Molecular genetic analysis of a cattle population to reconstitute the extinct Algarvia breed

Background: Decisions to initiate conservation programmes need to account for extant variability, diversity loss and cultural and economic aspects. Molecular markers were used to investigate if putative Algarvia animals could be identified for use as progenitors in a breeding programme to recover this nearly extinct breed. Methods: 46 individuals phenotypically representative of Algarvia cattle were genotyped for 27 microsatellite loci and compared with 11 Portuguese autochthonous and three imported breeds. Genetic distances and factorial correspondence analyses (FCA) were performed to investigate the relationship among Algarvia and related breeds. Assignment tests were done to identify representative individuals of the breed. Y chromosome and mtDNA analyses were used to further characterize Algarvia animals. Gene- and allelic-based conservation analyses were used to determine breed contributions to overall genetic diversity. Results: Genetic distance and FCA results confirmed the close relationship between Algarvia and southern Portuguese breeds. Assignment tests without breed information classified 17 Algarvia animals in this cluster with a high probability (q > 0.95). With breed information, 30 cows and three bulls were identified (q > 0.95) that could be used to reconstitute the Algarvia breed. Molecular and morphological results were concordant. These animals showed intermediate levels of genetic diversity (MNA = 6.0 ± 1.6, Rt = 5.7 ± 1.4, Ho = 0.63 ± 0.19 and He = 0.69 ± 0.10) relative to other Portuguese breeds. Evidence of inbreeding was also detected (Fis = 0.083, P < 0.001). The four Algarvia bulls had Y-haplotypes H6Y2 and H11Y2, common in Portuguese cattle. The mtDNA composition showed prevalence of T3 matrilines and presence of the African-derived T1a haplogroup. This analysis confirmed the genetic proximity of Algarvia and Garvonesa breeds (Fst = 0.028, P > 0.05). Algarvia cattle provide an intermediate contribution (CB = 6.18, CW = -0.06 and D1 = 0.50) to the overall gene diversity of Portuguese cattle. Algarvia and seven other autochthonous breeds made no contribution to the overall allelic diversity. Conclusions: Molecular analyses complemented previous morphological findings to identify 33 animals that can be considered remnants of the Algarvia breed. Results of genetic diversity and conservation analyses provide objective information to establish a management program to reconstitute the Algarvia breed.

The Ri chicken breed and livelihoods in North Vietnam: characterization and prospects

For the last twenty years, the consumption of poultry meat has boomed in Vietnam as in the rest of the developing world. Capital-intensive production has grown rapidly to satisfy this demand. Based on a few numbers of genetically uniform strains, these systems threaten biodiversity. In Vietnam, both rural and urban households still keep indigenous chickens as part of a diversified livelihood portfolio. In line with the national in situ conservation strategy, this study approached the context of local poultry keeping in two rural and one suburban districts of Northern Vietnam. It aimed at understanding households’ willingness, constraints and opportunities for practice improvement, including breeds’ management. As the Ri chicken constitutes the large majority of backyard flocks, two particular objectives of this study are the morpho-biometric characterisation of phenotypic diversity among individuals classified as Ri by farmers and an assessment of their productive potential. Chicken was found to hold a different place in livelihoods of the three districts with consequences on the management of genetic resources. The most favourable conditions for improvement of the Ri breed was found in the rural district of Luong-Son, due to market integration. In the more remote district of Ky-Son, living standards were lower and much would be gained from Ri conservation. Ri breed was the most threatened in the suburban Gia-Lam district, where poultry was a minor side-activity, lacking incentive for genetic management. From motives and constraints, tracks about breeding goals are suggested. Further considerations about conservation, improvement, market integration and livelihoods are proposed.

The Koundoum sheep breed in Niger: morpho-biometric study and description of the production system

The diffusion of highly productive breeds across developing countries goes along with a neglect of indigenous breeds, which are well suited to their environment but often show low yields. Thus, in Niger, the flock of Koundoum sheep are rapidly decreasing. The Koundoum is one of the few wool sheep breeds of Africa and shows important adaptive feature to its native environment, i.e. the humid pastures on the banks of the Niger River. To characterise the breed and to understand its production context, a survey has been conducted in 104 herds in four communes along the Niger River (Kollo, Tillabery, Say and Tera). Nine body measurements, including live weight, were taken on 180 adult sheep (101 females and 79 males). The herds varied from 2 to 60 heads, with a median size of eight animals and two thirds of the herds having less than 10 animals. Mainly fed on natural pastures, 85.6% of the herds received crop residues. Only natural mating was practiced. Veterinary care was restricted to anti-helminthic and some indigenous treatments. The frequent affiliation of breeders to professional unions appeared as favourable to the implementation of a collective conservation program. The Koundoum sheep were white or black coated, with the black colour being most frequent (75.6%). Wattles were present in both sexes at similar frequencies of around 14%. All biometric variables were significantly and positively correlated between them. The thoracic perimeter showed the best correlation with live weight in both males and females. Three variables were selected for live weight prediction: thoracic perimeter, height at withers and rump length. From the present study, it is expected that the in situ conservation of the Koundoum sheep will be highly problematic, due to lack of market opportunities for wool and the willingness of smallholders to get involved in pure Koundoum rearing.

