KAJIAN APLIKASI TEKNIK INSEMINASI BUATAN DALAM PENINGKATAN GENETIK BOBOT BADAN TERNAK SAPI PERANAKAN ONGOLE DI SULAWESI UTARA

THE STUDY OF ARTIFICIAL INSEMINATION APPLICATION ON GENETIC IMPROVEMENT OF LIVE WEIGHT IN ONGOLE GRADE CATTLE AT NORTH SULAWESI PROVINCE. This research was conducted to evaluate the effective application of artificial insemination compared with natural breeding on genetic improvement by grading up system involving semen sourced from Ongole bull for the Indonesian-grade cattle at rural areas in Minahasa regency of North Sulawesi province, Indonesia. Data on animal live weight were collected from all cows (n= 404) kept by the traditional household farmers. Data of the cows were corrected by adjusting for the six years old of age. Breeding of beef genetic ancestors used the natural breeding (NB) and the artificial insemination (AI), divided into three cow groups with the first group of NB-mating without grading up (G0 cows), the second group of AI-mating with grading up using semen of Ongole bull for the first generation (G1 cows), and the third group of AI-mating with grading up using semen of Ongole bull for the second generation (G2 cows). The genetic improvements from breeding program of each G0, G1 and G2 were analyzed involving the selection intensity (i), the accuracy of selection (r), the genetic standard deviation of the trait under selection (SDg), and the generation interval (L) expressed in years. Results of this study showed that the critical components was the genetic development of local beef cattle by grading up using semen of the selected elite Ongole bull mated by AI method producing G2 in North Sulawesi province of Indonesia. This method increased genetically four hundred percents of live weight per year under 48% to 10% proportions of elite cows at the truncation points from the animal population compared with those of the natural mating of G0 in increasing genetic development for animal genetically live weight per year.Key Words: artificial insemination, genetic development, Indonesian local-grade cattle, Ongole breed bull

The Price equation as a bridge between animal breeding and evolutionary biology

The genetic response to selection is central to both evolutionary biology and animal and plant breeding. While Price's theorem (PT) is well-known in evolutionary biology, most breeders are unaware of it. Rather than using PT, breeders express response to selection as the product of the intensity of selection ( i ), the accuracy of selection ( ρ ) and the additive genetic standard deviation ( σ A ); R = iρσ A . In contrast to the univariate ‘breeder's equation’, this expression holds for multivariate selection on Gaussian traits. Here, I relate R = iρσ A to PT, and present a generalized version, R = i w ρ A , w σ A , valid irrespective of the trait distribution. Next, I consider genotype–environment covariance in relation to the breeder's equation and PT, showing that the breeder's equation may remain valid depending on whether the genotype–environment covariance works across generations. Finally, I consider the response to selection in the prevalence of an endemic infectious disease, as an example of an emergent trait. The result shows that disease prevalence has much greater heritable variation than currently believed. The example also illustrates that the indirect genetic effect approach moves elements of response to selection from the second to the first term of PT, so that changes acting via the social environment come within the reach of quantitative genetics. This article is part of the theme issue ‘Fifty years of the Price equation’.

Genetic parameters and genomic breeding values for digital dermatitis in Holstein Friesian dairy cattle: host susceptibility, infectivity and the basic reproduction ratio

Background For infectious diseases, the probability that an animal gets infected depends on its own susceptibility, and on the number of infectious herd mates and their infectivity. Together with the duration of the infectious period, susceptibility and infectivity determine the basic reproduction ratio of the disease ($$ R_{0} $$R0). $$ R_{0} $$R0 is the average number of secondary cases caused by a typical infectious individual in an otherwise uninfected population. An infectious disease dies out when $$ R_{0} $$R0 is lower than 1. Thus, breeding strategies that aim at reducing disease prevalence should focus on reducing $$ R_{0} $$R0, preferably to a value lower than 1. In animal breeding, however, $$ R_{0} $$R0 has received little attention. Here, we estimate the additive genetic variance in host susceptibility, host infectivity, and $$ R_{0} $$R0 for the endemic claw disease digital dermatitis (DD) in Holstein Friesian dairy cattle, and estimate genomic breeding values (GEBV) for these traits. We recorded DD disease status of both hind claws of 1513 cows from 12 Dutch dairy farms, every 2 weeks, 11 times. The genotype data consisted of 75,904 single nucleotide polymorphisms (SNPs) for 1401 of the cows. We modelled the probability that a cow got infected between recordings, and compared four generalized linear mixed models. All models included a genetic effect for susceptibility; Models 2 and 4 also included a genetic effect for infectivity, while Models 1 and 2 included a farm*period interaction. We corrected for variation in exposure to infectious herd mates via an offset. Results GEBV for $$ R_{0} $$R0 from the model that included genetic effects for susceptibility only had an accuracy of ~ 0.39 based on cross-validation between farms, which is very high given the limited amount of data and the complexity of the trait. Models with a genetic effect for infectivity showed a larger bias, but also a slightly higher accuracy of GEBV. Additive genetic standard deviation for $$ R_{0} $$R0 was large, i.e. ~ 1.17, while the mean $$ R_{0} $$R0 was 2.36. Conclusions GEBV for $$ R_{0} $$R0 showed substantial variation. The mean $$ R_{0} $$R0 was only about one genetic standard deviation greater than 1. These results suggest that lowering DD prevalence by selective breeding is promising.

