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The aim of the present work was to analyze the quantity and quality of milk production at R1 crossbreeds in the first lactation resulting from crossing local sheep from the north-eastern area of the country with Awassi rams. For the determination of total milk production, the control of milk production includes the suckling period of the lambs and the milking period of the ewes. The AT4 method was used during the milking period following the technical specifications recommended by ICAR. During the suckling period, the amount of milk in R1 crossbreds ewes was 57.33 kg and the production of milked milk was 71.54 kg. The average daily milk production of the 4 controls for R1 crossbred ewes was 649.38±37.03 g, with limits between 285 and 1197 g milk. In 180 days of total lactation the milk production obtained in the first lactation of crossbreds R1 sheep was 128.87 kg, being 2% lower than that obtained in Awassi breed sheep. Thus, a significant improvement in the milk production of local sheep can be observed by using this type of crossbreeding. [ABSTRACT FROM AUTHOR]

This article discusses the risk factors associated with bovine clinical mastitis in Tamil Nadu, India. The study surveyed 300 dairy farmers and found that species, breed, parity, lactation stage, and milk yield were significant risk factors for mastitis in lactating dairy cows. The article emphasizes the economic importance of the dairy industry in India and the need for prevention and control measures. Another document provides a list of references and citations for various research articles and studies on mastitis in dairy cows. These articles cover topics such as prevalence, risk factors, economic impact, and prevention strategies, offering a diverse perspective on the issue. [Extracted from the article]

The purpose of the study was to compare the growth, slaughter performance and selected meat quality traits (meat texture and basic chemical composition) of New Zealand White (NZW) rabbits, Grey Flemish Giant (GFG) rabbits and their crossbreds. Pre-slaughter, slaughter and meat quality traits were analysed for 52 New Zealand White rabbits (26 male and 26 female), 42 Grey Flemish Giant rabbits (21 male and 21 female) and 78 crosses of these two breeds (39 male and 39 female). Two rabbits (1 male and 1 female) were selected from each litter for evaluation of slaughter performance and meat quality. At least 4 offspring from each male were selected for analysis. Each group comprised a total of 20 rabbits. After weaning at 35 days of age, the animals were fed pellets ad libitum. Rabbits were weighed weekly from birth to 12 weeks of age, when they were slaughtered and dissected. Body weight measurements showed that GFG rabbits had significantly higher body weights than NZW rabbits and their crossbreds up to and including week 4. After 5 and 6 weeks of rearing the differences between the kits were not significant. From 7 to 10 weeks of age, the crossbred rabbits had the highest body weight. In the last two weeks of life, the highest body weight was achieved by young rabbits of the GFG breed. Slaughter weight was significantly the highest in GFG rabbits and lowest in purebred NZW rabbits. The highest hot carcass weight and cold carcass weight were attained by animals from the crossbred group. The shear force value was identical in the NZW rabbits and the crossbred group, but lower in the GFG rabbits. Hardness and chewiness were lowest in the NZW rabbits, while springiness and cohesiveness were highest in that breed. The meat of the crossbreds had the highest protein content and the lowest fat content, as well as the highest water content, and thus statistically the lowest dry matter content. [ABSTRACT FROM AUTHOR]

Simple Summary: Enteric methane is the main greenhouse gas araising from livestock production, which greatly contributes to global warming. A trial was carried out with dairy cows with different genetic backgrounds to determine the effect of genetics on the emission of enteric methane. Crossbred cows (50% Bos taurus × 50% Bos indicus) presented a lower annual emission of enteric methane compared to other cows with a greater European background. Crossbred cows had a greater adaptation to low tropical areas and a lower conversion of energy consumed to enteric methane. This knowledge contributes to the development of competitive farming with low carbon emissions. Enteric methane (CH4) is one of the main greenhouse gases emitted in livestock production systems with ruminants. Among the options to reduce such emissions, animal genetics is one of the factors that is taking relevance in recent years. The aim of the present study was to assess the emission of enteric CH4 in dairy cows with different genetic backgrounds. Sixteen cows belonging to the following three genetic groups were selected for this study: seven F1 (50% Jersey × 50% Gyr), five Triple cross (50% Jersey × 31% Holstein × 19% Sahiwal) and four Jersey. Enteric CH4 emissions were measured in all cows for 15 months, at the middle of each month, using the SF6 technique. Enteric CH4 emissions did not differ (p > 0.05) among genetic groups, although it varied with the stage of lactation, due to differences in milk yield and dry matter intake (DMI). Pasture DMI and the intensity of CH4 emissions (g kg−1 DMI) differed (p < 0.05) between dry and lactating cows, with higher DMI in the lactation period, while CH4 emission intensity was higher for dry cows. Cows with the highest proportion of Bos taurus genes presented a higher annual mean methane conversion factor (Ym), with 7.22, 7.05 and 5.90% for the Triple cross, purebred Jersey and F1, respectively. In conclusion, non-significant differences in enteric CH4 emissions and Ym were detected among dairy cows with different genetic backgrounds. However, F1 cows tended to show lower enteric CH4 emission and Ym, compared to those with more Bos taurus genes. [ABSTRACT FROM AUTHOR]

Casein constitutes approximately 80% of the total protein in bovine milk and is regarded as a high-quality dietary protein embracing all the nine essential amino acids. However, the contested physiological effect of a bioactive peptide released upon digestion of a β-casein milk protein variant originating from a cow of a particular genetic makeup has evoked wide interest in research and industry. Present investigations were carried out to genotype the polymorphism in milk β-casein gene, delineate the seasonal, periodic, and parity variations in production and reproduction traits, and examine the genetic association between β-casein genotypes and production, and reproduction traits in Vrindavani crossbred cows. The study revealed that all three types of genotypes viz. A1A1, A2A2 and A1A2 were present in the Vrindavani crossbred population with genotypic frequencies of 12.3%, 39.6% and 48.1% respectively. The least-squares analysis revealed that the season of calving, period of calving, and parity affected several production and reproduction traits of Vrindavani cows significantly. It was found that β–Casein A1/A2 genotype had a significant effect on economic traits viz. LL (p ≤ 0.05), MY/LL (p ≤ 0.05), and Fat% (p ≤ 0.05) in Vrindavani crossbreds. The findings uncover the genetic constitution of the crossbreds for β-casein locus and emphasize its relationship with important economic traits that can aid in devising selection goals. [ABSTRACT FROM AUTHOR]

The research compares reproduction of female New Zealand White (NZW, n=55) and Californian (CAL, n=12) rabbits after mating with pure-bred Flemish Giant, Californian, and Burgundy Fawn males, as well as New Zealand White and Californian crossbred males. The influence of the dam’s breed, the birth season, and the parental component on reproduction parameters was analysed. Three groups of does were studied: those which had two litters (21 females), those which had three litters (15), and all does (irrespective of the number of litters, i.e. 67 females). In the first group, the mother’s breed was found to affect litter size at weaning (5.20 for Californian and 7.33 for New Zealand White), which was largest for the NZW×CAL crossbreed (10.50). Among the females with three litters, the breed of the dam influenced rearing efficiency, with greater efficiency noted for the New Zealand White breed (90.2%) than for the Californian breed (69.8%). Where all litters were considered, the two breeds differed in terms of the number of live-born kittens per litter (6.59 for NZW vs 7.71 for CAL) and litter size at weaning (6.34 vs 7.50). In this group, litter size at weaning was larger in winter (4.65) than in autumn (2.00). New Zealand White females that mated with Flemish Giant males produced fewer live-born kittens per litter (5.85) than Californian females that mated with Burgundy Fawn males (10.00). Pure-bred litters were smaller (2.04) at weaning than crossbred ones (from 5.39 to 10.00). For females with three litters, repeatability was 0.36 for total litter size and 0.35 for the number of live-born kittens per litter. For litter size at weaning, however, it was only 0.15, indicating a strong effect of environmental factors on rearing outcomes.

