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Öğe Age at first calving of Nellore cattle in the semi-arid region of northeastern Brazil using linear, threshold, censored and penalty models(Elsevier, 2013) Mendes Malhado, Carlos Henrique; Mendes Malhado, Ana Claudia; Martins Filho, Raimundo; Souza Carneiro, Paulo Luiz; Pala, Akin; Carrillo, Jose AdrianData are typically discarded when there are inconsistencies in a database, or when information is discrepant or out of range for the biological characteristics of the species being analyzed. However, such loss of information could have considerable implications for genetic evaluation of cattle. Here, we use different models to estimate genetic parameters for age at first calving in order to prevent data elimination. We used five approaches based on trait distribution to define the limits of censure/disposal: linear model, censorship, penalty and missing methods, and threshold model (binary and polychotomous). Data splitting and Pearson correlation were used to evaluate fitting and comparison of models. The lowest heritabilities were estimated for the missing method and the binary model. Exclusion of outliers from the data considerably affects the estimation of genetic parameters and the ranking of sires. Moreover, models that suffered from data elimination generated the worst classifications in terms of the comparison of models. Researchers should be extremely careful when deciding to discard data. For example, an age at first calving up to 72 months could be considered an outlier for other countries or even other areas in Brazil. Although this value is very high, it could be realistic under arid or semi-arid conditions. In these situations, the penalty or censure models are the most appropriate methods of analyses. (C) 2013 Elsevier B.V. All rights reserved.Öğe Detennination of erythrocyte potassium and glutathione polymorphism in Saanen, Maltese and Turkish hair goats(2011) Cobanoglu, Ozden; Gurcan, Eser Kemal; Pala, AkinMain purpose of this study was to investigate genetic polymorphisms of Saanen (S), Maltese (M) and Turkish Hair (TH) goats based on erythrocyte potassium and glutathione types. It was also designed to detect the association between these components and some blood parameters depending on the breed comparisons. The phenotypic and alleles frequencies were calculated for potassium and glutathione types of all three breeds. The difference between low and high potassium (LK and HK, respectively) types for the means of erythrocyte potassium concentration (Ke) were statistically important for all breeds (pÖğe Determination of Erythrocyte Potassium and Glutathione Polymorphism in Saanen, Maltese and Turkish Hair Goats(Medwell Online, 2011) Cobanoglu, Ozden; Gurcan, Eser Kemal; Pala, AkinMain purpose of this study was to investigate genetic polymorphisms of Saanen (S), Maltese (M) and Turkish Hair (TH) goats based on erythrocyte potassium and glutathione types. It was also designed to detect the association between these components and some blood parameters depending on the breed comparisons. The phenotypic and alleles frequencies were calculated for potassium and glutathione types of all three breeds. The difference between low and high potassium (LK and HK, respectively) types for the means of erythrocyte potassium concentration (K-e) were statistically important for all breeds (p<0.01). The significant relationships between erythrocyte potassium types and blood parameters of erythrocyte sodium (Na-e), whole blood potassium (K-wb), plasma potassium (K-p), erythrocyte potassium (K-e) were observed for S and TH goats. On the other hand, the important relationships were detected between erythrocyte potassium types and blood parameters of whole blood sodium (Na-wb), Na-e K-wb, K-p, K-e, total monovalent cation concentration in erythrocyte (Na-e+K-e) for M goat breed (p<0.05). The correlation coefficient between Na-e and K-e blood parameters was important and it was ranged from -0.26 to -0.34. In addition, Maltese goat breeds had a higher K-e than the others but Na-e was higher in TH goats. Even if parity and birth type differences were not statistically important for all blood parameters, there was indication of significant differences for these values except hematocrit value (PCV), Na-p and GSH concentrations depending on the potassium types within breed (p<0.05) and also among all breed analyses (p<0.001).