Crossbreeding Program Research Articles

A superior genetic source for late leafing in walnut 'Ahir Nut'

One of the main objectives of walnut crossbreeding programmes is to produce cultivars with late leafing dates. Sixteen years ago, a walnut crossbreeding programme was initiated by Prof. Mehmet Sütyemez, and now a new walnut genotype, namely ‘Ahir Nut’, has been generated with a leafing date that starts later than all commercially-famous walnut cultivars in the world. The present study describes this walnut genotype. For a detailed analysis, ‘Ahir Nut’ was compared with two French-origin walnut cultivars, i.e., ‘Franquette’ and ‘Ronde de Montignac’, which have had the latest leafing dates until now. In an experimental orchard in Turkey, the leafing date in ‘Ahir Nut’ was 14 May, whereas the leafing date in ‘Franquette’ and ‘Ronde de Montignac’ were 23 April and 25 April, respectively. This approximately 3-week difference between ‘Franquette’ and ‘Ronde de Montignac’ to ‘Ahir Nut’ reveals how valuable this genotype is for walnut breeding studies. The harvest dates for ‘Ahir Nut’, ‘Franquette’ and ‘Ronde de Montignac’ were 4 October, 3 October, and 7 October, respectively. The defoliation date for ‘Ahir Nut’ was 4 December. The nut weight and kernel percentage of ‘Ahir Nut’ were calculated as 11.61 g and 49.84%, respectively. Remarkable phenological traits were found in ‘Ahir Nut’, making it a promising option for future walnut cultivation. In the present study, the late leafing date of ‘Ahir Nut’ prompted further research into the molecular and walnut crossbreeding potentials. This new genotype has been conserved as an important genetic resource for future walnut breeding programmes around the world.

Promoting Sustainable Utilization and Genetic Improvement of Indonesian Local Beef Cattle Breeds: A Review

This paper reviews the literature relevant to the breeding of cattle grazed in tropical environments and particularly Indonesia. The aim is to identify new breeding opportunities for cattle owned by Indonesia’s smallholder farmers, whilst also conserving unique local cattle beef breeds. Crossbreeding has been practiced extensively in Indonesia, but to date there have been no well-designed programs, resulting in many mixed-breed animals and no ability to determine their genetic composition, productive capabilities or adaptation to environmental stressors. An example of within-breed selection of Bali cattle based on measured live weight has similarly disregarded other productive and adaptive traits. It is unlikely that smallholder farmers could manage effective crossbreeding programs due to the complexities of management required. However, a tropically adapted composite breed(s) could perhaps be developed and improved using within-breed selection. Establishing reference population(s) of local breeds or composites and using within-breed selection to genetically improve those herds may be feasible, particularly if international collaborations can be established to allow data-pooling across countries. The use of genomic information and a strong focus on all economically important traits in practical breeding objectives is critical to enable genetic improvement and conservation of unique Indonesian cattle breeds.

Molecular characterization and A1/A2 genotyping of casein beta gene in zebu and crossbred cattle of Bangladesh

Casein beta (CSN2) is the most explored gene in cattle due to its potential impact on human health. Here, we investigated the entire coding sequence of CSN2 gene except the last two codons for detection of polymorphisms in different cattle populations of Bangladesh as well as genotyping of A1 and A2 allelic variants using a newly developed allele specific polymerase chain reaction (AS-PCR) based the genotyping protocol. Five primer pairs were used to amplify the coding sequences of CSN2 gene. This study included a total of 258 DNA samples from six Bangladeshi zebu populations and one Holstein Friesian (HF) derived crossbred cattle population. Sequence analysis detected five nonsynonymous mutations in the coding sequence of CSN2 gene that defined five allelic variants as A1, A2, B, F and I. In addition, substitution of GTA (Val) by GCA (Ala) at position 197 resulted in an undefined allele in the zebu cattle population of Bangladesh that has not yet been reported elsewhere. Like other Bos indicus cattle populations, A2 allele is predominant in the studied zebu populations. The mean frequencies of A1A1, A1A2 and A2A2 genotypes were 0.02, 0.16 and 0.82, respectively, in zebu cattle populations while the corresponding allele frequencies were A1 (0.10) and A2 (0.90). In opposite, the aforesaid genotype frequencies were 0.14 (A1A1), 0.50 (A1A2) and 0.36 (A2A2) in the HF crossbred population with allele frequencies of 0.39 (A1) and 0.61 (A2). The adopted AS-PCR method was found cost-effective, rapid and had high specificity for genotyping of A1 and A2 allelic variants. Altogether, this study provides information for the selection of desired zebu and crossbred individuals in order to produce premium quality milk as well as to design a breeding plan in the crossbreeding program.

