1.
Dynamics Of Membrane Changes And Generation Of Reactive Oxygen Species During Bovine Sperm Death
by Mushtaq Ahmad | Prof. Dr. Nasim Ahmad | Dr. Amjad Riaz | Dr. Aneela Zameer Durrani.
Material type: ; Format:
print
Publisher: 2012Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1430,T] (1).
2.
Effect Of Cholesterol Addition On Cryopreservation Of Spermatozoa And Field Fertility Of Nili Ravi Buffalo
by Abdul Razzaq | Dr. Mian Abdul Sattar | Dr. Amjad Riaz | Dr. Muhammad Avais.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1821,T] (1).
3.
Effect Of Butylated Hydroxytoluene (Bht) On Beetal Buck Semen Following Cryopreservation
by Abdul Rehman | Prof.Dr. Mian Abdul Sattar | Dr. Amjad Riaz | Dr. Muhammad Ijaz.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1977,T] (1).
4.
Effect of Equine Chorionic Gonadotropin (eCG) on the Follicular Dynamics, Estrus Eepression, Ovulation and Pregnancy Rate in Control Internal Drug Release (CIDR) Based Estrus Synchronization Protocol in NIli-Ravi Buffalo.
by Muhammad Ilyas Naveed | Prof. Dr. Nasim Ahmad | Dr. Amjad Riaz | Prof. Dr. Muhammad.
Material type: ; Format:
print
Publisher: 2013Dissertation note: Buffalo is unique to livestock and dairy industry in Pakistan as its share is major (65%) in milk production major. Reproduction is crucial for profitable production in dairy sector. Buffalo reproduction is hampered due to small size ovaries, poor ovarian reserves, and less pronounced estrus intensity, ultimately leading to substandard fertility. Synchronization technology including CIDR based protocols are well established in cows and gaining popularity in buffaloes. However, this needs modifications based on estrous cycle physiology in buffaloes. It is hypothesized that addition of eCG at the time inducing luteolysis in CIDR based synchronization protocol will promote follicular growth, ovulation and pregnancy rates. The objective of this study is to determine the effect of addition of eCG to a CIDR based synchronization protocol on ovarian follicular dynamics, estrus rate, ovulation, and pregnancy rates in Nili-Ravi buffalo. Lactating multiparous suckled Nili-Ravi buffalo (n=63) milked twice daily were assigned in a CIDR (1.38 g progesterone Pfizer Co, USA) synchronization regimen. Animals were divided randomly to receive either saline (n=31) or 1000 IU eCG i.m. (n=32) (Chronogest PMSG, Intervet, Holland) concurrent with PGF2á (Dalmazine, cloprostenol, Fatro, Italy) treatment of the CIDR protocol (Day 6). Fixed time, two inseminations were performed at 48 and 60 hours after CIDR removal (Day 7). Number of follicles of variable size recruited at CIDR removal, dominant follicle size, its growth rate and ovulation time did not differ significantly between the groups. The estrus response was not higher significantly (P>0.14) in eCG group than control group but estrus intensity was significantly higher (P>0.001) in eCG group. Ovulation rate and 26 pregnancy per AI was higher (P>0.05 & 0.004) in buffaloes in eCG group. Therefore, It is concluded that eCG is helpful to improve estrus expression, ovulation rate and pregnancy per AI in FTAI program in Nili-Ravi buffaloes.
Availability: Items available for loan: UVAS Library [Call number: 1653,T] (1).
5.
