production performance and physiological traits was investigated in dual-purpose layers under subtropical farming. A total of 200, 25-week-old laying hens (Inshas strain) were randomly assigned to four dietary treatments including SLAE at 0, 2.5, 5.0, and 7.5 mL/kg, respectively. The average temperature-humidity index value was 26.69 during the experimental period. The SLAE contained saponin (0.045%), total flavonoid content of 17.9 mg of quercetin equivalent/ 100 g and overall antioxidant capacity concentration of 17.9 mg of ascorbic acid equivalent/100 g. The maximum final body weight (BW), BW gain, egg weight, number, and mass occurred at the level of SLAE7.5 inclusion. The egg quality was significantly higher in SLAE groups than in control, and overall, SLAE7.5 had the most favorable influence at 28 and 32 weeks. Liver and kidney function, as well as lipids profile, improved significantly by SLAE inclusion; the lowest concentrations of these parameters were in SLAE7.5 hens. Treatment with SLAE7.5 increased total antioxidant capacity and endogenous antioxidant enzymes compared to control, whereas no effect on superoxide dismutase was noticed. The addition of SLAE at 7.5 mL/kg diet improved egg laying performance and quality, metabolic profiles, and antioxidant status during hyperthermia conditions.

Comparative analysis on growth performance, survival and harvest traits between offspring from wild and mass-selected populations of Crassostrea nippona

Crassostrea nippona has recently been recognized as a preferred alternative to C. gigas in summer due to its firm flesh and high glycogen content. To promote industrial development, the mass selective breeding program was initiated to improve growth performance of C. nippona in 2014. Although a steady genetic gain of approximately 10% for growth traits was achieved in each of the first three generations of the selected strains, little is known about the cumulative genetic progress in desired traits contributed by the selective breeding in the genetic improvement program. In this study, the aquaculture performance of the selected population was comprehensively evaluated by comparing the production performance and reproductive traits of the progeny (WF1 and SF4) from the wild population and the third-generation selected line in commercial farming environments. The results showed that the diameters of eggs from both populations were at similar levels, but the fertilization and hatching rates of the progeny from the selected lines were significantly higher than those of the wild population (P < 0.05). At larval stages, the shell height and cumulative survival rate (CSR) of individuals from SF4 were consistently superior to that of WF1, especially on day 6 post-fertilization, in which CSR of the improved C. nippona was increased by 25.08% compared to that of wild oysters. Meanwhile, a significant 12.10% enhancement in the metamorphosis rate was observed in SF4 when compared with WF1. During the grow-out stage, SF4 displayed distinct advantages in growth performance and survival compared to the wild strain, with 23.19, 33.48, 34.18 and 79.11% improvement in shell height, body weight, CSR and final yield at harvest on day 800, respectively. Meanwhile, relative brood amount (RBA) associated with initial development of offspring was found to be significantly higher in SF4 compared with WF1 (P < 0.05). Remarkably, the gonadal development, sex ratios and biochemical composition of oysters from both populations were at similar levels at final harvest, implying that high-intensity artificial selection had no significant effect on reproductive characteristics and nutritional quality of C. nippona. The encouraging results in the present study suggest that the overall genetic progress contributed by genetic breeding is considerable in the fast-growing strain of C. nippona, and such gains are expected to continue to increase with further selective breeding.

Some productive and reproductive performance, eggshell quality, serum metabolitesand immune responses due to L-threonine supplementation in Japanese quail breeders'diet.

