RESUMEN
This study estimated the genetic parameters of productive and reproductive traits of Iranian Holstein cattle from data recorded between 2006 and 2018. The data analysis was performed using animal model, including the record of the first parity and the first three lactation records. Heritability values for milk, fat, and protein using a single record animal model were 0.29 ± 0.005, 0.22 ± 0.005, and 0.24 ± 0.005, respectively. The heritability of these traits based on a repeated model was estimated to be 0.19 ± 0.001, 0.15 ± 0.005, and 0.17 ± 0.006, respectively. Furthermore, the heritability of age at first calving (AFC) and length of lactation (LL) traits were 0.16 ± 0.004 and 0.02 ± 0.002, respectively. Repeatability for milk, fat, and protein yield was 0.38 ± 0.002, 0.34 ± 0.002, and 0.36 ± 0.002, respectively. Positive genetic trend was observed over the years of the study for production traits. Evaluation of the effect of herd-year-season (HYS) on the productive traits revealed that the management and environmental conditions of the farms including feed quality and disease control have been improved. The average heritability for milk, fat, and protein yield and AFC indicates the possibility of genetic improvement for these traits. Furthermore, the repeatability values show that the selection process can be performed based on the first lactation record. The positive genetic trend of productive traits demonstrates the improvement of breeding values in Iranian Holstein cattle.
Asunto(s)
Lactancia , Reproducción , Embarazo , Femenino , Bovinos/genética , Animales , Irán , Reproducción/genética , Lactancia/genética , Leche/metabolismo , FenotipoRESUMEN
The cotton plant (Gossypium hirsutum) is a shrub native to many arid and semi-arid regions around the world, while the nutritional value of its wastes has been less scientifically investigated. Different components of whole cotton plant wastes (WCPW) including leaf blade, cotton pod, stem, root, bract, petiole, and cottonseed were evaluated for their nutritional values by standard laboratory methods. After that, we tested the WCPW for partial substitution (0, 20, 40, and 60% substitution or 0, 10, 20, and 30% of dietary dry matter (DM)) with dietary common forage in a completely randomized design with 32 feedlot male lambs for 90 days. A diverse range of chemical and mineral compositions was found among the different WCPW's components. The cottonseed had the highest crude protein (CP) and ether extract (EE) contents, while the lowest neutral detergent fiber (NDF) and acid detergent fiber (ADF) were observed in the leaf blade (P < 0.0001). The highest contents of calcium, phosphorus, sodium, magnesium, and iron were also observed in the leaf blade (P < 0.0001). Higher potential gas production, in vitro organic matter digestibility (OMD), in vitro dry matter digestibility (DMD), and total volatile fatty acids (TVFA) were also related to the leaf blade (P < 0.0001). Bract had the highest acid-base buffering capacity (P < 0.0001). The lambs fed on 30% of dietary DM with WCPW exhibited lower final body weight (BW), average daily gain (ADG), CP or NDF digestibility, ruminal TVFA, propionate, plasma total protein, and higher feed conversion ratio (FCR) compared to the control group. Generally, WCPW can be substituted up to 40% of common forages (or 20% of diet DM) without any adverse effect on growth performance and blood metabolites of feedlot lambs, especially during feed shortages.
Asunto(s)
Fibras de la Dieta , Gossypium , Ovinos , Animales , Fibras de la Dieta/metabolismo , Aceite de Semillas de Algodón/metabolismo , Detergentes/análisis , Detergentes/metabolismo , Detergentes/farmacología , Digestión , Alimentación Animal/análisis , Oveja Doméstica , Dieta/veterinaria , Rumen/metabolismoRESUMEN
Inbreeding depression, the reduction of fitness and performance, is due to an increase in the mating of related individuals. Based on the purge hypothesis, inbreeding and breeding over generations reduce the effect of deleterious alleles responsible for inbreeding depression. Thus, recent inbreeding is assumed to be more harmful than ancestral inbreeding. This study aimed at evaluating the effects of new and ancestral inbreeding on milk, fat and protein production in Iranian Holstein cattle. The secondary objective was to examine the changes in predicted breeding values when the inbreeding effect was included in the model's analysis. To this end, inbreeding coefficients were calculated using the pedigree of 2,394,517 Holstein cattle to achieve these goals. In addition, 419,132 records of milk, fat and protein yields of first parity cows were collected to assess inbreeding depression and breeding values. The average inbreeding coefficients were 0.83% and 1.68% for the whole population and the inbred animals, respectively. A 1% increase in classical pedigree-based inbreeding coefficient was associated with a decrease of 11.99 kg in milk, 0.39 kg in fat and 0.29 kg in protein. The effect of ancestral inbreeding was more detrimental to performance traits than the effect of new inbreeding. This result contradicted the hypothesis of purging. By including the inbreeding coefficient in the model, the rank of animals remained unchanged, but the average predicted breeding values increased. In general, inbreeding depression was observed in Iranian Holstein cows; however, no evidence of purging was observed. The average of inbreeding coefficients was not high in this population, although accounting for inbreeding coefficients in the analytical model did significantly increase the predicted breeding values. It is recommended that the analytical model incorporate the inbreeding coefficient to improve the accuracy of genetic evaluation. In future studies, inbreeding depression should be assessed using genomic data for performance and reproduction traits.
