Journal of Livestock Science and Technology
Volume:11 Issue: 1, Jun 2023

The objective of present study was to assess the effects of unprotected and calcium salts of oils on total tract digestibility, ruminal degradation and fermentation in lambs. Four lambs fitted with ruminal fistula were used in a change-over design using 2 × 2 factorial arrangement. Levels of first factor (oils) were palm oil and linseed oil and levels of second factor were protected oil (calcium salts) and unprotected oil. Feeding of palm oil resulted in higher ruminal effective degradability of neutral detergent fiber (NDF) than linseed oil, and lambs fed protected oil had higher ruminal effective degradability of NDF than unprotected oil (P<0.05). Lambs fed palm oil had higher dry matter intake (DMI) and total tract digestibility of nutrients compared to those fed linseed oil. Acetate concentration in lambs fed palm oil was higher compared to linseed oil. Feeding of protected oil resulted in higher acetate concentration than unprotected oil (P<0.05). The lowest acetate concentration was found in lambs fed unprotected linseed oil (ULO) and the highest acetate concentration was observed in lambs fed unprotected and protected palm oil (UPO and PPO, respectively). Lambs fed palm oil had the highest gas and methane production compared to linseed oil. Protected oil resulted in higher gas and methane production than unprotected oil (P<0.05).  Lambs fed PPO had the highest, and those fed ULO had the lowest methane production (P<0.05). Based on the results, protection of linseed oil is necessary to enhance ruminal degradation and fermentation, but this process is not necessary for palm oil.

The proportion of adipose depots varies considerably between fat-tailed (FT) and thin-tailed (TT) sheep breeds. FT breeds accumulate majority of body fat in fat-tail depot, whereas TT breeds deposit considerable proportion of body fat in visceral depots. These differences in proportion of adipose depots seem to affect body metabolism due to differences in metabolism of different depots. Hence, the current research aimed to evaluate the response of fat-tailed lambs (FTL) and thin-tailed lambs (TTL) to glucose and insulin challenges during negative energy balance (NEB) and positive energy balance (PEB). Glucose tolerance and insulin challenge tests were conducted on randomly selected lambs from each genotypes at the end of induced NEB and PEB. Glucose injection during NEB caused greater plasma glucose concentration in TTL, whereas in PEB, the enhancement in glucose concentration as a consequence of glucose injection was higher in FTL (P≤0.09). The area under the glucose curve was higher in FT compared to TT lambs during glucose tolerance test regardless of energy balance (EB; P≤0.03). The clearance rates of insulin (P≤0.09) and glucose (P≤0.006) in the respective insulin and glucose tolerance tests were higher during PEB compared to NEB regardless of the genotypes. These results demonstrated that induced NEB can enhance insulin resistance in both FT and TT lambs, severity of which is greater in FT than in TT lambs.

The current experiment was conducted to evaluate the effects of replacing dietary corn/barley mixture with molasses, a ruminal fermentable carbohydrate source, at 0, 50 and 100 g/kg dietary dry matter (DM) in the diet of fattening lambs containing corn steep liquor (CSL, 130 g/kg DM), a ruminal degradable protein source. Twenty-four male Lori lambs (average body weight of 27.7±3.41 kg; 120.0±7.5 days of age) were randomly assigned into three groups of eight lambs each in a balanced completely randomized design. Results indicated that supplementing dietary CSL with increasing levels of molasses up to 100 g/kg DM linearly increased the digestibility of organic matter and ash-free neutral detergent fiber (P<0.05). Increasing the level of molasses in the CSL containing diets had no effect on ruminal pH (P>0.05), but linearly decreased rumen concentration of NH 3-N (P<0.05). Except for total volatile fatty acids (VFAs) and molar proportion of butyrate which were increased linearly with increasing dietary molasses level, other VFAs were not influenced by the experimental diets. Increasing the level of molasses in the diet up to 100 g/kg DM linearly increased plasma total protein concentration while linearly reduced blood urea nitrogen concentration. Total weight gain and average daily gain were improved but feed conversion ratio decreased linearly with increasing dietary level of molasses. In conclusion, supplementing CSL with molasses at the level of 100 g/kg dietary DM increased the nutrient digestibility and performance of fattening lambs.