A dose-response experiment was conducted to evaluate the effects of graded levels of dietary digestible threonine (dThr) during the first laying cycle on productive and reproductive performance, egg qualityand immune responses of Japanese quail breeders (Coturnix coturnix japonica). Also, dThr requirements were determined based on nutrient dose-response data. A total of 450 (360 females and 90 males) 11-week-old breeders were allocated to five increment (+0.03%) levels of dThr (0.49%, 0.52%, 0.55%, 0.58%, 0.61%and 0.64%) with five replicates per treatment and 15 (12 females and three males) birds each. The experiment lasted for 12 weeks. In response to increasing dietary dThr levels, egg production, egg mass, feed efficiency, egg specific gravity, eggshell relative weight, eggshell thickness, egg fertility (EF) and immune response against sheep red blood cell (SRBC) inoculation were improved with quadratic trends and egg hatchability as set eggs was improved with linear trends. Japanese quail breeders fed a diet with 0.58% dThr concentration (threonine/lysine ratio of 59%) showed the productive performance traits, EF, eggshell qualityand immune response against SRBC inoculation in the highest values. However, feed intake, egg weight, egg albumen and yolk relative weight, egg shape index, haugh unitand egg composition were not affected by increasing dietary dThr level. Based on the broken-line regression model, the dThr requirements to optimize productive performance, eggshell quality, EFand immune response against SRBC inoculation were estimated at 159-188, 169-183, 175and 178 mg/bird per day, respectively. It is concluded, in the Japanese quail breeders during the first laying phase a daily dThr intake of 188 mg/bird, dietary dThr concentration at 0.58% (threonine/lysine ratio of 59%) is adequate for optimized productive and reproductive performance, eggshell qualityand immune responses. The estimated requirements depend on what production parameter is taken into considered for optimization.

Evaluation of Native and Kadaknath chicken for production performance, egg quality traits and farmers acceptability in Western Himalayan region of Himachal Pradesh, India

The present study evaluated production performance and egg quality traits of native and Kadaknath chicken of Himachal Pradesh under sub-temperate western Himalayan region of India. External egg quality traits like egg weight, egg length, egg width, shell thickness and internal traits like length, height, width of albumen, yolk height, and yolk width were measured. Body weight of native and Kadaknath birds differed significantly at different age of measurements and body weight of native birds was significantly higher than Kadaknath. Age at sexual maturity was found less in native birds in comparison to Kadaknath. HHEP and HDEP was observed higher in native birds than Kadaknath. Mean value estimated for egg weight, egg length, egg width, shape index and shell thickness were 45.33 g, 54.99 mm, 41.27 mm, 75.02% and 0.36 mm, respectively in native eggs while corresponding values were 43.87 g, 53.61 mm, 40.80 mm, 76.20% and 0.34 mm, respectively in Kadaknath eggs. Albumen length, albumen width, yolk height and yolk index is observed significantly higher in native birds than Kadaknath. Appraisal of farm practices through field survey suggests that Kadaknath birds witnessed rising popularity in recent times. However, native birds of the region are better producers in comparison to Kadaknath. This suggests that native birds may be preferred over Kadaknath birds in similar regions where premium pricing of Kadaknath is unavailable. Occasionally peri-urban market offered opportunity of premium pricing based income through sale of Kadaknath birds. Thus, rearing of Kadaknath along with native birds is advised in such regions.

Genetic evaluation of crossbred Bos indicus cow temperament at parturition.

Cow temperament at parturition may be mostly a measure of aggressiveness. The heritability of cow temperament at parturition in Bos taurus cows has been reported to be low. The objectives of this study were to estimate the heritability of cow temperament at parturition, conduct a genome-wide association analysis of cow temperament at the time of parturition, and estimate the correspondence of cow temperament at the time of parturition with cow productive performance and early-life temperament traits in Bos indicus crossbreds. Cow temperament was assessed from 1 to 5 indicating increasing levels of aggressiveness of cows (937 cows and 4,337 parturitions) from 2005 to 2022. Estimates of heritability and repeatability were 0.12 ± 0.024 and 0.24 ± 0.018. The estimates of proportion of phenotypic variance were 0.13 ± 0.019 and 0.02 ± 0.011 for permanent and maternal permanent environmental components, respectively. Estimates of heritability for maximum lifetime temperament score and proportions of temperament scores >1 were 0.18 ± 0.07 and 0.13 ± 0.072. Within cycles (generations), 2-yr-old cows had lower temperament score means than cows in most other age categories. There were low to moderate positive estimates of unadjusted correlation coefficients (r = 0.22 to 0.29; P < 0.05) of unadjusted temperament score with temperament measured on the same females when they were 8 mo old. There were low to moderate positive estimates of correlation coefficients (r = 0.09 to 0.37; P < 0.05) of unadjusted temperament score with calving rate, weaning rate, weaning weight per cow exposed, and weaning weight per 454kg cow weight at weaning. Cows with the lowest temperament score had lower (P < 0.05) calving and weaning rate than cows in other temperament categories. Within 3 of 5 cycles, cows with the lowest temperament score (totally docile) had lower (P < 0.05) weaning weight per cow exposed than cows in other temperament categories. There were 2 SNP on BTA 4 associated with maximum lifetime temperament score (FDR < 0.05). The non-genetic influence of a cow's mother was documented in her own temperament measured at the time of calving; this may be a consequence of learned behavior. Less aggressiveness displayed by cows at the time of calving may be accompanied by lower reproductive and maternal performance.

