Rangeland Livestock Production in Relation to Climate and Vegetation Trends in New Mexico

A large statewide historical database involving livestock numbers, vegetation cover, precipitation, air temperature, and drought frequency and severity allowed us to explore relationships between climate and rangeland livestock grazing levels and livestock productivity from 1920 to 2017. Trends in vegetation cover and livestock grazing levels from 1984 to 2017 were also explored. Our climate time series was divided into two periods, 1920 ? 1975 and 1976 ? 2017, based on an apparent accelerated increase in mean annual air temperatures that began in the mid-1970s. Both mean annual precipitation (MAP) and mean annual air temperature (MAT) differed (P ≤ 0.05) between the two periods. MAP and MAT were 9.6% and 3.4% higher in period 2 compared with period 1, respectively. From the 1920s to 2010s the livestock grazing level and weaned calf numbers fell 30% and 40%, respectively, despite a significant increase in MAP. Long-term declines in livestock grazing levels and in weaned calf numbers were significantly (P ≤ 0.05) correlated with increasing MAT (r = ? 0.34 and r = ? 0.43, respectively). No long-term trends (1984–2017) in woody or perennial herbaceous cover were detected at the level of the entire state of New Mexico. Woody plant cover dynamics for New Mexico were not related to livestock grazing levels. However, at the county level we detected a 2% increase in woody plant cover coupled with a 9% decrease in cattle animal units between 2000 and 2002 and 2015 and 2017 for 19 select counties well distributed across New Mexico. Increases in woody plant cover varied greatly among counties and were higher for eastern than western New Mexico. Both global and New Mexico data show the climate warming trend is accelerating. Our findings have relevance to several other parts of the world because New Mexico occurs at midlatitude, has varied topography and climatic conditions, and several different range vegetation types.     

Seasonal Divergence of Landscape Use by Heritage and Conventional Cattle on Desert Rangeland

Adopting livestock with heritage genetics may help to improve the sustainability of agriculture on rangelands with harsh, challenging conditions. In the Chihuahuan Desert, preliminary evidence suggests that heritage Raramuri Criollo exploit a greater variety of range resources than do conventional cattle. Accordingly, the use of Raramuri Criollo may help sustain vegetation and soils, as well as agricultural production. To explore these possibilities, we used Global Positioning System collars to track Angus × Hereford and Raramuri Criollo cows in a 1 535-ha pasture in southern New Mexico in June–December 2008. As predicted on the basis of past research, home range sizes of Raramuri Criollo exceeded those of Angus × Hereford during seasons with low forage availability—by 31.4 ± 6.5 ha during Pregreenup and 17.2 ± 6.5 ha during Drydown—but sizes converged during more productive seasons (Greenup 1, Greenup 2). Angus × Hereford allotted more daily time to resting, with the difference most pronounced during Drydown (71.1 ± 21.1 min day^{? 1}). Angus × Hereford had twice as many hotspots of use (locations with multiple visits of long duration), with seasonal timing and location corresponding with distribution patterns known to impact desirable natural resources. Raramuri Criollo more strongly preferred the Bare/Forbs ecological state with seasonal timing that possibly signals an ability to use nutritious forbs on open ground despite summer heat. Results are consistent with conjectures that compared with conventional cattle, Raramuri Criollo have greater daily mobility and wider spatial distribution during dry seasons. Although not directly measured, results also suggest that the heritage breed has superior heat tolerance and lower impact on desirable natural resources. These findings provide evidence that Raramuri Criollo can support sustainable livestock production in the Chihuahuan Desert, but direct measurements of profitability and environmental effects are needed before adoption can be recommended widely.     

A combined coalescence gene‐dropping tool for evaluating genomic selection in complex scenarios (ms2gs)

We present ms2gs, a combined coalescence – gene dropping (i.e. backward–forward) simulator for complex traits. It therefore aims at combining the advantages of both approaches. It is primarily conceived for very short term, recent scenarios such as those that are of interest in animal and plant breeding. It is very flexible in terms of defining QTL architecture and SNP ascertainment bias, and it allows for easy modelling of alternative markers such as RADs. It can use real sequence or chip data or generate molecular polymorphisms via the coalescence. It can generate QTL conditional on extant molecular information, such as low‐density genotyping. It models (simplistically) sequence, imputation or genotyping errors. It requires as input both genotypic data in plink or ms formats, and a pedigree that is used to perform the gene dropping. By default, it compares accuracy for BLUP, SNP ascertained data, sequence, and causal SNPs. It employs VanRaden's linear (GBLUP) and nonlinear method for incorporating molecular information. To illustrate the program, we present a small application in a half‐sib population and a multiparental (MAGIC) cross. The program, manual and examples are available at https://github.com/mperezenciso/ms2gs .     