Assessment of genetic diversity and relationship of the two Sanga type cattle of Botswana based on microsatellite markers.

The study was performed to evaluate genetic variation on two Sanga type cattle found in Botswana: Tswana and Tuli using twelve microsatellite markers. All amplified loci were polymorphic with 75 and 77 alleles genotyped in the Tswana and Tuli populations, respectively. The total number of alleles per locus ranged from 2 (BM1818) to 10 (TGLA227) with total mean of 6.25 for Tswana and 6.43 for Tuli population. Almost all the markers showed high polymorphic information content (PIC) apart from BM1818 (0.375) and INRA23 (0.393) which were moderately informative in Tswana population. Most of the markers were in Hardy-Weinberg equilibrium except for CSSRM60 and CSSM66 loci in Tswana population and ETH10, ETH225 and CSSM66 loci in Tuli population. A total of 103 unique alleles were genotyped across the two breeds with 49-shared, and 26 and 28 were unique to Tswana and Tuli populations, respectively. The expected heterozygosity (He) values were higher than the observed heterozygosity (Ho) in both populations: Tswana (He = 0.7895 ± 0.033 vs Ho = 0.631 ± 0.091) and Tuli (He = 0.8123 ± 0.033 vs Ho = 0.556 ± 0.021). The inbreeding coefficient was 0.200 ± 0.002 and 0.332 ± 0.001 in Tswana and Tuli populations, respectively. Analysis of molecular variance revealed 6.8% of the total genetic variation corresponding to differences between the two breeds and 93.2% within populations. The genetic identity between the two breeds was 56% and there were similar levels of multilocus heterozygosity and allelic diversity in the two breeds. The use of Tswana and Tuli breeds in a crossbreeding programme is likely to result in minimal heterosis and therefore not recommended.

Genetic and non-genetic parameter estimates for growth traits and Kleiber ratios in Dorper × indigenous sheep

Genetic improvement programme will only be successful when accompanied by a good understanding of the influence of different environmental factors, knowledge of the genetic parameters and the genetic relationships between the traits of interest. This study aimed to evaluate the influence of non-genetic factors on growth traits and Kleiber ratios and to estimate genetic parameters for early growth traits in Dorper × indigenous crossbred sheep. The effects of fixed factors were analysed by the general linear model procedure of statistical analysis system, while the genetic parameters were estimated using a WOMBAT computer program fitted animal model. The overall least-square mean for birth weight (BRW), weaning weight (3MW), six-month weight, nine-month weight, and yearling weight were 3.03 ± 0.02, 14.5 ± 0.18, 20.4 ± 0.26, 24.8 ± 0.31, and 28.3 ± 0.40 kg, respectively. The overall least-square mean for Kleiber ratio from birth to weaning (KR1), weaning to six months, six to nine months and nine months to yearling age were 16.8 ± 0.10, 6.41 ± 0.17, 4.55 ± 0.21 and 3.38 ± 0.20 g/kg of metabolic weight, respectively. The inclusion of maternal genetic effect had a significant influence on BRW, and it explains 20% of the phenotypic variation. The total heritability estimates for BRW, 3MW, birth to weaning average daily weight gain and KR1 were 0.10, 0.14, 0.16 and 0.12, respectively. The phenotypic correlation varied from −0.11 ± 0.05 to 0.98 ± 0.02, whereas the direct genetic correlation ranged from −0.32 ± 0.40 to 0.98 ± 0.17. The mean inbreeding coefficient was 0.105% with an annual rate of 0.02%. The heritability estimates for growth traits and Kleiber ratio suggest that slow genetic progress would be expected from the selection. However, the integration of selection with crossbreeding programme can enhance genetic gain. Therefore, selection should be conducted based on breeding values estimated from multiple information sources to increase the selection response.

