Spanish Journal of Agricultural Research
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Short communication: Evaluation of tubal patency in repeat breeder Holstein cows
No full textAim of study: To evaluate tubal patency in repeat breeder Holstein cows with the purpose of estimating the frequency of oviduct obstruction as a cause of the repeat breeding syndrome.Area of study: Lugo (NW Spain)Material and methods: In 50 repeat breeding cows, a solution of the dye phenol-sulphon-phthalein (PSP) was instilled into one uterine horn with the aid of a balloon catheter. Urine was collected 15, 25 and 45 min post-PSP infusion. Urine of a reddish color was used as indicator of tubal patency, as the PSP had passed across the oviduct into the abdominal cavity and was eliminated in urine. The other oviduct was evaluated on a different day.Main results: Of the 50 cows tested, 44% had some degree of oviduct obstruction: 4% had bilateral oviduct occlusion, 20% unilateral oviduct occlusion, 16% bilateral oviduct stenosis and 4% unilateral oviduct stenosis. No significant relationship could be established between tubal impermeability and postpartum reproductive or metabolic diseases.Research highlights: Tubal stenosis or occlusions were frequent and they are likely to contribute to the repeat breeding syndrome in dairy cows; thus, tubal patency should be routinely evaluated in repeat breeders. The PSP test is easy to perform, well tolerated by animals, and allows evaluating both oviducts separately
Milk yield, periparturient diseases and body condition score as factors affecting the risk of fetal losses in high-yielding Holstein cows
No full textThe objective of this study was to assess various risk factors affecting fetal losses in high-yielding Holstein cows in a hot environment. In a retrospective observational study, 14,384 records from Holstein cows from a large highly technified dairy herd in northern Mexico were used. Logistic multivariate multiple-group response model indicated that fetal losses between 43 and 260 days of pregnancy were 23.8%. Dry periods >60 d were associated (p<0.05) with 0.8 (confidence interval CI=0.8–0.9) times lower incidence of fetal losses compared to cows with dry periods <60 d. Cows with body condition score (BCS) >3 at calving and 15 days postpartum had about half the risk of suffering fetal losses than cows with BCS <3.0. Cows with peak milk yield >38 kg were 5.5 times more likely to have a fetal loss than cows with peak milk yield <38 kg (36.9 vs. 9.6%; p<0.01). The risk of fetal loss increased with 305-d milk yield >9,000 kg (OR=2.1) compared with cows with milk yield <9,000 kg. Retained placenta was (p<0.05) associated with 1.2 (CI=1.1–1.4) times higher fetal losses than cows without this reproductive disorder. Cows suffering premature parturition had 1.2 (CI=1.0–1.4) greater (p<0.05) risk of suffering fetal losses than cows with normal parturition. Cows with twin pregnancies had significantly increased chances of losing their fetuses than cows with a single fetus (31.1 vs. 15.9 p<0.01). A bimodal distribution of fetal losses was observed with peaks around 50 and 220 days of pregnancy. It was concluded that in this particular hot environment fetal losses were associated with high milk yield, low body energy reserves at calving, reduced dry periods, occurrence of retained placenta, twin pregnancies and premature calving
Phenological asynchrony between the fruit fly Anastrepha fraterculus and early maturing peach cultivars could contribute to pesticide use reduction
No full textPhenological asynchrony between fruit crops and pests consists of a discrepancy between the period of fruit susceptibility and that of high pest abundance in the orchards. Therefore, it may be used for reducing pesticide applications. We assayed the potential phenological asynchrony between peach cultivars with different growing cycles and the Anastrepha fraterculus (Diptera: Tephritidae). To this end, we assessed fruit infestation by A. fraterculus at harvest for one growing season (2012-2013) in early, average and late maturing peach cultivars. Moreover, the fruit infestation was checked for non-cultivated native and non-cultivated wild exotic plant hosts around the peach orchards of the experimental area during 2013 and 2014. In addition, we monitored A. fraterculus abundance weekly during three consecutive growing seasons, S1 (2011-2012), S2 (2012-2013) and S3 (2013-2014), to assess phenological asynchrony between peach cultivars and A. fraterculus. In particular, we checked the influence of meteorological variables on A. fraterculus abundance, and tested if A. fraterculus abundance at the time when fruits are susceptible differed among cultivars. Eventually we discuss the possibility of sustainable management of peach in southern Brazil. This study constitutes a first assessment of the periods of crop vulnerability and pest presence in peach orchards in South of Brazil and provides necessary information for taking advantage of the phenological asynchrony phenomenon for this pest-crop association
Foraging behaviour and performance of steers from two local breeds (Asturian Valley and Asturian Mountain) grazing in Cantabrian (N Spain) summer pastures