Effect of breed, gender, housing system and dietary crude protein content on performance of finishing beef cattle fed maize-silage-based diets

Maize silage-based diets with three dietary crude protein (CP) supplements were offered to 96 finishing cattle of contrasting breed (Holstein Friesian (HF) v. Simmental x HF (SHF)) and gender (bull v. steer) housed in two types of feeding system (group fed v. individually fed). The three protein supplements differed either in CP or protein degradability (degradable (LUDP) v. rumen undegradable (HUDP)) and provided CP concentrations of 142 (Con), 175 (LUDP) and 179 (HUDP) g/kg dry matter (DM) respectively, with ratios of degradable to undegradable of 3.0, 1.4 and 0.9:1 for diets Con, LOP and HUDP respectively. DM intakes were marginally higher (P = 0. 102) for LOP when compared with Con and HOP Rates of daily live-weight gain (DLWG) were higher (P = 0.005) in LUDP and HOP when compared with Con. HF had higher DM intakes than SHF although this did not result in any improvement in HF DLWG. Bulls had significantly better DM intakes, DLWG and feed conversion efficiency than steers. Conformation scores were better in SHF than HF (P < 0.001) and fat scores lower in bulls than steers (p < 0.001). There was a number of first order interactions established between dietary treatment, breed, gender and housing system with respect to rates of gain and carcass fat scores.

Water-soluble precursors of beef flavour I: effect of diet and breed

The effects of diet and breed on the concentration of water-soluble flavour precursors, namely sugars, free amino acids, ribonucleotides, creatinine, carnosine and creatine, were studied in beef longissimus hanborum muscle. Diet had a significant effect on the concentration of free amino acids, with animals fed on grass silage having higher free amino acid levels than animals fed on a concentrate diet, whereas animals fed concentrates had a higher total reducing sugar content. Differences between a beef breed (Aberdeen Angus x Holstein-Friesian) and a dairy breed (Holstein-Friesian) were generally small. (C) 2007 Elsevier Ltd. All rights reserved.

The effects of diet, breed and age of animal at slaughter on the aroma compounds of grilled beef

The aroma volatiles of grilled beef, from animals fed either grass silage or cereal concentrates, were compared. Aberdeen Angus and Holstein-Friesian cross-breed steers, slaughtered at 14 or 24 months, were studied. Compounds formed from linoleic acid, in particular 2-pentylfuran, 1-octen-3-ol, (Z)-2-octen-1-ol, and hexanal were at higher levels in the meat from the animals fed concentrates. Phytenes and compounds formed from α-linolenic acid, in particular 1-penten-3-ol and (Z)-2-penten-1-ol, were at higher levels in the meat of animals fed silage. Differences due to breed were small and not consistent with slaughter age. Dimethyl disulfide, dimethyl disulfide and phenol were at higher levels in the meat of animals slaughtered at 24 months and may contribute to grilled beef aroma.

Whole-genome analysis for backfat thickness in a tropically adapted, composite cattle breed from Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of breed and corpus luteum on pregnancy rate of bovine embryo recipients

The objective of this study was to evaluate pregnancy rates of recipients of different breed groups (Nellore and crossbreed), as well as the effects of size and type of the corpus luteum (CL) on plasmatic concentrations of progesterone and pregnancy rates of embryo recipients. A total of 152 heifers were synchronized with progesterone implants and on the day of embryo transfer, previously obtained by superovulation and frozen in ethylene glycol, the diameter and type of the corpus luteum (cavitary and compact) was measured and blood was collected for progesterone measurement. The pregnancy rate was 44.1%, with a diameter of corpus luteum higher in recipients that became pregnant (2.03±0.41) compared with non-pregnant ones (1.86±0.34 cm). Plasmatic concentrations of progesterone did not differ between pregnant (1.50±1.05) and non-pregnant (1.31±0.91 ng/mL) animals. The type of corpus luteum did not influence the pregnancy rates. Only Angus and crossbred Marchigiana differ among themselves in pregnancy rates (33.3 and 59.2%, respectively). The pregnancy probability was affected only by CL diameter, but not by P4 plasmatic concentration. Selection of the corpus luteum size at the time of embryo transfer is an important factor to increase pregnancy rates in recipients, and compact and cavitary corpora lutea do not influence the pregnancy rates of bovine embryo recipients. Nellore recipients have pregnancy rates that are satisfactory and comparable to crossbred (Bos taurus × Bos indicus) recipients.

