Genetic parameters and purebred–crossbred genetic correlations for growth,meat quality,and carcass traits in pigs

Growth, meat quality, and carcass traits are of economic importance in swine breeding. Understanding their genetic basis in purebred (PB) and commercial crossbred (CB) pigs is necessary for a successful breeding program because, although the breeding goal is to improve CB performance, phenotype collection and selection are usually carried out in PB populations housed in biosecure nucleus herds. Thus, the selection is indirect, and the accuracy of selection depends on the genetic correlation between PB and CB performance (rpc). The objectives of this study were to 1) estimate genetic parameters for growth, meat quality, and carcass traits in a PB sire line and related commercial CB pigs and 2) estimate the corresponding genetic correlations between purebred and crossbred performance (rpc). Both objectives were investigated by using pedigree information only (PBLUP) and by combining pedigree and genomic information in a single-step genomic BLUP (ssGBLUP) procedure. Growth rate showed moderate estimates of heritability for both PB and CB based on PBLUP, while estimates were higher in CB based on ssGBLUP. Heritability estimates for meat quality traits were diverse and slightly different based on PB and CB data with both methods. Carcass traits had higher heritability estimates based on PB compared with CB data based on PBLUP and slightly higher estimates for CB data based on ssGBLUP. A wide range of estimates of genetic correlations were obtained among traits within the PB and CB data. In the PB population, estimates of heritabilities and genetic correlations were similar based on PBLUP and ssGBLUP for all traits, while based on the CB data, ssGBLUP resulted in different estimates of genetic parameters with lower SEs. With some exceptions, estimates of rpc were moderate to high. The SE on the rpc estimates was generally large when based on PBLUP due to limited sample size, especially for CBs. In contrast, estimates of rpc based on ssGBLUP were not only more precise but also more consistent among pairs of traits, considering their genetic correlations within the PB and CB data. The wide range of estimates of rpc (less than 0.70 for 7 out of 13 traits) indicates that the use of CB phenotypes recorded on commercial farms, along with genomic information, for selection in the PB population has potential to increase the genetic progress of CB performance.     

Comparative Pharmacokinetics of Diphenhydramine in Camels and Horses after Intravenous Administration

The pharmacokinetics of diphenhydramine (DPHM) was compared in camels (n = 8) and horses (n = 6) following intravenous (i.v.) administration of a dose of 0.625 mg/kg body weight. In addition, the metabolism and urinary detection time of DPHM was evaluated in camels. The data obtained (median and range in brackets) in camels and horses, respectively, were as follows. The terminal elimination half lives (h) were 1.58 (1.13–2.58) and 6.11 (4.80–14.1), and the total body clearances (L/h per kg) were 1.42 (1.13–1.74) and 0.79 (0.66–0.90). The volumes of distribution at steady state (L/kg) were 2.38 (1.58–4.43) and 5.98 (4.60–8.31) and the volumes of the central compartment of the two compartment pharmacokinetic model were 1.58 (0.80–2.54) and 2.48 (1.79–3.17). All the pharmacokinetic parameters in camels were significantly different from those of horses. Five metabolites of DPHM were tentatively identified in the camel's urine. Two metabolites, diphenylmethoxyacetic acid and 1-(4-hydroxyphenyl)-phenylmethoxyacetic acid, were present in the acid fraction. Two metabolites, desamino-DPHM and diphenylmethanol, were identified in the basic fraction, in addition to DPHM itself, which was present mainly as a conjugate. Even after enzymatic hydrolysis, DPHM could be detected for up to 24 h in camels after an i.v. dose of 0.625 mg/kg body weight.     