Biological Selenium Nanoparticles in Quail Nutrition: Biosynthesis and its Impact on Performance, Carcass, Blood Chemistry, and Cecal Microbiota.

This study was conducted to examine the influence of dietary supplementation of biological nano-selenium (BNSe) on productive performance, hematology, blood chemistry, antioxidant status, immune response, cecal microbiota, and carcass traits of quails. In total, 180 Japanese quails (1week old) were randomly allocated into four groups, with five replicates of nine chicks each in a complete randomized design. The 1st group was fed a control diet without BNSe, and the 2nd, 3rd, and 4th treatments were fed diets supplemented with BNSe (0.2, 0.4, and 0.6g /kg feed, respectively). The best level of BNSe in body weight (BW) and body weight gain (BWG) parameters was 0.4g/kg diet. Feed conversion was improved (P < 0.01) by adding BNSe in quail feed compared with the basal diet without any supplementation. The inclusion of different BNSe levels (0.2, 0.4, 0.6g/kg) exhibited an insignificant influence on all carcass traits. The dietary addition of BNSe (0.4 and 0.6g/kg) significantly augmented aspartate aminotransferase (AST) activity (P = 0.0127), total protein and globulin (P < 0.05), white blood cells (WBCs) (P = 0.031), and red blood cells (RBCs) (P = 0.0414) compared with the control. The dietary BNSe supplementation significantly improved lipid parameters, antioxidant and immunological indices, and increased selenium level in the blood (P < 0.05). BNSe significantly increased (P = 0.0003) lactic acid bacteria population number and lowered the total number of yeasts, molds, total bacterial count, E. coli, Coliform, Salmonella, and Enterobacter (P < 0.0001). In conclusion, adding BNSe up to 0.4 and 0.6g/kg can boost the growth, lactic acid bacteria population number, hematology, immunological indices, antioxidant capacity, and lipid profile, as well as decline intestinal pathogens in growing quail.

Development of selection strategies for genetic improvement in production traits of Mecheri sheep based on a Bayesian multi trait evaluation

The progression of genetic selection techniques to enhance farm animal performance traits is guided by the present level of genetic variation and maternal impact in each trait, as well as the genetic association between traits. This study was conducted on a population of Mecheri sheep maintained from 1980 to 2018 at Mecheri Sheep Research Station, Pottaneri, India, to determine variance and covariance components, as well as genetic parameters for various production performance traits. A total of 2616 lambs, produced by 1044 dams and 226 sires, were examined in the study and the production traits of Mecheri sheep assessed include birth weight (BW), weaning weight (WW), six-month weight (SMW), nine-month weight (NMW), and yearling weight (YW). The Bayesian approach, using the Gibbs sampler, analyzed six animal models with different combinations of additive direct and maternal additive effects. Direct genetics, maternal genetics, and residual effects models were the major contributors to total phenotypic variation for all the production traits studied. Direct heritability estimates of birth weight, WW, SMW, NMW, and YW were 0.25, 0.20, 0.12, 0.14, and 0.13, respectively. The maternal heritability estimated for BW, WW, SMW, NMW, and YW were 0.17, 0.10, 0.12, 0.14, and 0.14, respectively. The maternal effects had a major impact on the pre-weaning production traits. The genetic correlations estimated between different pairs of production traits studied ranged from 0.19 to 0.93. The body weight at birth exhibited a higher genetic relationship with weaning weight than post-weaning growth characteristics, and the genetic correlation between weaning weight and post-weaning attributes was moderate to high (0.52 to 0.72). Based on the additive genetic variance in weaning weight and the correlation estimates of weaning weight with post-weaning traits, weaning weight was proposed as a selection criterion for improving growth traits in Mecheri sheep.

