Browsing by Author "Cak, B."

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Effect of Timing of Artificial Insemination Relative To Spontaneous Estrus on Reproductive Performance and Calf Gender Ratio in Repeat Breeder Holstein Cows
(Pakistan Agricultural Scientists Forum, 2016) Bayril, T.; Yilmaz, O.; Cak, B.
This study was conducted to investigate the effect of the interval between the onset of spontaneous estrus and artificial insemination (AI) on reproductive performance and calf sex ratio in repeat breeder Holstein cows. Two hundred eighty lactating Holstein cows were used in this study. The animals were artificially inseminated at different times (0-6, 7-12, 13-18, or 19-24 h) after the onset of spontaneous estrus. Reproductive performance did not differ between cows inseminated at 0-6 h (n = 70), 7-12 h (n = 70), 13-18 h (n = 70), or 19-24 h (n = 70) after the onset of estrus [pregnancy rate: 0-6 h, 57.1%; 7-12 h, 65.7%; 13-18 h, 54.3%; and19-24 h, 62.9%; embryonic mortality rate: 0-6 h, 8.5%; 7-12 h, 5.7%; 13-18 h, 5.7%; and19-24 h, 7.1%; calving rate: 0-6 h, 48.6%; 7-12 h, 60%; 13-18 h, 48.6%; and19-24 h, 55.7%; twinning rate: 0-6 h, 2.9%; 7-12 h, 0%; 13-18 h, 5.7%; and 19-24 h 2.9%; and calf sex ratio (F/M): 0-6 h, 64/36%; 7-12 h, 48/52%; 13-18 h, 42/58%; and19-24 h, 46/54%; P>0.05]. In general, pregnancy rates of the groups inseminated at different postpartum times differed (P<0.01) and were higher in the group inseminated at >151 days postpartum. Pregnancy rates were similar in groups inseminated in the second and third parities, but were lower in the group inseminated in the fourth parity. In conclusion, rates of pregnancy, embryonic mortality, calving, and twinning of repeat breeder Holstein cows did not differ between cows subjected to AI at different times after the onset of spontaneous estrus. The timing of AI in repeat breeder cows did not influence the calf sex ratio. Pregnancy rate of repeat breeder cows was influenced by postpartum time and parity number.
Genetic Variability of Alpha-Casein, Beta-Casein, and Kappa-Casein Genes in Holstein-Friesian, Simmental and Brown Swiss Cattle
(Hellenic veterinary Medical Soc, 2025) Cak, B.; Dede, S.; Yuksek, V; Yilmaz, O.; Demirel, Af
This study aims to determine the genotypes and allele frequencies of polymorphisms of bovine alpha S1-ca-sein (CSN1S1), alpha S2-casein (CSN1S2), /3-casein (CSN2) and kappa-casein (CSN3) genes in Holstein-Friesian, Simmental, and Brown Swiss breeds. DNA was isolated from milk samples and gene regions were amplified using optimized PCR protocols. Sanger sequencing was performed to genotyping PCR products. CSN1S1 and CSN1S2 genes in three cattle breeds were observed to be monomorphic. Three different genotypes were observed for the CSN2 gene in Holstein-Friesian and two genotypes in Brown Swiss, while the Simmental breed was monomorphic. For the CSN3 gene was observed three different genotypes in Holstein-Friesian and Brown Swiss, two different genotypes in Simmental. Also, a novel single nucleotide polymorphism (SNP) was identified in the sequence region in the CSN2 gene exon 7 of three cattle breeds in this study. This SNP, c.249C>G, were non-synonymous, which leads to the change of p.N68K in amino acid residue of bovine /3-casein. This SNP is thought to be detected for the first time in Bos taurus genus. However, it was concluded that it would be appropriate to carry out more studies on this new SNP point in larger populations.
Investigation of Calpastatin (Cast) Gene Polymorphism in Norduz Sheep by Pcr-Rflp Method
(Hellenic veterinary Medical Soc, 2024) Yilmaz, O.; Cak, B.; Demirel, A. F.
The objective of this research was to determine polymorphism in the calpastatin (CAST) gene in a group of 102 Norduz sheep. Polymorphism was identified using the PCR-RFLP technique. The amplified PCR product with the length of 622 bp was digested with restriction enzymes MspI. It was found that the M and N alleles were present in CAST/MspI locus, their frequency being 78.43% and 21.57%, respectively. Homozygous for the M allele (MM) produced two bands of 336 and 286 bp. Three bands of sizes 622, 336 and 286 bp were seen in case of heterozygous genotype (MN), and homozygous for the N allele (NN) showed a 622 bp band only. The frequencies of homozygous MM, heterozygous MN and homozygous NN genotype were 64.7%, 27.5% and 7.8%, respectively. The genotype frequency distributions were in Hardy-Weinberg Equilibrium. In conclusion, the current study is the first study on genotyping of the CAST gene in Norduz sheep. The CAST gene was polymorphic in Norduz sheep. In the CAST gene, the predominant allele in the population was M, with a frequency of 78.43%. The MM and MN genotypes represented 92.2% of the genotype frequencies. The MM genotype was the most common, and NN genotype had the lowest genotype frequency. These results also indicate that in order to be used the polymorphism in the exon 1C/1D region of the CAST gene as a biomarker in Norduz sheep, primarily, association studies with economic traits should be performed.