Effect of different levels of dried citrus pulp on performance,egg quality,and blood parameters of laying hens in early phase of production

Utilization of agricultural wastes in animal nutrition is a matter of great concern. Dried citrus pulp (DCP) is a potential source of some valuable nutrients for animal and poultry. In an experiment with completely randomized design, the effect of different levels (0%, 4%, 8%, 12%, and 16%) of DCP was evaluated on performance, egg quality, and blood parameters of laying hens from 25 to 37 weeks of age. The birds were randomly allocated to five groups with six replicates and three birds in each replicate. The results showed that with increasing the level of DCP up to 12%, there were no significant differences among treatments for feed intake, egg production, egg mass, feed conversion ratio, final body weight, yolk index, and yolk color. There were no significant differences between treatments in shell thickness, eggshell index, egg score, and Haugh unit. Utilization of DCP up to 16% significantly increased serum glucose and high-density lipoprotein and reduced cholesterol, low-density lipoprotein, and triglycerides (P < 0.05). Results of the present study indicated that use of 12% DCP in laying hen diets had no adverse effect on performance and egg quality of laying hens in early phase of production.     

Estimation of additive and non-additive genetic variance component for growth traits in Adani goats

Tropical Animal Health and Production - Non-additive genetic effects are important to increase the accuracy of estimating genetic parameters for growth traits. The aim of this study was to estimate...     

Factors affecting calf mortality in Iranian Holstein dairy herds

The objective of this study was to document mortality reasons and risk factors for mortality in dairy calves in the northeast of Iran. This was a prospective cohort study of calves born on ten commercial dairy herds from 21 March 2009 to 20 March 2010. A total of 4097 live calves were followed for 90 days after birth. For each calf details of sex, parity of the dam, type of parturition and season of birth were recorded. The interval (in days) from the date of birth to the date of death and the reason for death was recorded for those calves that died before 90 days of age. A Cox proportional hazards model, including a frailty term to account for unmeasured herd-level effects was developed to quantify the effect of factors associated with time to death. Two hundred and sixty-six (6.5%, 95% CI: 5.8-7.3%) of the 4097 live-born calves died or were euthanised before 90 days of age. The most important reasons for death were digestive tract disorders (58% of all deaths, 95% CI: 52-64%) followed by respiratory diseases (13% of all deaths, 95% CI: 9-17%). Calves exposed to dystocia at birth had 2.09 (95% CI: 1.49-2.92) times the daily hazard of death compared with calves born from a normal calving. The daily hazard of death for calves born in the summer was 1.93 (95% CI: 1.41-2.64) times greater than the hazard for those calves born in the autumn. Inclusion of the herd-level frailty term had a significant effect on hazard estimates indicating that the study herds were heterogeneous in the distribution of unmeasured herd-level factors influencing calf survival. Our results show that diarrhoea is the most important cause of calf mortality in dairy herds in this area of Iran and that environmental and management factors affect calf mortality rate.     

Molecular characterization of the surface glycoprotein genes of highly pathogenic H5N1 avian influenza viruses detected in Iran in 2011

Highly pathogenic avian influenza (HPAI) H5N1 virus is causing the death of a large number of wild birds and poultry. HPAI H5N1 was reported in the north of Iran in 2011. In this study, two A/Chicken/Iran/271/2011 and A/Duck/Iran/178/2011 viruses were genetically characterized by sequence analysis of Hemagglutinin (HA) and Neuraminidase (NA) genes. Phylogenetic analysis revealed that these viruses were different from previous Iranian isolates (Clade 2.2) and belonged to the subclade 2.3.2.1. The results showed that the detected viruses are almost identical to each other and closely related to HPAI H5N1 strains isolated in Mongolia in 2010. Based on the amino acid sequence analysis, these viruses at their HA cleavage sites contained the multibasic amino acid motif PQRERRRK-R/GLF lacking a lysine residue compared with the previous reports of the same motif. There is also a 20-amino acid deletion (resides 49–69) in the NA stalk similar to other viruses isolated after 2000. It seems that introduction of HPAI H5N1 to Iran might have happened by wild birds from Mongolian origin virus.     