The Effect of Organic Trace Mineral Supplementation in the Form of Proteinates on Performance and Sustainability Parameters in Laying Hens: A Meta-Analysis.

The effect of supplementing organic trace minerals (OTM), in the form of mineral proteinates (Bioplex® Cu, Fe, Mn, and Zn, Alltech Inc., Nicholasville, KY, USA), in the diets of laying hens was examined using Comprehensive Meta-Analysis (CMA) statistical software. The impact on production performance, egg quality traits, and sustainability parameters related to the carbon footprint of egg production was assessed. Data were obtained from 32 global studies, comprising 107 dietary assessments of 30,992 laying hens. Overall pooled effect size (raw mean difference) of production performance when dietary organic trace minerals were supplemented either in basal diets, partial replacement of inorganic trace minerals (ITM), or total replacement of ITM, indicated that use of Bioplex minerals resulted in 2.07% higher hen-day production (HDP), whilst feed conversion ratio (FCR) was lower by 51.28 g feed/kg egg and 22.82 g feed/dozen eggs, respectively. For egg quality traits, daily egg mass was 0.50 g/hen/day higher and egg weight was 0.48 g per egg greater when Bioplex minerals were incorporated in the diet. The mean difference in egg loss was -0.62%. Eggshell thickness was greater by 0.01 mm, and a higher eggshell strength of 0.14 kgf was observed. Eggshell weight was heavier by 0.20 g, eggshell percentage was higher by 0.15%, and Haugh unit was 1 point higher (0.89). We also carried out a meta-regression of the effects of the study factors (location, year of study, hen breed/strain, age of hens, number of hens, and study duration) on the overall pooled effect size of the production performance and egg quality traits in response to supplementary OTM inclusion, and it indicated that certain factors had a significant (p < 0.05) impact on the results. Finally, a life cycle assessment (LCA) model was selected to evaluate the impact of feeding organic trace mineral proteinates on the carbon footprint (feed and total emission intensities) of the egg production using the data generated from the meta-analysis. Results showed that the inclusion of OTM proteinates resulted in an average drop in feed and total emission intensities per kg eggs of 2.40% and 2.50%, respectively, for a low-global-warming-potential (GWP) diet and a drop of 2.40% and 2.48% for feed and total emissions, respectively, based on high-GWP diet. Based on the overall results, the inclusion of organic trace mineral proteinates in layer diets can benefit production performance and egg quality traits while contributing to a lower carbon footprint.

Effects of Supplementation of Eurca Seeds as Nutraceutical Feed Additive on Productivity, Antioxidant Activity, and Yolk Cholesterol Level of Laying Hens

Eruca sativa (ES) seeds are annual herbs belonging to the Brassicaceae family, widely grown in Mediterranean countries, such as Egypt, Italy, and Greece. The ES is rich in macronutrient components and phytochemical content, exhibiting potent antioxidant properties and functional properties for vital processes such as digestion and absorption of nutrients. Therefore, this research was conducted to evaluate the effects of dietary ES supplementation on laying performance, some blood parameters, and egg yolk cholesterol. A total of 300 Silver Sabahia strain hens, aged 26 weeks, were randomly distributed among four groups of five replicates, each replicate consisting of 15 hens. Chickens in group 1 served as a control and were fed the basal diet. Those in groups 2, 3, and 4 were fed basal diet supplemented with 1, 2, and 3% ESs, respectively. Productive performance traits, egg quality traits, hematological parameters, blood parameters, and yolk cholesterol profiles were performed throughout the study. The study lasted for 13 weeks (until week 39 of chickens' age). Results indicated that 3% ES supplementation had higher results on egg mass (35.68%), egg production (21.13%), and improved feed conversion ratio by 30.37%, compared to all groups. Furthermore, ESs supplementation positively affects the shell thickness and yolk color score compared to the control. Compared to the control, the highest significant blood hemoglobin and lymphocytes were recorded in the groups supplemented with 2% and 3% of ESs. The ES inclusion at a higher level (3%) in the diet of laying hens led to significantly enhanced serum high-density lipoprotein and total antioxidant capacity, while reducing cholesterol, low-density lipoprotein, and malondialdehyde levels, compared to the control diet. Serum calcium, tri-iodothyronine, and alkaline phosphatase levels increased significantly in response to 3% ES treatment, while liver enzymes decreased significantly compared to the control diet. Notably, the addition of 2% and 3% ESs to the hens’ ration resulted in reduced egg cholesterol content, which is desirable for consumers seeking healthier dietary choices. Finally, adding 3% ESs to hens’ diet improves productive performance, egg quality traits, hematological parameters, blood parameters, and yolk cholesterol profile.

