Normal view MARC view ISBD view

Genetic Evaluation Of Teddy Goats In Pakistan

By: Zulfiqar Hussan Kuthu | Prof. Dr. Khalid Javed.
Contributor(s): Prof. Dr. Masroor Ellahi Baber.
Material type: materialTypeLabelBookPublisher: 2012Subject(s): Department of Livestock ProductionDDC classification: 1582,T Dissertation note: Data available on 20455 kidding and performance records of 5545 Teddy goats and progeny of 406 sires maintained as separate flocks at three different locations i,e (I) Livestock Experiment Station Rakh Ghulaman, District Bakkhar (1983-2008) (II) Livestock Experiment Station, Rakh Khariewala District Layyah (1971-2008) and (III) Livestock Experiment Station Chak Katora, District Bahawalpur (1975-2008) Punjab, Pakistan were analyzed for documenting both genetic and environmental sources which influence growth and reproductive traits. Breeding values of sires and does were estimated and genetic and phenotypic trends for various performance traits were drawn. The data was analyzed using the GLM procedure (General Linear Models) of the Statistical Analysis Systems (SAS, 2004) to study the influence of environmental sources of variation on various growth and reproductive traits. The genetic parameter estimation was done using REML procedure fitting an Individual Animal Model. Estimates of breeding values for various performance traits were also calculated by using BLUP. For these purposes WOMBAT software was used. The Least squares means for Age at first service, Age at first kidding, Weight at first service, weight at first kidding, services per conception, service period, kidding interval, birth weight, weaning weight, weight at six months, weight at nine months, yearling weight, pre-weaning daily gain, post-weaning daily gain at six months, post-weaning daily gain at nine months and post-weaning daily gain at twelve months the least squares means were 245.65±0.73 days, 14.07±0.01 kg, 394.14±0.76 days, 18.06±0 kg, 1.24±0.004, 153.58±0.73 days, 327.53±1.12 days, 1.66±0.03 kg, 9.59±0.01 kg, 11.70±0.02 kg, 16.69±0.02 kg, 21.03±0.03 kg, 70.21±0.16 grams, 31.39±0.08 grams, 45.25±0.03 grams and 45.95±0.02 grams, respectively. The percentage of single births was 43 percent, while multiple births were 57 percent. The sex ratio was 51:49 males and females. Year, sex, flock, and type of birth were main sources of variation on all the growth traits. The influence of season of birth was significant on yearling weight; however its effect on weight at six and nine months was non-significant. A significant influence of (p<0.01) birth and weaning weight was noticed on weight at 6, 9, 12 months and on post-weaning daily gain at 6,9 and 12 months. A significant effect (p<0.01) of year, birth weight and weight at service were observed on age of does at first service, while the seasonal and flock effect on the trait was non-significant. The influential environmental sources of variation on weight of does at first service were year, season and age at first service(p<0.01). A significant effect (p<0.01) of year, season, type, age and weight at service on age and weight at first kidding was noticed. The influence of year of service, flock, age and weight at service on services per conception was significant (p<0.01); however, effect of season of service on the trait was non-significant. A highly significant effect (p<0.01) of year and season of service, services per conception and weight at service were observed on service period. A significant effect (p<0.01) of year and season on kidding interval was noticed. The effect of flock was non-significant on the trait, however, age and weight at kidding had a significant effect (p<0.05) on the service period and kidding interval. The heritability estimates for birth weight, weaning weight, weight at six, nine and twelve (yearling) months, pre-weaning daily gain, post-weaning daily gain at six, post-weaning daily gain at nine, post-weaning daily gain at nine, post-weaning daily gain at twelve months, age at first service, weight at first service, age at first kidding, weight at first kidding, services per conception, service period and kidding interval were 0.28±0.23, 0.23±0.32, 0.19±0.42, 0.09±0.01 and 0.12±0.01, 0.21±0.32, 0.17±0.42, 0.12±0.02, 0.15±0.01, 0.19±0.22, 0.21±0.01, 0.19±0.04, 0.20±0.04, 0.07±0.01, 0.06±0.05 and 0.05±0.03, respectively. The repeatability estimates for birth weight, weaning weight, services per conception, service period and kidding interval were 0.53±0.02, 0.38±0.01, 0.02±0.05, 0.01±0.04 and 0.05±0.03, respectively. The estimates of genetic, Phenotypic and environmental correlations between birth weight and other growth traits were; weaning weight 0.61, 0.20 and 0.19, with weight at six months 0.39, 0.24 and 0.23, with weight at nine