Effect Of Taurine Supplementation On Post-Thaw Quality Of Sahiwal Bull Semen
by Muhammad Irfan (2013-VA-599) | Dr. Aijaz Ali Cheema | Dr. Muhammad Younas | Dr. Amjad Riaz | Dr. Muhammad Haroon Akbar.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: It is well recognized that cryopreservation of bovine semen results in decreased spermatozoal viability due to cryodamages. Oxidative stress is produced due to Reactive Oxygen Species (ROS) during freez-thaw process.Extreme production of ROS during cryopreservation has been associated with decreased post thaw %age motility, viability, and membrane integrity and sperm fertility capability. Basically antioxidants works to reduce or, taking up the formation of ROS. In recent years, taurine has been used as anti-oxidant in semen extenders and has been used in the cryopreservation of sperm from many species to improve post-thaw quality of spermatozoa by inhibiting lipid peroxidation and protecting cells against accumulation of ROS. Therefore, supplementation of taurine in semen extendercontaining 0,15,30,45 and 60mM concentration was used to decrease the harmful effects of cryopreservation on Sahiwal bull spermatozoa. Three Sahiwal bulls (4-8years) were used in the present study. The bulls were maintained at Semen production unit, Qadirabad and were offered good quality seasonal fodder (at the rate of 10% body weight), supplemented with concentrates (2-4kg/day). The semen was collected from each bull twice a week. Initially the semen was assessed for volume, motility, and concentration. Then the semen was pooled from all bulls and divided into 5 aliquots (150 ul each). Each aliquots diluted with 5groups extender which contain 0, 15, 30, 45 and 60mM taurine concentration. The semen was filled in 0.5ml straws cooled to 5c for 4 h, then frozen and stored in liquid nitrogen (-196c). Post-thaw motility, viability, plasma membrane integrity, acrosome and DNA integrity was evaluated and statistically analyzed by one way ANOVA. The group supplemented with 60mM concentration of taurine decreased all parameters of post thaw quality ofSahiwal bull spermatozoa. However the group supplemented with 15mM concentration of taurine show higher significantly (p<0.05) results than control and other groups. The post-thaw motility of the group supplemented with 15mM taurine concentration (54.50±2.1) higher significantly (p<0.05) than control (45.50±0.90) and other groups. The treatment group of 15mM taurine concentration show signifantly (p<0.05) higher viability (58.60±1.58 vs50.80±0.70) , plasma membrane integrity (57.10±1.43 vs 49.00±0.65) acrosome integrity (56.80±0.59 vs48.10±1.66) and DNA integrity (98.80±0.23 vs 97.54±0.39) as compared to the control and other groups. It is concluded that the maximum beneficial effect of addition 15mM taurine in tris-based egg yolk extender gives better post-thaw parameters. Availability: Items available for loan: UVAS Library [Call number: 2269-T] (1).
6.
Effect Of Molting On Reproductive Performance Of Indigenous Aseel Chicken
by Bashir Ahmad Khan (2013-VA-447) | Dr. Aijaz Ali Channa | Dr. Amjad Riaz | Prof. Dr. Athar Mahmud.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: The native breeds of Aseel chicken are playing vital role by producing organic meat and eggs. The Aseel chicken breed has some advantage as compared to other native breeds like, Lyallpur Silver black and Desi for their growth traits. However the growth and production traits need to be enhanced. There is no commercial farming system of Aseel chicken due to its poor fertility and hatchability. To overcome these problems the breeding roosters must be physiologically elite having excellent semen quality for better growth and egg production. The objective of this study was to enhance the semen quality, fertility and hatchability of Aseel roosters by the process of induced molting. For this purpose molting was induced in the 3 old males. There were three groups of Aseel Lakha cockerels’ i.e. molted, non-molted and fresh. The research was performed at Indigenous Genetic Resource Center (ICGRC), Department of Poultry Production, Ravi Campus, Pattoki.
To evaluate the impact of induced molting on semen quality, fertility and hatchability followed by natural mating of females to get better fertility and hatchability in eggs. Six Aseel roosters up to 60 weeks of age having 3.5 to 4kg body weight were divided into two groups’ as molted and non-molted. Third group of fresh birds more than 30 weeks of age were selected in this experiment as control. In one older group molting was induced by feed restriction. After completion of molting, two weeks rest was given to birds to recover body weight. These birds were trained for semen collection by abdominal massage method for two weeks. Semen was brought to the laboratory for evaluation after collection in all three groups. The significant difference (P < 0.05), was observed for volume, concentration, motility, livability and morphological defects in molted, non-molted and fresh groups. Eggs collected from the females mated with three groups were stored at 40C for two weeks. After that these
Summary
26
fertility, infertile eggs, and dead germs, dead in shell and hatchability% were recorded in three experimental groups. There was significant difference (P < 0.05), between fertility % infertile eggs % dead germs % and hatchability %. It is concluded that the semen quality is improved by the process of induce molting. Further egg sets from the females mated with induced molted males’ yielded better fertility (77%) and hatchability (54.1%) in indigenous Aseel chicken so induced molting is a better tool for the old males after 60 weeks of age for their reproductive performance. Availability: Items available for loan: UVAS Library [Call number: 2423-T] (1).