Comparative evaluation of different moulting methods on productive performance, egg quality, and antibody response of leghorn hens.

The aim of the study was to compare three moulting procedures and their effect on productive performance, egg quality, and antibody response of leghorn hens. For this, a total of 324 laying hens were distributed into three treatment groups having 12 replicates of 9 birds each according to completely randomized design. Treatments consisted of three moulting procedures based on feed and light restriction. The targeted weight at the end of moulting was 1450-1470 g. As soon as the moulting procedure is complete, the comparative analysis of post-moult productive performance (feed intake, egg production, egg weight, egg mass, feed per dozen eggs, feed per kg egg mass, livability), egg quality characteristics (egg weight, egg length and width, shape index, surface area, volume, albumen height, weight, Haugh unit score, yolk width, height, index, egg shell pore number, shell weight, thickness, breaking strength), and antibody response against Newcastle disease and avian influenza (H-9) were evaluated. Birds subjected to moulting procedure 3 (8 days fasting and gradual decrease in light) showed improvement in productive performance, egg geometry and quality traits, and antibody response against Newcastle disease virus. Birds experienced moulting procedure 1 (11 days fasting) had improved feed intake, egg production, and livability. However, birds moulted with procedure 2 (6 days fasting) revealed intermediate result in all the studied parameters. In conclusion, moulting through feed and light restriction with 8 days fasting and gradual reduction in light has potential to improve performance of leghorn hens.

Interactions of dietary wheat cultivars and NSP-degrading enzyme on productive performance and egg quality traits.

The nutritional value of enzyme-supplemented wheat-contained diets can be influenced by interactions between wheat cultivar and exogenous enzyme, which in turn cause various effects on the performance of poultry. The effects of diets including various wheat cultivars with or without enzyme on productive performance and egg quality characteristics were evaluated. A total of 270 58-week-old Lohmann LSL-Lite were allocated to 9 experimental dietary groups with 5 replicate cages and 6 birds per each cage. Based on a 4×2 factorial arrangement of treatment, nine iso-caloric and iso-nitrogenous experimental diets, including four wheat cultivars (Sardari, Azar 2, Pishgam and Sirvan) with and without enzymes plus a corn-based control diet, were tested in a completely randomized design during an 8-week trial period. From weeks 58 to 63 and 63 to 67 of age, the hens fed with Sardari-included diet showed the lowest feed intake compared to other groups (p<0.05). Egg production (EP), feed conversion ratio (FCR) and egg mass (EM) were not influenced by the experimental diets. At the age of 62 weeks, the effect of adding enzyme on egg shape index was significant. Moreover, in sampling week 67, increased eggshell weight (%) was detected in enzyme-supplemented diets compared to diets with no enzyme (10.03 vs. 9.37, respectively). Besides, the shell thickness was the highest in the group fed with Azar 2, and the lowest in the group fed with Sirvan at the age of 67 weeks (p<0.05). Albumen weights (%) were also significant in some cases. The highest albumen weight was observed in Sirvan-included diet without enzyme on week 62. Reduced yolk weight was detected in enzyme-supplemented Pishgam-included diet on 62 weeks of age (p<0.05). The inclusion of the diets of laying hens with the four tested Iranian wheat cultivars has no negative impact on most productive performance and egg quality indices. Moreover, supplementing the wheat-included diets with non-starch polysaccharidase enzyme (beta-endopower) improved eggshell weight on week 67.