A segmentation clock with two-segment periodicity in insects

Vertebrate segmentation relies on a mechanism characterized by oscillating gene expression. Whether this mechanism is used by other segmented animals has been controversial. Rigorous proof of cyclic expression during arthropod segmentation has been lacking. We find that the segmentation gene odd-skipped (Tc-odd) oscillates with a two-segment periodicity in the beetle Tribolium castaneum. By bisecting embryos and culturing the two halves over different time intervals, we demonstrate that Tc-odd cycles with a period of about 95 minutes at 30°C. Using live imaging and cell tracking in green fluorescent protein-expressing embryos, we can exclude that cell movements explain this dynamic expression. Our results show that molecular oscillators represent a common feature of segmentation in divergent animals and help reconcile the contrasting paradigms of insect and vertebrate segmentation.     

Optimizing phenotypic and genotypic selection for Fusarium head blight resistance in wheat

Fusarium head blight (FHB), or head scab, is an economically important disease of wheat (Triticum aestivum L.). In developing FHB-resistant soft winter wheat cultivars, breeders have relied on phenotypic selection, marker assisted selection (MAS), or a combination of the two. The objectives of this study were to estimate heritability of resistance in a resistant × susceptible cross and to simulate selection in order to determine the optimal combination of phenotypic and genotypic selection. F₂ derived lines from the cross of KY93C-1238-17-2 (high yielding, susceptible) × VA01W-476 (resistant line with two exotic quantitative trait loci (QTL) and additional resistance) were grown under artificial inoculation in scab nurseries at Lexington (2007 and 2008) and Princeton (2008), KY. Visual symptoms were estimated on a 1–3 scale; percentage Fusarium damaged kernels (FDK), and deoxynivalenol (DON) concentration were measured. VA01W-476 contributed resistance alleles at two major QTL: Fhb1 and a QTL on chromosome 2DL, QFhs.nau-2DL. In this genetic background, the effect of QFhs.nau-2DL was more pronounced than that of Fhb1: 55 vs. 25% DON reduction and 40 vs. 32% FDK reduction. Genotypic selection based on both QTL was equivalent to phenotypic selection of the most resistant 28% of the population for DON and the most resistant 24% of the population for FDK. We propose that an initial round of phenotypic selection at moderate selection intensity will enrich the population with major QTL resistance alleles while maintaining variation at minor scab resistance loci and for other traits in general. Genotyping can then be used to extract lines whose phenotypic worth has been demonstrated and which are homozygous for resistance alleles at the major QTL.     

Genetic basis of semen traits and their relationship with growth rate in rabbits

This work aims to estimate the genetic parameters of seminal and production traits in a paternal line of rabbits selected for ADG during the fattening period. The considered traits were male libido (Lib) defined as successful mounting of an artificial vagina; presence of urine (Ur) and calcium carbonate deposits (Ca) in the ejaculate; semen pH; individual sperm motility (IM); the suitability for AI of the ejaculate (Sui), which involves the subjective combination of several quality traits; the average ejaculate volume (Vol); sperm concentration (Conc); and the average sperm production per ejaculate (Prod = Vol × Conc). The genetic relationship between all of these traits with ADG is also provided. Male libido and seminal data came either from routine evaluations of the ejaculates in an AI center or from 2 experiments in which bucks from the same population were used. Two consecutive ejaculates per male and per week were collected, leaving 7 d within weekly collections. A linear tri-trait model was used to analyze Conc, Vol, and ADG, whereas linear and threshold-linear 2-trait models were used to analyze male libido and the remaining seminal traits with ADG. A Bayesian approach was adopted for inference. Approximately 38% of ejaculates were rejected for AI primarily due to low IM scores. Variables related to the quality of the ejaculate (Ur, Ca, pH, IM, Sui) and Lib were found to be lowly heritable (h(2) ranged from 0.04 to 0.11), but repeatable. This indicates performance of bucks for seminal quality traits and libido in AI centers would be more strongly affected by management practices rather than genetic selection. Semen production traits exhibited moderate values of h(2) (0.22, 0.27, and 0.23 for Conc, Vol, and Prod, respectively), suggesting the possibility of effective selection for these traits. A moderate to high negative genetic correlation (r(g); posterior mean; highest posterior density at 95%, HPD(95%)) was estimated between Conc and Vol (-0.53, HPD(95%) = -0.76, -0.27). The ADG was estimated to have an h(2) of 0.16, to have a low, positive r(g) with Conc (0.21, HPD(95%) = -0.03, 0.48), to have a low, negative r(g) with Vol (-0.19, HPD(95%) = -0.47, 0.08), and to be genetically uncorrelated with all remaining traits analyzed. Therefore, selection for increasing ADG in paternal lines is expected to have no detrimental effects on Ur, Ca, pH, IM, Sui, and Lib and little to no effect on Conc, Vol, and Prod.     

