Prevalence of coccidia and gastrointestinal nematode infections in cross bred goats in the dry areas of Sri Lanka

The prevalence and intensity of oocysts of coccidia, particularly Eimeria species, and eggs of gastrointestinal nematodes in kids (2–4 months), young goats (5–12 months) and adult goats (>1 year) were determined in five large herds managed extensively in five villages in the dry zone. Of the representative samples examined, oocysts were found in 88% of kids, 91% of young goats and 83% of adults. Seven species of Eimeria were identified in faecal samples by salt flotation. Eimeria ninakohlyakimovae (31%), E. alijevi (29%) and E. arloingi (21%) were the most common species in all age categories. Other species encountered were E. christenseni (7%), E. jolchijevi (6%), E. hirchi (3%) and E. aspheronica (1%). Gastrointestinal nematode eggs were found in 89% of the kids, 94% of the young goats and 84% of the adult goats. Identification of gastrointestinal nematodes revealed Haemonchus contortus (90%) followed by Oesophogostomum spp. (8.5%) and Trichostrongylus spp. (1%) in all three age categories examined. Both Eimeria and gastrointestinal nematodes were found in 77% of the kids, 86% of the young goats and 71% of adult goats. The mean oocyst counts per gram of faeces in kids, young goats and adult goats were 9728, 1946, and 2667, respectively. The oocyst counts were not different significantly between age groups (P>0.05). The mean egg counts per gram of faeces in kids, young goats and adult goats were 1217, 1641 and 1092, respectively. The egg counts in kids were significantly lower than that in young goats (P<0.05). The intensity of Eimeria and gastrointestinal nematode infections between herds were significantly different (P<0.01).     

The effect of breed and parity on curves of body condition during lactation estimated using a non-linear function

The objectives of this study were to see if the body condition score curve during lactation could be described using a model amenable to biological interpretation, a non-linear function assuming exponential rates of change in body condition with time, and to quantify the effect of breed and parity on curves of body condition during lactation. Three breeds were represented: Danish Holstein (n = 112), Danish Red (n = 97) and Jerseys (n = 8). Cows entered the experiment at the start of first lactation and were studied during consecutive lactations (average number of lactations 2, minimum 1, maximum 3). They remained on the same dietary treatment throughout. Body condition was scored to the nearest half unit on the Danish scale (see Kristensen (1986); derived from the Lowman et al. (1976) system) from 1 to 5 on days: 2, 14, 28, 42, 56, 84, 112, 168, 224 after calving. Additionally, condition score was recorded on the day of drying off the cow, 35, 21, and 7 days before expected calving and finally on the day of calving. All condition scores were made by the trained personal on the research farm, where the same person made 92% of the scores. The temporal patterns in condition score were modelled as consisting of two underlying processes, one related to days from calving, referred to as lactation only, the other to days from (subsequent) conception, referred to as pregnancy. Both processes were assumed to be exponential functions of time. Each process was modelled separately using exponential functions, i.e. one model for lactation only and one for pregnancy, and then a combined model for both lactation only and pregnancy was fitted. The data set contained 467 lactation periods and 378 pregnancy periods. The temporal patterns in condition score of cows kept under stable and sufficient nutritional conditions were successfully described using a two component non-linear function. First lactation cows had shallower curves, they had greater condition scores at the nadir of the curve. Danish Holstein and Jersey were thinner at the end of the mobilisation period having lost more body condition than the Danish Red breed. Although the dairy breeds ended up being thinner there were no significant differences in the rate at which they lost body condition.     

Influence of production system in local and conventional pig breeds on stress indicators at slaughter,muscle and meat traits and pork eating quality

Sensory quality of pork is a complex phenotype determined by interactions between genetic and environmental factors. This study aimed at describing the respective influences of breed and production system on the development of pork quality. Plasma stress indicators and Longissimus muscle (LM) composition, physicochemical and sensory quality traits were determined in two contrasted breeds – the conventional Large White (LW, n=40) and the French local Basque (B, n=60). Pigs were reared in either a conventional (C; n=20 per breed), alternative (A; sawdust bedding and outdoor area, n=20 per breed) or extensive system (E; free-range, n=20 B). All the pigs from A and C systems were slaughtered at the same slaughterhouse, whereas B pigs from the E system were slaughtered at a local commercial abattoir. Major breed differences were found for almost all traits under study. LM from B pigs exhibited higher lipid, lower water and collagen concentrations, as well as lower collagen thermal solubility (P<0.001). Although plasma stress indicators at slaughter did not differ between breeds, except lower (P<0.05) lactate levels in B pigs, they exhibited higher LM pH1 and pHu values, and lower meat lightness, hue angle, water (drip, thawing and cooking) losses, glycolytic potential and shear force. Sensory analyses highlighted higher redness, marbling, tenderness, juiciness and flavour scores (P<0.01) of meat from B compared with LW pigs. Within both LW and B breeds, compared with C, the A system did not (P>0.05) influence plasma stress indicators, LM chemical composition and physicochemical or sensory traits of pork. In contrast, within the B pigs, the E system affected the meat quality more. Lower plasma cortisol levels (P<0.05), but higher plasma lactate, creatine kinase and lactate dehydrogenase activities, and more skin lesions (P<0.05), indicating higher muscular activity during pre-slaughter handling, were found in pigs produced in the E compared with the C system. E pigs exhibited higher meat pH1 and pHu values and shear force (P<0.01) and exhibited lower lightness, hue angle and drip and thawing losses (P<0.01) compared with the C pigs, whereas LM lipid, protein or collagen concentrations were not affected. Regarding sensory traits, the E system produced redder meat, but did not impact the eating quality of pork. Altogether, this study demonstrates that differences in meat quality between B and LW breeds can be modulated by extensive pig production system.     