The aim of this work was to evaluate the effect of birth weight on the survival of Charollais, Kent and their crossbreds in breeding and also on their meat performance for Charollais and Kent lambs. Data were evaluated for the six years period in the commercial flock. The total number of lambs used for evaluation was 1,197. The data were passed through the SAS STAT program using the MIXED method. In the model equation, all the dependent variables of the survival indicator were significantly statistically detectable with a significance level of P < 0.01. The results indicated that survivability lambs was significantly influenced by birth weight and litter size (P < 0.05). Meat performance of lambs was affected the most combined year and month, breed and litter size (P < 0.05). The results suggest better survivability abilities for the crossbred than the pure-bred population. Despite the lack of meat performance data, it is interesting to consider a possible selection program for the breeds, Charollais and Kent, to improve the survival of lambs for extending extensive farming methods. However, also by improving flock management we will achieve better survivability results for lambs.

Enteric methane (CH4) is one of the main greenhouse gases emitted in livestock production systems with ruminants. Among the options to reduce such emissions, animal genetics is one of the factors that is taking relevance in recent years. The aim of the present study was to assess the emission of enteric CH4 in dairy cows with different genetic backgrounds. Sixteen cows belonging to the following three genetic groups were selected for this study: seven F1 (50% Jersey × 50% Gyr), five Triple cross (50% Jersey × 31% Holstein × 19% Sahiwal) and four Jersey. Enteric CH4 emissions were measured in all cows for 15 months, at the middle of each month, using the SF6 technique. Enteric CH4 emissions did not differ (p > 0.05) among genetic groups, although it varied with the stage of lactation, due to differences in milk yield and dry matter intake (DMI). Pasture DMI and the intensity of CH4 emissions (g kg−1 DMI) differed (p < 0.05) between dry and lactating cows, with higher DMI in the lactation period, while CH4 emission intensity was higher for dry cows. Cows with the highest proportion of Bos taurus genes presented a higher annual mean methane conversion factor (Ym), with 7.22, 7.05 and 5.90% for the Triple cross, purebred Jersey and F1, respectively. In conclusion, non-significant differences in enteric CH4 emissions and Ym were detected among dairy cows with different genetic backgrounds. However, F1 cows tended to show lower enteric CH4 emission and Ym, compared to those with more Bos taurus genes.

The partition of the total genetic variance into its additive and non-additive components can differ from trait to trait, and between purebred and crossbred populations. A quantification of these genetic variance components will determine the extent to which it would be of interest to account for dominance in genomic evaluations or to establish mate allocation strategies along different populations and traits. This study aims at assessing the contribution of the additive and dominance genomic variances to the phenotype expression of several purebred Piétrain and crossbred (Piétrain × Large White) pig performances. A total of 636 purebred and 720 crossbred male piglets were phenotyped for 22 traits that can be classified into six groups of traits: growth rate and feed efficiency, carcass composition, meat quality, behaviour, boar taint and puberty. Additive and dominance variances estimated in univariate genotypic models, including additive and dominance genotypic effects, and a genomic inbreeding covariate allowed to retrieve the additive and dominance single nucleotide polymorphism variances for purebred and crossbred performances. These estimated variances were used, together with the allelic frequencies of the parental populations, to obtain additive and dominance variances in terms of genetic breeding values and dominance deviations. Estimates of the Piétrain and Large White allelic contributions to the crossbred variance were of about the same magnitude in all the traits. Estimates of additive genetic variances were similar regardless of the inclusion of dominance. Some traits showed relevant amount of dominance genetic variance with respect to phenotypic variance in both populations (i.e. growth rate 8%, feed conversion ratio 9% to 12%, backfat thickness 14% to 12%, purebreds-crossbreds). Other traits showed higher amount in crossbreds (i.e. ham cut 8% to 13%, loin 7% to 16%, pH semimembranosus 13% to 18%, pH longissimus dorsi 9% to 14%, androstenone 5% to 13% and estradiol 6% to 11%, purebreds-crossbreds). It was not encountered a clear common pattern of dominance expression between groups of analysed traits and between populations. These estimates give initial hints regarding which traits could benefit from accounting for dominance for example to improve genomic estimated breeding value accuracy in genetic evaluations or to boost the total genetic value of progeny by means of assortative mating.

Endometritis is a postpartum uterine disease of cows that interrupts reproductive cycles resulting in suboptimal fertility, reduced performance and profitability of the dairy herd. The objective of the study was to estimate the perceived and observed prevalence of endometritis among zero-grazed dairy cows in smallholder farms in Rwanda. A snowball sampling method was applied in cross-sectional survey to obtain data from 370 farms on 466 cows within their 21–60 days postpartum (dpp). The survey, conducted from September 2018 to March 2019, simultaneously examined cows using the Metricheck Device (MED) to determine the presence and type of vaginal mucus (VMC) based on a score scale of 0 to 3. Cows scoring VMC ≥ 1 were recorded as clinical endometritis (CLE)–positive. Cytotape (CYT) was used to determine the percentages of polymorphonuclear cells (PMN) in endometrial cytology sample. Cows with ≥ 5% PMN were recorded subclinical endometritis (SCLE)–positive, whereas cows with VMC-0 and < 5% PMN were considered healthy cows. At cow-level, endometritis prevalence was 70.2% with 67.2% CLE and 31.8% SCLE while at the herd-level, prevalence was 71.1% with 68.1% CLE and 34.4% SCLE. The differences between the diagnostic performance of the MED and CYT were significant (p < 0.001). Perceived prevalence by farmers was much lower (3.2%) and without agreement with the observed prevalence (kappa = − 0.02, p > 0.05). The highly observed prevalence and farmer underestimation of endometritis prevalence indicate knowledge gaps about endometritis. The extension service therefore needs to increase awareness and education among smallholder farmers about detection and management of endometritis. [ABSTRACT FROM AUTHOR]

Cattle production is an essential livelihood strategy in south-western Burkina Faso. Although having a distinct cultural role and known to be resistant against African animal trypanosomosis, the Lobi taurine cattle breed is endangered due to its low market value. As the first step in preservation efforts, our study aimed to develop a typology of production systems at the farm level. We used a structured questionnaire and focus group discussions for collecting data on household characteristics, socioeconomic activities, livestock, and access to services. The sample comprised 169 households in three communities. The analytical strategy included factor analysis of mixed data and hierarchical clustering. We identified four distinct types of cattle production systems: (1) sedentary Lobi farms, (2) sedentary crossbreed farms, (3) semi-transhumant Fulani zebu farms, and (4) transhumant Fulani zebu farms. Significant factors in developing this typology were the farmers' ethnic group, crop diversity, cattle herd size, cattle herd composition, number of small ruminants, and livestock management strategies. Across all production systems, men were considered being primary decision-makers in cattle production, with women, herders, and children being responsible for specific tasks. All identified production systems are increasingly confronting disease pressure and scarcity of water and land. Future efforts in preservation and breeding will need to respond to these trends in the agroecosystem, integrate risk management measures, and resonate with the specific needs of the different household members involved in cattle rearing. [ABSTRACT FROM AUTHOR]