Evaluation of the productive performance of Colombian hair sheep based on growth traits

Contextualization: Colombian hair sheep [CHS] are animals of great importance, because their genetic material has been adapting for more than 500 years to the environment; besides, these animals have a transcendental role in Colombia for their contribution to food security and family economy. However, a great part of the sheep production in the country presents low production parameters. Knowledge gap: ignorance of Colombian hair sheep (CHS) biotypes’ productivity has led to the undervaluation of the genetic resource found in these animals, accompanied by insufficient efforts to improve sheep production systems. Purpose of the study: determine the productive performance of three biotypes of Colombian hair sheep. Methodology: this study was conducted in these biotypes of hair sheep: Ethiopian [CHSE] (40 individuals), Sudan [CHSS] (60) and Creole crossed with Pelibuey [CHSP] (60). Five growth traits [birth weight, adjusted weaning weight at 90 days, adjusted final weight at the age of 1 year, and pre-weaning and post-weaning weight gain] were evaluated. Descriptive statistical and variance analysis were performed based on variables such as sex, farm, type of birth, parent, and season of birth. Also, a Duncan's multiple range test was performed. Results and conclusions: CHSE showed low productive parameters that were mostly affected by the variables sex and farm [p ≤ 0.05]. CHSs displayed a low to moderate productive performance and many traits were also affected by sex and farm [p ≤ 0.05]. Lastly, CHSP showed moderate to high productive parameters, which were mainly affected by parent, season, and type of birth [p ≤ 0.05]. The results determined the productive performance of the three sheep biotypes, among which CHSE showed low growth parameters, CHSS showed low to moderate parameters, and CHSP displayed moderate to high parameters. In all cases, the three biotypes were mostly affected by non-genetic variables.

Genetic parameter estimation for pork production and litter performance traits of Landrace, Large White, and Duroc pigs in Japan.

We estimated genetic parameters for two pork production and six litter performance traits of Landrace, Large White, and Duroc pigs reared in Japan. Pork production traits were average daily gain from birth to end of performance testing and backfat thickness at end of testing (46,042 records for Landrace, 40,467 records for Large White, and 42,920 records for Duroc). Litter performance traits were number born alive, litter size at weaning (LSW), number of piglets dead during suckling (ND), survival rate of piglets during suckling (SV), total piglet weight at weaning (TWW), and average piglet weight at weaning (AWW) (27,410, 26,716, and 12,430 records for Landrace, Large White, and Duroc, respectively). ND was calculated as the difference between LSW and litter size at start of suckling (LSS). SV was calculated as LSW/LSS. AWW was calculated as TWW/LSW. Pedigree data for Landrace, Large White, and Duroc breeds contained 50,193, 44,077, and 45,336 pigs, respectively. Trait heritability was estimated via single-trait analysis and genetic correlation between two traits was estimated via two-trait analysis. When considering the linear covariate of LSS in the statistical model for LSW and TWW, for all breeds, the heritability was estimated to be 0.4-0.5 for pork production traits and below 0.2 for litter performance traits. Estimated genetic correlation between average daily gain and backfat thickness was small, ranging from 0.057 to 0.112, and those between pork production traits and litter performance traits were negligible to moderate, ranging from -0.493 to 0.487. A wide range of genetic correlation values among the litter performance traits was estimated, while that between LSW and ND could not be obtained. The results of genetic parameter estimation were affected by whether the linear covariate of LSS was included in the statistical model for LSW and TWW or not. This finding implies the necessity of carefully interpreting the results according to the choice of statistical model. Our results could give fundamental information on simultaneously improving productivity and female reproductivity for pigs.

