جستجوی مقالات مرتبط با کلیدواژه « birth weight » در نشریات گروه « علوم دام »

The aim of this study was to investigate maternal factors including dry period length, parity, calving type, calf number per calving, and calving body condition score on body weight (BW), serum total protein (STP) concentration, and body structure growth of female Holstein dairy calves.

152 Holstein dairy cows and their female calves were studied in this experiment. The calves were weighed at birth and moved to individual pens bedded with sawdust, Fresh colostrum samples were collected from 152 Holstein dairy cows. Maternal effects include: number of births from 2 to 5. Type of childbirth: single or multiple, natural or hard birth. Dry period length which includes: Group 1 - under 45 days. Group 2- 46 to 60 days. Group 3 - 61 to 75 days and group 4- Over 75 days. Calves' BW was also measured on days 30 and 60 of the study.

Birth BW was not affected by the mother's parity. The parity had an effect on the BW of calves at day 30 and 60, whereas, the lowest calves BW at day 30 was revealed in the five lactation cows. Also, the calves that were born to mothers who entered their second lactation were heavier than other calves at day 60 (P <0.05). Calf BW at birth, 30, and 60 days of age was affected by the number of calves at birth and the type of calving (P <0.05) so that singleton calves and normal birth calves had more BW. day 60 (P <0.05) was significant so that the mothers with dry period length less than 45 and more than 75 days had the lowest and highest 60-day calves BW. Serum total protein was affected by parity, calves’ number per calving, type of calving, and calving body condition score (P <0.05). In addition, the effect of calving type on STP concentration at birth and day 10 tended to be significant, while at day 35 normal birth calves had greater STP than dystocia birth calves. Withers height and body length in calves born to five lactations mothers were lower than other parities (P <0.05). Heart girth at birth and hip height at day 60 of age was higher in calves were born to mother with a dry period length more than 75 days (P <0.05). Body structure at birth and day 60 was higher for singleton calves than for twin calves and calves born with normal calving than calves born with dystocia (P <0.05).

The results of the current experiment showed that factors related to the physiological status of dams and calving type affect the immunity status and performance of infant's calves.

Uneven distribution of recessive alleles among founder animals genomes leads to the heterogeneity of inbreeding depression among their descendants. In this study, pedigree information, birth weight, and weaning weight records of 4032 Baluchi sheep collected between 1989 to 2017 at the Baluchi sheep breeding station were used to assess the heterogeneity of inbreeding depression between founders of the population. The Wright inbreeding coefficient of the inbred animals was decomposed to the partial inbreeding of the four founder animals with the greatest contribution to the inbreeding of the population. Wright inbreeding coefficients and partial inbreeding coefficients of the founder animals were included as a covariate in the animal model, in two separate analyses. The regression coefficients of birth weight and weaning weight from Wright inbreeding were estimated to be -6.4 and -61.9 g, respectively. The effect of partial inbreeding from different founders on the studied traits was heterogeneous. The regression coefficient of birth weight on partial inbreeding of founder B was -79 g, while partial inbreeding from founder D caused an increase of 121 g in this trait. In weaning weight, partial inbreeding of founder D caused an increase of 83 g in this trait, while partial inbreeding of other founders did not affect this trait. The observed heterogeneity in the effects of partial inbreeding of the different animals can confirm the hypothesis that a few recessive alleles with major effects are contributing to the inbreeding depression of these traits. According to the results of this study, the heterogeneity of the effect of inbreeding of the founder animals should be considered in the genetic evaluation model of this breed.

Genetic parameters for birth weight and survival traits were estimated using data collected from 1995 to 2009 in Jafarabad Moghani Sheep Breeding Station. Number of observation for survival and birth weight were 7202 and 6585, respectively. Genetic parameters were estimated using restricted maximum likelihood (REML) procedure under 16 different models, including animal, threshold and sire models using ASReml software. The most appropriate model for each trait was determined based on Akaike’s Information Criterion (AIC) method. The appropriate model for birth weight was included direct additive genetic, maternal additive genetic and common litter effects. Also, the animal model for lamb survival were included direct additive genetic, maternal additive genetic, maternal permanent environmental, common litter effects and covariance between direct and maternal additive genetic effects. The appropriate sire model for lamb survival was included sire direct additive genetic and common litter effects. Estimated direct heritability for birth weight was 0.09±0.02. The direct heritabilities for survival with animal model and sire model was 0.070±0.002 and 0.05±0.02, which after correction was changed to 0.22 and 0.15, respectively. Also, the estimation of heritability for lamb survival from threshold model was 0.30±0.10. Genetic, environmental and phenotypic correlation between birth weight and lamb survival were 0.61±0.24, 0.08±0.02 and 0.07±0.01, respectively. Consideration of environmental factors, including common litter effects, is essential for unbiased estimation of genetic parameters.