Investigation of Survival Rate, Growth Performance and Some Body Measurements of Saanen X Hair Goat F1 Crossbred and Pure Hair Goat Kids Raised in Semi-Intensive Conditions
(2013) Yilmaz, O.; Kucuk, M.; Bolacali, M.; Cak, B.
The goal of this study was to determine survival rate, growth performance and some body measurements of Saanen x Hair goat F1 crossbred and pure Hair goat kids raised in semi-intensive conditions. The study was conducted at Research Farm of Yuzuncu Yil University in Van province, Turkey. Data were collected using 72 Saanen x Hair goats F1 crossbred and 41 Hair goat kids born in February and April in 2011. The survival rates of Saanen x Hair goat F1 crossbred and Hair goat kids at 90 (weaning) and 180 days of age were 90.28 and 90.24 %; 84.72 and 90.24 %, respectively. Effects of genotype, gender and birth type on survival rates of kids at 90 and 180 days of age were not significant (P>0.05). Body weights at birth, weaning and 180 days of age of Saanen x Hair goat F1 crossbred and Hair goat kids were 3.13 and 3.15 kg; 12.22 and 11.90 kg; 22.52 and 21.82 kg, respectively. Effects of dam's age (P<0.05) and dam's live weight (P<0.01) on birth weight of kids were significant; effects of gender, birth type (P<0.05) and dam's live weight (P<0.01) on live weight of kids at 90 days of age (weaning) were significant. The effect of only dam's live weight (P<0.01) on live weight of kids at 180 days of age was significant. Wither heights, body lengths, chest circumferences, chest lengths and chest depths of Saanen x Hair goat F1crossbred and Hair goat kids at 180 days of age were 54.5 ve 52.3 cm; 56.1 ve 53.2; 64.3 ve 65.7 cm; 31.4 ve 30.4 cm; 25.7 ve 25.7 cm, respectively. The findings of the present study showed that survival rates and live weights in various growth periods of Saanen x Hair goat F1 crossbred and Hair goat kids raised in semi-intensive conditions were similar. Furthermore, wither heights, chest circumference, chest lengths and chest depths of Saanen x Hair goat F1 crossbred and Hair goat kids did not differ, however body length was significant in favour of Saanen x Hair goat F1 crossbred kids.
Milk Yield Performances of Brown Swiss Cows Raised at Mus Alparslan State Farm in Turkey
(National Centre for Agrarian Sciences, 2015) Cak, B.; Yilmaz, O.
This research was carried out to reveal milk yield performances of Brown Swiss cows bred at Mus Alparslan State Farm in Turkey, and contribute to projection of the farm in the future. In the research, a total of 935 data belonging to 280 cows between the years 2005-2010 were used. Average lactation milk yield, 305-days milk yield, and lactation length of Brown Swiss cows, are determined respectively as 4639.79 kg, 4478.31 kg and 308.83 days. It is founded that effect of lactation number, calving year, and calving season are significant (P < 0.001) on lactation milk yield and 305-days milk yield, but the effect of calving age was not significant (P > 0.05); furthermore effects of calving age, lactation number, calving year, and calving season were not significant (P > 0.05) on lactation length. The results of this study showed that milk yield performances of Brown Swiss cows raised at Mus Alparslan State Farm are better than findings of researches conducted in previous years in the same farm, and lactation length resembles to standard lactation length suggest that herd directing programs is directed well, however lactation milk yield of Brown Swiss cows is lower than findings stated for the same breed cow in some local and foreign literatures. For this reason, making researches for improving milk yield performances of Brown Swiss cows in the farm will be beneficial. © 2015, National Centre for Agrarian Sciences. All Rights reserved.
Regression Tree Analysis for Determining of Affecting Factors To Lactation Milk Yield in Brown Swiss Cattle
(2013) Cak, B.; Keskin, S.; Yilmaz, O.
Lactation Milk Yield (LMY) in cows is one of the major characteristics for animal breeding programs. The aim of this study is to investigate the effects of possible environmental factors on lactation milk yield. In this study, 696 records of 280 Brown Swiss cattle that raised at Mus Alparslan State Farm in Turkey were analyzed using regression tree method to determine the several affecting factors to lactation milk yield. Lactation period, lactation number and calving season variables were considered to explanatory variables for lactation milk yield and all of these variables were found statistically significant factors. Lactation period was primarily and lactation number as well as calving season secondary factor. Thus, it can be concluded that optimal calving season may be winter and optimal lactation period can be considered as 307 days or greater for the increasing of milk yield. In addition, optimal lactation number should be greater than 1 for lactation duration is 263 to 292 days. © 2013 Academic Journals Inc.