74 research outputs found
Genetic parameters of live body weight, body measurements, greasy fleece weight, and reproduction traits in Makuie sheep breed
Genetic parameters of production and reproduction traits were estimated using 39,926 records from 5,860 individual progenies of 163 sires and 1,558 dams. The data were collected at Makuie Sheep Breeding and Raising Station (Maku, Iran) from 1989 through 2013. Nineteen traits were classified in four main groups: a) live body weight traits, b) body measurement traits, c) greasy fleece weight traits, and d) reproduction traits. Year of birth, lamb sex, age of dam, and birth type were considered as fixed effects in the animal model. Four different animal models that are differentiated by including or excluding maternal effects were fitted for each trait. The Akaike information criterion was used to determine the most appropriate model for each trait. Parameters were overestimated substantially when maternal effects, either genetic or environmental, were ignored from the models. By ignoring the maternal effects, the traits could be classified into three main groups: body live weight traits with high heritability (0.34-0.46), body measurement and greasy fleece weight traits with medium heritability (0.11-0.27) and reproduction traits with low heritability (0.03-0.20). The genetic correlations among the traits ranged from-0.41 to 0.99. The estimated genetic parameters may be used to set up short/long term breeding program for the selection purpose of Makuie sheep breed.</p
Population genetic structure and performing assignment test on six Iranian native goats using simple sequence repeat markers
The native goat breeds could be better managed and their genetic diversity to be conserved through identification of population genetic structure. Total of 299 animals from six goat breeds, which are major native breeds of Iran, were used to study their genetic structure and understand relationship among the breeds using SSR markers on 13 microsatellite loci. The breeds were selected from different geographic regions of Iran. The results indicated that there is high genetic diversity at the population level (HS of 0.78) and at the species level (HT of 0.86). The level of inbreeding was low across the breeds and even genetic diversion was observed among them, indicating a low level of gene flow at the regional scale. Some level of admixtures was observed among breeds, which supported by clustering of the breeds based on their geographic origin. Analysis of the population genetic structure indicated that all breeds are grouped into four clusters. The assignment accuracy per locus ranged from 40.1% (BM4621) to 66.9% (oarJMP23). The assignment power of microsatellites based on the Bayesian method had positive correlation with the number of alleles and gene differentiation coefficient (Gst) per locus. In conclusion, this study provided a genetic profile for the conservation and improvement and origin of the studied breeds
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Analysis of pre-weaning feeding policies and other risk factors influencing growth rates in calves on 11 commercial dairy farms
Growth rates in pre-weaned calves influence their health, age at first calving and lifetime productivity. Many farms restrict milk rations to encourage solid feed intake and facilitate early weaning, but this can compromise growth. This study determined the milk feeding policies and associated growth rates on 11 commercial dairy farms in South East England, each following their normal management regime. Between 26 and 54 heifers were recruited per farm, providing a final cohort of 492, of which 71% were pure Holstein. Information on calf rearing practices (feeding, weaning, housing) and health was collected via questionnaires and weekly observations. Estimates of actual milk fed (kg solids) between 1 and 63 days were calculated for individual calves. Morphometric data (weight, height, length) were taken at weeks 1, 5 and 9 and at a median age of 7.5 months and growth rates were calculated. Most calves were fed milk replacer via automated feeders (four farms), teat feeder (one) or buckets (four) whereas two farms provided drums of acidified waste milk. Farms fed between 4 and 6 l/day of milk at mixing rates of 10% to 15%, providing 400 to 900 g/day of milk solids. Both skeletal growth rates and average daily weight gain (ADG) increased in the second month of life compared with the first: height growth from 0.17±0.14 to 0.25±0.16 cm/day and ADG from 0.48±0.25 to 0.71±0.28 kg/day. Post-weaning heifers up to 7.5 months had height increases of 0.16±0.035 cm/day and ADG of 0.83±0.16 kg/day. From 1 to 63 days 70% of calves had growth rates <0.7 kg/day and of these 19.6% gained <0.5 kg/day. Mean ADG before 9 weeks varied between farms from 0.52±0.30 to 0.75±0.20 kg/day. This was related to the amount of milk fed at both a farm and individual calf level. Increasing the total milk solids fed between 1 and 63 days from 20.4 to 46.3 kg (the 10th to 90th percentile observed) was associated with an increase of 0.11 kg/day ADG. All farms had a wide variation in growth rates despite single feeding policies. Higher circulating immunoglobulin G and IGF1 concentrations were associated with better growth, whereas low temperatures in month of birth, high scores for diarrhoea, respiratory and umbilical disease and large birth size reduced growth. Many commercially grown dairy heifers therefore experienced growth restriction in the pre-weaned period, potentially reducing their health, welfare and productivity
