Moslem Beygi; Mahmood Vatankhah; Mostafa Faghani
Abstract
In this study, the number of 1802 longevity records of ewes collected during 1989 to 2010 in Breeding Station of Lori-Bakhtiari sheep flocks were used to estimate of genetic, environmental and phenotypic trends for economic lifetime. The breeding values of a ewe’s lifetime were estimated by restricted ...
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In this study, the number of 1802 longevity records of ewes collected during 1989 to 2010 in Breeding Station of Lori-Bakhtiari sheep flocks were used to estimate of genetic, environmental and phenotypic trends for economic lifetime. The breeding values of a ewe’s lifetime were estimated by restricted maximum likelihood procedure under an animal model of univariate analysis. The best linear unbiased prediction of breeding values estimated and genetic trends were estimated as a regression coefficient of average breeding values on the birth year of ewes. The environmental and phenotypic trends estimated as a regression coefficient of average environmental deviation and phenotypic deviation (deviations of phenotypic values from overall mean) on the birth year of ewes. The results showed that, genetic trend of longevity was positive (0.033 days) but insignificant from zero. While the environmental and phenotypic trends were equal to -27.81 and -27.78 days, respectively, and significantly different from zero (P<0.05). Thus, selection for growth traits did not affect longevity traits as genetically and to exhibit negative phenotypic trend for longevity the environmental factors should improve firstly
mahmoud vatankhah
Abstract
Data utilized in this study were 6800 records of lambs’ life longevity, and survival rate from 263 sires and 1839 dams collected from 1989 through 2009, from the Lori-Bakhtiari flock at Shooli Station in Shahrekord. The data were analyzed, using Linear and Hazard Ratio models along with Weibul function. ...
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Data utilized in this study were 6800 records of lambs’ life longevity, and survival rate from 263 sires and 1839 dams collected from 1989 through 2009, from the Lori-Bakhtiari flock at Shooli Station in Shahrekord. The data were analyzed, using Linear and Hazard Ratio models along with Weibul function. These models included such non genetic factors as year and month of birth, sex of lamb, type of birth, age of dam and lambs birth weight as linear and quadratic covariates. Results revealed that the overall mean of lamb’s life longevity and cumulative survival rate, up to yearling, were 301.60 days vs. 78.68%, respectively. The effect of non genetic factors on survival rate resulted from linear model were almost the same as hazard ratio model of Wiebull function. The effect of year and month of birth, sex of lamb and lamb’s birth weight as quadratic covariate were significant (p0.05) on the longevity of lamb’s life as well as survival rate. The survival rate and hazard ratio of lambs born in the first vs. the second months were higher vs. lower than those in the third month respectively. The male lambs suffered from a lower survival rate and higher hazard ratio than the females. Lambs with medium birth weight benefited from a higher survival rate and lower hazard ratio than lambs with either too low or too high birth weights. Although, lambs born from younger and older dams suffered from lower survival rates and higher hazard ratios, but they did not any significant differences with lambs born from middle aged dams. Twin lambs suffered from lower survival rates and higher hazard ratios than single lambs, but the differences were not significant. According to the results obtained in this study, the effect of non genetic factors on lamb’s survival rate to yearling age, achieved from liner and non linear models were similar and to increase the survival rate by correcting the non genetic factors, one could use the results obtained from either linear or non linear models.
mahmood vatankhah; mehrab faraji; aliakbar gharedaghi; alireza aghashahi
Abstract
Four hundred and ninety five smallholder dairy farms in 52 villages of different cities in Chaharmohal and Bakhtiari province including 1321 lactating cows and totalling 2811 total mature cows (lactating and dry)were employed during winter 2009 to summer 2010 to estimate the economic opportunities as ...
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Four hundred and ninety five smallholder dairy farms in 52 villages of different cities in Chaharmohal and Bakhtiari province including 1321 lactating cows and totalling 2811 total mature cows (lactating and dry)were employed during winter 2009 to summer 2010 to estimate the economic opportunities as per cow in smallholder dairy farms. A questionnaire survey was employed to collect data from the previous years information, already recorded information, direct recordings during visiting of the farm as well as interview with the small holder farmer. A number of 5 economic opportunities were evaluated using revenue and expense for each farm. An economic opportunity is considered as the level the amount of additional revenue that could be obtained if farmers could improve various productivity indexes to meet the reasonable targets. The overall means of indexes were: 6.99% for average calf mortality, 30.07 months for average age at first calving, 15.77 months for average calf production interval, 335.93 days for average lactation period and 13.30 kg for average daily milk produce per cow the reasonable targets for which were 3.85%, 29 months, 15 months, 376 days and 18 kg, respectively. The sum of economic opportunities per cow per year were estimated as 10523 thousand Rails comprised of 5769 thousand Rails (57.22% total) for average daily milk produce per cow, 1630 thousand Rails (23.06% total) for average lactation length, 1586 thousand Rails (12.68% total) for average age at first calving, 169 thousand Rails (5.46% total) for average calf production interval and 180 thousand Rails (1.58% total) for average calf mortality, respectively. Considerable variations were observed for quintuplet economic opportunities, percent of total and sum of economic opportunities in different cities, seasons and for different breeds. Thus, increasing the average daily milk produce per cow and average lactation duration as well as decreasing average age at first calving along with average calf production interval could considerably affect profit and productivity.
mohammadreza bakhtiarizade; mohammad moradi shahre babak; hossein moradi; mahmood vatankhah
Abstract
The relationship between live body weight, body length, girth circumference, animal hight, upper, middle as well as lower width of fat-tail, fat-tail length, fat-tail gap length, fat-tail depth and fat-tail circumference along with fat-tail weight were determined using records of 731 Loribakhtiari sheep. ...