A Selection Index for Improving the Carcass Traits in the Pannon Large Rabbit Breed

Loin muscle volume and hind leg muscle volume measured by computer tomography are economically valuable traits in rabbit breeding. Hence, genetic parameters were calculated to these new selection criteria, and a two-trait selection index was created in order to modify the current selection process of the Pannon large rabbit breed. The evaluated animals (n = 312) were randomly selected from 2014 and 2018, and the total number of animals in the pedigree file was 2758. Loin muscle volume (LMV) and hind leg muscle volume (HLV) were analyzed in a two-trait animal model. The estimated heritability for LMV was h2 = 0.4 and h2 = 0.42 for the HLV respectively. The selection index was created with desired gains by improving each trait in the selection criteria with one additive genetic standard deviation and the final index was Z transformed. Correlation coefficients between the index and the examined traits were high, 0.86 for LMV and 0.87 for HLV, thus this method could be announced into the breeding program.

Parametric and non-parametric indexes applied in the selection of sour passion fruit progenies

Several traits must be observed in the selection of sour passion fruit progenies. For such, selection indices could be used for gradually increasing the frequency of favorable genotypes for the set of the traits of interest. This study aimed to compare parametric and non-parametric selection indices to be used in the selection of passion fruit progenies and identify the best economic weights. Thus, 118 full-sib families and three controls were assessed for days regarding flowering, productivity in kg ha-1 year, fruit mass in g, number of fruits, average length of fruits in mm, average fruit diameter in mm, fruit shape, average shell thickness in mm, pulp yield, pulp color, total soluble solids, titratable acidity and SS/ATT ratio. The non-parametric selection indexes used to obtain genetic gains were Mulamba and Mock, genotype-ideotype distance, multiplicative and Elston. Smith and Hazel, Williams and Pesek and Baker parametric indexes were used, with different economic weights attributed. The Mulamba and Mock, genotype-ideotype distance nonparametric selection indexes and the Williams parametric index showed satisfactory and balanced gains. The genetic variation coefficient, genetic standard deviation and random weight economic weights provided higher gains for non-parametric selection indexes. Similar gains were obtained for parametric indexes, regardless of assigned weight, except for Pesek and Baker, whose genetic standard deviation provided the highest gain.

Joint estimation of (co) variance components and breeding values for mean and dispersion of days from calving to first service in Holstein cow

The present study explored the possibility of selection for uniformity of days from calving to first service (DFS) in dairy cattle. A double hierarchical generalised linear model with an iterative reweighted least-squares algorithm was used to estimate covariance components for the mean and dispersion of DFS. Data included the records of 27 113 Iranian Holstein cows (parity, 1–6) in 15 herds from 1981 to 2007. The estimated additive genetic variance for the mean and dispersion were 32.25 and 0.0139; both of these values had low standard errors. The genetic standard deviation for dispersion of DFS was 0.117, indicating that decreasing the estimated breeding value of dispersion by one genetic standard deviation can increase the uniformity by 12%. A strong positive genetic correlation (0.689) was obtained between the mean and dispersion of DFS. This genetic correlation is favourable since one of the aims of breeding is to simultaneously decrease the mean and increase the uniformity of DFS. The Spearman rank correlations between estimated breeding values in the mean and dispersion for sires with a different number of daughter observations were 0.907. In the studied population, the genetic trend in the mean of DFS was significant and favourable (–0.063 days/year), but the genetic trend in the dispersion of DFS was not significantly different from zero. The results obtained in the present study indicated that the mean and uniformity of DFS can simultaneously be improved in dairy cows.