7.
Qualitative And Quantitative Assessment Of Fertile Period In Bitches
by Anam Mushtaq (2009-VA-388) | Dr. Muhammad Zahid Tahir | Dr. Amjad Riaz | Dr. Muhammad Hassan Saleem.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: The estrous cycle of the bitch consists of 4 phases including proestrus, estrus, diestrus and an obligatory anestrus. Most of the owners normally assess the fertile period on the base of qualitative parameters and mate their bitches on predetermined days. This is the major cause of apparent infertility in bitches. The most reliable assessment for timing of mating is through quantitative assessment through vaginal cytology and progesterone assay. The objective of this study was to compare the outcomes of qualitative and quantitative assessment of fertile period in bitches. Furthermore, the effect of assessment method was studied on fertility (number of pregnant bitches) and prolificity (number of pups in a litter).
This study was conducted on 148 referral cases of bitches brought to Theriogenology Laboratory. The data of qualitative assessment by the owners was collected by a questioner while quantitative assessment was based on vaginal cytology and progesterone assay. Statistical analysis was done using SPSS and logistic regression to compare the fertility (number of pregnancies) and prolificacy (number of pups) among groups.
In qualitative group, only 32% bitches were diagnosed pregnant. In contrast, the quantitative group showed a significantly higher fertility (83%) as compared to qualitative group (P<0.05) with odd ratio of 3 times higher fertility. Similarly, in qualitative group, 58% bitches had litter of 1-4 pups while the rest had a litter ranging in 5-10 pups. In contrast, quantitative group showed significantly (P<0.05) higher prolificity with 79% bitches having a litter of 5-10 with 4 times higher odd ratio. Meanwhile, the percentage of bitches having a smaller litter (1-4 pups) was considerably low (21%). In conclusion, the quantitative assessment of fertile period is more accurate and results in significantly higher fertility and prolificity. Availability: Items available for loan: UVAS Library [Call number: 2946-T] (1).
8.
Follicular Dynamics During Estrous Cycle In Sahiwal Cows
by Muhammad Yasir Arfat (2007-VA-102) | Prof. Dr. Nasim Ahmad | Dr. Amjad Riaz | Dr. Jawad Nazir | Faculty of Veterinary Sciences.
Material type: ; Format:
print
Publisher: 2014Dissertation note: Pakistan by default is an agricultural country. Livestock is mainstay of the farming
communities and has exclusive position in national agenda of the development. It plays an
important role in poverty alleviation and can uplift the socioeconomic condition of our rural
masses. Livestock contribution to agricultural GDP is 55.9 % and its contribution to National
GDP is 11.8 % (Anonymous,2013-2014). Total cattle population of Pakistan is 39.7 M
(Anonymous, 2013-2014). Livestock, especially cattle, play an important role in agriculture
economy of Pakistan in form of milk, meat and draught power. Milk is one of the cheapest
sources of nutrition and is beneficial for the human health in all stages of life. Despite the
nutritional importance of milk, its per capita availability and consumption is low in our country.
This inadequacy is due to suboptimal performance of indigenous dairy cattle due to lack of
modern technologies in cattle farming.
Pakistan is blessed with the finest breeds of dairy cattle such as Sahiwal, Cholistani and
Red Sindhi. Sahiwal cattle breed initially named as Montgomery breed (Bos indicus) is one of
the important breeds of indigenous cattle in Pakistan having dairy characteristics. The average
milk yield is about 1500 liters per lactation with 4% butter fat. But still its potential of milk
production is far less as compared to the exotic breeds e.g. Holstein Friesian etc. This is
primarily due to compromised feeding and management and little attention in the past for the
selection and breed improvement in Sahiwal cows. Moreover, late age at maturity and longer
calving interval (Makuza and McDaniel 1996) are major reproductive issues in Sahiwal cows.