Breed and selection line differences in the temperament of beef cattle

O temperamento de quatro raças bovinas foi avaliado utilizando-se o teste de velocidade de fuga (FT) e o escore de comportamento (BST). FT foi definida como o tempo necessário para animais percorrerem uma distância de 2 m após a pesagem. BST foi baseada no comportamento dos animais na balança, amostrando-se quatro categorias de comportamento: movimentos, intensidade de respiração, vocalizações e coices. Os coeficientes de herdabilidade de FT e BST foram estimados com uso de um modelo de máxima verossimilhança restrita, considerando meio irmãos paternos. Caracu apresentou menores médias para BST do que as demais raças. Nelore apresentou resultados intermediários, seguida por Guzerat e Gyr com médias mais elevadas (p < 0,05). Resultados similares foram observados para FT, mas as médias de Caracu e Nelore não diferiram entre si. Observou-se baixa associação entre FT e BST (r p= -0,36; p < 0,01). A correlação entre rank de touros ordenados pelos seus valores preditos (p) para FT e BST foi moderada e negativa (r s = -0,63; p < 0,001). A herdabilidade de FT e BST foi de 0,35 e 0,34, respectivamente. A comparação de rebanhos Nelore com diferentes critérios de seleção para peso corporal mostrou que linhas de seleção podem modular positivamente o temperamento de Bos indicus.

Genetic analysis of visual scores and their relationships to mature female weight in Nellore breed

Dados de 79.884 animais da raça Nelore foram utilizados para estimar parâmetros genéticos e avaliar as relações entre os escores de conformação, precocidade e musculatura obtidos à desmama e ao sobreano e o peso das fêmeas à idade adulta. Utilizou-se o método da máxima verossimilhança restrita, em análise multicaracterísticas, com modelo que incluiu os efeitos genéticos aditivos direto e residual, como aleatórios, e os efeitos fixos de grupo de contemporâneos e, como covariáveis, a idade do animal à pesagem e a idade da mãe ao parto (exceto para o peso das fêmeas à idade adulta). Os grupos contemporâneos à desmama foram definidos pelas variáveis: sexo, rebanho, ano e mês de nascimento, grupo de manejo ao nascimento e à desmama. Na definição de grupo contemporâneo ao sobreano também foi incluída a variável grupo de manejo ao sobreano. Para o peso das fêmeas à idade adulta, o grupo de contemporâneos foi composto por rebanho, ano de nascimento, grupo de manejo ao sobreano, ano e estação da pesagem. Os efeitos genético materno e de ambiente permanente materno também foram incluídos no modelo para análise dos escores de conformação, precocidade e musculatura à desmama. As estimativas de herdabilidade direta obtidas foram 0,18 ± 0,02 para o escore de conformação; 0,21 ± 0,01 para o escore de precocidade; 0,22 ± 0,01 para o escore de musculatura à desmama e 0,24 ± 0,01 para o escore de conformação; 0,27 ± 0,01 para o escore de precocidade; e 0,26 ± 0,01 para o escore de musculatura ao sobreano e 0,42 ± 0,02 para o peso das fêmeas à idade adulta. As correlações genéticas estimadas entre os escores visuais medidos à desmama e ao sobreano foram positivas, variando de média a alta magnitude (0,56 ± 0,03 a 0,85 ± 0,01). Por outro lado, as correlações genéticas estimadas entre os escores visuais e o peso das fêmeas à idade adulta foram positivas e moderadas, variando de 0,21 ± 0,03 a 0,35 ± 0,03. Os resultados obtidos indicam que a seleção de animais com maiores escores visuais, principalmente ao sobreano, deve promover aumento do peso das fêmeas à idade adulta.