Öğe Effects of different weaning programs on growth of Saanen kids(Wiley, 2007) Ugur, Feyzi; Atasoglu, Cengiz; Tölü, Cemil; Diken, Figen; Pala, AkinThe aim of the study reported here was to compare the performances of kids reared according to three different weaning programs. In the first program (T1), the dams were not milked in the evening and the kids accompanied their dams from 17.00 hours until the next morning. In the second program (T2), the dams of the kids were milked at 17.00 hours and then the kids accompanied their dams until the next morning, being separated from their dams at 08.00 hours. In the third program (T3), the kids were subjected to the T1 program for the first 4 weeks of the study, and to the T2 program for the last 4 weeks of the study. The kids in all the groups were weaned at 8 weeks of age. The weaning programs had significant effects on average daily weight gains (ADG) of the kids during weeks 1-4 and weeks 1-8 of the study (P < 0.05). In the weeks 1-8 period, the kids on the T1 program had a higher ADG than those on the T2 program (P < 0.05). However, the kids on T1, T2 and T3 programs had similar ADG post-weaning. The dry matter intake of the starter feed of the kids of the T3 program was higher than that of the kids of the T1 and T2 programs. The results of the present study indicated that the three weaning programs did not result in any significant effect on the growth of Saanen kids. Hence, the T3 program can be used if the starter feed intake is desirable.Öğe Effects of short period frequent milking on milk yield and udder health in Turkish Saanen goats(Blackwell Publishing, 2008) Koyuncu, Emrah; Pala, AkinThe major purpose of this study was to investigate whether increasing milking frequency for a short period (21 days) increases milk yield and milk components and improves udder health throughout lactation in Turkish Saanen goats. Two groups were formed (control, n = 14, treatment, n = 14); balanced by parity, bodyweight and birth type to make them homogenous. Feeding and management practices were the same for both groups. The treatment group was milked four times a day (4x) for 21 days after weaning whereas the control group was milked twice a day (2x). All the animals were milked twice daily thereafter. The pyronin methyl green stain method was used to estimate the somatic cell count (SCC), which is an indication of udder health. This method provided a count that excluded RNA and background noise while including cells with DNA. Repeated measures analyses indicated that overall differences between the 2x and 4x groups were significant for the morning, evening and total test day milk yields, in that values for the 4x group were increased 14.7, 8.8 and 12.1%, respectively. Differences between the groups for SCC were not significant. The results of this study indicate that increasing milking frequency to 4x, even for a short time (21 days), increases overall milk yield throughout lactation in dairy goats.Öğe Effects of short period frequent milking on milk yield in two East Friesian crosses: Tahirova and Sonmez sheep(Archiv Fur Tierzucht, 2011) Pala, Akin; Sahin, SeferThough East Friesian sheep are known to have very high milk yield, their various degree crosses may have different levels of milk yield under different conditions due to genotype x environment interaction. The major purpose of this study was to investigate whether increasing milking frequency for a short period (21 days) increases milk yield in two East Friesian crosses, Tahirova and Sonmez sheep. Tahirova is 75% East Friesian and 25% Kivircik, while Sonmez is 75% Tahirova and 25% Sakiz (Chios). Two milking groups were formed and were treated the same in terms of feeding and management. The sheep in the 4x group were milked 4 times a day after weaning for a short period, namely 21 days and then were milked twice a day for the rest of the lactation. The sheep in the 2x group were milked twice a day throughout the whole milking season. Repeated measures analyses indicated that overall differences between the 2x (520.68g) and 4x (873.03g) groups were highly significant for milk yield (P<0.01). Parity differences were significant in the treatment group and the 3rd lactation animals responded better to the 4x treatment (P<0.01), but they were non-significantly different than the 2nd lactation animals in the 2x group. Sheep in the 4x group had higher milk fat yield (P=0.02) but the groups were similar in terms of fat percentage (P=0.11). Differences between the breeds were highly significant (P<0.01) also. Tahirova breed, which has a higher percentage of East Friesian had a daily milk yield of 566.66g, while Sonmez breed with a lower percentage of East Friesian produced a higher daily milk yield of 827.05g. Results of this study suggests that increasing milking frequency for a short time increases milk yield throughout lactation, especially for older animals, and sheep with too high East Friesian breeding may have lower milk yield than those with lower East Friesian breeding.