months 0.25, 0.38 and 0.36, with yearling weight 0.29, -0.01 and -0.02 and with pre-weaning daily gain 0.55, 0.31 and 0.29, respectively, while corresponding values for correlations between weaning weight and other growth traits were; with weight at six months 0.29, 0.19 and 0.17, with weight at nine months 0.23, 0.27 and 0.25, with yearling weight 0.45, 0.29 and 0.27 and with pre-weaning daily gain 0.97, 0.68 and 0.65, respectively, while the corresponding values for these correlations between weight at six months and other growth traits were; with weight at nine months 0.71, 0.27 and 0.25 with yearling weight 0.64, 0.21 and 0.19 and with pre-weaning daily gain were 0.31, 0.33, 0.31, respectively. The values for these correlations between weight at nine months and other traits were; with yearling weight 0.79, 0.23 and 0.21, with pre-weaning daily gain 0.25, 0.39 and 0.37, with post-weaning daily gain at six months 0.72, 0.81 and 0.79, respectively, while the estimates of these three correlations between yearling weight and other traits were; with pre-weaning daily gain 0.47, 0.41 and 0.42 and with post-weaning daily gain at six months 0.65, 0.10 and 0.08, while the corresponding values between pre-weaning daily gain and other traits were; with post-weaning gain at six months were 0.34, 0.15 and 0.13, with post-weaning gain at nine months 0.22, 0.13 and 0.12 and with post-weaning daily gain at twelve months were 0.54, 0.17 and 0.14, respectively. The estimates of genetic, Phenotypic and environmental correlations between age at first serviceand other traits were; with weight at first service 0.22, 0.79 and 0.76, with age at first kidding 0.76, 0.97 and 0.91 and with weight at first kidding 0.34, 0.14 and 0.11, respectively, while the corresponding values for these correlations between weight at first service and other traits were; with age at first kidding 0.39, 0.81 and 0.80, with weight at first kidding 0.35, 0.22 and 0.21 and with weight at first kidding 0.82, 0.18 and 0.16, respectively. Analysis of pedigree records for coefficient of inbreeding revealed that number of animals being 4465 (42.61 percent) with an average inbreeding of 2.43 percent and the highest level being 46.48 percent. The number of non-inbred animals was 6014 (57.39%). Out of the total of 406 sires used 23 were found inbred having an average inbreeding coefficient of 3.125 percent. Most frequent value for this category of animals was zero. The highest number of animals 1531 (14.61 percent) had an inbreeding percentage between 0.1 to 3.125, while only 104 animals (0.99 percent) were found with inbreeding of more than 25 percent. Most of the growth traits were statistically better in non-inbreds as compared to inbreds except yearling weight and post-weaning weight gain at twelve months, in which the means of both the traits were similar in both the groups. Among reproductive traits, age at first serviceand kidding, services per conception, service period and kidding interval were also statistically better in non-inbreds as compared to inbreds, while weight at first service and kidding interval were similar in both the groups. The ranges for estimated breeding values for different traits were, birth weight (-0.18 to 0.08 kg), weaning weight (-0.61 to 0.40 kg), weight at six months (-0.27 to 0.11 kg), weight at nine months, (-0.07 to 0.09 kg), yearling weight (-0.12 to 0.18 kg), pre-weaning daily gain (-0.30 to 1.20 grams), post-weaning daily gain at 6 months (-0.74 to 1.27 grams), post-weaning daily gain at 9 months (-0.32 to 0.57 grams), post-weaning daily gain at 12 months (-1.08 to 1.57 grams), age at first service(-43.23 to 58.06 days), weight at first service (-0.55 to 1.07 kg), age at first kidding (-53.31 to 48.34 days), weight at first kidding (-1.19 to 3.50 kg), services per conception (-0.18 to 0.16), service period (-7.07 to 9.80 days) and kidding interval (-13.23 to 20.89 days), respectively. The genetic trend in both birth weight and weaning weight showed an increasing trend during the period of study, while the genetic trend in weight at six, nine and twelve (yearling) months had no significant trend and fluctuated in the vicinity of zero. It is envisaged from the present study that over the 34 years period selection remained ineffective to bring the desired changes and it will remain so if random use of breeding animals is practiced. The possible use of ineffective selection could be unavailability of efficient techniques for the evaluation of animals and incorrect performance recording etc. It is therefore, necessary to correct all these discrepancies by taking corrective measures as discussed above. The following corrective measures may be a first step towards a goal oriented breeding policy. 