No full textSteer meat production in northern Spain is deficient to attend market demand. This research aimed to compare the foraging behaviour and production of yearling steers from two local breeds differing in body weight (BW), Asturian Valley (AV, 372 kg) and Asturian Mountain (AM, 307 kg), grazing in summer pastures consisting of 70% grassland and 30% heathland. Bodyweight gains from a total of 42 steers were recorded during four grazing seasons (from June to October). In two years, in July and September, plant community selection and diet composition were estimated by direct observation and using faecal markers, respectively. Grazing time increased from July to September (488 vs. 557 min/day; p<0.001) as sward height in the grassland decreased. Although AV steers grazed proportionally for longer on herbaceous pastures than AM steers (81.3 vs. 73.3%; p<0.05), no differences between breeds were found in diet composition. AM steers showed greater mean daily BW gains than AV steers (252 vs. 133 g/day; p<0.01). From June to August, steers from both breeds gained BW (487 vs. 360 g/day for AM and AV, respectively; p<0.01), but thereafter BW gains decreased (120 vs. –12 g/day for AM and AV, respectively; p<0.05), because of reduced availability of grassland herbage. Yearling steers from AM breed seem to be better suited to mountain conditions than those from AV breed, probably because of their smaller body size and lower total nutrient requirements for maintenance
Comparison of the parameters of the lactation curve between normal and difficult calvings in Iranian Holstein cows
No full textTo evaluate effect of dystocia on the lactation curve characteristics for milk yield and composition in Holstein cows, six non-linear models (Brody, Wood, Sikka, Nelder, Dijkstra and Rook) were fitted on 5,917,677 test day records for milk yield (MY), fat (FP) and protein (PP) percentages, fat to protein ratio (FPR) and somatic cell score (SCS) of 643,625 first lactation Holstein cows with normal calving or dystocia from 3146 herds which were collected by the Animal Breeding Center of Iran. The models were tested for goodness of fit using adjusted coefficient of determination, root means square error, Akaike’s information criterion and Bayesian information criterion. Rook model provided the best fit of the lactation curve for MY and SCS in normal and difficult calvers and dairy cows with dystocia for FP. Dijkstra model provided the best fit of the lactation curve for PP and FPR in normal and difficult calvers and dairy cows with normal calving for FP. Dairy cows with dystocia had generally lower 100-d, 200-d and 305-d cumulative milk yield compared with normal calvers. Time to the peak milk yield was observed later for difficult calvers (89 days in milk vs. 79 days in milk) with lower peak milk yield (31.45 kg vs. 31.88 kg) compared with normal calvers. Evaluation of the different non-linear models indicated that dystocia had important negative effects on milk yield and lactation curve characteristics in dairy cows and it should be reduced as much as possible in dairy herds
A comparison of empirical BLUP with different considerations of residual error variance for genotype evaluation of multi-location trials
No full textAbstractThe empirical best linear unbiased prediction (eBLUP) is usually based on the assumption that the residual error variance (REV) is homogenous. This may be unrealistic, and therefore limits the accuracy of genotype evaluations for multi-location trials, where the REV often varies across locations. The objective of this contribution was to investigate the direct implications of the eBLUP with different considerations about REV based on the mixed model for evaluation of genotype simple effects (i.e. genotype effects at individual locations). A series of 14 multi-location trials from a rape-breeding program in the north of China were simultaneously analyzed from 2012 to 2014 using a randomized complete block design at each location. The results showed that the model with heterogeneous REV was more appropriate than the one with homogeneous REV in all of the trials according to model fitting statistics. Whether the REV differences across locations were accounted for in the analysis procedure influenced the variance estimate of related random effects and testing of the variance of genotype-location (G-L) interactions. Ignoring REV differences by use of the eBLUP could result not only in an inflation or deflation of statistical Type I error rates for pair-wise testing but also in an inaccurate ranking of genotype simple effects for these trials. Therefore, it is suggested that in application of the eBLUP for evaluation of genotype simple effects in multi-location trials, the heterogeneity of REV should be accounted for based on mixed model approaches with appropriate variance-covariance structure
Genetic relationships between local Brazilian goat breeds based on mtDNA D-loop region similarity
No full textAim of study: Our objective was to investigate the mitochondrial DNA of local Brazilian goats to gain insights into the genetic composition of this precious genetic resource.Area of study: The study was developed in BrazilMaterial and methods: We analyzed a hypervariable region of the mitochondrial DNA of 83 goats belonging to four local Brazilian breeds, including Canindé (CAN-RN), Moxotó (MOX-CE), Marota (MAR-PI) and Azul (AZU-PE) as well as of exotic breeds raised in different states of the Federation. Sequences related to local Brazilian goats showed a dispersed distribution throughout the median-joining network, and clustering with sequences of exotic breeds occurred in some haplotypes. The obtained sequences were analyzed and compared with different haplogroups (A, B1, B2, C, D, F, and G) available on GenBank.Main results: The local Brazilian goat breeds showed significant diversity, with 16 (0.8240) haplotypes. Population structure analysis revealed substantial differences among breeds (p < 0.05). Mitochondrial lineage A was observed in Brazilian goats. Phylogeny showed European goats as the dominant stock for Brazilian goats, but there weare some haplotypes within haplogroup A, clustering with African and Asian haplotypes.Research highlights: These results could be suitable for creating a strategic conservation program, potentially benefitting future breeding programs