Regrouping in Dairy Ewes—Effects on Productive Performance and Specific Behavioral Traits

The regrouping of ruminants is a common practice in dairy farms and is targeting at the improvement of milk production efficiency. However, changing the established hierarchy in a group affects both productivity and behavioral attributes. The aim of the present study was therefore to examine the possible effects of regrouping on milk yield, composition and several behavioral indices in dairy ewes. The experimental period was divided into two sub-periods of 20 days each. During the first period, 30 Chios ewes were used, while 15 Chios and 15 Karagouniko ewes were mixed during the second period. Milk yield, composition, oxidative stability, flow rate and number of kick responses during milking were recorded for each ewe. An isolation-flight distance test was also performed on a weekly basis. As indicated, the parameters recorded during the behavioral tests, such as the number of bleats, heart rate and flight distance, and the milk oxidation rate and number of kick responses were significantly increased immediately after regrouping compared to the following days during both sub-periods (p < 0.05). Moreover, milk yield was reduced in the second sub-period by 8.61% (p < 0.05). It can be concluded that regrouping could negatively influence productive and behavioral traits, and the effect was more pronounced when sheep of different breeds were mixed.

Impact of Cannabis Seed Incorporation in Layer Diet on Productive Performance and Egg Quality Traits.

The production of nonindustrial cannabis is highly developed in the Moroccan Rif region; however, local farmers consider hemp seeds which are rich in omega 3 and tocopherols, only as by-products of cannabis cultivation with low market value. The local ecotype is considered to be a plant with a cannabinoid content of more than 0.4%. So, the objective of this research is to investigate how the incorporation of this local hemp seed affects productive performance and egg quality traits. The experiment is conducted to evaluate the effects of hemp seed (HS) incorporation on hen laying performance and physical egg quality at three levels: 10% (HS-10% group), 20% (HS-20% group), and 30% (HS-30% group). Ninety-six Lohmann Brown classic laying hens were randomly assigned to a control group and three feed treatments. The sampling was taken after the 28-week rearing period (peak egg laying). Throughout the experiment, low-rate HS inclusion (HS-10%) showed no significant differences in egg-laying performance (p > 0.05). However, the high incorporation rates of HS (20% and 30%) negatively affected the egg-laying performance (84-94% and 80-86%, respectively). The albumen quality was also improved by the HS inclusion, where the highest values of the Haugh unit were recorded, ranging between 68.69 and 73.91 for the HS-30% groups. The results also show that HS inclusion and duration influence significantly the yolk color (p < 0.001). The yellow intensity decreases with HS incorporation and aging, from a dark yellow (b ∗ = 38.63 for the control group) to a very pale yellow (b ∗ = 26.29 for HS 30% group). Based on these findings, we can conclude that the incorporation of nonindustrial Moroccan cannabis seeds (ecotype Beldiya) at low rate in the diet of laying hens does not alter the laying performance or the quality of the egg; therefore, they could be used in poultry feeding as an alternative constituent to partially replace high-cost imported ingredients, such as corn and soybeans.

The Effect of Early Feeding and Transporting Time from Hatcher to Farm On the Productive Performance and Carcass Traits of Broiler Chickens.

New researches suggest that an early feeding approach has a long-term influence on chick growth performance and nutrient metabolism. The present study was designed to determine the effect of early feeding and the time of chickens transferring from the hatchery to the field on broiler chickens' productive performance and carcass traits. Two hundred twenty-five chickens, one-day-old of broiler chickens Ross 308 with a mean live body weight of 45 g, were used and were randomly distributed to five treatments by 45 chickens per treatment with three replicates (15 chickens per replicate). The experimental treatments were as follows: T1 (control treatment) - the chickens were transferred 24 hours after hatching to the field without feeding, and in groups T2 to T5, the chickens were fed immediately and transferred to the field 24, 6,12,18 hours after hatching, respectively. The current results showed no significant (P>0.05) effects of the experimental treatments on final body live weight, weight gain, feed intake, and feed conversion ratio. In addition, the treatments' insignificant (P>0.05) effects on the weights of the carcass, abdominal fat, breast, thigh, back, wing, neck, heart, liver, and gizzard were found. It can be concluded that there was no evidence of a positive effect of early feeding and transporting duration after hatching on productive performance and carcass characteristics of broilers.

Assessments of productive performance, eggshell quality, excreta moisture, and incubation traits of laying breeder hens fed a proprietary blend of Quillaja and Yucca.