The aim of this work was to evaluate the effect of birth weight on the survival of Charollais, Kent and their crossbreds in breeding and also on their meat performance for Charollais and Kent lambs. Data were evaluated for the six years period in the commercial flock. The total number of lambs used for evaluation was 1,197. The data were passed through the SAS STAT program using the MIXED method. In the model equation, all the dependent variables of the survival indicator were significantly statistically detectable with a significance level of P < 0.01. The results indicated that survivability lambs was significantly influenced by birth weight and litter size (P < 0.05). Meat performance of lambs was affected the most combined year and month, breed and litter size (P < 0.05). The results suggest better survivability abilities for the crossbred than the pure-bred population. Despite the lack of meat performance data, it is interesting to consider a possible selection program for the breeds, Charollais and Kent, to improve the survival of lambs for extending extensive farming methods. However, also by improving flock management we will achieve better survivability results for lambs. [ABSTRACT FROM AUTHOR]

Objective The objective of the present study was to compare growth performance of Berkshire purebred pigs (BB), Hereford (HB) and/or Tamworth (TB) sired Berkshire crossbred pigs reared in a hoop structure in two experiments. Methods In the first experiment, BB was compared to TB while HB and TB were compared in the second. Body weights (BW) were recorded at 3 days of age and every 28 days from birth until 140 days of age. There was no significant difference between the BW of BB and TB, but HB was heavier than TB by 84 days of age. Least square means of average daily gain (ADG) were evaluated using one-way analysis of variance. Results The mean parity (±standard deviation) of the sows was 3.42±2.14 and a total of 45 farrowing occurred from year 2012 to 2014. The mean number of total born, number born alive, number of mummies, and number weaned were 9.23±2.52, 7.87±2.53, 0.04±0.21, and 5.94±2.74, respectively. Parity did not have a significant effect on the growth performance of the pigs. For BB and TB, there was only one time frame in which there was a significant difference in the ADG: between 28 and 56 days of age. For HB and TB, the overall ADG of HB was significantly greater than the total ADG of TB. Conclusion The breed of the sire did not affect the growth performance of the progeny between Berkshire purebreds and Tamworth×Berkshire crossbreds. The breed of the sire did have an effect between Hereford and Tamworth sired Berkshire crossbreds (p

The partition of the total genetic variance into its additive and non-additive components can differ from trait to trait, and between purebred and crossbred populations. A quantification of these genetic variance components will determine the extent to which it would be of interest to account for dominance in genomic evaluations or to establish mate allocation strategies along different populations and traits. This study aims at assessing the contribution of the additive and dominance genomic variances to the phenotype expression of several purebred Piétrain and crossbred (Piétrain × Large White) pig performances. A total of 636 purebred and 720 crossbred male piglets were phenotyped for 22 traits that can be classified into six groups of traits: growth rate and feed efficiency, carcass composition, meat quality, behaviour, boar taint and puberty. Additive and dominance variances estimated in univariate genotypic models, including additive and dominance genotypic effects, and a genomic inbreeding covariate allowed to retrieve the additive and dominance single nucleotide polymorphism variances for purebred and crossbred performances. These estimated variances were used, together with the allelic frequencies of the parental populations, to obtain additive and dominance variances in terms of genetic breeding values and dominance deviations. Estimates of the Piétrain and Large White allelic contributions to the crossbred variance were of about the same magnitude in all the traits. Estimates of additive genetic variances were similar regardless of the inclusion of dominance. Some traits showed relevant amount of dominance genetic variance with respect to phenotypic variance in both populations (i.e. growth rate 8%, feed conversion ratio 9% to 12%, backfat thickness 14% to 12%, purebreds-crossbreds). Other traits showed higher amount in crossbreds (i.e. ham cut 8% to 13%, loin 7% to 16%, pH semimembranosus 13% to 18%, pH longissimus dorsi 9% to 14%, androstenone 5% to 13% and estradiol 6% to 11%, purebreds-crossbreds). It was not encountered a clear common pattern of dominance expression between groups of analysed traits and between populations. These estimates give initial hints regarding which traits could benefit from accounting for dominance for example to improve genomic estimated breeding value accuracy in genetic evaluations or to boost the total genetic value of progeny by means of assortative mating. [ABSTRACT FROM AUTHOR]

Cutaneous evaporative heat loss in Bos indicus and Bos taurus has been well documented. Nonetheless, how crossbreds with different fractional genetic proportions respond to such circumstances is of interest. A study to examine the physiological responses to cutaneous evaporative heat loss, also lactation period and milk yield, were conducted in Sahiwal (Bos indicus, n = 10, 444±64.8 kg, 9±2.9 years), Holstein Friesian (Bos taurus, HF100% (n = 10, 488±97.9 kg, 6±2.8 years)) and the following crossbreds: HF50% (n = 10, 355±40.7 kg, 2±0 years) and HF87.5% (n = 10, 489±76.8 kg, 7±1.8 years). They were allocated so as to determine the physiological responses of sweating rate (SR), respiration rate (RR), rectal temperature (RT), and skin temperature (ST) with and without hair from 06:00 h am to 15:00 h pm. And milk yield during 180 days were collected at days from 30 to 180. The ambient temperature-humidity-index (THI) increased from less than 80 in the early morning to more than 90 in the late afternoon. The interaction of THI and breed were highly affected on SR, RR, RT, and ST (p0.05) but did change over time. The ST with and without hair were similar, and was higher in HF100% (37.4°C; 38.0°C) and their crossbred HF50% (35.5°C; 35.5°C) and HF87.5% (37.1°C; 37.9°C) than Sahiwal (34.8°C; 34.8°C) (p

The first aim of the study was to compare selected meat quality parameters in porkers without the gene RYR1T (ryanodine receptor gene). These were porkers slaughtered at 100 to 115 kg and 116 to 130 kg live weight. The second aim of the study was to determine the occurrence frequency of standard-quality meat (red, firm, nonexudative [RFN]) and the occurence frequency of defective meat (pale, soft, exudative [PSE] and acid, soft, exudative [ASE]). The analysis was conducted on the longissimus lumborum muscle in 114 crossbred porkers. The porkers were a cross of Camborough 22 sows and boars from lines 337PIC (Pig Improvement Company), Norsvin Landrace and Pietrain. All of the animals were provided with identical environmental and nutritional conditions. The average weight of the slaughtered animals in the light and heavy groups was 110 kg and 122 kg, respectively. Both groups had the same average post-slaughter meatiness (56.5%). A statistical analysis of selected meat-quality parameters did not show any significant differences between the weight groups. On the other hand, the classification based on carcass quality showed an occurence frequency of defective meat in heavier crossbred porkers (116 to 130 kg) that was three times higher than in those crossbred animals which weighed 100 to 115 kg when slaughtered. In porkers without the gene RYR1T, the defective meat types PSE and ASE occurred with a frequency of 17.54%.