Growth performance and meat composition of rabbits fed diets supplemented with silkworm pupae meal
No full textAim of study: To determine the effect of different dietary levels of silkworm pupae meal (SWPM) on the growth performance of broiler rabbits and the chemical composition of their meat.Area of study: Southern Poland, Europe.Material and methods: Ninety Termond White rabbits were divided into three feeding groups. Control group rabbits were fed a diet containing 10% soybean meal (SBM). In the first experimental group, rabbits received a diet containing 5% SBM and 5% SWPM. The diet administered to the second experimental group was supplemented with 10% SWPM.Main results: Both partial and complete replacement of SBM with SWPM in diets contributed to a decrease in the final body weights of rabbits (2416.50 and 2390.78 vs. 2616.78 g), average daily gains (30.23 and 30.52 vs. 33.12 g) and feed intake (5.61 and 5.15 vs. 6.51 kg), but it improved the feed conversion ratio (3.28 and 3.05 vs. 3.41 kg/kg). Rabbits fed diets supplemented with SWPM were characterized by lower values of selected carcass parameters such as carcass weight and dressing percentage. Experimental diets had no significant effect on the proximate chemical composition of meat, but they increased the levels of fatty acids C18:3, C22:5 and C22:6.Research highlights: The results of this study can be put into practice to replace conventional protein and fat sources in rabbit diets with insect meals (SWPM) in the production of rabbit meat for human consumption. Our findings can also contribute to the recycling of sericultural waste
Economic profitability of agroforestry in nitrate vulnerable zones in Catalonia (NE Spain)
No full textThe impact of agricultural practices and the excess application of nitrogen can negatively impact the environment and cause human health problems. In Spain, the liquid manure applied in areas of intensive agriculture is creating groundwater nitrate pollution problems. The purpose of this paper is to evaluate the economic profitability of agroforestry practices in North East Spain. Therefore, it deals with an alternative land use that has attracted attention in recent years, considering its potential to reduce the negative impact of modern agriculture that combines concurrent forestry and agricultural production in the same area. Specifically, silvoarable practices, such as alley cropping (AC), edge row planting and riparian buffer (RB) strips were compared to conventional agricultural land use. Considering the current agricultural policy framework in Spain, which does not favour these practices, our results showed the economic profitability of alley-cropping practices in comparison to conventional barley production of 25 to 64 € ha-1 yr-1. However, AC systems presented negative results compared to the traditional wheat crop (-122 to -63 € ha-1 yr-1). The results for RB strips were strongly influenced by the high initial costs, both in irrigated and non-irrigated scenarios. Economic results were negative (between -137 and -85 € ha-1 yr-1) compared to the conventional crops, barley and corn. These figures could be greatly increased with a policy framework that promotes these practices based on the fundamental ecosystem services they provide. Moreover, these practices allow an economic diversification that could prove to be beneficial for the majority of farmers
Identification, pathogenicity and distribution of the causal agents of dieback in avocado orchards in Spain
No full textAn increased incidence of dieback from branches in several avocado orchards in southern Spain was observed in 2014. Surveys were conducted from May to October 2014, sampling the affected branches to isolate the causal agents. A total of 68 fungal isolates, recovered from ten avocado orchards, were identified, by morphological characterisation and DNA sequencing, as belonging to the genera: Neofusicoccum parvum (50%), Colletotrichum gloeosporioides (17.6%), Neofusicoccum luteum (16.2%), Neofusicoccum australe (13.2%), Neofusicoccum mediterraneum (1.5%) and Lasiodiplodia theobromae (1.5%). A decreasing level of virulence in artificial inoculations on avocado plants was observed in N. parvum, N. luteum, N. mediterraneum, N. australe, C. gloeosporioides and L. theobromae, there were significant differences among N. parvum and the rest of species of this genus, and significant differences were only observed between N. luteum and C. gloeosporioides. The geographical distribution of N. parvum and N. Luteum covers different areas, while C. gloeosporioides and N. australe are located only in the areas around Benamocarra and Vélez-Málaga (southern Spain), while N. mediterraneum and L. theobromae appear only occasionally. This is the first study of avocado branch cankers in Spain which identifies the causal agents and establishes their pathogenicity groups, with N. parvum as the most important causal agent of avocado dieback in this area