A study was conducted to evaluate performance, eggshell quality, nutrient metabolizability, and incubation traits of laying breeder hens fed diets supplemented with an additive containing polyphenols and saponins of a proprietary blend from Quillaja saponaria and Yucca schidigera (QY) biomass. Hens were fed 4 feeds in 5 periods of 28 days each from 30 to 49 weeks of age. Experimental feeds were a Control diet; Control + virginiamycin (33 g/ton); Control + QY (250 g/ton) and Control + virginiamycin + QY. A total of 40 White Plymouth Rock and 44 Rhode Island Red breeder hens were allocated in individual cages using a completely randomized block design with 21 replicates. Performance parameters, evaluated per period, were egg production, egg weight, FCR, egg mass, and culled eggs. All eggs were collected in the last 4 days of each period to evaluate specific egg weight, percentage of albumen, yolk and shell, and Haugh unit as well as cuticle quality, shell strength, and shell thickness. At the end of the experiment, nutrient metabolizability assessment and four incubations were conducted. There were no interactions between diet and period in all evaluated responses (P > 0.05). Experimental diets did not affect daily egg production, egg weight, and egg mass as well as Haugh unit, yolk and albumen percentage, and yolk color (P > 0.05). However, hens fed Control + QY produced eggs with better shell strength, shell thickness, and cuticle quality than hens fed the Control (P < 0.05). Hens fed Control + QY or Control + virginiamycin + QY had lower culled eggs, better FCR and higher egg specific weight, shell percentage, and yolk strength compared to breeder hens fed the Control (P < 0.05). In general, hens fed QY achieved enhanced performance and egg quality compared to virginiamycin. In conclusion, laying breeder hens fed diets supplemented with Quillaja and Yucca additive, from 30 to 49 weeks of age, maintained their productive performance, had improved eggshell and cuticle quality and reduced culled, dirty and contaminated eggs.

Dietary inclusion of flaxseed oil, fish oil and their combinations on production performance and egg quality traits in White Leghorn hens

A total of 120, 28-week-old White Leghorn hens were randomly selected to study the effect of dietary inclusion of flaxseed oil (FSO) , fish oil (FO) and their combinations on production performance and egg quality traits in White Leghorn hens and the birds were divided into six treatments that had four replicates of five birds each. The experimental groups were fed with control diet and diet containing 5.0 per cent FSO, 5.0 per cent FO, 2.5 per cent FSO + 2.5 per cent FO, 3.5 per cent FSO + 1.5 per cent FO and 1.5 per cent FSO +3.5 per cent FO. The experiment was conducted from 29 to 40 weeks of age comprising three, 28-day periods. The obtained data on statistical analysis, did not reveal any significant difference in body weight, egg production, feed intake, feed conversion ratio, egg weight and egg quality traits of White Leghorn hens among all the treatment groups at all the periods of age.

ENZYMES FROM Pleurotus ostreatus SPENT SUBSTRATE USED FOR FATTENING RABBITS: EFFECTS ON PRODUCTIVE PERFORMANCE, CARCASS TRAITS AND MEAT CHARACTERISTICS

Rabbit meat has a high nutritional value. The cost of rabbit feed is high, and thus it is important to find alternative feed sources with reduced costs. The objective was to evaluate the effects of enzymes obtained from the spent substrate of Pleurotus ostreatus on carcass traits and meat characteristics of fattening rabbits in order to recommend an alternative additive for rabbit feed. Spent substrate of P. ostreatus with different levels of enzymatic activity was used to feed growing rabbits. Ninety-sixty rabbits were selected and randomly distributed to four treatments: 0 (control without enzyme extract, C); 20000 (T20); 40000 (T40); and 60000 (T60) IU kg-1 of laccase enzymes from the spent substrate of P. ostreatus. The experiment included six repetitions (four animals each) per treatment. Rabbits were fattened over 28 d and productive performance parameters were determined. Then, the animals were slaughtered, and carcass traits and meat characteristics were measured. The results indicated that total weight gain, total feed consumption, total daily weight gain, hot carcass weight, and dressing percentage decreased (p 0.05) as the amount of enzyme increased. However, the T40 treatment was similar to the control (p 0.05) for carcass traits, texture and pH, although L , cooking loss and hardness recorded higher values (p 0.05). In conclusion, the spent substrate of P. ostreatus can be used to feed rabbits as some parameters of productive performance and carcass traits were similar to the control treatment.