树鼩实验室繁殖及育幼的探讨

探讨实验室内树鼩的人工繁殖和育幼情况。结果显示在16个月的观察期内,35只雌性、2 0只雄性成年树共产仔14 7窝4 0 4只,平均每只母树年产仔3 2窝、8 7只,平均每次妊娠的合笼天数为6 8±32天。在非繁殖高峰期给雄、雌性树鼩用激素可使合笼时间缩短至6 1±14天,用药有效率为6 1. 5 %。仔树出生后经被动母乳联合人工配方乳喂养的成活率达92. 2 %。表明在实验室条件下,非繁殖期使用激素类药物能提高成年树鼩的受孕率;被动母乳联合人工配方乳喂养仔树的方法简单易行。     

Genetic variation (protein markers and microsatellites) in endangered Catalonian donkeys

Genetic variation of the endangered Catalonian donkey breed (Equus asinus) has been analysed at 19 loci including seven protein loci and 12 microsatellite loci isolated from the domestic horse, in 98 individuals of both sexes. Only four protein markers and three microsatellites were polymorphic. Allele frequencies of the analysed loci showed close agreement with Hardy–Weinberg proportions, with the exception of the MPZ002 locus (P<0.01). The within-population inbreeding estimate was not significantly different from zero (as measured by F_IS-statistic). The cumulative-exclusion probability for all polymorphic loci was 82.9%, this value still being very low so that these markers could efficiently be utilised for verification of parentage.     

Exploration of genetic factors resulting in abnormal disease in cattle experimentally challenged with bovine spongiform encephalopathy

ABSTRACT

Since the discovery of bovine spongiform encephalopathy (BSE), researchers have orally challenged cattle with infected brain material to study various aspects of disease pathogenesis. Unlike most other pathogens, oral BSE challenge does not always result in the expected clinical presentation and pathology. In a recent study, steers were challenged orally with BSE and all developed clinical signs and were sacrificed and tested. However, despite a similar incubation and clinical presentation, one of the steers did not have detectable PrP^Sc in its brain. Samples from this animal were analysed for genetic differences as well as for the presence of in vitro PrP^Sc seeding activity or infectivity to determine the BSE status of this animal and the potential reasons that it was different. Seeding activity was detected in the brainstem of the abnormal steer but it was approximately one million times less than that found in the normal BSE positive steers. Intra-cranial challenge of bovinized transgenic mice resulted in no transmission of disease. The abnormal steer had different genetic sequences in non-coding regions of the PRNP gene but detection of similar genotypes in Canadian BSE field cases, that showed the expected brain pathology, suggested these differences may not be the primary cause of the abnormal result. Breed composition analysis showed a higher Hereford content in the abnormal steer as well as in two Canadian atypical BSE field cases and several additional abnormal experimental animals. This study could point towards a possible impact of breed composition on BSE pathogenesis.     

Breed difference and regulation of the porcine adipose triglyceride lipase and hormone sensitive lipase by TNFα

Adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) are major novel triglyceride lipases in animals. The aim of this study was to determine if there are differences in the porcine ATGL ( pATGL ) and HSL genes between Jinhua pigs (a fatty breed) and Landrace pigs (a leaner breed). In addition, the effect of TNFα and pATGL-specific siRNA ( pATGL-siRNA ) on the expression of pATGL and HSL in porcine adipocytes was also examined. Compared with Landrace pigs, the body weight ( BW ) of Jinhua pigs was lower ( P <  0.01), while intramuscular fat content (in the longissimus dorsi muscle), as well as the back fat thickness and body fat content were higher ( P <  0.01). The expression of pATGL and HSL mRNA in Jinhua pigs was lower ( P <  0.01) in subcutaneous adipose tissue, and greater ( P <  0.01) in longissimus dorsi muscle compared with Landrace pigs. In vitro treatment of porcine adipocytes with TNFα decreased ( P <  0.01) the glycerol release and the gene expression of pATGL , HSL and PPARγ in porcine adipocytes. Furthermore, transfection with pATGL-siRNA significantly decreased ( P <  0.01) the expression of pATGL , while it had no effect on the expression of HSL . Treatment with 25 ng/ml TNFα in conjunction with pATGL-siRNA significantly decreased ( P <  0.01) the expression of pATGL and HSL in cultured porcine adipocytes. These results provide useful information to further the understanding of the function of pATGL and HSL in porcine lipid metabolism, which should be applicable to the regulation of fat deposition and improvement of meat quality.     