Öğe Effects of short periods of frequent milking on the persistency of milk yield and SCS in Turkish Saanen goats(Wiley-Blackwell Publishing, Inc, 2007) Pala, Akin; Koyuncu, EmrahThe major purpose of this study was to investigate if increasing milking frequency for a short period of 3 weeks had any effects on the persistency of milk yield and the persistency of the somatic cell score (SCS). The methyl green-pyronin method was used for the direct microscopic SCS, converted to SCS for the analyses. Two groups were formed (control, n = 14 and treatment, n = 14). The treatment group was milked four times a day for 3 weeks after weaning. Both groups were milked twice a day outside this 3-week period, throughout lactation. For the milk yield, persistencies were higher in the treatment group when the distance between the test days was equal to or less than 3 months. The exact opposite was true for the SCS; that is, the treatment group had higher persistencies when the distance between the test days was more than 3 months. Overall, persistencies related to milk yield were higher than persistencies related to SCS. For fat corrected milk yield, treatment persistencies were always higher than the control group persistencies, regardless of the distance between the tests. The same was true for the fat content. Increasing milking frequency for a short period of time (3 weeks) after weaning may help to increase the persistency of the milk yield, fat corrected milk yield and fat content. A 3-D plot of least squares means indicated that the milk yield tended to show a classical lactation curve in lower SCS values while forming an unstable curve in higher SCS values.Öğe EVALUATION OF CROSSBRED CALF AND COW TYPES; SUBJECTIVE TRAITS(Univ Zagreb, Fac Agriculture, 2006) Pala, Akin; McCraw, Roger; Robison, Odis WayneData in this experiment consisted of birth weight, calving score, thickness and grade records of 600 crossbred calves. Angus, Brangus, and Gelbvieh sires were mated to purebred Hereford cows. Yearling and 2-yr-old Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters then were bred to Polled Hereford bulls (Data Set 2). Later-parity Angus-Hereford, Brangus-Hereford, and Gelbvieh-Hereford daughters were mated to Salers or Simmental sires (Data Set 3). The traits evaluated were birth weight, thickness and feeder grade of calves and degree of calving difficulty. Calving difficulty, grade, muscling or thickness evaluation is a subjective assessment. Progeny of Angus cattle were lighter and born easier than progeny of Brangus and Gelbvieh cattle. Gelbvieh crosses had the highest frequency of thickness 1 calves and Brangus crosses had the highest frequency of medium size calves. Angus calves were lighter than Brangus calves in all the data sets but they had thicker muscles. Adding Bos Indicus genes to a cross may increase birth weight while decreasing muscling and calving ease.Öğe Genetic Analyses for Milk Yield, Lactation Period and Fat Percentage in Brown Swiss Cattle(Medwell Online, 2009) Zulkadir, Ugur; Aytekin, Ibrahim; Pala, AkinIn this study, a total of 733 milk yield records of Brown Swiss cows raised at Konuklar State Farm in Konya Province in Turkey were used for estimation of phenotypic and genetic parameters for milk yield, lactation period and fat percentage. The Phenotypic and genetic parameters were estimated by the MTDFREML program using Multiple Trait Animal Model. The model included individual, permanent environment and errors as random effects, year and season of calving, parity, year and age as fixed effects and days in milk as a covariate for milk yield; milk yield as a covariate for lactation period and milk yield and lactation period as covariate for fat percentage. Genetic parameters and breeding value of cow, sire and dam for milk yield in kg, for lactation period in days and for fat percentage in percent were estimated. Cow breeding values ranged from -3006-1724 kg for milk yield, from 10.81-14.22 days for lactation period and from -1.48-0.97% for fat percentage. Likewise, dam breeding values ranged from -1628-862 kg, from -5.69-7.74 days and from -0.76-0.48% for the same traits, respectively. Sire breeding value ranged between -1129 and 862 kg, -8.63 and 5.73 days and -0.68 and 0.83% for the above mentioned traits, respectively. Estimates of heritability were 0.33, 0.11 and 0.39 for milk yield, lactation period and fat percentage, respectively. The genetic correlation between milk yield and fat percentage was positive and high (0.95), whereas the genetic correlation between lactation period and milk yield and between lactation period and fat percentage was negative, -0.49 and -0.73, respectively. Repeatability estimates were 0.34, 0.47 and 0.54 for the same traits, respectively.