Factor influencing sex ration in Brown swiss cattle

Translational Animal Science

Commercial dairy producers may get frustrated by the lower ratio of female to male calves born because female calves are more valuable than bull calves. Our objective was to determine if parity or stage of lactation at the time of breeding, using conventional semen, influenced the sex of the calf. Data from the University of Illinois and the University of New Hampshire dairy herds were collected and summarized for calf sex, the number of services to achieve a calf and the lactation number when conception of that calf occurred. Logistical regression procedures were used to analyze the dataset via version 9.4 of SAS. The final dataset contained 2,987 calvings, which consisted of 1,406 females and 1,581 males (47.1% and 52.9% for females and males, respectively). The frequency distribution of the number of services to achieve a calf was highest for the first service and progressively declined with increasing services (52.06%, 21.66%, 10.75%, 6.66%, 4.22%, and 4.65% for 1 to 6 services,...

Theriogenology, 2012

The objective of this study was to evaluate the factors affecting secondary sex ratio (SSR) in Iranian Holsteins. Data of 942,941 Holstein calving events from the Animal Breeding Center of Iran, recorded between January 1996 and December 2007, were used in the analysis. A multivariable logistic regression model was used to model the logit of the probability of a male calf being born. Male births accounted for 49.6% of the total observations. The ratio of males to females varied from 52.5:47.5 in calving year 1996-1999 (odds ratio (OR) ϭ 1.18; P Ͻ 0.0001), to 48.5:51.5 in calving year 2004-2007. The greatest occurrence of male births was observed in spring (OR ϭ 1.02; P Ͻ 0.0001), and the lowest incidence of male births was for summer or fall calvings. Also, the frequency of male births decreased from parity 1 to parity 4 and beyond (P Ͻ 0.0001; OR ϭ 1.11). The greatest number of sires had the SSR equal to 0.5 with a minimum SSR of 32% while the maximum was 97%. Among cows that had a male birth, the chance of delivering a male calf again was 25.5% when cows had delivered a male once (OR ϭ 1.14; P Ͻ 0.0001), and 12.7% if a male calf was delivered twice by a cow. This indicated that characteristics peculiar to the dam influence the sex of her offspring and suggests some degree of repeatability of calf sex within cows.

Journal of Animal and Plant Sciences

ABSTRACTThe aim of this study is to determine the environmental factors related to sex of calves born from Brown-Swiss cattle reared at Malya (M) and Konuklar (K) State Farms in Türkiye. A total of 7055 calves (1861 calves for K and 5194 calves for M state farms) were used as animal material. Unlike previous studies, a new ratio called “Relative Female Ratio (RFR)” (the superiority of female to male calves) was firstly suggested in this study for dairy cattle. The data on sex of all these calves, calving year, season, and parity of their dams were recorded. By using G statistic, an alternative of Pearson Chi-Square statistic, (which test an association between two categorical variables), calving year-sex, calving season-sex, parity-sex and sire-sex associations were examined for these two state farms. The proportions of male and female calves born in K and M state farms were 50.05:49.95 and 52.47:47.53, respectively. RFR values for K and M state farms were 0.998 (942 female calves/9...

2019

Breeding and calving records from 2013-2016 maintained at Adami Tulu Agricultural Research center was used for current study with aim of assessing ratios of calves born and identifying some of the factors affecting ratios of calves born. The data was cleared, arranged, categorized and pulled into years and analyzed by using Statistical Package for Social Science Version 20.0 (SPSS). The probability of a male calf being born was analyzed by chi square test. A threshold significance level was determined at the P <0.05. The result indicated that the overall sex ratio of calves born was i.e. the ratio of male to female is 57.1 to 42.9. Parity of the breeding cow doesn't have statistically significant effect on the sex ratio of calves born. The statistically analysis also shows that breeding year and season had not have the significant effect the sex ratio of calves born. In addition the sire line with which the animals inseminated has no significant effect. The result also indicted for the presence of significant difference of breeding method on sex ratio of calves born. From this it was concluded that breeding method has a significant effect on sex ratio of calves born in which number of male calves were higher in animals inseminated artificial and vice versa. Modern dairy reproductive technologies which enables to get more number of female calves has to be look into consideration to increase number of female animals for dairy producers in addition to providing efficient artificial insemination service in the country.

Theriogenology, 2014

A study was undertaken with the objective to identify some intrinsic (genotype of the cow, estrus time and parity) and extrinsic factors (service type, service time and estrus seasons) that affect calf sex ratio in naturally and artificially bred cattle in the central highlands of Ethiopia. A total of 4657 calving events were extracted from the long-term dairy cattle genetic improvement experiment at Holetta Agricultural Research Center. Factors that affect the logit of the probability of a female calf being born were obtained by using PROC GENMODE in Statistical Analysis System. Moreover, multivariate analysis was performed using PROC LOGISTIC procedure using forward selection procedure. Accordingly, genotype of the cow, parity, estrus season, and service type had considerable influences on calf sex ratio. However, estrus time and service time did not affect calf sex ratio (c 2 ¼ 0.83 and 0.79, respectively). In Ethiopia, smallholder dairy farmers often complain that artificial insemination (AI) skewed to producing more male calves. However, our study showed that AI did not alter female-to-male calf sex ratio. On the contrary, natural mating increases the probability of female calves born (odds ratio 1.38) over AI. Heifer/cows that showed estrus and bred during the harsh seasons of the years produced more female calves than those that bred during the good seasons of the year. This strongly agreed with Trivers and Willard sex allocation theory.

Journal of Environmental Science and Natural Resources, 2018

The study was conducted on 244 crossbred cows of CCBS Savar, Dhaka to evaluate the effect of different genetic groups on their lifetime performance of various reproductive traits using twenty years data. Data were accumulated from a prescribed data sheet maintained by Central Cattle Breeding Station, Dhaka. Genetic groups for this experiment were (LF), (LJ), (LH x F), (LF x LF) and (LJ x LJ). The studied parameters were age at puberty, service per conception, post-partum heat period, calving interval, total number of calving in lifetime. ANOVA showed that genetic groups had a significant effect on age at puberty, post-partum heat period, total number of calving in lifetime and calving interval (P&lt;0.05). From result it was found that earliest age at puberty were in L x F (749.27±99.01), service per conception, postpartum heat period was lower in L x F (1.60±0.19 and (145.75±94.44 days respectively). Calving interval was lower in L x J (411.18±136.87 days) and almost similar result...

Journal of Animal Breeding and Genetics, 2000

Roczniki Naukowe Polskiego Towarzystwa Zootechnicznego

Estimation of genetic parameters is a crucial element in the process of population improvement. In the case of farm animals this process is based on a sample which is a subset of the whole population. For this reason it is important to know the effect of the size of paternal groups and of the herd on the accuracy of estimations of these parameters, particularly heritability. The aim of this study was to show the effect of the population size of paternal groups and herds on the accuracy of estimation of the heritability index (h2). The material for the analyses comprised data of Holstein-Friesian cattle born in 2005-2010 and subject to use value assessment in Poland. The trait analysed was gestation length. Calculations using a linear mixed model were performed using the R 3.1.3 platform. The analyses showed that calculations concerning daughters in paternal groups are more accurate when the daughters are in a smaller number of herds, but of greater size. An increase in the size of p...

2000

Genetic evaluation of Holstein dairy cows, heifers and bulls for non-return 90 (NR90) is carried out in Germany since the mid-eighties. NR reflects only part of fertility. Additional time traits are necessary. There are indications that NR in heifers and in cows are genetically different traits. A model for multitrait genetic evaluation of fertility is described. The four traits included