1. The animals kept mainly for producing meat, the single most important factor is reproductive rate, which contributes to the efficiency of production (Shelton 1978). The most striking feature of sheep and goat enterprise is the ability to breed, off-season. Teddy goat is a non-seasonal breeder as kidding was observed throughout year with 36%, 19%, 25% and 20% kiddings recorded during spring, summer, autumn and winter, respectively, therefore a controlled breeding programme being practiced at times (as was observed during the present study at all the three stations) should not be advocated in any form at all and the desirable trait of non-seasonality should be the main pillar of a meat goat enterprise. 2. Although a higher percentage of abortions (70%) was observed in summer months but the percentage of dead births and mortality was almost equally distributed throughout the year, which indicates that better management of the flock during extremes of weather will results in less abortions and reduced mortality. 3. The high percentage of multiple births (57%) as against single births (43%) in teddy goats found in present study has backing of several studies, which showed that although there was slow growth rate in multiple births, yet they performed better by producing more total weight of kid weaned. Therefore prolificacy becomes a very important reproductive criteria and therefore emphasis should be selection of those animals with higher percentage of multiple births. 4. Environmental effects on productive and reproductive traits were significant; therefore through better management there are ample chances of improvement in these traits. 5. Low to medium heritability was recorded in all the growth traits, which offers scope for genetic selection. 6. Selection of animals to be the parents of future flock must be based on EBVs of growth traits. 7. Reproductive performance in present study was more than satisfactory. Early maturity which has been the main characteristic of Teddy breed was better as compared to many other breeds of the tropics (Beetal, Kamori, Jamunapari and Sirohi). Teddy goats were efficient than other breeds of the region when the means of the other reproductive traits like services per conception, service period and kidding interval were taken into consideration, however, room for improvement is still there. 8. Inbreeding in present study showed some increasing trend during the last five years and the percentage of animals kept on increasing during the last decade, therefore to control inbreeding a breeding plan with introduction of new blood from time to time is of utmost importance.
List(s) this item appears in: Phd. Theses
Tags from this library: No tags from this library for this title. Add tag(s)
Log in to add tags.
    average rating: 0.0 (0 votes)

Data available on 20455 kidding and performance records of 5545 Teddy goats and progeny of 406 sires maintained as separate flocks at three different locations i,e (I) Livestock Experiment Station Rakh Ghulaman, District Bakkhar (1983-2008) (II) Livestock Experiment Station, Rakh Khariewala District Layyah (1971-2008) and (III) Livestock Experiment Station Chak Katora, District Bahawalpur (1975-2008) Punjab, Pakistan were analyzed for documenting both genetic and environmental sources which influence growth and reproductive traits. Breeding values of sires and does were estimated and genetic and phenotypic trends for various performance traits were drawn. The data was analyzed using the GLM procedure (General Linear Models) of the Statistical Analysis Systems (SAS, 2004) to study the influence of environmental sources of variation on various growth and reproductive traits. The genetic parameter estimation was done using REML procedure fitting an Individual Animal Model. Estimates of breeding values for various performance traits were also calculated by using BLUP. For these purposes WOMBAT software was used.
The Least squares means for Age at first service, Age at first kidding, Weight at first service, weight at first kidding, services per conception, service period, kidding interval, birth weight, weaning weight, weight at six months, weight at nine months, yearling weight, pre-weaning daily gain, post-weaning daily gain at six months, post-weaning daily gain at nine months and post-weaning daily gain at twelve months the least squares means were 245.65±0.73 days, 14.07±0.01 kg, 394.14±0.76 days, 18.06±0 kg, 1.24±0.004, 153.58±0.73 days, 327.53±1.12 days, 1.66±0.03 kg, 9.59±0.01 kg, 11.70±0.02 kg, 16.69±0.02 kg, 21.03±0.03 kg, 70.21±0.16 grams, 31.39±0.08 grams, 45.25±0.03 grams and 45.95±0.02 grams, respectively. The percentage of single births was 43 percent, while multiple births were 57 percent. The sex ratio was 51:49 males and females.