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The relationship between live body weight, body length, girth circumference, animal hight, upper, middle as well as lower width of fat-tail, fat-tail length, fat-tail gap length, fat-tail depth and fat-tail circumference along with fat-tail weight were determined using records of 731 Loribakhtiari sheep. Principal Component and Least Square Analyses were applied to solve the collinearity instability. Collinearity problems as portrayed by variance inflation factors above 5 or 10 were evident in some of independent variables. Results showed that the problem of collinearity in relation with fat-tail weight of 11 independent variables could be solved by using Principal Component Analysis method. Fat-tail gap length, fat-tail depth, and fat-tail circumference vs. girth circumference, and fat-tail length respectively represented the highest and the lowest coefficients regarding the estimation of fat-tail weight.
Mahmoud Vatankhah; Mehrab Faraji
Volume 42, Issue 4 , March 2012, , Pages 285-296
Abstract
Four hundered and ninety five (495) smallholder dairy farms active in 52 villages of different cities in Chaharmohalo Bakhtiari Province, keeping 1321 lactating within a total of 2811 mature cows (lactating and dry) were used. These herds were taken during winter 2009 to summer 2010 to assess some of ...
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Four hundered and ninety five (495) smallholder dairy farms active in 52 villages of different cities in Chaharmohalo Bakhtiari Province, keeping 1321 lactating within a total of 2811 mature cows (lactating and dry) were used. These herds were taken during winter 2009 to summer 2010 to assess some of the production, reproductive and economic performance traits under smallholder management system. A questionnaire survey was applied to collect retrospective data from the previous year's information, recorded information, direct recordings during the visit of the farms and as well interview with the smallholder farmer. The smallholder dairy farms included 441 small farms (89.09%), and 54 medium size farms (10.91%). From a breed aspect, there were: 11 native breed farms (2.22%), 327 cross bred farms (66.06%), and 157 Holstein breed ones (31.72%). The production performance figures were recorded as 30.56, 22.21 and 13.30 kg for total milk yield on farm, milk sold on farm and daily milk production per cow, respectively. A 62.75% of milk was reported as sold per total milk produced. The overall mean reproductive figures were recorded as 30.07 months for age for the first calving, 15.77 months for calving interval, 335.96 days for average lactation length and 6.99% for calf mortality rate. The mean daily feed consumption per cow was recorded as 15.85 kg, containing 25.69% of concentrate. The mean daily feed expenses and return from sale of milk were 35786 and 45765 rails, respectively. The ratio of feed expenses to income from milk and price of milk to feed ratio were found as 75.76% and 159%, respectively. The average herd size was 5.86 heads, including 2.21 lactating cows, and 2.67 total mature cows while the rest male and female calves. Also, the proportion of lactating cows to total cows and to total herd were estimated as 84.83% and 42.66% respectively. There were significant variations observed among different seasons, city and breed for most of the traits.
Mahmoud Vatankhah; MohammadAli Talebi; Mohsen Bagheri
Volume 41, Issue 3 , December 2010, , Pages 193-201
Abstract
In this study, production, reproduction, management and economic parameters deduced from recordings of 5 flocks with 720 heads of native goats during an annual cycle of production in transhumance, village and farming systems were employed to determine the traits' economic values. The economic values ...
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In this study, production, reproduction, management and economic parameters deduced from recordings of 5 flocks with 720 heads of native goats during an annual cycle of production in transhumance, village and farming systems were employed to determine the traits' economic values. The economic values of the traits were estimated, using maximizing profit, revenue per cost as well as minimizing cost situations. The relative economic values of traits for transhumance system resulted from maximizing profit situation were 15.29 for survival rate in goat, 5.60 for conception rate, 4.92 for kidding frequency, 2.37 for kidding rate, 3.34 for kid survival rate up to weaning, 2.74 for kid survival rate to yearling, 1.00 for kid live weight at sale, -5.45 for body weight of goat and 13.37 for milk yield. In village system, these values were 8.30, 4.52, 4.16, 1.21, 1.55, 1.38, 1.00, -6.42 and 4.96, respectively. In farming system, these values were estimated as 1.73, 1.13, 0.73, 0.37, 0.53, 0.50, 1.00, -0.77 and 1.16, respectively. The absolute economic values of traits increased with improving economic efficiency from transhumance to farming systems, but the relative economic values decreased. Although, the calculated economic values from all the three situations were different numerically, but from the rank point of view of traits they ended up with apporoximatly similar results.