Reproductive and Productive Performance of Crossbred and Terai Cattle in Bardiya District of Nepal

To compare the reproductive and productive performance of exotic crossbreds and indigenous Terai cattle under farmers' management condition, a household survey was carried out in 218 households of Bardiya, Nepal. Total of 262 cows [Jersey cross (n=107), Holstein cross (n=24) and indigenous Terai cattle (n=131)] were considered to determine the production and reproduction parameters. The age at first calving in months was the lowest in Jersey crossbred (27.8±1.8) followed by Holstein cross (29.5±4.0) and Terai cattle (45.7±3) (P<0.05). However, the number of services per conception, calving to conception interval (in months) and inter-calving interval (in months) were shorter in Terai cattle (1.3±0.7, 3.4±1.4 and 12.6±1.9) compared to Jersey cross (1.7±1.3, 4.4±2.2 and 13.5±3.1) and Holstein cross (1.8±0.9, 5.7±2.8 and 14.9±4.7), respectively (P<0.05). Total 6.5% of cattle had a history of reproductive problems; Incidence of repeat breeding tended (P<0.1)) to be higher in Jersey cross (8.4%) and Holstein cross (8.3%) than in Terai cattle (3.0%). Daily peak milk yield (L/day) was significantly lower in Terai cattle (1.7±1.1) than Jersey cross (13.5±3.1) and Holstein cross (14.9±4.7). The lactation length (months) was significantly shorter in Terai cattle than exotic crossbreds. Consequently, the length of dry period (in months) was significantly longer in Terai cattle (5.2±2.1) than in Jersey cross (2.5±0.9) and Holstein cross (2.2±0.7). The reproductive performance parameters in exotic crossbred cows under the farmers' management condition were satisfactory; however, their productivity was low. Thus, the good reproductive traits and variations in productivity of Terai cattle can be utilized in cross breeding programs.

Imputation of non-genotyped F1 dams to improve genetic gain in swine crossbreeding programs.

This study investigated using imputed genotypes from non-genotyped animals which were not in the pedigree for the purpose of genetic selection and improving genetic gain for economically relevant traits. Simulations were used to mimic a 3-breed crossbreeding system that resembled a modern swine breeding scheme. The simulation consisted of three purebred (PB) breeds A, B, and C each with 25 and 425 mating males and females, respectively. Males from A and females from B were crossed to produce AB females (n = 1,000), which were crossed with males from C to produce crossbreds (CB; n = 10,000). The genome consisted of three chromosomes with 300 quantitative trait loci and ~9,000 markers. Lowly heritable reproductive traits were simulated for A, B, and AB (h2 = 0.2, 0.2, and 0.15, respectively), whereas a moderately heritable carcass trait was simulated for C (h2 = 0.4). Genetic correlations between reproductive traits in A, B, and AB were moderate (rg = 0.65). The goal trait of the breeding program was AB performance. Selection was practiced for four generations where AB and CB animals were first produced in generations 1 and 2, respectively. Non-genotyped AB dams were imputed using FImpute beginning in generation 2. Genotypes of PB and CB were used for imputation. Imputation strategies differed by three factors: 1) AB progeny genotyped per generation (2, 3, 4, or 6), 2) known or unknown mates of AB dams, and 3) genotyping rate of females from breeds A and B (0% or 100%). PB selection candidates from A and B were selected using estimated breeding values for AB performance, whereas candidates from C were selected by phenotype. Response to selection using imputed genotypes of non-genotyped animals was then compared to the scenarios where true AB genotypes (trueGeno) or no AB genotypes/phenotypes (noGeno) were used in genetic evaluations. The simulation was replicated 20 times. The average increase in genotype concordance between unknown and known sire imputation strategies was 0.22. Genotype concordance increased as the number of genotyped CB increased with little additional gain beyond 9 progeny. When mates of AB were known and more than 4 progeny were genotyped per generation, the phenotypic response in AB did not differ (P > 0.05) from trueGeno yet was greater (P < 0.05) than noGeno. Imputed genotypes of non-genotyped animals can be used to increase performance when 4 or more progeny are genotyped and sire pedigrees of CB animals are known.