Year, sex, flock, and type of birth were main sources of variation on all the growth traits. The influence of season of birth was significant on yearling weight; however its effect on weight at six and nine months was non-significant. A significant influence of (p<0.01) birth and weaning weight was noticed on weight at 6, 9, 12 months and on post-weaning daily gain at 6,9 and 12 months. A significant effect (p<0.01) of year, birth weight and weight at service were observed on age of does at first service, while the seasonal and flock effect on the trait was non-significant. The influential environmental sources of variation on weight of does at first service were year, season and age at first service(p<0.01). A significant effect (p<0.01) of year, season, type, age and weight at service on age and weight at first kidding was noticed. The influence of year of service, flock, age and weight at service on services per conception was significant (p<0.01); however, effect of season of service on the trait was non-significant. A highly significant effect (p<0.01) of year and season of service, services per conception and weight at service were observed on service period. A significant effect (p<0.01) of year and season on kidding interval was noticed. The effect of flock was non-significant on the trait, however, age and weight at kidding had a significant effect (p<0.05) on the service period and kidding interval.
The heritability estimates for birth weight, weaning weight, weight at six, nine and twelve (yearling) months, pre-weaning daily gain, post-weaning daily gain at six, post-weaning daily gain at nine, post-weaning daily gain at nine, post-weaning daily gain at twelve months, age at first service, weight at first service, age at first kidding, weight at first kidding, services per conception, service period and kidding interval were 0.28±0.23, 0.23±0.32, 0.19±0.42, 0.09±0.01 and 0.12±0.01, 0.21±0.32, 0.17±0.42, 0.12±0.02, 0.15±0.01, 0.19±0.22, 0.21±0.01, 0.19±0.04, 0.20±0.04, 0.07±0.01, 0.06±0.05 and 0.05±0.03, respectively. The repeatability estimates for birth weight, weaning weight, services per conception, service period and kidding interval were 0.53±0.02, 0.38±0.01, 0.02±0.05, 0.01±0.04 and 0.05±0.03, respectively.
The estimates of genetic, Phenotypic and environmental correlations between birth weight and other growth traits were; weaning weight 0.61, 0.20 and 0.19, with weight at six months 0.39, 0.24 and 0.23, with weight at nine months 0.25, 0.38 and 0.36, with yearling weight 0.29, -0.01 and -0.02 and with pre-weaning daily gain 0.55, 0.31 and 0.29, respectively, while corresponding values for correlations between weaning weight and other growth traits were; with weight at six months 0.29, 0.19 and 0.17, with weight at nine months 0.23, 0.27 and 0.25, with yearling weight 0.45, 0.29 and 0.27 and with pre-weaning daily gain 0.97, 0.68 and 0.65, respectively, while the corresponding values for these correlations between weight at six months and other growth traits were; with weight at nine months 0.71, 0.27 and 0.25 with yearling weight 0.64, 0.21 and 0.19 and with pre-weaning daily gain were 0.31, 0.33, 0.31, respectively. The values for these correlations between weight at nine months and other traits were; with yearling weight 0.79, 0.23 and 0.21, with pre-weaning daily gain 0.25, 0.39 and 0.37, with post-weaning daily gain at six months 0.72, 0.81 and 0.79, respectively, while the estimates of these three correlations between yearling weight and other traits were; with pre-weaning daily gain 0.47, 0.41 and 0.42 and with post-weaning daily gain at six months 0.65, 0.10 and 0.08, while the corresponding values between pre-weaning daily gain and other traits were; with post-weaning gain at six months were 0.34, 0.15 and 0.13, with post-weaning gain at nine months 0.22, 0.13 and 0.12 and with post-weaning daily gain at twelve months were 0.54, 0.17 and 0.14, respectively.
The estimates of genetic, Phenotypic and environmental correlations between age at first serviceand other traits were; with weight at first service 0.22, 0.79 and 0.76, with age at first kidding 0.76, 0.97 and 0.91 and with weight at first kidding 0.34, 0.14 and 0.11, respectively, while the corresponding values for these correlations between weight at first service and other traits were; with age at first kidding 0.39, 0.81 and 0.80, with weight at first kidding 0.35, 0.22 and 0.21 and with weight at first kidding 0.82, 0.18 and 0.16, respectively.