Öğe Genetic parameters by Bayesian inference for dual purpose Jaffarabadi buffaloes(Archiv Fur Tierzucht, 2012) Mendes Malhado, Carlos Henrique; Mendes Malhado, Ana Claudia; Ramos, Alcides Amorim; Souza Carneiro, Paulo Luiz; Siewerdt, Frank; Pala, AkinKnowledge of genetic parameters is essential for improved reproductive management and increased yield. Quantitative analysis of genetic parameters is lacking for many breeds of buffaloes. This article provides the first estimate of genetic parameters for dual purpose (meat and milk) Brazilian Jaffarabadi buffaloes, using Bayesian inference. Data on milk yield (MY), lactation length (LL), weight at 205 days (W205) and 365 (W365) days of age, and average daily gain (ADG) from 205 to 365 days of age were collected in two herds. Bivariate analyses (using the program MTGSAM) were performed with the Gibbs sampler to obtain estimates of variance and covariance. Average lactation milk yield and lactation length were 1 620.2 +/- 450.9 kg and 257.6 +/- 46.8 days, respectively, and the mean values for weight traits (kg) were 181.6 +/- 63.3 (W205), 298.04 +/- 116.1 (W365), and 0.73 +/- 0.35 (ADG). Heritability estimates (modes) were 0.16 for MY, 0.10 for LL, 0.43 for W205, 0.48 for W365 and 0.32 for ADG. There was a high genetic correlation (0.96) between milk yield and lactation length and very high genetic correlations (0.99) between the three growth traits. Our data suggest that both milk production and growth traits have clear potential for yield improvement through direct selection in this dual purpose breed. The selection for weight at an early age would be successful and selection for MY can be performed in the first lactation.Öğe Genetic parameters for milk yield, lactation length and calving intervals of Murrah buffaloes from Brazil(Revista Brasileira Zootecnia Brazilian Journal Animal Sci, 2013) Mendes Malhado, Carlos Henrique; Mendes Malhado, Ana Claudia; Ramos, Alcides de Amorim; Souza Carneiro, Paulo Luiz; de Souza, Julio Cesar; Pala, AkinThe major objective of this study was to estimate heritability and genetic correlations between milk yield (MY) and calving interval (CI) and lactation length (LL) in Murrah buffaloes using Bayesian inference. The database used belongs to the genetic improvement program of four buffalo herds from Brazil. To obtain the estimates of variance and covariance, bivariate analyses were performed with the Gibbs sampler, using the program MTGSAM. The heritability coefficient estimates were 0.28, 0.03 and 0.15 for MY, CI and LL, respectively. The genetic correlations between MY and LL was moderate (0.48). However, the genetic correlation between MY and CI showed large HPD regions (highest posterior density interval). Milk yield was the only trait with clear potential for genetic improvement by direct mass selection. The genetic correlation between MY and LL indicates that indirect selection using milk yield is a potentially beneficial strategy. The interpretation of the estimated genetic correlation between MY and CI is difficult and could be spurious.Öğe Growth curves of Turkish Saanen goats' kids grouped for weight and body mass index(2005) Pala, Akin; Savaş, Türker; U?ur, Feyzi; Daş, GürbüzGrowth curves and weaning stress differences were investigated in Turkish Saanen kids grouped for their weight and Body Mass Index (BMI = weight/height2). Data included 884 records collected from 61 Turkish Saanen kids raised in Canakkale, Turkey. Slopes were calculated for each kid and were analyzed as data using ordinary least squares, and repeated weights for each kid were analyzed using various covariance structures. Differences between male and female kids were small and non-significant before weaning (P = 0.55), while larger (P=0.06) after weaning. Heavy animals grew faster than light animals before weaning (P < 0.01) but lost their advantage after weaning (P > 0.05). Fat animals (high BMI) grew faster than lean animals (low BMI) before weaning (P < 0.01) while the differences slightly diminished after weaning (P=0.04). This may be because light and lean kids were not affected from the weaning shock as much as the heavy and fat kids, which had stuttered growth after weaning. Fit statistics indicated that first-order ante dependence was the best fit covariance structure for these data. Analyses specifying random model and covariance structures did not have an advantage over an approach where slopes were manually calculated and analyzed as data using ordinary least squares.