Implementation of an algorithm for automated phenotyping through plant 3D-modeling: A practical application on the early detection of water stress

High-throughput plant phenotyping requires integrated image-based tools for automated and simultaneous quantification of multiple morphological and physiological traits, which are valuable indicators of plant sensitivity to limiting environmental conditions. In this study, we proposed a novel segmentation algorithm for the automatic collection of plant structural parameters based on three-dimensional (3D)-modeling obtained through a phenotyping platform and a Structure from Motion (SfM) approach. The algorithm was initially tested on a 3D-reconstruction of four potted commercial tomato cultivars, namely “Saint Pierre” (S), “Costoluto Fiorentino” (C), “Reginella” (R), and “Gianna” (G) for the identification of the main phenotypic plant traits (heights, angles and areas). The results pointed out that the proposed algorithm was able to automatically detect and measure the plant height (R2¯ = 0.98, RMSE¯ = 0.34 cm, MAPE¯ = 3.12% and AIC¯ = 6.03), petioles inclination (R2¯ = 0.96, RMSE¯ = 1.35°, MAPE¯ = 3.64% and AIC¯ = 22.16), single-Leaf Area (R2¯ = 0.98, RMSE¯ = 0.95 cm2, MAPE¯ = 7.40% and AIC¯ = 14.91) and single-leaf angle (R2¯ = 0.84, RMSE¯ = 1.43°, MAPE¯ = 2.17% and AIC¯ = 15.83). As a study case, the algorithm was applied for monitoring plant’s dynamic responses to early water stress, measured according to Fraction of Transpirable Soil Water (FTSW), of the same tomato varieties, grown in pots, during 20 consecutive days under three treatments (full-irrigation, 50% deficit irrigation and no-irrigation). The results showed that for R and G cv., plant height was the phenotypic trait most sensitive to water stress (plant growth inhibition at 0.58 of FTSW value), while Total Leaf Area and transpiration rates started to be affected at lower FTSW (0.52 and 0.40, respectively). Conversely, S and C cv. did not exhibit any significant change in phenotypic traits under analysis, likely because these varieties exhibited a slow growth rate, allowing them to consume less water and therefore not reach a water stress threshold. The results indicated that plant height trait might be used in subsequent analyses to facilitate the rapid identification of tomato varieties resistant to water stress, thus enhancing crossbreeding programmes.

Performance Evaluation of Boer × Central Highland Crossbred Bucks and Farmers’ Perceptions on Crossbred Goats in Northeastern Ethiopia

The study aimed to characterize the production system, to evaluate the genetic merit of Boer × Central Highland crossbred bucks, and to solicit the perception of farmers about crossbred goats and crossbreeding program. Data were collected through a personal interview, focus group discussion, field observation, and measurement of the live animal. Besides, data on growth performance were extracted from available performance records at Sirinka sheep and goats breeding station. Data were analyzed using SAS, and the breeding values for bucks were estimated using WOMBAT software. Goats were the second most important animal species, and income generation, home meat consumption, and saving were found to be the main reasons for keeping goats with index values of 0.484, 0.355, and 0.085, respectively. The production system was characterized as a low-input production system. Feed shortage and disease/poor veterinary service were the most important constraints for the goat crossbreeding program. The overall mean estimated breeding values (EBV) for three- and six-month weight of disseminated crossbred bucks were 0.53 and 0.31 kg, respectively. The three-month weight EBV for crossbred goats disseminated in Amhara Sayint and Habru district was lower than their contemporary group. Likewise, the six-month weight EBV for crossbred goats distributed in Amhara Sayint was lower than the contemporary group mean. These results depict the absence of buck selection based on their genetic merit. As per farmers’ perception, crossbred goats were superior (odds ratio = 3.94 to 20.9, P &lt; 0.001 ) to indigenous goats in terms of production traits. Besides, the price of the crossbred goat was higher (213 to 372 ETB/head) than indigenous goats with similar management and age. However, poor adaptability and fitness were the major demerits of Boer × Central Highland crossbred goats under a smallholder management system. Therefore, while introducing exotic breeds, it is imperative to give due attention to nutrition and veterinary service.

Evaluation and Pre-selection of New Grapevine Genotypes Resistant to Downy and Powdery Mildew, Obtained by Cross-Breeding Programs in Spain.