Lighting is one of the important management factors affecting the health and welfare of birds. The objective of this study was to assess the effects of light-emitting diodes (LEDs) on production, reproduction, blood metabolites, immunology, and hepatic sterol regulatory element binding protein-1 (SREBP1) gene expression in broiler breeders. One-day-old Ross 308 female breeder chicks (n=100) were randomly assigned to 20 light-proof pens and reared under five lighting regimens, including green (GL) or white (WL) LED at two exposure photophases (8 or 12 hours) as a 2 ´ 2 factorial experiment plus a control group (incandescent lamp at 8L:16D duration; CON). The LED color affected the feed intake during the rearing period, being higher in white than in green light; however, green light resulted in more medium and large white follicles on the ovaries, higher mean corpuscular hemoglobin concentration, and plasma cholesterol level. In WL8 lighting, the relative weight of the bursa of Fabricius was higher (P≤0.05) than in CON birds. Plasma cholesterol level in GL12 was higher compared to CON. Conventional and WL12 regimens resulted in lower plasma alkaline phosphatase activity. Twelve hours of GL lighting resulted in higher eggshell weight and strength while it caused a small but significant decrease in egg shape index. Greater numbers of medium white (MWF) and large white (LWF) follicles were recorded in GL12 birds, and there were more small white follicles (SWF) in GL8 group (P≤0.05). The GL12 and CON lighting resulted in higher concentrations of WBC and Hb compared with WL. Hepatic expression of SREBP1 was higher in WL8 birds. The results indicated that green LED improved egg quality while white LED caused higher relative weight of bursa and hepatic SREBP1 expression, indicating the LED light may be beneficial to broiler breeder productivity. However, more studies are required to substantiate these findings.

Inflammatory-dependent events in the aged commercial laying hens reduce production rate and egg quality. Our study was aimed to evaluate the phosphodiesterase (PDE) inhibitor Theophylline on the ovarian and fallopian-inflammatory traits in the commercial laying hens at the late stage of the production period. Twenty-four White Leghorn hens aged 92 weeks were used for four weeks to be orally supplemented by Theophylline (3 mg/kg/Body weight, BW). Ovulation rate and follicular growth were measured by laying frequency and, visual evaluation after euthanizing, respectively. The mRNA expressions of follicular and fallopian cyclooxygenases 1 and 2 (COX-1,-2), and cytokines were detected by real-time PCR. Plasma concentrations of ovarian hormones (Two hours after lighting) were measured via enzyme-linked immunosorbant assay (ELISA). The results showed that the mRNA expression of the IL-1β, IL-6 and TNF-α in the ovary and IL-1β and TNF-α in the infundibulum were significantly decreased (P<0.01) by Theophylline treatment; however, the mRNA abundance of COX-2 and IL-10 in both of ovary and infundibulum were increased (P<0.01). Plasma concentrations of estradiol and progesterone were elevated (P<0.05) in the hens treated with Theophylline. Ovulation rate and follicular size were not significantly (P>0.05) influenced by Theophylline. As a phosphodiesterase inhibitor, Theophylline retained the laying frequency in addition to enhancing its anti-inflammatory capability in the late stage of production period in laying hens.