Introduction
2
Physiology of oestrus cycle has been extensively studied in Holstein cows ( ). With the
advent of ultrasonography in early 1980’s it became possible to study follicular and luteal
dynamics during the estrous cycle in detail in Bos taurus (Fortune 1994; Lucy et al. 1992; Savio
et al. 1988; Wolfenson et al. 1995), and some beef breeds of Bos indicus cattle (Bó et al. 2003;
Figueiredo et al. 1997) and in buffalo (bubalis bubalis) as well (Warriach and Ahmad 2007).
The benefit of these studies was that the information on follicular dynamics in Bos taurus breeds
has been used to manipulate the estrous cycle in order to improve estrus synchronization
(Thatcher et al. 1993; Twagiramungu et al. 1995; Wolfenson et al. 1994) fixed time artificial
insemination (FTAI) (Pursley et al. 1997; Schmitt et al. 1996a; Schmitt et al. 1996b;
Twagiramungu et al. 1995) and embryo transfer procedure (Mapletoft et al. 1994; Roberts et al.
1994).
Sahiwal is one of the established zebu cattle (bos indicus) milk breeds of tropical and
subtropical region. It is known for its remarkable power of endurance for hot climate, resistance
to ticks and other diseases and has high producing ability under harsh environment and low cost
of maintenance as compared to the Bos indicus and Bos taurus crossbreds. Due to its promising
dairy characteristics and better adaptation to tropical environmental conditions, both the semen
and female of this breed have been exported from Pakistan and in Africa and Australia.
Differences on the reproductive characteristics between Bos taurus and few breeds of Bos
indicus cattle have been reported like luteal tissue characteristics (Pathiraja et al. 1986), Graafian
follicle (DF) diameter (Figueiredo et al. 1997) and estrous cycle duration (Castilho et al. 1996).
However, surprisingly, there has been no thorough study on the reproductive physiology of the
estrous cycle in Sahiwal cows. Therefore, the objective of the present study is to determine the
Introduction
3
follicular dynamics, luteal tissue development and regression, estrous cycle length, timing of
ovulation, estrus signs and fertility.
It is hoped that these data will be helpful for improved assisted reproductive technology
e.g. AI, ET etc. (Andrabi and Maxwell., 2007), timing of the treatment of the various hormones
(Krininger et al., 2003) and development of new technologies like fixed time A.I, estrus
synchronization, super ovulation, embryo transfer in Sahiwal cows. Ultimately, these can
increase herd reproductive, productive performance and for preservation of Sahiwal cattle breed. Availability: Items available for loan: UVAS Library [Call number: 2183,T] (1).
9.
Comparison Between Aspiration And Slicing Methods For Retrieval Of Oocytes In Bovine
by Muhammad Husnain (2008-VA-281) | Prof. Dr. Mian Abdul Sattar | Dr. Qaiser Shahzad | Dr. Amjad Riaz | Dr. Muhammad Avais.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Livestock contribution to agriculture stood at 55.9 percent while it contributes 11.8 percent to the national GDP during 2013-14. Buffalo, cattle, sheep and goat population in Pakistan is 34.6, 39.7, 29.1 and 66.6 million numbers during 2013-14. Total milk production from buffalo and cattle as major milk producing animals is 31,252 and 18,027 (000 tons) (Economic Survey of Pakistan 2013-14).
Advanced biotechnologies coming from different areas of biological sciences exhibit great promise to enhance the efficiency of livestock production. From these technologies one such biotechnology is the use of in vitro maturation of follicular oocytes and in vitro fertilization for production of livestock embryos in laboratory. Proper oocytes recovery and their selection in the laboratory are of great importance for successful in vitro embryo production. Total one hundred and forty four ovaries (n=144) from cattle (72 ovaries) and buffalo (72 ovaries) were collected and 223 oocytes were retrieved from these ovaries. Average oocytes per ovary were 1.66 + 0.43 oocytes per ovary were obtained via aspiration and 1.89 + 0.00 average oocytes per ovary through slicing method from cattle ovaries. Average 1.55 ± 0.55 oocytes per ovary via aspiration and 1.53 ± 0.20 oocytes per ovary through slicing from buffalo ovaries.