Sperm density, seminal plasma composition and their physiological relationship in the endangered Caspian brown trout (Salmo trutta caspius)

Sperm density, mineral and organic composition of the seminal plasma and their physiological relationship were investigated in the Caspian brown trout (Salmo trutta caspius). To establish a rapid and accurate method for assessment of sperm density, three different techniques were used: sperm counting, spectrophotometry (at 480 nm) and determination of the spermatocrit. The seminal plasma contained 159.26±8.84 mM sodium (Na), 33.72±2.01 mM potassium (K), 133.04±5.96 mM chlorine (Cl), 1.68±0.2 mM calcium (Ca) and 0.988±0.13 mM magnesium (Mg). The following organic components were found: total protein 0.75±0.14 mg 100 mL⁻¹, cholesterol 2.86±0.58 mg L⁻¹ and glucose 3.81±1.04 mM L⁻¹. The mean sperm density was estimated to be 3.3 × 10⁹ spermatozoa mL⁻¹. The spermatocrit (%) ranged from 25 to 52 in sperm samples. Highly significant linear relationships were found between sperm density and spermatocrit (R²=0.703, P<0.001) and sperm density and optical density (R²=0.909, P<0.001), indicating that optical density can be used as a quick and accurate method of estimating sperm density. Significant relationships were also found between sperm density and Ca, Mg and total protein of seminal plasma. A significant correlation was also observed between the Ca and Mg concentrations (R²=0.774, P<0.01). The following correlations were observed between mineral and organic components: total protein and Ca (R²=0.462, P<0.05), total protein and Mg (R²=0.518, P<0.05) and glucose and Cl (R²=0.374, P<0.05). These parameters should be considered when developing procedures for either artificial fertilization or for cryopreservation of sperm.     

Callus induction and in vitro plant regeneration of rice (Oryza sativa L.) under various conditions

The objective of the present study was to develop an effective protocol for optimum callus induction and complete plant regeneration for four varieties of rice (Oryza sativa L.) i.e., Super Basmati, Basmati-370, Basmati-371 and Fakhre Malakand. Calli were induced from mature seed scutelum. The Murashige and Skoog (MS) and Chu's N6 media containing hormone 2, 4-D (2, 4-Dichlorophenoxy acetic acid) in different concentrations were used for callus induction. Fakhre Malakand produced maximum calli on N6 media containing 3 mg L(-1) 2,4-D. while other three varieties showed maximum callus induction on N6 media containing 2.5 mg L(-1) 2,4-D. N6 media was found better than MS media for callus induction. For complete plant regeneration the calli of two varieties i.e., Basmati-370 and Basmati-371 were plated on N6 media containing different concentrations of NAA (1-Naphthalene acetic acid) and BAP (6-benzyl aminopurine). The maximum regeneration frequency (%) was observed on N6 media containing NAA 1 mg L(-1) and BAP 2.5 mg L(-1). It took 27-30 days for the callus to regenerate into a complete plant. Basmati-370 produced 4-7 plantlets per callus whereas Basmati-371 produced 4-8 plantlets per callus with regeneration frequencies of 61 and 69%, respectively.     

Wool characteristics in the third generation of Arkharmerino × Ghezel and Arkharmerino × Moghani crossbreed sheep

This investigation was conducted to evaluate the comparative productive performances and effect of some environmental factors on wool characteristics of Arkharmerino × Ghezel (Ar × Gh) and Arkharmerino × Moghani (Ar × Mo) crossbreed sheep. The mid-side fleece samples taken from animals during 2 years (2007–2008) were analyzed. Each sample was measured for average fiber diameter, fiber diameter variability, staple length, proportion of medullated fiber, proportion of kemp, and comfort factor. The comparative values for these fleece characteristics in F₃ generation Ar × Gh were 28.78 ± 0.48 μm, 36.84 ± 1.16%, 11.94 ± 0.35 cm, 7.07 ± 0.93%, 1.02 ± 0.23%, and 68.93%, respectively; while those traits were 29.79 ± 0.43 μm, 41.86 ± 1.16%, 11.96 ± 0.37 cm, 8.13 ± 1.06%, 2.71 ± 0.45%, and 63.33 ± 3.66% for Ar × Mo, respectively. The effects of genotype, sex, birth type, and year of birth were analyzed. Genotype had a significant (P < 0.01) effect on average fiber diameter and proportion of kemp, and Ar × Gh crossbreeds had lower diameter with less proportion of kemp. The two differences in fiber characteristics that were attributable to sex were fiber diameter variability and proportion of medullated fiber, and females had higher measure than males for both traits. Statistical analysis showed that crossbreeding with Arkharmerino generally had positive effects on the fleece favored to be used in the hand woven authentic carpet production.