The need to develop an environmentally friendly, sustainable viticulture model has led to numerous grapevine improvement programmes aiming to increase resistance to downy and powdery mildew. The success of such programmes relies on the availability of protocols that can quantify the resistance/susceptibility of new genotypes, and on the existence of molecular markers of resistance loci that can aid in the selection process. The present work assesses the degree of phenotypic resistance/susceptibility to downy and powdery mildew of 28 new genotypes obtained from crosses between “Monastrell” and “Regent.” Three genotypes showed strong combined resistance, making them good candidates for future crosses with other sources of resistance to these diseases (pyramiding). In general, laboratory and glasshouse assessments of resistance at the phenotype level agreed with the resistance expected from the presence of resistance-associated alleles of simple sequence repeat (SSR) markers for the loci Rpv3 and Ren3 (inherited from “Regent”), confirming their usefulness as indicators of likely resistance to downy and powdery mildew, respectively, particularly so for downy mildew.

Cross-breeding program in the genus Camellia involving the “everblooming” camellia (C. azalea C.F. Wei)

Cross-breeding program in the genus <i>Camellia</i> involving the “everblooming” camellia (<i>C. azalea</i> C.F. Wei)

Induced variability and assessment of mutagenic effectiveness and efficiency in sorghum genotypes [Sorghum bicolor (L.) Moench

Purpose Sorghum is an important cereal crop, cultivated for food, fodder and biofuel. Mutation breeding techniques are used to create genetic variability for qualitative and quantitative traits in crop plants. The purpose of this study was to create induced variability and estimate mutagenic effectiveness and efficiency of physical and chemical mutagens in two sorghum cultivars. Materials and methods Gamma rays (100, 200, 300 and 400 Gy, Co60 source, Bhabha Atomic Research Center, Mumbai, India), ethyl methane sulfonate (0.1%, 0.2%, 0.3%, and 0.4% EMS, Sigma-Aldrich, Bangalore, India) and their combinations were used to mutagenize 296B (rainy season) and Parbhani moti (post-rainy) cultivars. Morphological and yield traits were analyzed for enhanced variability in qualitative and quantitative traits across M2 and M3 generations. Results Based on the mutagenic sensitivity, lethal dose at 50% survivability (LD50) for both the genotypes was found to be 269–281 Gy in case of gamma rays and 0.32–0.33% for EMS. Based on reduced germination and survivability, mutagenic sensitivity was dose dependent and genotype independent. High frequency of chlorophyll mutations (albino, xantha, viridis, variegated and chlorina) was linearly correlated with dose in both the genotypes. Among the favorable mutants, dwarf and brown midrib were isolated from Parbhani moti population, which could be used in the cross breeding programs. A combined treatment, 100 Gy + 0.1% EMS showed high mutagenic effectiveness and efficiency. Enhanced genetic variation for quantitative traits as measured by wide range values and coefficient of variation was attributed to the effect of physical and chemical mutagens. Early flowering and high grain yield (24–49% increase over control) mutants were identified in M2 and validated in M3 generation in both genotypes. Conclusions This study has revealed wide genetic variability and better effectiveness and efficiency of the physical (300 Gy) and chemical mutagens (0.2%) and their combination (200 Gy + 0.2%) across two sorghum genotypes. Significant correlations identified between quantitative traits will help in better selection in the segregating generations.

Genetic Performance of Inbred and Hybrids of Maize Under Irrigation Interval

A field experiment was carried out using four inbred lines of maize BK112, Inb17, ZP607 and Zm6, as they were entered into half-diallel cross-breeding program in the fall season 2019, and 10 genotypes (6 crosses + 4 parents) were obtained according to the second Griffing method, the first model, in the spring season of 2020, the behavior of these inbreds and their hybrids were evaluated with three irrigation intervals with the aim of obtaining one or more distinct hybrids of pure strains derived from maize Zea mays L. under the irrigation interval and the study of hybrid vigor. The experiment was carried out in the fields of a farmer in Anbar Governorate, using the RCBD randomized complete block design (split – plot) with three replications. The irrigation interval (4, 8 and 12) days occupied the main plots, while the inbred and hybrids occupied the sub-plots. The results of the statistical analysis showed a significant effect of genotypes on the studied traits. The studied hybrids Zm6 × ZP607 were distinguished by their weight of 300 grains and the grain yield (85.83 g and 186.70 g) respectively. The plants grown under the irrigation interval 4 days outperformed the grain yield of the plant by giving it the highest yield of 156.03 g. It did not differ significantly with the 8-day irrigation interval, while the yield decreased significantly at the 12-day irrigation interval with a decrease of 120.8% and 120.5% than the 4 and 8 irrigation treatments, respectively. It was also found that the interaction was significant and reached the highest grain yield with an irrigation interval of 8 days, 224.0 g. The hybrid Zm6 × ZP607 gave the highest positive hybrid vigor for individual plant yield, which was 119.24%, 126.72% and 166.05% for the irrigation interval of 4, 8 and 12 days, respectively. Therefore, the plant breeder can use the characteristics of the yield components as selection guides with the superior hybrids in yield and the strength of the hybrid.