The paper aim to present the variation of body parts and the main characteristics of carcasses obtained from sheep youth of the Tsigai breed and crossbred (German Blackheaded breed x Tsigai breed) fattened in intensive system. The intensive fattening experiment developed over a 100-day time period was performed on Tsigai young male sheep (lot 1), and young male sheep crossbred German Blackheaded (GBH) x Tsigai (lot 2). The two batches of animals subjected under fattening were made up of 12 heads each. At the end of experiment were slaughtered 5 animals from each lot. The subjective assessment of the carcasses through the SEUROP classification system after conformation and the fattening status led to framing in a superior classification of carcasses provided from the crossbreds compared to those obtained from Tsigai breed. The warm carcass weight in crossbred and Tsigai breed recorded average values of 19.04 kg at GBH x Tsigai and 16.95 kg at Tsigai breed, with distinctly significant difference to the advantage of the GBH x Tsigai (+2.09 kg, p <0.01). Also, distinctly significant differences in favor of the batch GBH x Tsigai (+2.10 kg) were recorded regarding the cold carcass weights compared with the Tsigai breed batch. Regarding the main cut sections of carcass from young sheep submitted to intensive fattening, the crossbred lot recorded greater average values (in particular in the cuts of first quality - pulp and cutlet) compared to the Tsigai breed lot. In conclusion, the assessment of the carcasses according to subjective and objective methods highlights a higher potential of meat production and of better quality at GBH x Tsigai lot, compared with the Tsigai breed lot. [ABSTRACT FROM AUTHOR]

In pig breeding, the final product is a crossbred (CB) animal, while selection is performed at the purebred (PB) level using mainly PB data. However, incorporating CB data in genetic evaluations is expected to result in greater genetic progress at the CB level. Currently, there is no optimal way to include CB genotypes into the genomic relationship matrix. This is because, in single-step genomic BLUP, which is the most commonly used method, genomic and pedigree relationships must refer to the same base. This may not be the case when several breeds and CB are included. An alternative to overcome this issue may be to use a genomic relationship matrix (G matrix) that accounts for both linkage disequilibrium (LD) and linkage analysis (LA), called GLDLA. The objectives of this study were to further develop the GLDLA matrix approach to utilize both PB and CB genotypes simultaneously, to investigate its performance, and the general added value of including CB genotypes in genomic evaluations. Data were available on Dutch Landrace, Large White, and the F1 cross of those breeds. In total, 7 different G matrix compositions (PB alone, PB together, each PB with the CB, all genotypes across breeds, and GLDLA) were tested on 3 maternal traits: total number born (TNB), live born (LB), and gestation length (GL). Results show that GLDLA gave the greatest prediction accuracy of all the relationship matrices tested for PB prediction, but not for CB prediction. Including CB genotypes in general increased prediction accuracy for all breeds. However, in some cases, these increases in prediction accuracy were not significant (at P < 0.05). To conclude, CB genotypes increased prediction accuracy for some of the traits and breeds, but not for all. The GLDLA matrix had significantly greater prediction accuracy in PB than the other G matrix with both PB and CB genotypes, except in one case. While for CB, the G matrix with genotypes across all breeds gave the greatest accuracy, though this was not significantly different from GLDLA. Computation time was high for GLDLA, and research will be needed to reduce its computational costs to make it feasible for use in routine evaluations. The main conclusion is that inclusion of CB genotypes is beneficial for both PB and CB animals. [ABSTRACT FROM AUTHOR]

The purpose of this study was that to evaluate the differences regarding the milk quantity and the biochemical composition of milk between primiparous goats of Carpathian breed and F1 hybrids of Alpin x Carpathian and Saanen x Carpathian, bred and exploited in the same conditions. The F1 hybrid females of Alpine x Carpathian and Saanen x Carpathian were obtained by artificial insemination of a lot of females of Carpathian breed with seminal material provided from he-goats of Alpine and Saanen pure breed. After weaning, the goats were milked 2 times a day, for 5 months. The control of milk production was done monthly. It was individually weighed the quantity of milked milk in the morning and in the evening. Also, there were taken individual samples of milk for the qualitative analysis. The bio-chemical parameters (fat, protein, lactose) were analysed by ultrasonic method at a Lactoscan analyser standardized for milk. The results shows that the average amount of milked milk of hybrids is significantly increased (p<0.05) compared to the Carpathian breed (2031g, 2033g, vs 1145g). The proportion of fat is significantly higher (p<0.05) at both categories of half-bred besides Carpathians (3.74%, 3.84%, vs 3.69%). In conclusion, the crossbreeding of the Carpathian breed with specialized breeds for the milk production leads to an increase of the productive potential. [ABSTRACT FROM AUTHOR]

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The objective of this study was to establish the impact of crossing the indigenous Cres sheep with Awassi and, respectively, Awassi and East Friesian sheep on the milk yield and quality. For this purpose, through regular monthly milk yield recordings a total of 824individual milk samples from 139 sheep in the second lactation of the same flock were collected, of which: 46 purebred Cres sheep, CS; 33 crosses with 50 % Cres sheep and 50 % Awassi, CA; 60 crosses with 50 % Cres sheep, 25 % Awassi and 25 % East Friesian, CAEF. The obtained results show a significant (P

The analysis comprised purebred Charolais bull calves (CH) and crossbred bull calves born from Hereford (CH × HE) and Simmental (CH × SI) cows. Body weights and daily gains were measured in subsequent periods of the experiment and the post-slaughter evaluation was carried out. Carcass lean weight and dressing percentage were evaluated, as well as the lean content of five prime cuts. Total weight of the five prime cuts was measured and its share in the half-carcass weight was determined. The rib-eye area was also measured. The CH × SI crossbreds reached significantly higher body weights at weaning, 210-day body weights and weights at finishing, as well as significantly higher daily gains in all the periods (P < 0.05, P < 0.01) and were characterized by the heaviest carcasses and most cuts, particularly the round. The crossbreds had the highest total weight of five prime cuts and total lean weight, highest weight of the round and lean weight in the round. Other relationships were found analyzing the share of each cut in the carcass. The share of tenderloin and rump in the carcass of CH × SI was significantly lower compared to the purebred bulls (P < 0.01) and CH × HE (P < 0.05). They also had a significantly lower share of the shoulder, shank and shin, as compared to the other groups, as well as a significantly higher (P < 0.05) share of the neck, as compared to the purebred bulls. The purebred bulls also achieved good results and had the highest share of the prime cuts and the largest mean rib-eye area.

Two experiments were conducted to investigate the birds’ responses to diets of varying nutrient concentrations, one with 126 eight-week old F1 crossbred (Rhode Island Red male×Fayoumi female) birds up to 20 weeks of age (growing stage) and another with ninety 20-week-old birds up to 22 weeks (pre-layer stage) under semi-scavenging condition in the poultry farm. Dietary treatments consisted of an arrangement of three diets that contained 14% crude protein (CP) and 2550kcal metabolizable energy (ME)/kg (low nutrient density ; LND), 15% CP and 2750kcal ME/kg (moderate nutrient density ; MND) and 16% CP and 2950kcal ME/kg (high nutrient density ; HND). The contents of CP, ME and calcium (Ca) in MND diet were fitted with the requirements calculated in this experiment based on five nutrient specifications in the world. All diets were formulated using locally available conventional feedstuffs and un-conventional feed ingredients employing a free software of computer program for least-cost feed formulation. The responses of grower birds to different diets showed that the highest body weight and live weight gain were achieved by the birds that received HND diet that differed significantly from those of LND diet (p