In this study, the antioxidant properties of fennel essential oil nanoemulsion (FEON) and its effect on European production efficiency factor, blood metabolites, immune system, and cecal microbial population of broiler chickens under heat stress conditions were investigated. Two hundred one-d-old Ross broiler chickens were arranged in a completely randomized design with 5 treatments, 4 replicates, and 10 birds each. The birds were fed on a basal diet (control), basal diets supplemented with 50, 100, and 200 mg kg-1 fennel essential oil nanoemulsion (FEON50, FEON100, and FEON200) and 200 mg kg-1 fennel essential oil (FEO). The results showed that compared with FEO, all concentrations of FEON had greater antioxidant activity (P≤0.001). During the starter, grower, and the whole phase of the rearing period, the performance indicators such as the European production efficiency factor and European broiler index, were not affected by dietary treatment. Further, blood total cholesterol and low-density lipoprotein contents were significantly decreased by supplementation of broiler diets with FEON (P≤0.01). Primary antibody titer against sheep red blood cells (SRBC) was affected by the addition of FEO and FEON50 into broiler diets (P≤0.05). Moreover, the Lactobacillus population of cecal content was significantly increased and coliform populations were decreased when FEON was added to the diet. The Escherichia coli population of cecal content decreased when FEO and FEON were supplemented into the diets (P≤0.05). The jejunal, ileal, and cecal digesta pH decreased significantly in the FEON50 treatment. The results of this experiment showed that under heat stress conditions, supplementation of broiler chickens' diets with FEON can enhance primary humoral immunity and improve the broiler gut health and FEON50 was the optimal level.

The present study was performed to quantify a latent variable for body size (BS) from the five linear body measurements, including body length (BL), body height (BH), chest width (CW), chest girth (CG), and tube girth (TG). The study population consisted of N= 5573 Yorkshire pigs, 592 individuals out of them were genotyped using a PorcineSNP80 BeadChip. The body size latent variable was determined using Confirmatory Factor Analysis (CFA). Then, the accuracy of breeding values was obtained using pedigree-based best linear unbiased prediction (PBLUP), genomic best linear unbiased prediction (GBLUP), and single-step genomic best linear unbiased prediction (ssGBLUP) models. The overall fit indices, including standardized root mean square residual (SRMR), root mean square error of approximation (RMSEA), Tucker-Lewis Index (TLI), and comparative fit index (CFI) were obtained for the BS as 0.03, 0.09, 0.93, and 0.96, respectively which imply the adequacy of the considered model for BS construct. The performance of models was measured in a 5-fold cross-validation with 10 repeats to get a more accurate measure of the model's performance. The accuracy of models was compared via the correlation between predicted breeding values (PBV) and estimated breeding values (EBV) metric which was 0.37, 0.30, and 0.28 for PBLUP, ssGBLUP, and GBLUP, respectively. Furthermore, the goodness of fit is measured by the mean square of error (MSE) and Pearson's correlations r(y, ) between observed and predicted phenotypes. The lowest MSE and the highest Pearson's correlations were obtained under PBLUP while the highest MSE and the lowest Pearson's correlations were obtained under GBLUP. The obtained results showed the GBLUP method generally provided lower prediction accuracies than PBLUP and ssGBLUP methods, and also ssGBLUP generated lower prediction accuracy than traditional PBLUP. The performance of ssGBLUP and GBLUP was lower than expected mainly due to the small number of genotyped animals.

The purpose of this research was to compare different statistical methods such as GBLUP, BayesA, BayesB, BayesC, BayesL, Ridge regression, Boosting and SVM for genomic evaluation of traits with additive and dominance genetic architecture. A genome consisting of 5 chromosomes was simulated, with 1000 single nucleotide polymorphism markers (SNP) uniformly distributed on each chromosome. In two different scenarios, 50 and 500 quantitative trait loci (QTL) were considered and in each scenario of QTL number, 0.00, 10, 20, 50 and 100% of QTLs were given dominance genetic effect. The prediction accuracy, bias and reliability of genomic breeding values were used for analyzing the results and comparing the methods. The results showed that not separating the dominance effects from the additive effects lead to a decrease in the accuracy and reliability and an increase in the bias of the predicted genomic breeding values. In all examined scenarios of the QTL number and percentages of QTLs with dominance effect, the Bayesian methods had higher prediction accuracy and reliability and their predictions had the least bias. Boosting predicted the genomic breeding values with the lowest accuracy and reliability and highest bias. The performance of SVM and Ridge regression was better than Boosting, but lower than Bayesian methods and GBLUP. In terms of computing speed, GBLUP and Boosting were, respectively, the fastest and the slowest method. It can be concluded that to increase the efficiency of genomic selection, first, the dominance genetic effects need to be included in the model and, second, methods with the highest predictive performance should be used.