Analysis of pedigree records for coefficient of inbreeding revealed that number of animals being 4465 (42.61 percent) with an average inbreeding of 2.43 percent and the highest level being 46.48 percent. The number of non-inbred animals was 6014 (57.39%). Out of the total of 406 sires used 23 were found inbred having an average inbreeding coefficient of 3.125 percent. Most frequent value for this category of animals was zero. The highest number of animals 1531 (14.61 percent) had an inbreeding percentage between 0.1 to 3.125, while only 104 animals (0.99 percent) were found with inbreeding of more than 25 percent. Most of the growth traits were statistically better in non-inbreds as compared to inbreds except yearling weight and post-weaning weight gain at twelve months, in which the means of both the traits were similar in both the groups. Among reproductive traits, age at first serviceand kidding, services per conception, service period and kidding interval were also statistically better in non-inbreds as compared to inbreds, while weight at first service and kidding interval were similar in both the groups.
The ranges for estimated breeding values for different traits were, birth weight (-0.18 to 0.08 kg), weaning weight (-0.61 to 0.40 kg), weight at six months (-0.27 to 0.11 kg), weight at nine months, (-0.07 to 0.09 kg), yearling weight (-0.12 to 0.18 kg), pre-weaning daily gain (-0.30 to 1.20 grams), post-weaning daily gain at 6 months (-0.74 to 1.27 grams), post-weaning daily gain at 9 months (-0.32 to 0.57 grams), post-weaning daily gain at 12 months (-1.08 to 1.57 grams), age at first service(-43.23 to 58.06 days), weight at first service (-0.55 to 1.07 kg), age at first kidding (-53.31 to 48.34 days), weight at first kidding (-1.19 to 3.50 kg), services per conception (-0.18 to 0.16), service period (-7.07 to 9.80 days) and kidding interval (-13.23 to 20.89 days), respectively. The genetic trend in both birth weight and weaning weight showed an increasing trend during the period of study, while the genetic trend in weight at six, nine and twelve (yearling) months had no significant trend and fluctuated in the vicinity of zero.
It is envisaged from the present study that over the 34 years period selection remained ineffective to bring the desired changes and it will remain so if random use of breeding animals is practiced. The possible use of ineffective selection could be unavailability of efficient techniques for the evaluation of animals and incorrect performance recording etc. It is therefore, necessary to correct all these discrepancies by taking corrective measures as discussed above. The following corrective measures may be a first step towards a goal oriented breeding policy.
1. The animals kept mainly for producing meat, the single most important factor is reproductive rate, which contributes to the efficiency of production (Shelton 1978). The most striking feature of sheep and goat enterprise is the ability to breed, off-season. Teddy goat is a non-seasonal breeder as kidding was observed throughout year with 36%, 19%, 25% and 20% kiddings recorded during spring, summer, autumn and winter, respectively, therefore a controlled breeding programme being practiced at times (as was observed during the present study at all the three stations) should not be advocated in any form at all and the desirable trait of non-seasonality should be the main pillar of a meat goat enterprise.
2. Although a higher percentage of abortions (70%) was observed in summer months but the percentage of dead births and mortality was almost equally distributed throughout the year, which indicates that better management of the flock during extremes of weather will results in less abortions and reduced mortality.
3. The high percentage of multiple births (57%) as against single births (43%) in teddy goats found in present study has backing of several studies, which showed that although there was slow growth rate in multiple births, yet they performed better by producing more total weight of kid weaned. Therefore prolificacy becomes a very important reproductive criteria and therefore emphasis should be selection of those animals with higher percentage of multiple births.
4. Environmental effects on productive and reproductive traits were significant; therefore through better management there are ample chances of improvement in these traits.
5. Low to medium heritability was recorded in all the growth traits, which offers scope for genetic selection.
6. Selection of animals to be the parents of future flock must be based on EBVs of growth traits.
7. Reproductive performance in present study was more than satisfactory. Early maturity which has been the main characteristic of Teddy breed was better as compared to many other breeds of the tropics (Beetal, Kamori, Jamunapari and Sirohi). Teddy goats were efficient than other breeds of the region when the means of the other reproductive traits like services per conception, service period and kidding interval were taken into consideration, however, room for improvement is still there.
8. Inbreeding in present study showed some increasing trend during the last five years and the percentage of animals kept on increasing during the last decade, therefore to control inbreeding a breeding plan with introduction of new blood from time to time is of utmost importance.

There are no comments for this item.

Log in to your account to post a comment.


Implemented and Maintained by UVAS Library.
For any Suggestions/Query Contact to library or Email:rehana.kousar@uvas.edu.pk Phone:+91 99239068
Website/OPAC best viewed in Mozilla Browser in 1366X768 Resolution.