Multiple-breed genomic evaluation by principal component analysis in small size populations

In this study, the effects of breed composition and predictor dimensionality on the accuracy of direct genomic values (DGV) in a multiple breed (MB) cattle population were investigated. A total of 3559 bulls of three breeds were genotyped at 54 001 single nucleotide polymorphisms: 2093 Holstein (H), 749 Brown Swiss (B) and 717 Simmental (S). DGV were calculated using a principal component (PC) approach for either single (SB) or MB scenarios. Moreover, DGV were computed using all SNP genotypes simultaneously with SNPBLUP model as comparison. A total of seven data sets were used: three with a SB each, three with different pairs of breeds (HB, HS and BS), and one with all the three breeds together (HBS), respectively. Editing was performed separately for each scenario. Reference populations differed in breed composition, whereas the validation bulls were the same for all scenarios. The number of SNPs retained after data editing ranged from 36 521 to 41 360. PCs were extracted from actual genotypes. The total number of retained PCs ranged from 4029 to 7284 in Brown Swiss and HBS respectively, reducing the number of predictors by about 85% (from 82% to 89%). In all, three traits were considered: milk, fat and protein yield. Correlations between deregressed proofs and DGV were used to assess prediction accuracy in validation animals. In the SB scenarios, average DGV accuracy did not substantially change when either SNPBLUP or PC were used. Improvement of DGV accuracy were observed for some traits in Brown Swiss, only when MB reference populations and PC approach were used instead of SB-SNPBLUP (+10% HBS, +16%HB for milk yield and +3% HBS and +7% HB for protein yield, respectively). With the exclusion of the abovementioned cases, similar accuracies were observed using MB reference population, under the PC or SNPBLUP models. Random variation owing to sampling effect or size and composition of the reference population may explain the difficulty in finding a defined pattern in the results.     

Pedigree analysis in the Polish Red cattle population

The objective of this study was to describe the population structure and inbreeding level of the population of Polish Red Cattle (PRC). The structure of the breed was analysed in the context of the existing genetic resources conservation programme. The level of genetic diversity and the effective population size were also determined. The analyses were carried out based on pedigree records of 9 170 animals. Data and pedigree information were collected during the time period of 1950–2014. Records were collected by the National Research Institute of Animal Production in Balice, Poland. The population structure was analysed using the CFC programme. All the animals were grouped into five classes according to their inbreeding coefficient: the first class included non-inbred animals; and the next classes included inbred animals 0% < F ≤ 5%, 5% < F ≤ 10%, 10% < F ≤ 20%, 20% < F ≤ 30% or F > 30%. The average inbreeding in PRC population was 4% and there were 2 182 (23.8%) inbred animals. The study also included the determination of ancestral paths for the PRC population. The longest ancestral path (LAP) consisted of 12 generations (three animals) while only 229 animals (2.53%) had an LAP comprising at least 10 generations. Therefore, a need exists, particularly in PRC as a small local breed, to manage selection and mating decisions to control future coancestry and inbreeding, which would lead to better handling of the effective population size. The study results showed the possibility of disrupting the balance of the structure of a small population like PRC. Hence, endangered populations need to be monitored on a continuous basis.     

Genetic parameters of traits associated with the growth curve in Segureña sheep

This paper studies the genetic importance of growth curve parameters and their relevance as selection criteria in breeding programmes of Segureño sheep. Logistic and Verhulst growth functions were chosen for their best fit to BW/age in this breed; the first showed the best general fit and the second the best individual fit. Live weights of 41 330 individuals from the historical archives of the National Association of Segureña Sheep Breeders were used in the analysis. The progeny of 1464 rams and 27 048 ewes were used to study the genetic and phenotypic parameters of growth curve parameters and derived traits. Reproductive management in the population consists in controlled natural mating inside every herd, with a minimum of 15% of the females fertilized by artificial insemination with fresh semen; with the purpose being the herd genetic connections, all herd genealogies are screened with DNA markers. Estimates of growth curve parameters from birth to 80 days were obtained for each individual and each function by the non-linear regression procedure using IBM SPSS statistics (version 21) with the Levenberg–Marquart estimation method. (Co)variance components and genetic parameters were estimated by using the REML/Animal model methodology. The heritability of mature weight was estimated as 0.41±0.042 and 0.38±0.021 with the logistic and Verhulst models, respectively, and the heritability of other parameters ranged from 0.41 to 0.62 and 0.37 to 0.61, with the models, respectively. A negative genetic correlation between mature weight and rate of maturing was found.