The aim of this study was to identify the influence of cattle breed, age, live weight, carcass weight, and yield on beef carcass conformation class. The electronic databases from “Meat master” program, operated in Lithuanian slaughterhouses, were used in this study. The data, without being tied to one of them, taken from 75 bulls’ classified carcasses, were divided into 5 (EUROP) conformation classes. Before slaughtering bulls according to their age were divided into 2 age categories A (up to 24 months) and B (over 24 months). Study results shown that bulls carcasses, included into supreme (E & U) conformation classes were obtained from specialized beef breeds (mostly Aubrac, or their crossbreds). It was detected that carcasses assessed by the lowest (O and P) conformation classes, bulls, mothers and fathers most frequently (79.7%) were obtained from a Lithuanian black and white and Lithuanian red breed cattle and their crossbreds; only 20.3% of the slaughtered bull parents were specialized beef (Charolais, Limousin, Simmental beef) breeds. Bulls, whose carcasses were evaluated with the excellent (E) conformation class, were 9.4 months (P ≤ 0.001) older than those with the lowest rate – poor (P) class. B category live cattle before slaughter were in 142 kg heavier (P ≤ 0.004), their carcass weight was in 130 kg more (P ≤ 0.0001), and carcass yield in 6.69% (P ≤ 0.001) greater than A. This study showed that beef carcass conformation class related to carcass weight. Increasing in carcass conformation class (from P to E) lifted carcass weight (from 250.7 kg. up to 399.1 kg.), as well as carcass yield percentage (on average about 3% for each of the class). [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the effect of a genotype on growth and basic carcass characteristics in male lambs. The experiment was carried out at an organic farm in Proseč and four different genotypes were included in the experiment: Šumavská sheep (S) 100, n = 8; S 50 Texel (T) 50, n = 11; T 75 S 25, n = 13 and S 75 T 25, n = 11. The genotype had no significant effect on most of the monitored growth parameters. The highest daily gain (DG) in the interval from birth to 100 days of age was found out in S 75 T 25 (327 g) but the highest DG from birth until the end of the experiment was found in S 50 T 50 (199 g). By contrast, the lowest DGs in both above mentioned intervals were found out in S 100 (265 and 147 g, respectively). With regards to basic carcass characteristics, the genotype had a signifi cant effect only on proportion of kidney. The highest carcass yield (44.80%) was found in S 50 T 50 and the lowest (37.66%) in S 100. The best conformation score was found in S 75 T 25 (3.18) and the lowest fatness score in S 50 T 50. To conclude, it is possible to state that use of the Texel rams in crossing with the Šumavská ewes had a positive effect on both growth and basic carcass characteristics. [ABSTRACT FROM AUTHOR]

A random sample of 40 goats was used to study the partitioning, yield and composition of milk: 8 of Saanen breed (S), 8 of Damascus breed (D), 8 crossbreds Saanen × Local Greek goat (S × L), 8 backcrosses Saanen × Local Greek goat {(S × L) × S} and 8 crossbreds Saanen × Alpine (S × A). Four dams of each genotype were of the first and four of the second parity. Goats were milked twice daily (8:00, 18:00 h) in a 1 × 12 side by side milking parlour with 6 milking units. Milk yield and milk fractions (machine milk, machine stripped milk and hand stripped milk) were recorded twice daily each 14 days (from 7th-8th to 29th week of lactation). Milk composition was examined once a month separately for morning and afternoon samples. The ponderable mean was used for the calculation of milk fat, protein and lactose percentage. The results of the experiment showed that milk partitioning in purebred and crossbred goats ranged on satisfactory levels (machine milk - MM: morning 69.8-81.6%, afternoon 66.2-77.4%; machine stripping milk - MSM: morning 12.2-19.3%, afternoon 19.2-23.4%; hand stripping milk - HSM: morning 6.1-10.9%, afternoon 5.4-11.9%; total machine milk - TMM: morning 89-94.6%, afternoon 88-94.6%). The effect of breed (crossbred) was found to be significant for all milk fractions (ml and %, P < 0.001 and P < 0.05, respectively). The effect of parity was significant except for MSM (%) and HSM (%). The effect of lactation stage (control day) and the animals was also found to be significant (P < 0.001). The fat percentage of S, D, S × L, S × A and (S × L) × L was 3.82, 5.1, 4.8, 3.88 and 3.95%, respectively (P < 0.001). Protein percentage ranged from 3.1 to 3.6% in the different genotypes (P< 0.001) while lactose percentage was from 4.51 to 4.66%. In conclusion it may be said that imported dairy goat breeds and different crosses with local Greek breed are characterized by good milkability. So the best technique of machine milking is the "routine" milking without applying hand stripping.

Foram avaliadas as características das partes não-integrantes da carcaça de novilhos 5/8 Nelore 3/8 Charolês terminados em confinamento e abatidos com 425, 467 e 510 kg. Os períodos de alimentação foram 30, 65 e 94 dias, respectivamente. A idade e peso médio iniciais foram de 660 dias e 361 kg, respectivamente. A dieta alimentar, com relação volumoso:concentrado de 60:40 com base na matéria seca (MS), continha 10,25% de proteína bruta e 3,18 Mcal de energia digestível/kg MS. De acordo com estimativa da equação de regressão, os rendimentos de carcaças quente e fria elevaram com o aumento no peso de abate (P). No entanto, quando expressos por peso de corpo vazio (PCV), houve similaridade entre os diferentes tratamentos. Quando os componentes foram expressos em valores absolutos, couro, total de componentes externos (TCE), fígado, total de órgãos vitais (TOV), total de gorduras internas (TGORD) e total de trato gastrintestinal vazio (TGVZ) apresentaram incremento com o aumento no P. Quando expressos por 100 kg de P e PCV, os componentes couro, TCE, fígado e TGVZ apresentaram similaridade; coração e TOV, decréscimo; e TGORD, acréscimo, com o aumento no P. Houve correlação positiva entre peso de fígado com consumo de matéria seca (r = 0,91) e com energia líquida de mantença (ELm) (r = 0,91) e entre TGORD com ELm (r = 0,78).The characteristics of the body parts non-integrant of the carcass of 5/8 Nellore 3/8 Charolais steers feedlot finished and slaughtered with 425, 467 and 510 kg, were evaluated. The feeding periods were 30, 65 and 94 days, respectively. The average initial age and weight were 660 days and 361 kg, respectively. The diet, with 60% roughage and 40% concentrate dry matter basis (DM), contained 10.25% of crude protein and 3.18 Mcal of digestible energy/kg DM. According to regression equation estimate, the hot and cold carcass dressing increased as slaughter weight (SW) increased. However, when expressed per empty body weight (EBW), similarity among the different treatments was verified. When the components were expressed in absolute values, rawhide, total external components (TEC), liver, total vital organs (TVO), total internal fats (TFAT) and total empty gastrintestinal tract (TEGT) showed increase with increase in SW. When expressed per 100 kg of body weight and EBW, the rawhide, TEC, liver and TEGT components showed similarity; heart and TVO showed decrease; and TFAT showed increase, with increase in SW. Positive correlations between liver weight with dry matter intake (r=.91) and with net energy maintenance (NEm) (r=.91), and between TFAT with NEm (r=.78) were observed.