Effects of ignoring inbreeding in model-based accuracy for BLUP and SSGBLUP

Model-based accuracy, defined as the theoretical correlation between true and estimated breeding value, can be obtained for each individual as a function of its prediction error variance (PEV) and inbreeding coefficient F, in BLUP, GBLUP and SSGBLUP genetic evaluations. However, for computational convenience, inbreeding is often ignored in two places. First, in the computation of reliability = 1-PEV/(1 + F). Second, in the set-up, using Henderson's rules, of the inverse of the pedigree-based relationship matrix A . Both approximations have an effect in the computation of model-based accuracy and result in wrong values. In this work, first we present a reminder of the theory and extend it to SSGBLUP. Second, we quantify the error of ignoring inbreeding with real data in three scenarios: BLUP evaluation and SSGBLUP in Uruguayan dairy cattle, and BLUP evaluations in a line of rabbit closed for >40 generations with steady increase of inbreeding up to an average of 0.30. We show that ignoring inbreeding in the set-up of the A- inverse is equivalent to assume that non-inbred animals are actually inbred. This results in an increase of apparent PEV that is negligible for dairy cattle but considerable for rabbit. Ignoring inbreeding in reliability = 1-PEV/(1 + F) leads to underestimation of reliability for BLUP evaluations, and this underestimation is very large for rabbit. For SSGBLUP in dairy cattle, it leads to both underestimation and overestimation of reliability, both for genotyped and non-genotyped animals. We strongly recommend to include inbreeding both in the set-up of A- inverse and in the computation of reliability from PEVs.     

Quantitative ultrasound elastography and biometry of the bitch uterus in the early puerperium after vaginal delivery and caesarean section

Elastography is an actual imaging method used to qualitatively and quantitatively evaluate the elastic properties of tissues. The aim of this study was to evaluate and compare uterine tissue biometry and stiffness during post-partum period in brachycephalic bitches (n = 12) after c-section (GCS; n = 8) or normal delivery (GNB; n = 4). These animals were evaluated daily by abdominal ultrasound from the day of delivery until the 10th day post-partum; measuring uterine diameter, myometrial and endometrial thickness (mm) and shear wave velocity (SWV; m/s), by B-mode and ARFI (acoustic radiation force impulse) elastography, respectively. Uterine diameter was higher (p = .012) in animals submitted to c-section (15.26 ± 4.73 mm) than in normal birth (12.53 ± 2.64 mm) during the first 7 days post-partum. Uterine thickness gradually involuted in both groups (p < .0001), the myometrium during the first 9 days (p = .005) and the endometrium during the first 6 days (p = .003). The myometrial and endometrial SWVs were similar between types of delivery (p = .7846 and .8273) and presented a gradual increase (p = .411; .0043, respectively), during the first 10 days post-partum. It was concluded that bitches with normal delivery had smaller uterine thickness and faster puerperal involution than submitted to c-section, while uterine tissue stiffness was similar between delivery types and increased gradually during post-partum.     

Comparison between the 2013–2014 and 2009–2012 annual porcine reproductive and respiratory syndrome virus epidemics in a cohort of sow herds in the United States

The purpose of this study was to describe the 2013/2014 porcine reproductive and respiratory syndrome virus (PRRSV) epidemic in the United States and compare it with the previous 4 y of data from 2009 to 2012. A total of 371 herds participated in the study, representing nearly 1.2 million sows in 15 States. There were significantly fewer PRRSV cases during this study period and the onset of the annual epidemic was delayed approximately 3 wk. Cluster analysis revealed a pattern similar to previous years. The roles of spurious observations, increased awareness of PRRSV epidemics, and porcine epidemic diarrhea virus detection in the United States swine herd are considered.     

Effect of menadione sodium bisulfite,an inducer of plant defenses,on the dynamic of banana phytoalexin accumulation during pathogenesis

Using an authentic sample of 2-hydroxy-9-(p-hydroxyphenyl)-phenalen-1-one, a banana phenalenone-type phytoalexin, we studied its dynamic of accumulation during pathogenesis of banana plants (Musa acuminata (AAA), Grand Nain) inoculated with Fusarium oxysporum f.sp. cubense (FOC), Race 4, the causal agent of Panama disease. The results obtained demonstrate that banana plants treated prior inoculation with menadione sodium bisulfite (MSB), an inducer of plant defenses, are capable of changing the dynamic of accumulation (higher amount and speed of biosynthesis) of this banana phytoalexin, biosynthesized by the banana plant during pathogenesis.