About 6 million heads of cows in Iran are native cattle, but their characteristics and production potential remains unknown. Inbreeding is one of the important factors which must be considered in the herd and can be of considerable economic loss to producers. In this research, we tried to investigate the occurrence of inbreeding and its effects on the production traits of Serabi native cattle in a breeding center related to agricultural ministry located in Sarab. The aim of this study was to evaluate inbreeding effects on milk yield, fat percentage, protein percentage, and birth weight of Sarabi dairy cattle. In this research, the effects of inbreeding and environmental factors on production traits and birth weight of Sarabi cows have been studied. The data were collected from 1250 Sarabi cows during 1992- 2012 years by Sarabi Breed Center in East Azerbaijan province. In the present study, a pedigree file containing 1250 head (764 females and 486 males) of dairy cows was used, including data about the registration number of the livestock, date of birth, gender, father's registration number, and registration number of the mother, date of birth, parity, and production records. After the removal of animals with unknown and unregistered parents in the flock, the pedigree was arranged using pedigree software. Pedigree software was used to calculate the inbreeding coefficient for each animal. The principles of this software in the calculation of inbreeding coefficient is based on the formation of a kinship matrix among the individuals. The inbreeding coefficients of animals were considered as a discrete trait in 4 groups. In this herd, inbreeding coefficient was estimated between 0- 0.28. Average inbreeding coefficients of all cows and inbred cows are 0.0109 and 0.0574, respectively. Totally, 19% of all animals were inbred. In this study, inbreeding coefficient has been included in the model either as a continuous variable or as a classification variable. When inbreeding factor considered as continuous variable in the model, its effect on milk yield, fat and protein percentage, and birth weight was significant (P<0.01). When inbreeding considered as a continuous trait, 1% increase in inbreeding coefficient had an effect equal to -2.69 kg, 1.59%, and +18.1% on milk yield, fat, and protein percentage, respectively. Miglior et al. (1995a) reported a 1% increase in inbreeding coefficient in Holstein cows reduced calf weaning by 0.44 kg and reduced milk production by 25 kg. Mohammadkarim (2006) using a univariate model reported for 1% increase in inbreeding coefficient, changes in milk yield, fat yield, open days and length of first lactation equal to -14.02, -0.349 kg, + 0.4839 and + 0.148 days, respectively. Inbreeding has a negative effect on production traits and birth weight. Results showed that the effects of year-season of calving and parity on production traits and birth weight were significant (P<0.01). The regression coefficient of milk, fat and protein percentages and birth weight on inbreeding, when inbreeding considered as a discrete variable, were -0.129kg, +0.093%, +0.072% and -0.564 kg, respectively. In this study, when inbreeding traits considered as a continuous variable, did not show any linear or nonlinear relation with birth weight trait of Sarabi cows. It can be concluded that in order to maintain the genetic reserves of Sarabi cattle breed, it is necessary to carefully monitor the reproduction breedings in this native cattle population. In the case of endangered breeds, such as Sarabi breed, these breeds have beneficial properties, particularly in relation to resistance to diseases, and tolerance to stressful environments. These desirable traits can be transferred to future genetic composition cattle breeds. Preserving the genetic resources of the country's livestock and pay attention to similar breeds of Sarabi should be taken into consideration by decision makers at livestock breeding centers. In Holstein cows it has been found that high milk production is associated with a genetic susceptibility to disease (Khaleghi & Rafat 2018), so the desirable characteristics of the Sarabi breed should be studied in this regard of susceptibility to diseases. The existence of a complete family tree in computer registrations is the first step in controlling inbreeding. The existence of this pedigree will help breeders to avoid breeding between close-up animals, like a brother-sister and a father -daughter, which will increase the incidence of inbreeding in the population. For this purpose, it is recommended to use optimal mixing softwares that controls inbreeding. There are programs for managing the breeding to identify animals as soon as possible and calculate their relativeness in the herd. By this method, it is possible to prevent the occurrence of high inbreeding in the herd and produce calves with high profitability. The prospect of this research is to carry out further research on the issue of inbreeding and effective population size on local breeds of dairy cattle to prevent the replacement of these breeds with Holstein. It is imperative to prevent the replacement of the foreigner breeds (Holstein generally) instead of Sarabi breed and its extinction as much as possible.

In this research the causal structure among calving traits of 29950 first-parity Holstein cattles of Iran including calving difficulty (CD), birth weight of calves (BW) and gestation length (GL) was revealed applying data collected by Iranian Animal Breeding in 131 herds from 1995 to 2004 by Inductive Causation (IC) searching algorithm. Significant structural coefficients were found for causal effects of BW on CD (0.060±0.002) and of GL on CD (0.007±0.002). Furthermore, the causal effect of GL on BW was significant (0.219±0.005). Considering the revealed causal structure, standard and recursive multivariate models were compared applying deviance Information criterion (DIC) and predictive ability of models in terms of two measures including mean square of error and correlation between observed and predicted values. The obtained results revealed the causal effect of BW and GL on CD and the plausibility of recursive multivariate model over standard multivariate one. Therefore, considering the causal structure among calving traits is of crucial importance.