The aim of our study was to evaluate the effects of chosen factors (crossbreds, sex, litter size, age of ewes and interaction between sex and litter size) on the growth of lambs crossbreds of the breeds Charollais (Ch), Suffolk (Sf) and Improved Valachian (IV). The evaluation was performed in the year 2004 on the farm Růžďka and involved altogether 96 lambs. The growth ability was evaluated at the following crossbreds: Ch x Sf (n = 28), (Ch x Sf) x Sf (n = 28), IV x Sf (n = 21) and (IV x Sf) x Sf (n = 19). All lambs under study were born indoor in January. Lambs were kept indoor till the end of the evaluation. From the evaluation of effects of crossbreds, sex and age of ewes on the live body weights and daily gains of lambs above all result that these factors showed a significant effect only on the live body weight at birth. On the other hand, the factors of litter size and interaction between sex and litter size showed a highly significant (P < 0.01) effect on the live body weights of lambs at birth, at 70 and at 100 days of age as well as on their daily gains within the intervals from birth to 70 and 100 days of age. It can be concluded that the daily gains were highly uniform but relatively low in all crossbreds under the study within the time interval from birth to the age of 100 days, while the non-significantly highest daily gain was recorded in the crossbreds of IV x Sf (211 g). On the other hand the lowest ones were observed in the crossbreds of CH x Sf and (IV x Sf) x Sf (199 g).

Cutaneous evaporative heat loss in Bos indicus and Bos taurus has been well documented. Nonetheless, how crossbreds with different fractional genetic proportions respond to such circumstances is of interest. A study to examine the physiological responses to cutaneous evaporative heat loss, also lactation period and milk yield, were conducted in Sahiwal (Bos indicus, n = 10, 444±64.8 kg, 9±2.9 years), Holstein Friesian (Bos taurus, HF100% (n = 10, 488±97.9 kg, 6±2.8 years)) and the following crossbreds: HF50% (n = 10, 355±40.7 kg, 2±0 years) and HF87.5% (n = 10, 489±76.8 kg, 7±1.8 years). They were allocated so as to determine the physiological responses of sweating rate (SR), respiration rate (RR), rectal temperature (RT), and skin temperature (ST) with and without hair from 06:00 h am to 15:00 h pm. And milk yield during 180 days were collected at days from 30 to 180. The ambient temperature-humidityindex (THI) increased from less than 80 in the early morning to more than 90 in the late afternoon. The interaction of THI and breed were highly affected on SR, RR, RT, and ST (p<0.01). The SR was highest in Sahiwal (595 g/m2/h) compared to HF100% (227 g/m2/h), and their crossbreds both HF50% (335 g/m2/h) and HF87.5% (299 g/m2/h). On the other hand, RR was higher in HF87.5% (54 bpm) and both HF100% (48 bpm) and HF50% (42 bpm) than Sahiwal (25 bpm) (p<0.01). The RT showed no significant differences as a result of breed (p>0.05) but did change over time. The ST with and without hair were similar, and was higher in HF100% (37.4°C; 38.0°C) and their crossbred HF50% (35.5°C; 35.5°C) and HF87.5% (37.1°C; 37.9°C) than Sahiwal (34.8°C; 34.8°C) (p<0.01). Moreover, the early lactation were higher at HF100% (25 kg) and 87.5% (25 kg) than HF50% (23 kg) which were higher than Sahiwal (18 kg) while the peak period of lactation was higher at HF100% (35 kg) than crossbreds both HF87.5% and HF50% (32 kg) which was higher than Sahiwal (26 kg) (p<0.05). In conclusion, sweating and respiration were the main vehicle for dissipating excess body heat for Sahiwal, HF and crossbreds, respectively. The THI at 76 to 80 were the critical points where the physiological responses to elevated temperature displayed change. [ABSTRACT FROM AUTHOR]

The first aim of the study was to compare selected meat quality parameters in porkers without the gene RYR1T (ryanodine receptor gene). These were porkers slaughtered at 100 to 115 kg and 116 to 130 kg live weight. The second aim of the study was to determine the occurrence frequency of standard-quality meat (red, firm, nonexudative [RFN]) and the occurence frequency of defective meat (pale, soft, exudative [PSE] and acid, soft, exudative [ASE]). The analysis was conducted on the longissimus lumborum muscle in 114 crossbred porkers. The porkers were a cross of Camborough 22 sows and boars from lines 337PIC (Pig Improvement Company), Norsvin Landrace and Pietrain. All of the animals were provided with identical environmental and nutritional conditions. The average weight of the slaughtered animals in the light and heavy groups was 110 kg and 122 kg, respectively. Both groups had the s ame average post-slaughter meatiness (56.5%). A statistical analysis of selected meat-quality parameters did not show any sign ificant differences between the weight groups. On the other hand, the classification based on carcass quality showed an occur ence frequency of defective meat in heavier crossbred porkers (116 to 130 kg) that was three times higher than in those cross bred animals which weighed 100 to 115 kg when slaughtered. In porkers without the gene RYR1T, the defective meat types PSE and ASE occurred with a frequency of 17.54%. [ABSTRACT FROM AUTHOR]

This study aimed to assess and compare the non-carcass components, carcass measurements and meat cut production of Pantaneiro (P) sheep and their Texel (TP) and Santa Inês (SIP) crossbreds. Ninety-six lambs, of which 51 were male and 45 were female, with a mean weaning weight of 15.21 ± 1.25 kg and age of 78 ± 13 days were slaughtered at 32 kg of body weight. TP lambs had greater leg compactness and weight and percentage of pelt, whereas genotypes (G) P and SIP had higher carcass depth. P and SIP females had weights omental fat percentages that were superior to the other animals, whereas SIP females had higher mesenteric fat. TP males had higher production of white viscera. There was no effect of sex, G or interaction for production and percentage of all meat cuts. Pantaneiro lambs and their crosses with meat breeds could be useful in meat production systems under Savannah environmental conditions. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare slaughter value, collagen profile, shear force and sensory quality of muscles originating from carcasses of heifers and single-calf cows of Polish Holstein-Friesian x Limousine crossbreds. Eight heifers (540 days old) and eight single-calf cows (836 days old), which were produced in a semi-intensive system, were included in the study. Single-calf cows were heavier than the heifers, which had higher dressing percentages and average daily gains. Calving and age at slaughter did not influence cooking loss of semimembranosus (SEM) and infraspinatus (INF) muscles or the shear force of SEM. The ventral part of the INF muscle from single-calf cows exhibited higher shear force values. In both muscles, higher water-soluble and lower acid-soluble collagen contents were noted in heifers compared with single-calf cows. There were no differences in sensory quality of SEM obtained from the carcasses of single-calf cows and heifers, whereas cross-section appearance, tenderness, juiciness and overall acceptability of INF were scored higher for single-calf cows than for heifers. Thus, it can be concluded that heifers and single-calf cows produce meat with similar eating quality. [ABSTRACT FROM AUTHOR]

A study was conducted on comparative productive performance of indigenous Naked Neck (NN) and Naked Neck Crossbred (NNC) i.e., Naked Neck x White Leg Horn at Poultry and Wildlife Programme, National Agricultural Research Centre (NARC), Islamabad, Pakistan. A total of 72 birds (16 weeks of age) comprising 30 females and 6 males of each breed were divided into six experimental units / replicates (10 females and 2 male / replicate). Separate breeding pen were allotted to each replicate. The birds were fed ad-libitum. The data on body weight, feed consumption, daily egg production, egg weight, egg shell thickness and mortality were recorded. Naked Neck Crossbred (NNC) layers exhibited relatively less body weight (1461g) at 40 weeks of age, better egg production (66.36 %) and feed efficiency (761.32 g feed bird-1 week-1) and produced heavier eggs (average weight 60.89g) than those produced by Naked Neck (NN). However, the difference in the feed intake values was found to be non 0.05). The Naked Neck layers produced thicker shelled eggs (0.390mm) and showed better livability than their counterparts. [ABSTRACT FROM AUTHOR]