Novel monitoring systems to obtain dairy cattle phenotypes associated with sustainable production
Improvements in production efficiencies and profitability of products from cattle are of great interest to farmers. Furthermore, improvements in production efficiencies associated with feed utilization and fitness traits have also been shown to reduce the environmental impact of cattle systems, which is of great importance to society. The aim of this paper was to discuss selected novel monitoring systems to measure dairy cattle phenotypic traits that are considered to bring more sustainable production with increased productivity and reduced environmental impact through reduced greenhouse gas emissions. With resource constraints and high or fluctuating commodity prices the agricultural industry has seen a growing need by producers for efficiency savings (and innovation) to reduce waste and costs associated with production. New data obtained using fast, in some cases real-time, and affordable objective measures are becoming more readily available to aid farm level monitoring, awareness, and decision making. These objective measures may additionally provide an accurate and repeatable method for improving animal health and welfare, and phenotypes for selecting animals. Such new data sources include image analysis and further data-driven technologies (e.g., infrared spectra, gas analysis), which bring non-invasive methods to obtain animal phenotypes (e.g., enteric methane, feed utilization, health, fertility, and behavioral traits) on commercial farms; this information may have been costly or not possible to obtain previously. Productivity and efficiency gains often move largely in parallel and thus bringing more sustainable systems
Measuring enteric methane emissions from individual ruminant animals in their natural environment
Ruminant livestock are an important source of meat, milk, fiber, and labor for humans. The process by which ruminants digest plant material through rumen fermentation into useful product results in the loss of energy in the form of methane gas from consumed organic matter. The animal removes the methane building up in its rumen by repeated eructations of gas through its mouth and nostrils. Ruminant livestock are a notable source of atmospheric methane, with an estimated 17% of global enteric methane emissions from livestock. Historically, enteric methane was seen as an inefficiency in production and wasted dietary energy. This is still the case, but now methane is seen more as a pollutant and potent greenhouse gas. The gold standard method for measuring methane production from individual animals is a respiration chamber, which is used for metabolic studies. This approach to quantifying individual animal emissions has been used in research for over 100 years; however, it is not suitable for monitoring large numbers of animals in their natural environment on commercial farms. In recent years, several more mobile monitoring systems discussed here have been developed for direct measurement of enteric methane emissions from individual animals. Several factors (diet composition, rumen microbial community, and their relationship with morphology and physiology of the host animal) drive enteric methane production in ruminant populations. A reliable method for monitoring individual animal emissions in large populations would allow (1) genetic selection for low emitters, (2) benchmarking of farms, and (3) more accurate national inventory accounting
Genetic parameters of live body weight, body measurements, greasy fleece weight, and reproduction traits in Makuie sheep breed
Genetic parameters of production and reproduction traits were estimated using 39,926 records from 5,860 individual progenies of 163 sires and 1,558 dams. The data were collected at Makuie Sheep Breeding and Raising Station (Maku, Iran) from 1989 through 2013. Nineteen traits were classified in four main groups: a) live body weight traits, b) body measurement traits, c) greasy fleece weight traits, and d) reproduction traits. Year of birth, lamb sex, age of dam, and birth type were considered as fixed effects in the animal model. Four different animal models that are differentiated by including or excluding maternal effects were fitted for each trait. The Akaike information criterion was used to determine the most appropriate model for each trait. Parameters were overestimated substantially when maternal effects, either genetic or environmental, were ignored from the models. By ignoring the maternal effects, the traits could be classified into three main groups: body live weight traits with high heritability (0.34-0.46), body measurement and greasy fleece weight traits with medium heritability (0.11-0.27) and reproduction traits with low heritability (0.03-0.20). The genetic correlations among the traits ranged from-0.41 to 0.99. The estimated genetic parameters may be used to set up short/long term breeding program for the selection purpose of Makuie sheep breed