Response of Maize Hybrids and Inbred to Yield and its Components Under Irrigation Interval

In order to estimate some genetic parameters for five inbred lines AG116, AG-M20, MH17, MH121 and ZM4, they were entered into a complete cross-breeding program. Khalidiya - east of Ramadi in two seasons (fall 2019 and spring 2020). The comparison experiment was applied using the RCBD randomized complete block design in the order of split-plot and with three replications, where the main plots for irrigation was interval 6, while 12 days and the secondary plots for genotypes (breeds and hybrids) to estimate some characteristics of yield and its components. Parental inbred and their reciprocal and inverse hybrids differed significantly in number of days from planting to 50% tasseling, number of rows per ear, number of grains per row, grain weight and grain yield in the two seasons of the study, cross-hybrid MH17 × AG-M20 and the inverse hybrid AG116 × ZM4 outperformed in the fall season 2019 when it gave a yield of 173.00 g plant-1 and 169.60 g plant-1, respectively. In the spring season 2020, the cross-hybrid MH121×MH17 and the reverse hybrid AG116×AG-M20 recorded the highest average for the character, reaching 165.20 and 142.90 g plant-1, respectively.

Cross breeding programme modulates reproductive outcomes, growth performances and cellular muscle growth of indigenous climbing perch, Anabas testudineus

An experiment was carried out for quality seed production of indigenous climbing perch, Anabas testudineus using cross breeding technique. Live fingerlings of A. testudineus were collected from three wild sources such as Kailla beel of Mymensingh (Mk), Salakandi beel of Mymensingh (Ms) and Shamganj beel of Netrokona (Ns) of Bangladesh. The collected wild A. testudineus were separately reared for a year in three replicated cages installed in separate earthen ponds for each stock. Forty eight mature broods (16 from each wild source stock with 1:1 sex ratio) were successfully induced bred with carp pituitary extracts following cross-breeding technique for producing three conspecific and three heterospecific cross groups. Three conspecific groups were designated as Line-1, Kailla beel ♀ × Kailla beel ♂ (Mk♀ × Mk♂); Line 2, Salakandi beel ♀ × Salakandi beel ♂ (Ms♀ × Ms♂) and Line 3, Shamgonj beel ♀ × Shamgonj beel ♂ (Ns♀ × Ns♂); whereas three heterospecific groups were designated as Line 4, Salakandi beel ♀ × Shamgonj beel ♂ (Ms♀ × Ns♂); Line 5, Kailla beel ♀ × Salakandi beel ♂ (Mk♀ × Ms♂) and Line 6, Shamgonj beel ♀ × Kailla beel ♂ (Ns♀ × Mk♂). In general, heterospecific crossbred groups (Line 4–6) showed higher reproductive performances than the conspecific crossbred groups (Line 1–3). More precisely, Line 4 (Ms♀ × Ns♂) showed the significantly (p < 0.05) highest rate of fertilization (82.43 ± 1.56%), hatching (93.79 ± 1.96%) and survival of larvae (77.54 ± 2.21%) compared to other crossbred line groups. After six months rearing of 30 dph fry of different crossbred lines, the significantly (p < 0.05) highest performances of all growth parameters and survival rate were found in Line 4 than the others crossbred lines. Muscle cellularity analyses also demonstrated that both the percentages of new hyperplastic muscle fibers and hypertrophic fibers were significantly higher in heterospecific crossbred groups (Line 4–6) than the conspecific crossbred groups (Line 1–3). The findings of our study suggested that heterospecific crossbreds of A. testudineus, particularly Line 4 showed improved reproductive outcomes, growth performances and cellular muscle growth over the conspecific crossbred groups. Therefore, Line 4 (Salakandi beel ♀ × Shamgonj beel ♂) can be considered as superior stock and base population for continuing the future breeding and stock improvement programme of A. testudineus in the hatcheries of Bangladesh and elsewhere.