Overall grade-A oocytes were 28 (40) percent with aspiration in cattle and 25(36.76) through slicing method. In buffalo overall grade-A oocytes retrieval was obtained in percentage as 20 (44.44) and 26 (52) through aspiration and slicing methods respectively. Grade-B oocytes recovery obtained was in percentage as 23 (33.82) with slicing and 19 (31.67) through aspiration technique from cattle ovaries.
Summary
26
Commonly used methods of recovery of oocytes from slaughterhouse animals are aspiration and slicing. Recovery rate of oocytes is different from slaughterhouse ovaries. Aspiration is the best method for retrieval of good quality oocytes from slaughterhouse bovine ovaries because it gave more good quality oocytes in less time than slicing method. In this study, it is found that weight of ovary and no. of follicles/ovary in cattle have strong correlation of 71% existed between weight of ovary and no. of follicles /ovary in buffalo was observed. Correlation between average number of follicles on ovary and weight /ovary was stronger in cattle. The more the number of follicles present on the ovaries and more weight of the ovary, the more will be the recovery of oocytes.
In cattle average number of follicles was 10.09 ± 0.30 and when it was checked in buffalo, differed significantly and it was found as 7.16 ± 0.19 on an average per ovary. Likewise weight of buffalo in this study was differed significantly from cattle 4.04 ± 0.10 and 7.62 ± 0.15 respectively. It is suggested that oocytes retrieval should be done in buffalo using aspiration method to retrieve better quality oocytes.
It is concluded that aspiration is the suitable method for retrieval of good quality oocytes from slaughterhouse buffalo ovaries because it gave more good quality oocytes in less time than slicing method. But both methods have minor difference between recovery rates but aspiration is more convenient than slicing and it yields more quality oocytes. It is also found that there is very strong correlation existed between average weight of ovary and number of follicles per ovary and the both parameters play a great help for more quality and quantity oocytes. Availability: Items available for loan: UVAS Library [Call number: 2279-T] (1).
(1 votes)
10.
Effect Of Antibiotic Treatment During Ovulation Synchronization In Repeat Breeder Holstein Friesian Cows
by Masood Shabbir (2010-VA-120) | Dr. Muhammad Zahid Tahir | Dr. Amjad Riaz | Dr. Muhammad Avais.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: Repeat breeding is one of the major causes of reproductive, productive and economic
losses in dairy sector. The main causes of repeat breeding include sub-clinical infection of
reproductive tract, age of the animal, error in the detection of estrus, endocrine dysfunction and
nutritional deficiencies. In Pakistan, a very high incidence of repeat breeding has been
documented (Kakar et al. 1997). In the past, intrauterine infusions have successfully been used
with a variety of antiseptic and antibiotic solutions. Meanwhile, therapeutic use of GnRH and
PGF2α has also been demonstrated to result in improved pregnancy rates. In particular, Ovsynch
protocol leads to an increase of 6-17% in conception rate.
The objective of the present study was to evaluate the reproductive efficiency with
antibiotic treatment during ovulation synchronization in repeat breeder Holstein Friesian cows.
This study was conducted on 30 pure bred Holstein Friesian cows kept under standard farm
conditions of feeding and management at Hussain Cattle and Dairy Farm, Kasur. The
reproductive efficiency of treated and control animals was based on ovulation rate, non-return
rate, conception rate, pregnancy rate, embryonic losses and luteal function. Results were
analyzed by independent T-test. A probability level of 95% was consider as significant (P<0.05).