Comparison carcass traits of Azeri buffalo, native and crossbred (native * Holstein) male calves in west Azerbaijan-Iran
Iran has 500thousand heads buffalo that 80percent of them distributed in North and North West of Iran and they reared as multi purpose animals providing milk and meat. Farmer believe that buffalo milk had the best quality but because of huge and large head and skin buffaloes carcass isn’t suitable that governmental programmer pay a low facilities to buffalo fattener in comparison the cattle fattener thus the objective of this investigation was to the Comparison carcass traits of buffalo, native and Native cows* Holstein (NH) male calves that mostly fattened in this region. Eighty head claves (six heads of each treat) with average 160 kg body weight (BW) were fattened till the 300 kg. Ration and other environmental factors were the same. Three heads of each group’s according Iranian Standards slaughtered at abattoir. The slaughter weight, hot carcass weight, and the individual weights of the different slaughter by-products and organs were measured. The carcasses were chilled at 5o C for 24 h. One side of each carcass was cutting into wholesales cuts. Traits included Hot and cold carcass weight, bone, internal fat, meat, cut ability fat, dressing percent, wholesales cuts weight and percent. Wholesales cuts include neck, shoulder, loin, rib and flank and leg weight and percent. The results showed that there were not significant differences between hot and cold carcass weigh, meat, bone and cut ability fat percent. There were significant differences on internal fat, dressing percent and leg (P<0.05). The lowest and highest values for internal fat were observed buffalo and native carcass, respectively. In conclusion because of low internal fat deposition and high valuable wholesales cuts percent may buffalo carcass composition had a better quality in comparison cattle and fattening of buffalo is economically
Effect of supplemented ration on some reproductive traits in Azeri Buffaloes of Iran
Reproduction efficiency is one of the most important factors for productivity and profitably of dairy animals. Late or delayed oestrus in buffalo heifers is one of the major factors limiting its overall productive and reproductive performance. Feeding and general management have been reported to improve reproduction efficiency of buffaloes. Reproduction is partly affected by nutrition supplementation. Thus the objective of this study was to investigate the effect of supplemented ration on some reproductive traits in Azeri buffaloes. One hundred and twenty female buffalo calves with 8 months age were randomly divided into four groups (30 calves in each group). Calves received I) traditional ration (TR) II) TR plus 0.5 kg concentrate III) TR plus 1 kg concentrate IV) TR plus 1.5 kg concentrates till the age at first estrous. There was no difference between initial weights of calves before the treatments. The reproductive traits considered were age at first oestrus, weight at first oestrus, number of oestruses before gestation, age at gestation, age at calving. Although there were no significant differences between the all studied traits among treatments, the supplementation in Group 4 improved the traits somehow; in particular, treatment 4 decreased by 70 days the age at calving compared to treatment 1. This indicates that the W. Azerbaijan buffaloes suffer a nutritional deficiency in their lifetime and that quality /quantity supplementation of ration can improve their reproductive performance
Genetic parameters of live body weight, body measurements, greasy fleece weight, and reproduction traits in Makuie sheep breed
Genetic parameters of production and reproduction traits were estimated using 39,926 records from 5,860 individual
progenies of 163 sires and 1,558 dams. The data were collected at Makuie Sheep Breeding and Raising Station (Maku,
Iran) from 1989 through 2013. Nineteen traits were classified in four main groups: a) live body weight traits, b) body
measurement traits, c) greasy fleece weight traits, and d) reproduction traits. Year of birth, lamb sex, age of dam, and
birth type were considered as fixed effects in the animal model. Four different animal models that are differentiated
by including or excluding maternal effects were fitted for each trait. The Akaike information criterion was used to
determine the most appropriate model for each trait. Parameters were overestimated substantially when maternal
effects, either genetic or environmental, were ignored from the models. By ignoring the maternal effects, the traits
could be classified into three main groups: body live weight traits with high heritability (0.34-0.46), body measurement
and greasy fleece weight traits with medium heritability (0.11-0.27) and reproduction traits with low heritability (0.03-
0.20). The genetic correlations among the traits ranged from-0.41 to 0.99. The estimated genetic parameters may be
used to set up short/long term breeding program for the selection purpose of Makuie sheep bree
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