Abstract: This study tested the effects of Spirulina supplementation level, basal diet and their interactions with sire breed and sex on liveweight, body conformation and growth traits in dual-purpose Australian lambs. In two concurrent feeding trials utilising typical pasture-based and simulated-drought basal diets, a total of 48 lambs was randomly allocated to treatment groups of Spirulina supplementation levels (CONTROL – 0ml, LOW – 50ml, MEDIUM – 100ml and HIGH – 200ml), balanced by sire breed (Black Suffolk, Dorset, Merino and White Suffolk) and sex (ewes and wethers). In both feeding trials, Spirulina was supplemented daily for 9-weeks, following a 3-week adjustment phase. Weekly data of liveweight and body conformation measurements; chest girth (CG), wither height, body length, and body condition score (BCS), were taken throughout the trials. These were transformed into changes between initial and final periods of the feeding trial. Average daily liveweight gain (ADG) was computed from the differences in liveweight divided by duration in days. All data were analysed using Factorial ANOVA analysis in SAS. Medium and high Spirulina supplementation levels were found to improve the liveweight and ADG of White Suffolk- and Merino-sired lambs on simulated-drought basal diets. BCS improved with Spirulina supplementation in lambs on simulated-drought basal diets. Under typical pasture-based basal diet, supplemented lambs had comparatively higher CG, BCS, liveweight and ADG than their counterparts on simulated-drought basal diets. These findings are of practical significance to the sheep industry because of the potential selection aid to Australian farmers in identifying the usefulness of Spirulina as a supplement and the optimal sire breed choice for the best performance response that is cost-effective when using dietary protein-rich supplements for their dual-purpose prime lamb operations. [Copyright &y& Elsevier]

The study was carried out in collaboration with the Regional Agriculture and Rural Development Directorate specialists of Elbasani within the 2012-2013 periods. The objective of the study was: the assessment of the radius meat of different pigs' breeds and crossbreds: Great White (Yorkshire), Pietren and crossbreds of Pietren X Great White (Yorkshire) (♂ X ♀). The experiment's animals consisted at a total of 136 effective leaders respectively: 50 heads of Yorkshire, 27 heads of Pietren and 59 heads of crossbreds' have been: live weight of pigs before slaughtering, hot slaughtering weight. Live ëeight of pigs was estimated as the difference12 hours weighing between meals which means when the body was empty ëith food. Cold Yield was estimated by the ratio: (cold carcasses weight/live weight) x100. Cold weight was rated as a hot carcass weight discount 2.5-3% presenting the carcass with or without blood. The database was processed statistically using ANOVA. Results of the study are as follows: the genetic type of Great White (Yorkshire) represented by 50 heads, has had an average of the cold yield 74.9% (STDEV., 3.086); the genetic type of Pietren represented by 45 heads of 74.2% (STDEV 1.932) and the genetic type of crossbreds Pietren Great white (Yorkshire) (♂ x ♀) resulted 75.4% (STDEV., 3.043). [ABSTRACT FROM AUTHOR]

Linkage disequilibrium (LD) and the persistence of its phase across populations are important for genomic selection as well as fine scale mapping of quantitative trait loci. However knowledge of LD in beef cattle, as well as the persistence of LD phase between crossbreds and purebreds, is limited. The objective of this study was to understand the patterns of LD in Angus, Charolais, and crossbred beef cattle based on 31’073, 32’088 and 33’286 SNP in each population, respectively. Amount of LD decreased rapidly from 0.29 to 0.23 to 0.19 in Angus (AN), 0.22 to 0.16 to 0.12 in Charolais (CH), 0.21 to 0.15 to 0.11 in Crossbreds (C), when the distance range between markers changed from 0-30kb to 30-70kb and then to 70-100kb, respectively. Breeds and chromosomes had significant effects (P

Eating-quality attributes of meat from Ankole cattle and their Friesian and Boran crossbreds finished in different feeding systems were evaluated. Seventy two 8-month-old bulls (24 each of pure Ankole (A), Ankole x Boran (B) and Ankole x Friesian (F) (191 ± 9.6 kg average weight) were allotted to three feeding systems in a completely randomized design with a 3 x 3 factorial treatment, and were slaughtered after 120 days. The longissimus dorsi muscle was excised from the carcasses and divided into five samples for sensory and shear force analysis. Samples aged 2, 7, 14 and 21 days were subjected to the Warner Braztler shear force (WBSF) machine for textural tenderness determination. Steaks from Ankole and Friesian crossbreds attained WBSF values below 55N within 7 days of post mortem storage, whereas Boran crossbreds attained a similar level of tenderness at 14 days. Steaks from Ankole and Friesian crossbreds were rated more tender, juicy and acceptable than Boran crossbreds by panelists. Steaks from grazed bulls were rated less tender, juicy and palatable than steaks from supplemented and feedlot finished bulls. It was concluded that when grazed and supplemented or finished in a feedlot and meat aged for 7 days, Ankole bulls produce tender meat of an as high eating-quality as their Ankole x Friesian crossbreds. [ABSTRACT FROM AUTHOR]

The article discusses the study that evaluates and compares the carcass quality traits of male birds of four different crossbreds chicken developed for backyard poultry farming using the rearing system, and examines the effect of age on different carcass quality traits in each of the cross. At 10 weeks, the study found significant difference in pre-slaughtered body weight between genetic groups with PD1 x PB2, called B, recording significantly higher weight.

The aim of the study was to evaluate heterotic and combining ability effects for growth in nine chicken genotypes. A 3 × 3 complete diallel mating system involving two indigenous breeds named Venda (V) and Naked Neck (N) and one commercial broiler breed named Ross 308 (R) were used. The nine genetic groups of crosses were reared up from hatch to 13 weeks of age in deep litter open house. Body weights of 180 chicks (20 chicks per genetic group), recorded at 0, 3, 5, 7, 9, 11, and 13 weeks of age, were used to estimate heterosis, general combining ability (GCA), and specific combining ability (SCA). Results showed that the Ross 308 had the heaviest body weight at all weeks of measurement except for hatch. With respect to crosses, the V × R and its reciprocal cross, R × V had the heaviest body weights at 13 weeks. Heterosis estimates for body weight were higher in the Venda male × Ross 308 female and Venda male and Naked Neck female crosses. GCA was significant ( P ≤ 0.01) for body weight from hatch to 13 weeks of age while SCA and reciprocal effects were both significant ( P ≤ 0.05) for body weight at all ages of measurement except for hatch. The Ross 308 gave the highest positive effect of GCA for body weight except for hatch. V × N gave the highest and positive effects of SCA for body weight. [ABSTRACT FROM AUTHOR]