Success rate, genetic improvement and economic analysis of artificial insemination delivery models for smallholder pig production systems

Context Smallholder pig production systems in the north-eastern region of India are characterised by inefficiency due to use of unselected local pigs, and multiple breeding constraints such as paucity of superior germplasm, high mating costs, and poor access to artificial insemination (AI). Effective AI is the most viable option for genetic improvement and enhancing pig productivity. Aim The study was designed to assess the success rate and economic efficacy of four AI delivery models (Models I–IV): (I) AI at farmer’s doorstep through direct linkage to tribal farmers; (II) AI at farmer’s doorstep through trained, educated youth; (III) oestrus synchronisation and fixed-time AI; and (IV) mobile van-based AI delivery system. The study also sought to ascertain the benefits of adopting a crossbreeding program through AI over the existing use of local pigs for smallholder systems. Methods Semen collected from nine Hampshire boars was routinely utilised for AI after processing as per standard protocols. For Models I–IV, respectively, 259, 154, 183 and 284 sows from 75 villages/clusters were inseminated. Reproductive and litter performance as well as insemination cost were evaluated for each model. Growth performance of crossbred pigs obtained through AI was compared with that of local pigs in the smallholder production system. Key results Farrowing rate and mean litter size at birth were 74.90% and 8.57 ± 0.52 for Model I, 68.83% and 8.08 ± 0.37 for Model II, 80.87% and 9.31 ± 0.41 for Model III, 75.00% and 8.54 ± 0.64 for Model IV, and 81.58% and 6.81 ± 0.29 for natural service. Farrowing rate, litter size at birth and at weaning, and litter weight at weaning were significantly (P &lt; 0.05) affected by AI delivery model in the order: Model III &gt; Model I = Model IV &gt; Model II. Litter weight at birth was significantly (P &lt; 0.05) affected by AI delivery model in the order: Model III &gt; Model I = Model II = Model IV. Lowest cost per insemination was found for Model IV (INR 319.00) followed by Model II (INR 449.00), Model III (INR 629) and Model I (INR 899). All models had lower cost than the natural service system (INR 2200). The growth performance of crossbred pigs obtained through AI was significantly (P &lt; 0.01) higher than of the local pigs reared in the same production system. Conclusion The present study justifies the accessibility, feasibility and potential benefit of AI delivery models in smallholder/backyard pig production systems in the north-eastern region of India. Use of these AI delivery models will overcome the breeding constraints and reward farmers with more rapid genetic improvement in productivity with lower production costs. Model III (oestrus synchronisation and fixed time AI) shows best productivity and Model IV (mobile van-based AI delivery system) has lowest cost. Implications These AI delivery models will be effective for sustainable and economic piggery development and improve the socioeconomic livelihood of pig farmers in South Asian countries.

Dry matter intake, body condition score, beta-hydroxy-butyrate, milk yield, and composition of Holstein and crossbred Holstein x Simmental cows during the transition period

ABSTRACT We compared the dry matter intake (DMI), body condition score (BCS), body weight (BW), beta-hydroxy-butyrate (BHB), milk yield, and milk composition during the transition period of Holstein and crossbred Holstein x Simmental cows. Thirty cows were used in the study. Each cow entered the study 21 days before their expected calving day (prepartum) and remained in the study until day 21 after calving (postpartum). DMI, and milk yield were recorded daily. Once a week, BW and BCS were recorded and blood was collected to measure the BHB. The SAS software was used for the statistical analysis. Holstein and crossbred Holstein x Simmental cows had similar DMI during the prepartum and postpartum periods with higher intakes after calving. Crossbred Holstein x Simmental cows had a higher BCS than Holstein cows during the prepartum and postpartum periods. BHB does not differ between genetic groups, but between periods – with lower values in the prepartum period. The genetic groups had similar milk yield and composition. Both genetic groups lost BCS after calving, but Holstein cows showed a greater decrease in BCS. The use of a crossbreeding programme with Simmental has no negative effect on the performance during the transition period in Holstein herds.