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Endogamia , Leche , Femenino , Bovinos/genética , Animales , Leche/metabolismo , Lactancia/genética , Irán , Reproducción , LinajeRESUMEN
We designed this project to determine the nutritional potential and ruminal microbial fermentation properties of eight rangeland plants (Dracocephalum moldavica L., Melissa officinalis L., Ruta graveolens L., Perovskia abrotanoides Kar., Cichorium intybus L., Borago officinalis L., Peganum harmala L., and Teucrium polium L.) collected from the semi-arid region of Iran at two consecutive years (2019 and 2020) for ruminant diets. Medicago sativa as a common forage was also considered as control. We determined the chemical-mineral composition, buffering capacity, in vitro gas yield, ruminal fermentation, and protozoa population in a culture medium with the standard laboratory methods. A significant difference in chemical-mineral compounds was observed among the studied plants (p < 0.05). A lower crude protein range (6.28% for Cichorium intybus L. to 18.4% for Melissa officinalis L.) was observed rather than Medicago sativa (20.3%). The amount of calcium was highest in Peganum harmala L. (23.5-24.2 g/kg DM) and lowest in Ruta graveolens L. (1.15-1.25 g/kg DM). Dracocephalum moldavica L. exhibited the highest acid-base buffering capacity (235-242 mEq×10-3) among other plants. The highest decrease in total protozoa and other protozoan populations was observed when Perovskia abrotanoides Kar. was added to the culture medium. Teucrium Polium L. had the greatest potential gas yield and its total volatile fatty acid was comparable with Medicago sativa. It seems that eight plants are nutritionally suitable for partial replacement of the conventional plants such as Medicago sativa in diets of small ruminants, however dietary supplementation of Peganum harmala L. due to its alkaloids content should be done with caution.
RESUMEN
Salmonella Enteritidis is a major cause of food poisoning worldwide, and poultry products are the main source of S. Enteritidis contamination for humans. Among the numerous strategies for disease control, improving genetic resistance to S. Enteritidis has been the most effective approach. We investigated the association between S. Enteritidis burden in the caecum, spleen, and liver of young indigenous chickens and seven candidate genes, selected on the basis of their critical roles in immunological functions. The genes included those encoding interleukin 2 (IL-2), interferon-γ (IFN-γ), transforming growth factor ß2 (TGF-ß2), immunoglobulin light chain (IgL), toll-like receptor 4 (TLR-4), myeloid differentiation protein 2 (MD-2), and inducible nitric oxide synthase (iNOS). Two Malaysian indigenous chicken breeds were used as sustainable genetic sources of alleles that are resistant to salmonellosis. The polymerase chain reaction restriction fragment-length polymorphism technique was used to genotype the candidate genes. Three different genotypes were observed in all of the candidate genes, except for MD-2. All of the candidate genes showed the Hardy-Weinberg equilibrium for the two populations. The IL-2-MnlI polymorphism was associated with S. Enteritidis burden in the caecum and spleen. The TGF-ß2-RsaI, TLR-4-Sau 96I, and iNOS-AluI polymorphisms were associated with the caecum S. Enteritidis load. The other candidate genes were not associated with S. Enteritidis load in any organ. The results indicate that the IL-2, TGF-ß2, TLR-4, and iNOS genes are potential candidates for use in selection programmes for increasing genetic resistance against S. Enteritidis in Malaysian indigenous chickens.
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Pollos/genética , Polimorfismo de Longitud del Fragmento de Restricción/genética , Enfermedades de las Aves de Corral/inmunología , Salmonelosis Animal/inmunología , Salmonella enteritidis/patogenicidad , Animales , Pollos/inmunología , Pollos/microbiología , Cartilla de ADN/genética , Frecuencia de los Genes , Genotipo , Cadenas Ligeras de Inmunoglobulina/genética , Interferón gamma/genética , Interleucina-2/genética , Intestino Grueso/microbiología , Modelos Lineales , Hígado/microbiología , Antígeno 96 de los Linfocitos/genética , Malasia , Óxido Nítrico Sintasa de Tipo II/genética , Enfermedades de las Aves de Corral/genética , Enfermedades de las Aves de Corral/microbiología , Salmonelosis Animal/genética , Salmonelosis Animal/microbiología , Salmonella enteritidis/inmunología , Bazo/microbiología , Receptor Toll-Like 4/genética , Factor de Crecimiento Transformador beta2/genéticaRESUMEN
The influences of dopamine (DA) and zinc (Zn) on some physiological parameters of plasma such as growth hormone, cholesterol, 3-glyceride and growth rate, feed conversion ratio and abdominal fat of broilers between the ages of 21 to 42 day were investigated. The experiment was designed on a total of 180 commercial meat-type chicks as a randomized complete block with a 3x2x2 factorial arrangement of treatments with three levels of DA (0, 50 and 100 mg kg(-1)) and two levels of Zn (0 and 40 mg kg(-1)) in each sex. At the first day of trial, chicks were randomly distributed in 36 boxes at the same condition until day 15. Then, the treatments were administered in a low dosage for acclimating of chicks to them. From day of 21, the main dose of treatments was used. The effects of DA and Zn and interaction between them on cholesterol concentration of plasma were significant (p < 0.05). But the effects on concentration of growth hormone (GH) and 3-glyceride of plasma were not significant. The maximum concentration ofcholesterol in plasma was observed in male chicks administered 40 mg kg(-1) of Zn and the minimum concentration was related to female chicks administered 50 mg kg(-1) of DA. In this period, the main and interaction effects of all treatments on weight gain mean of chicks were significant. Also, Zn and DA and interaction of DA x sex improved feed conversion ratio (p < 0.05). The results of this experiment confirmed the lipolytic effect of DA on plasma cholesterol and abdominal fat and also showed that consumption of 100 mg kg(-1) of DA plus 40 mg kg(-1) of Zn cause to improve growth performance of male chicks.