Genetics of bovine respiratory disease in cattle: can breeding programs reduce the problem?

Genetics is responsible for approximately half the observed change in performance internationally in well-structured cattle breeding programs. Almost all, if not all, individual characteristics, including animal health, have a genetic basis. Once genetic variation exists then breeding for improvement is possible. Although the heritability of most health traits is low to moderate, considerable exploitable genetic variation does exist. From the limited studies undertaken, and mostly from limited datasets, the direct heritability of susceptibility to BRD varied from 0.07 to 0.22 and the maternal heritability (where estimated) varied from 0.05 to 0.07. Nonetheless, considerable genetic variation clearly exists; the genetic standard deviation for the direct component (binary trait), although differing across populations, varied from 0.08 to 0.20 while the genetic standard deviation for the maternal component varied from 0.04 to 0.07. Little is known about the genetic correlation between genetic predisposition to BRD and animal performance; the estimation of these correlations should be prioritized. (Long-term) Breeding strategies to reduce the incidence of BRD in cattle should be incorporated into national BRD eradication or control strategies.

Estimation of breeding values for functional productive life in the Slovak Holstein population

Genetic evaluation of length of functional productive life was carried out using a Weibull proportional hazard sire-maternal grandsire model. The database included 405 624 Holstein cows with 19.24% censoring. The analyzed effects were parity × stage of lactation, within-herd standard deviations of milk production, herd × year × season interaction, change of herd size with respect to the previous year, age at first calving, and sire and maternal-grandsire effects. Parity × stage of lactation had the most important influence on functional productive life. The results of the analysis confirmed more intensive selection at the beginning of each lactation, whereby the risk ratio increased with each other lactation. Heritability of functional productive life was 0.13 on the original scale. Breeding values of sires were expressed as relative breeding values with a mean of 100 and genetic standard deviation of 12.  

A Connection Between Mastitis During Early Lactation and Reproductive Performance of Dairy Cows – A Review / Związek mastitis we wczesnej laktacji z użytkowością reprodukcyjną krów mlecznych – artykuł przeglądowy

The objective of this study was to present a relationship between mastitis in the post-calving period and fertility traits of dairy cows. The threshold of 200,000 cells/ml for somatic cell count is used as a reference for healthy quarters of the cow’s udder. The genetic correlation between mastitis and somatic cell count is strong (from 0.7 to 0.8). Although heritability for fertility traits is low (from 0.01 to 0.02), the genetic standard deviation for mastitis varies from 1.2 to 7.0 percentage units, suggesting that genetic gain can be achieved by selecting for mastitis. Results of this study suggest that mastitis in the postpartum period can have a markedly negative impact on the reproductive performance of dairy cows. The synergistic effect of common conditions (somatic cell count, body condition score and lameness score) or other factors (e.g. heat stress, fertility management, the presence of repeat breeders) also lowers fertility of cows. Production of milk with fewer than 100,000 cells/ml leads to improved health and fertility in the cows.

Economic weights for conformation traits in Mountain sheep

Between October 2004 and April 2005, data of 304 and 504 Mountain sheep rams and ewes, respectively, were collected at seven auction sales for sheep breeding stock. Conformation scores of all animals were assessed before the auction started. In Mountain sheep, the scores 1 (worst) to 9 (best) are assigned for the conformation traits type, frame, form, feet and legs and wool. For the analysis of auction price, effects accounted for were the fixed effects of conformation traits, auction and lamb(s) sold with ewe (ewes only) as well as the covariate success at exhibitions. Auction had a significant effect on price in rams (P<0.05) and ewes (P<0.001), while for exhibition success only a trend (P<0.10) could be observed in ewes. Ewes sold with lambs did not achieve significantly higher prices. Within conformation traits, only type was found to have a significant effect in both sexes (P<0.01 in rams and P<0.001 in ewes). In rams, frame had a significant effect on auction price (P<0.001) while only a trend could be observed for form and feet and legs (P<0.10). Contrary to these results, in ewes higher scores for form and wool led to significantly higher prices (P<0.05 and <0.001, respectively). By means of the obtained Least Squares Means for score classes, economic weights for conformation traits were derived. The economic weights per genetic standard deviation, ewe place and year range from approximately € 0.9 to € 4.9 in ewes and € 1.3 to € 4.8 in rams.