All the experimental animals were screened to confirm non-pregnant and normal genitalia. Both
the treatment and control groups were synchronized using ovsynch protocol. Following first
injection of GnRH, the treatment group was subjected to intrauterine antibiotic infusion for five
days. On Day 7 of protocol both groups received an injection of PGF2α. At day 9 of ovsynch
protocol before second injection of GnRH both groups were scanned for ovarian status. Follicles
and CL measurement were noted and mapped by using 7.5 MHz trans-rectal probe (Honda
22
Summary
Model HS-1600) in both groups and second injection of GnRH was given. Timed artificial
insemination was performed after 16-20 hours of second injection of GnRH in both groups. After
8 hours of artificial insemination again ultrasonography was conducted to check the ovulation
rate in both groups, there was no significant difference between control and treatment, 60% and
75% of the animals in control and treatment groups ovulate respectively. At day 11 blood
samples were collected for progesterone assay. Non-return rate was visually observed at day 18
to 21 of artificial insemination. Blood was collected at day 18 for progesterone assay by puncture
of tail vein. After D28 andD42 of artificial insemination first and second pregnancy test were
conducted by using 7.5 MHz trans-rectal probe (Honda Model HS-1600) in control and treatment
group. There was a significant difference of pregnancy among the control and treatment group
by independent T-test. 3
rd
and 4
th
blood samples were collected for progesterone assay at day28
and 42 of artificial insemination in both groups respectively. Availability: Items available for loan: UVAS Library [Call number: 2951-T] (1).
11.
Reproductive and Productive Performance of Dairy Animals Maintained at Mulitary Dairy Farm Lahore Cantt.
by Abrar Ahmed | Dr. Mian Abdul Sattar | Dr. Amjad Riaz | Prof. Dr. Muhammad.
Material type: ; Format:
print
Publisher: 2012Dissertation note: NILI RAVI BUFFALOES
Average age at maturitywas 829.11 ± 30.34 days. Heiferscalved in1999 and 2008 were found to have maximum and minimum age at maturity, respectively. Heifers calved during the winter and dry summer season were found to have maximum and minimum age at maturity, respectively. Mean birth weight of calves was found 28.16±2.8 kg. The effect of birth weight on age at maturity was found to be significant and it was observed that 1 kg increase in birth weight resulted in 16 days decrease in age at maturity. Average age at first conception was 923.37 ± 30.34 days. Heifers calved in 1996 and 2008 were found to have maximum and minimum age at first conception, respectively. Heifers calved during the winter and dry summer season were found to have maximum and minimum age at first conception, respectively. Average age at first calving was 1295.66 ± 62.91 days. Heifers calved in 2002 and 2008 were found to have maximum and minimum age at first calving, respectively. Heifers calved during the dry summer andautumn season were found to have maximum and minimum age at first calving, respectively. Average service period was 164.1 ± 30.15 days. Maximum and minimum service period was in year of 2002 and 2008, respectively. In dry summer and autumn season, service period was maximum and minimum, respectively. In 11th and 10thlactation, service period was maximum and minimum, respectively.Average services per conception were 1.95 ± 0.23. Maximum and minimum services per conception were in 2005 and 2008, respectively. In humid summer and autumn season, services per conception were maximum and minimum respectively. In 11th and 9th lactation, the services per conception were maximum and minimum, respectively. Average gestation period was 310.90 ± 3.07 days. Maximum and minimum gestation periodwas in 2000 and 2009 2009 respectively. In humid summer and dry summer season, gestation period?
was maximum and minimum respectively. In 12th and 8th lactation, the gestation period was maximum and minimum, respectively. Average calving interval was 474.59 ± 29.88 days. Maximum and minimum calving interval was in 2005 and 2001, respectively. In dry summer and autumn season, calving interval was maximum and minimum respectively. In 11th and 10th lactation, calving interval was maximum and minimum, respectively. Average milk yield was 1973.15 ± 53.23 liters. Maximum and minimum milk yield was in 2010 and 2002, respectively. In winter and spring season, milk yield was maximum and minimum respectively. In 4th and 11th lactation, milk yield was maximum and minimum, respectively. Average lactation length was 295.23 ± 64.30 days. Maximum and minimum lactation length was 2001 and 2000, respectively. In spring and humid summer season, lactation length was maximum and minimum respectively. In 10th and 11th lactation, lactation length was maximum and minimum, respectively. Average dry period was 184.93 ± 30.99 days. Maximum and minimum dry period was in 2005 and 2001, respectively. In dry summer and autumn season, dry period was maximum and minimum respectively. In 11th and 10th lactation, dry period was maximum and minimum, respectively.