Short communication: Heterosis and breed effects for milk production and udder health traits in crosses between Danish Holstein, Danish Red, and Danish Jersey

During the last decade, the use of systematic crossbreeding in dairy cattle herds has increased in several countries of the world. The aim of this study was to estimate the effect of breed proportion and heterosis on milk production traits and udder health traits in dairy cattle. The study was based on records on milk yield (MY), protein yield (PY), fat yield (FY), somatic cell score (SCS), and mastitis (MAST) from 73,695 first-lactation dairy cows in 130 Danish herds applying systematic crossbreeding programs. Around 45% of the cows were crosses between Danish Holstein (DH), Danish Red (DR), or Danish Jersey (DJ), and the remaining were purebred DH, DR, or DJ. The statistical model included the fixed effects of herd-year, calving month, and calving age and an effect representing the lactation status of the cow. In addition, the model included a regression on calving interval from first to second lactation, a regression on the proportion of DH, DR, and DJ genes, and a regression on the degree of heterozygosity between DH and DR, DH and DJ, and DR and DJ. Random effects were the genetic effect of the cow and a residual. The effect of breed proportions was estimated relatively to DH. For MY, a pure DR yielded 461 kg milk less than DH, whereas a pure DJ yielded 2,259 kg milk less than a pure DH. Compared with DH, PY was 41.7 kg less for DJ, whereas PY for DR was 4.0 kg less than for DH. For FY, a DR yielded 10.6 kg less than DH, whereas there was no significant effect of breed proportion between DJ and DH. A DR cow had lower SCS (0.13) than DH, whereas DJ had higher SCS (0.14) than DH. There was no significant effect of breed proportion on MAST between the 3 breeds. Heterosis was significant in all combinations of breeds for MY, FY, and PY. Heterosis for crosses between DH and DR was 257 kg (3.2%), 11.9 kg (3.2%), and 8.9 kg (3.2%) for MY, PY, and FY, respectively. Corresponding figures for crosses between DH and DJ were 314 kg (4.4%), 14.3 kg (4.4%), and 10.4 kg (4.0%), whereas heterosis between DR and DJ was 462 kg (6.7%), 19.6 kg (6.7%), and 13.9 kg (5.4%) for MY, PY, and FY, respectively. Heterosis was only significant for SCS in the crosses between DH and DR. Heterosis effects for MAST were nonsignificant for all the crosses. The results obtained in this study demonstrate that in first lactation cows, there is a positive effect of heterosis on milk production traits, but limited effect on udder health traits.

Selection of Habanero Pepper F1 Hybrids (Capsicum chinense Jacq.) at the Yucatan Peninsula, Mexico with a High Potential for Different Markets

This study evaluated 29 F1 lines and the 11 genotypes of habanero peppers used in the crossbreeding program developed by the Scientific Research Center of Yucatan, México. A randomized complete block design with four repetitions was used. Eight plants of each of the genotypes were studied per block. A total of 22 qualitative and 18 quantitative descriptors established in the manuals of the International Plant Genetic Resources Institute (IPGRI) and the National Service for Seed Inspection and Certification (SNICS) was used. The multiple correspondence analysis of the qualitative traits explained 38.2% of the total variability. The trait that contributed the most to the qualitative variability identified was the presence of anthocyanins in the node. Principal component analysis showed that the first two axes explained 85.1% of the total variability and that capsaicin content and fruit pericarp thickness were the major contributors to the variation recorded. Based on these results, four F1 hybrids of habanero pepper were selected because of their promising traits for the different markets, i.e., high productive potential and/or high pungency. These traits are described in the section on Results.

Effectiveness of genetic selection for prolificacy in pigs

Summary. This paper attempts to summarize and discuss the new evidence on the effectiveness of selection for prolificacy. In recent years selection between lines, and the adoption of formal cross-breeding programmes, have led to considerable improvements at a commercial level. Within-line selection has not been tackled seriously except in a few experiments. The mainly negative results from these should not lead to the conclusion that progress is impossible, but rather that it needs larger resources, applied consistently for several generations, to overcome the inherent problems.