Breed and season influence on milk quality parameters and in mastitis occurrence

Os objetivos do presente estudo foram avaliar a performance das raças Jersey e Holandesa em diferentes condições de pluviosidade (estações seca e chuvosa) através do monitoramento de aspectos relacionados com a mastite subclínica (contagem de células somáticas, isolamento microbiológico, tipo de patógeno isolado), qualidade do leite (lactose, proteína, gordura e sólidos totais) e produção (media da produção de leite) de ambas as raças. O estudo foi conduzido em propriedade leiteira localizada no estado de São Paulo, Brasil. Oito visitas foram realizadas a propriedade, quatro em período de alta pluviosidade e outro em período de baixa pluviosidade. Amostras de leite foram colhidas de todos os animais para contagem eletrônica de células somáticas e determinação dos principais componentes do leite (proteína, gordura, sólidos totais, lactose). Gordura, proteína, sólidos totais e produção leiteira foram influenciadas tanto pela raça como pela estação, apresentando tendências similares para ambas raças em ambas estações. A contagem de células somáticas (CCS) apresentou resultados similares para ambas as raças. Vacas holandesas com infecção intramamária (IIM) apresentaram um maior aumento na CCS quando comparadas as vacas Jersey (P<0.001). Na estação seca, 53 animais tiveram IIM em pelo menos um mês do estudo. Destes, 32 eram da raça Holandesa e 21 da raça Jersey. Na estação chuvosa, 65 animais possuíram infecção intramamária, dos quais 43 eram da raça Holandesa e 22 da raça Jersey. A frequência de casos de IIM foi maior na estação chuvosa em comparação à estação seca. Vacas Jersey apresentaram uma menor chance de desenvolver sinais e sintomas de IIM em relação às vacas holandesas na estação chuvosa (razão de chances=0.52). O maior numero de casos de IIM na estação chuvosa pode ter contribuído para uma menor taxa de lactose no leite para ambas as raças, sendo que esta pode ser considerada como um indicador do status de IIM. Existiu uma prevalência de patógenos contagiosos durante todo o experimento. O modelo estatístico aplicado mostrou que patógenos ambientais foram mais frequentemente isolados da raça Jersey, independentemente do período do estudo. Aparentemente existem diferenças na resposta imune das raças Jersey e Holandesa.

Growth hormone 1 gene (GH1) polymorphisms as possible markers of the production potential of beef cattle using the Brazilian Canchim breed as a model

The growth hormone 1 gene (GH1) is a candidate gene for body weight and weight gain in cattle since it plays a fundamental role in growth regulation. We investigated the GH1 gene AluI and DdeI restriction enzyme polymorphisms, located 149 bp apart in the cattle genome, as possible markers of the production potential of Canchim crossbreed cattle, a 5/8 Charolais (Bos taurus) and 3/8 Nelore (Bos indicus) breed developed in Brazil, by evaluating the birth weight, weaning weight, yearling weight and plasma insulin-like growth factor-1 (IGF-1) concentration of 7 month to 10 months old Canchim calves (n = 204) of known genealogy and which had been genotyped for the AluI and DdeI markers. Our results showed significant effect (p < 0.05) between the homozygous DdeI+/DdeI+ polymorphism and the estimated breeding value for weaning weight (ESB-WW), while the AluI leucine homozygous (L/L) and leucine/valine (L/V) heterozygous polymorphisms showed no significant effect on the traits studied. The restriction sites of the two enzymes led to the formation of haplotypes which also exerted a significant effect (p < 0.05) on the ESB-WW, with the largest difference being 8.5 kg in favor of the homozygous L plus DdeI+/L plus DdeI+ genotype over the heterozygous L plus DdeI-/V plus DdeI+ genotype.

Influence of sire and sire breed (Gyr versus Holstein) on establishment of pregnancy and embryonic loss in lactating Holstein cows during summer heat stress

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Brazilian summer were determined. In Experiment 1, cows (n = 302) were AI after estrus detection or at a fixed-time with semen from one Gyr (B. t. indicus) or one Holstein sire (B. t. taurus). Pregnancy was diagnosed 80 days after AI. In Experiment 2, cows (n = 811) were AI with semen from three Gyr and two Holstein sires. Pregnancy was diagnosed at 30-40 and at 60-80 days after AI. Cows diagnosed pregnant at the first examination but non-pregnant at the second were considered as having lost their embryo or fetus. Data were analyzed by logistic regression. The model considered the effect of sire within breed, sire breed, days postpartum, period of lactation, and AI type (AI after estrus versus fixed-time). There was no effect of the AI type, days postpartum or milk production on conception or embryonic loss rates. The use of Gyr bulls increased pregnancy rate when compared to Holstein bulls [9.1% (60/657) versus 5.0% (23/456), respectively, P = 0.008; data from Experiments 1 and 2 combined]. Additionally, in Experiment 2, cows inseminated using semen from sire #4 (Gyr) had lower embryonic loss (10%) when compared with other B. t. indicus (35.3% and 40%) or B. t. taurus sires (18.2% and 38.5%, P = 0.03). In conclusion, the use of B. t. indicus sires may result in higher conception rates in lactating Holstein cows during summer heat stress. Moreover, sire can affect embryonic loss and selection of bulls according to this criterion may result in higher parturition rates in lactating Holstein cows. (c) 2006 Elsevier B.V. All rights reserved.