To determine of MEG9 gene polymorphism and its association with birth weight in Sistani cattle, the blood sample of 130 calves (male and female) were randomly collected belonging to Sistani cattle Research Center. The DNA extraction from whole blood was performed using phenol-chloroform procedure. Polymerase chain reaction was performed for amplification of 210-bp segments of exon 3 of MEG9 gene using specific primers. Detection of mutations were carried out by electrophoresis of poly-acrylamide gel 8% and silver staining using SSCP method. Association study of allele patterns with birth weight was done with fixed linear model and comparison of means was conducted by Tukey-kramer method. Results showed that three allele patterns including q1, q2 and q3 in PCR product of MEG9 gene in Sistani cattle with frequency of 37, 34 and 29 % respectively. The genetic diversity in MEG9 gene had significant correlation with birth weight (P

The objective of this research was to study polymorphism of CAST gene and its association with birth weight and cashmere traits in Kerman Raini goat. Blood samples were randomly collected from 108 Kerman Raini goats. DNA was extracted by salting out method and a fragment length of 247 bp of exon 6 of the gene using polymerase chain reaction (PCR) was amplified. SSCP obtained by acrylamide gel and stained with silver nitrate. Three patterns AA, AB and AC were detected for CAST gene with frequencies of 0.426, 0.28 and 0.296, respectively. The population deviated from Hardy–Weinberg equilibrium. Birth weight and year of shearing had no significant effects on cashmere wool but the effect of genotype was significant on birth weight (P

The present experiment was performed to study the relationship between sources of oil in flushing ration and reproductive efficiency of Markhoz goats. For this purpose, the correlation between some blood metabolites and hormone with number of offspring was estimated. Thirty-two Markhoz goats with average body weight of 44 ± 1.62 kg were used. Flushing treatments were including: group A (400 g barley grain), group B1 (93 g sunflower oil), group B2 (88 g soybean oil) and group c or control (basal diet). Flushing period started 4 weeks before and continued 2 weeks later of artificial insemination. Estrus was synchronized using CIDR for 18 days and goats were inseminated with fresh semen 48 h after CIDR removing. Blood samples collected three times after CIDR removal and 20 days after artificial insemination. All of the flushing rations improved fertility and kidding rates (P<0.01). Consumption of fat in the flushing rations, increased birth weight (P< 0.01). There was a significant correlation between blood estrogen, glucose and protein levels in the follicular phase with kidding rate (P<0.05). A positive correlation was found between estrogen and serum protein with flushing rations (P<0.02). Based on the proposed model, estrogen changes had the greatest impact on the number of offspring among the metabolites at follicular phase (P<0.01). At 20 days after insemination, a positive and significant correlation was found between progesterone and number of offspring (r= +0.58) (P<0.01). Overall, these results indicate that dietary fat sources and barely during the flushing period improve reproductive traits in Markhoz doe.

Researchers believe that the addition of supplemental fat in close up period can improve the status of cows and calves. To this end,Twenty seven Holstein cows were selected by the expected date of parturition (around 30 days before calving) and randomly assigned to one of the three experimental treatments including: 1) control (with carbohydrate source), 2 rumen-protected fat (RF) and 3 roasted soybean (RS). The diets were formulated as isonitrogenous and not iso-caloric. Dry matter intake and body condition score of cows in transition period and blood parameters of cows and calves were determined at the birthday. Also, calves weight was measured at birth. Difference in calf weight, plasma glucose and triglycerides concentrations in calves were significant (P<0.05). Glucose concentration were higher in calves born from cows were fed RS diet than 2 other groups. Difference in dry matter intake, body condition score and plasma non esterified fatty acids concentration of cows between 2 and 3 groups were significant.

In this research, in order to predict genetic parameters and genetic and environmental trends of birth weight and weaning weight of Najdi calves, 1249 records collected during the period of 1989 - 2004 in Najdi cattle Research Station of Khuzestan were used. Variance components, genetic parameters and predicted breeding values were estimated for traits, using animal model with direct and maternal additive genetic effects as the best model and restricted maximum likelihood method based on a derivative-free algorithm. Phenotypic, genetic and environmental trends were calculated as the regression of average phenotypic values, predicted breeding values and environmental values on year of calf birth, respectively. Direct and maternal heritability for birth weight and weaning weight were estimated 0.37±0.11, 0.08±0.04, 0.13±0.06 and 0.1±0.06, respectively. Phenotypic trends of traits were 0.07±0.05 kg/year and 0.21±0.3 kg/year for birth weight and weaning weight, direct additive genetic trends for these traits were 0.06±0.01 kg/year and 0.13±0.04 kg/year, and maternal additive genetic trends for these traits were 0.03±0.005 kg/year and 0.13±0.01 kg/year, respectively. Environmental trends were estimated as 0.02±0.06 kg/ year and 0.04±0.3 kg/year, respectively.