The pork supply chain values steady and undisturbed piglet production. Fertilization and maintaining gestation in warm and hot climates is a challenge that can be potentially improved by selection. The objective of this study was to estimate 1) genetic variation for farrowing rate of sows in 2 dam lines and their reciprocal cross; 2) genetic variation for farrowing rate heat tolerance, which can be defined as the random regression slope of farrowing rate against increasing temperature at day of insemination, and the genetic correlation between farrowing rate and heat tolerance; 3) genetic correlation between farrowing rate in purebreds and crossbreds; and 4) genetic correlation between heat tolerance in purebreds and crossbreds. The estimates were based on 93,969 first insemination records per cycle from 24,456 sows inseminated between January 2003 and July 2008. These sows originated from a Dutch purebred Yorkshire dam line (D), an International purebred Large White dam line (ILW), and from their reciprocal crosses (RC) raised in Spain and Portugal. Within-line and crossbred models were used for variance component estimation. Heritability estimates for farrowing rate were 0.06, 0.07, and 0.02 using within-line models for D, ILW, and RC, respectively, and 0.07,0.07, and 0.10 using the crossbred model, respectively. For farrowing rate, purebred-crossbred genetic correlations were 0.57 between D and RC and 0.50 between ILW and RC. When including heat tolerance in the within-line model, heritability estimates for farrowing rate were 0.05,0.08, and 0.03 for D, ILW, and RC, respectively. Heritability for heat tolerance at 29.3°C was 0.04, 0.02, and 0.05 for D, ILW, and RC, respectively. Genetic correlations between farrowing rate and heat tolerance tended to be negative in crossbreds and ILW-line sows, implying selection for increased levels of production traits, such as growth and reproductive output, is likely to increase environmental sensitivity. This study shows that genetic selection for farrowing rate and heat tolerance is possible. However, when this selection is based solely on purebred information, the expected genetic progress on farrowing rate and heat tolerance in crossbreds (commercial animals) would be inconsequential. [ABSTRACT FROM AUTHOR]

The present study was aimed at evaluating -- for the domestic meat industry -- the crosses of Danish pig breeds, originating from mating Landrace--Yorkshire (LY) sows with Duroc or Duroc-Pietrain (DP) boars, as regards their burdening with RYR1 gene, as well as meat quality and technological value (including hot carcass weight). The studies were conducted on 64 porkers from two genetic groups: LY x D and LY x DP. Within each genetic group two weight classes were separated - 80 kg and 90 kg hot carcass weight. The model values for physicochemical properties and the technological value of meat obtained from LY x D fatteners, irrespective of the weight class (80 kg or 90 kg), as well as the 100% resistance of those animals to stress, fully justify their use for the commercial production of fatteners. In the national programme for commercial production the LY x DP crosses may also be used, though a preference should be made for slaughter at the higher hot carcass weight (90 kg) as a clear improvement was observed of the most important for the processing industry meat quality traits, expressed by the significantly lower drip loss during storage and higher technological yield (TY). [ABSTRACT FROM AUTHOR]

Rumen fluid collected from three rumen fistulated N'Dama and three crossbred animals fed three different diets at medium supplementation level, was used to compare the plant cell wall degrading community of the two breeds of cattle. In vivo digestibility was also examined and compared using 12 animals (six of each breed) fed the same diets. The microbial community of the rumen was analyzed by 16S rRNA hybridisation, using phylogenetic probes of different levels: a universal probe, domain-specific probes for Bacteria, Eukarya and Archaea, and probes targeting cellulolytic organisms: Chytridiomycetes, Fibrobacter spp., Ruminococcus albus and Ruminococcus flavefaciens. In vivo, organic matter (OM) and neutral detergent fibre (NDF) digestibility were significantly higher in N'Dama compared to crossbred animals when they were fed either baby corn stover and concentrate, or groundnut hay and moringa. In contrast, when the animals were fed groundnut hay and concentrate there was no difference in OM and NDF digestibility between the two breeds. Results of the microbial community analysis showed that RNA concentration of total Bacteria and Archaea was not affected by the breeds of animal, but were significantly affected by diet. The eukaryotic RNA concentration was higher in crossbred animals compared to the N'Dama and was not affected by the diet. Fibrobacter and R. flavefaciens RNA concentrations (μg/mL) were significantly dependent on diet and breed. Ruminococcus albus and Chytridiomycetes RNA concentrations were neither affected by the breed, nor by the diet of the animals. This suggested that the differences between breeds observed in digestibility could be partially explained by the composition of the cell wall degrading community. [ABSTRACT FROM AUTHOR]

The objective of this study was to establish the impact of crossing the indigenous Cres sheep with Awassi and, respectively, Awassi and East Friesian sheep on the milk yield and quality. For this purpose, through regular monthly milk yield recordings a total of 824 individual milk samples from 139 sheep in the second lactation of the same flock were collected, of which: 46 purebred Cres sheep, CS; 33 crosses with 50 % Cres sheep and 50 % Awassi, CA; 60 crosses with 50 % Cres sheep, 25 % Awassi and 25 % East Friesian, CAEF. The obtained results show a significant (P<0.05; P<0.01) impact of the genotype and the lactation stage on the yield and chemical composition of milk, and the somatic cell count. The most milk was yielded by CAEF crosses (690 mL/ewe/day, i.e., 133.8 L per lactation) and the least by CS (340 mL/ewe/day, i.e., 58.48 L per lactation). The content of total solids, fat and protein increased as lactation advanced, whereas the trend of the lactose content was opposite. The highest content of total solids, fat and protein were established in the milk of the indigenous Cres sheep. A positive correlation was established between the amount of yielded milk and the somatic cell count, whereas a negative correlation was established between the amount of milk and the content of solids, fat and proteins. [ABSTRACT FROM AUTHOR]

Approximately 110 million birds from nineteen documented indigenous, heavier and lighter bodied chicken breeds and numerous non-descript types are bought and sold at unorganized meat markets in India. Improving the economic production profile for poultry farmers had been a focus since independence. Genetic improvements by selection over seven generations in non-descript chicken breeds has resulted in 19 more eggs and 4 g higher egg weight. Indigenous exotic crossbreds have shown an increase of 24-45 eggs, which has been associated with increased body weight and earlier age of sexual maturity. Heterosis for egg number ranged from 15-23 percent. Hybrids of the Aseel and Delhem Red breeds produced more eggs than either of the parents. Exotic crossbreds, including the Vanraja, Giriraja, Nadanum, Kuroiler (semi-broiler types) and Krishna-J, Grampriya, Krishipriya, Hit-CARI, Up-CARI (lighter weight) were introduced to scavenging in small scale poultry operations by both public and private sector organisations. The production of the Kalyani-DK and Satpura-Desi synthetic hybrid prototypes, which resemble indigenous fowl in body conformation, multi coloured plumage, dull shanks, pink skin and single comb have generated new opportunities for poultry production in rural areas. The Satpura-Desi attained 1.0 kg bodyweight in 8-9 weeks with 2.45 kg feed. In the ‘quick return’ scheme for free range flocks the 200-300 g birds grew to marketable weight in another 50-60 days and were worth 150% in market price compared to the broiler chicken. Whereas, in a gradual income scheme, the egg produced, surplus cockerels and culled hens resulted in a net gain of US$64-70 annually; the quick return scheme for meat chicken produced a net income of US$96 for village women which exceeded the gradual financial returns generated from egg production. Small scale poultry farmers, raising 100-2000 Satpura-Desi chickens, have been able to capitalize on its acceptance as an indigenous breed in the local meat markets, which has been apparent from the sale of 0.67 million chicks in last 12 months. [ABSTRACT FROM PUBLISHER]