CROSSBRED COWS
Average age at maturity was 828.33 ± 20.39 days. Heifers calved during the year of 1998 and 1997 were found to have maximum and minimum age at maturity, respectively. Heifers calved during the humid summer and winter season were found to have maximum and minimum age at maturity, respectively. In 15/16 and 1 /2 crossbred level, age at maturity was maximum and minimum, respectively. Mean birth weight of crossbred cow calves was found 23.35 ± 2.8 kg. The effect of birth weight on age at maturity was found to be significant and it was observed that 1 kg increase in birth weight resulted in 07 days decrease in age at maturity. Average age at first conception was 944.18 ± 30.42 days. Heifers calved in 2004 and 1996 were found to have maximum and minimum age at first conception, respectively. Heifers calved during the humid summer and dry summer season were found to have maximum and minimum age at first conception, respectively. In 15/16 and 1 /2 crossbred level, age at first conception was maximum and minimum, respectively. Average age at first calving was 1245.29 ± 40.96 days. Heifers calved in 2008 and 1995 were found to have maximum and minimum age at first calving, respectively. Heifers calved during autumn and winter season were found to have maximum and minimum age at first calving, respectively. In 7/8 and 5/8 crossbred level, age at first calving was maximum and minimum, respectively. Average service period was 252.83 ± 32.56 days. Maximum and minimum service period was in year of 2006 and 2010, respectively. In winter and humid summer season, service period was maximum and minimum respectively. In 10th and 8th lactation, service period was maximum and minimum, respectively. In 7/8 and 15/16 crossbred level, service period was maximum and minimum, respectively. Average services per conception were 2.13 ± 0.31. Maximum and minimum services per conception were in 1999 and 2002, respectively. In winter and dry summer season, services per conception were maximum and minimum respectively. In 9th and 8th lactation, the services per conception were maximum and minimum, respectively. In 15/16 and 5/8 crossbred level, services per conception were maximum and minimum, respectively. Average gestation period was 278.90 ± 4.36 days. Maximum and minimum gestation period was in 2010 and 2003 respectively. In autumn and winter season, gestation period was maximum and minimum, respectively. In 2nd and 7th lactation, the gestation period was maximum and minimum, respectively. In 7/8 and 15/16 crossbred level, gestation period was maximum and minimum, respectively. Average calving interval was 507.03 ± 33.61 days. Maximum and minimum calving interval was in 2006 and 2000, respectively. In winter and humid summer season, calving interval was maximum and minimum respectively. In 11th and 10th lactation, calving interval was maximum and minimum, respectively. In 5/8 and 15/16 crossbred level, calving interval was maximum and minimum, respectively. Average milk yield was 2141.05 ± 90.10 liters. Maximum and minimum milk yield was in 2008 and 2003, respectively. In dry summer and autumn season, milk yield was maximum and minimum respectively. In 11th and 1st lactation, milk yield was maximum and minimum, respectively. In 15/16 and 3/4 crossbred level, milk yield was maximum and minimum, respectively. Average lactation length was279.31 ± 8.33 days. Maximum and minimum lactation length was 2001 and 2003, respectively. In dry summer and autumn season, lactation length was maximum and minimum respectively. In 11th and 5th lactation, lactation length was maximum and minimum, respectively. In 3/4 and 15/16 crossbred level, lactation length was maximum and minimum, respectively. Average dry period was 238.64 ± 33.93 days. Maximum and minimum dry period was in 2006 and 2000, respectively. In winter and humid summer season, dry period was maximum and minimum respectively. In 5th and 11th lactation, dry period was maximum and minimum, respectively. In 5/8 and 15/16 crossbred level, dry period was maximum and minimum, respectively.
Availability: Items available for loan: UVAS Library [Call number: 1624,T] (1).