Öğe Inbreeding depression on production and reproduction traits of buffaloes from Brazil(Wiley-Blackwell, 2013) Mendes Malhado, Carlos Henrique; Mendes Malhado, Ana Claudia; Souza Carneiro, Paulo Luiz; Ramos, Alcides Amorim; Carrillo, Jose Adrian; Pala, AkinThe objective of this study was to evaluate the influence of inbreeding depression on traits of buffaloes from Brazil. Specifically, the traits studied were body weight at 205 and 365 days of age, average daily gain from birth to 205 days (ADG_205), average daily gain between 205 and 365 days (ADG205_365) in Mediterranean buffaloes, and milk yield, lactation length, age of first calving and calving intervals in Murrah buffaloes. Inbreeding effects on the traits were determined by fitting four regression models (linear, quadratic, exponential and Michaelis-Menten) about the errors generated by the animal model. The linear model was only significant (P<0.05) for growth traits (exception of ADG205_365). The exponential and Michaelis-Menten models were significant (P<0.01) for all the studied traits while the quadratic model was not significant (0.05) for any of the traits. Weight at 205 and 365 days of age decreased 0.25kg and 0.39kg per 1% of increase in inbreeding, respectively. The inbred animals (F=0.25) produced less milk than non-inbred individuals: 50.4kg of milk. Moreover, calving interval increased 0.164 days per 1% of increase in inbreeding. Interestingly, inbreeding had a positive effect on age at first calving and lactation length, decreasing age of first calving and increasing lactation length.Öğe Population structure and genetic variability in the Murrah dairy breed of water buffalo in Brazil accessed via pedigree analysis(Springer, 2012) Mendes Malhado, Carlos Henrique; Mendes Malhado, Ana Claudia; Souza Carneiro, Paulo Luiz; Ramos, Alcides Amorim; Ambrosini, Diego Pagung; Pala, AkinThe objective of this study was to use pedigree analysis to evaluate the population structure and genetic variability in the Murrah dairy breed of water buffalo (Bubalus bubalis) in Brazil. Pedigree analysis was performed on 5,061 animals born between 1972 and 2002. The effective number of founders (fe) was 60, representing 6.32 % of the potential number of founders. The effective number of ancestors (fa) was 36 and the genetic contribution of the 17 most influent ancestors explained 50 % of the genetic variability in the population. The ratio fe/fa (effective number of founders/effective number of ancestors), which expresses the effect of population bottlenecks, was 1.66. Completeness level for the whole pedigree was 76.8, 49.2, 27.7, and 12.8 % for, respectively, the first, second, third, and fourth known parental generations. The average inbreeding values for the whole analyzed pedigree and for inbreed animals were, respectively, 1.28 and 7.64 %. The average relatedness coefficient between individuals of the population was estimated to be 2.05 %-the highest individual coefficient was 10.31 %. The actual inbreeding and average relatedness coefficient are probably higher than estimated due to low levels of pedigree completeness. Moreover, the inbreeding coefficient increased with the addition of each generation to the pedigree, indicating that incomplete pedigrees tend to underestimate the level of inbreeding. Introduction of new sires with the lowest possible average relatedness coefficient and the use of appropriate mating strategies are recommended to keep inbreeding at acceptable levels and increase the genetic variability in this economically important species, which has relatively low numbers compared to other commercial cattle breeds. The inclusion of additional parameters, such as effective number of founders, effective number of ancestors, and fe/fa ratio, provides better resolution as compared to the inclusion of inbreeding coefficient and may help breeders and farmers adopt better precautionary measures against inbreeding depression and other deleterious genetic effects.Öğe Relationships between daily, morning, evening and peak yield and persistency in Turkish Saanen goats(Blackwell Publishing, 2006) Pala, Akin; Savaş, TürkerA matrix of persistency values is given instead of one value of persistency or persistency values based on succeeding test days. Overall, the persistency matrix of morning milk had higher values than the persistency matrix of evening milk. As the distance between the test days increased, the correlations dramatically decreased. The effects of morning milk yield b = 0.23 (P < 0.01) on standard deviation of morning and evening milk yield and on peak the milk yield was higher compared to the evening daily milk yield b = 0.03 (P = 0.05) and the total daily milk yield 0.10 (P < 0.01). Increased persistency means that the lactation curve may be flatter. Since the peak value of morning milk (1597 mL) was lower than evening milk (1799 mL), and morning milk was more persistent than evening milk, morning milk can be said to contribute more to the flatness of the lactation curve. Overall, the morning milk volume (938 mL) was larger than the evening milk volume (835 mL). A 3D plot of peak milk versus morning and evening milk yield indicated that increasing the evening milk yield increases the peak yield while the morning milk yield holds the peak value lower and the curve stable.
