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Gastrointestinal nematodes (GIN) negatively affect the performance and well-being of sheep. Due to anthelmintic resistance, GIN are difficult to control leading producers to choose breeds that can exhibit resistance to parasitism. An example is Katahdin sheep. Katahdins are raised in various climates and management systems in the United States. These environmental factors can be combined to form eco-management groupings or clusters. We hypothesized that GIN challenge varies predictably based on the characteristics of these environmental clusters. Forty Katahdin producers from across the United States were surveyed for management information, with body weights (BW), fecal egg counts (FEC), and FAMACHA scores (FAM) available from 17 of the 40 flocks. The performance data included 3,426 lambs evaluated around 90 d of age. Management and climate data were combined into clusters using multiple correspondence and principal component (PC) analysis. Performance data were aligned with their corresponding cluster. Depending on the trait, eco-management cluster, birth-rearing type, sex, and, as a covariate, dam age, were fitted as systematic effects with ANOVA. Clusters also were formed based on climate or management data alone. When compared with fitting the eco-management clusters, they defined less variation in each of the traits based on Akaike and Bayesian information criterion, and adjusted r2 values. To further examine variation defined by eco-management clusters, residuals from an ANOVA model excluding eco-management cluster were retained, and their correlation with PC loadings calculated. All PC loadings were included as potential independent variables and tested for significance using backward stepwise regression. The PC loadings with a correlation |≥0.49| explained significant variation in each trait and were included in the final models chosen; adjusted r2 values for BW, FEC, and FAM were 0.90, 0.81, and 0.97, respectively. When analyzing GIN challenge, eco-management clusters corresponding with hotter temperatures and greater rainfall, and with pasture-born lambs, suffered greater parasitism. Conversely, the eco-management clusters with lambs turned out to pasture at older ages benefited from reduced parasitism. Through the formation of eco-management clusters, an environmental variable can be defined to study interactions of genotypes to their environment, providing a potentially useful tool for identifying parasite-resistant sheep.

Genetic selection of sheep for resistance to gastrointestinal nematodes (GIN) has become a priority for pasture-based production of lambs to minimize the need for deworming. The first objective of this experiment was to determine the impact of sire weaning or post-weaning fecal egg count (FEC) estimated breeding value (EBV; WFEC and PFEC, respectively) from the National Sheep Improvement Program (NSIP) on GIN infection in Katahdin lambs born in fall (Oct – Nov; n = 459) or winter (Jan – Feb; n = 378) of 2018 through 2021 at the USDA Agricultural Research Service (ARS). FAMACHA scores were determined, and blood samples and feces were collected from the lambs to determine packed cell volume (PCV), and FEC at 60, 90, 120, and 150 days of age, and lambs were selectively dewormed if anemic. Data were analyzed using mixed models. The offspring FEC was positively (P < 0.001) and the PCV negatively (P < 0.001) related to the sire WFEC and PFEC. This implies that offspring parasitism would be less and survival greater from highly resistant sires. A second objective was to examine effects on sale prices of breeding-quality ram lambs from four farms, including ARS, of lamb EBV for WFEC and ewe productivity trait (EPT) designed to identify ewes with superior maternal ability. Sale price effects were dominated by sale type with a premium of $1,086/animal relative to direct sales from the farm for animals in NSIP or specialty sales. EPT EBV was impactful yielding a-SD increase of 2.3 units or an extra $39/animal. WFEC had no effect on sale value. Thus, while more parasite-resistant sires produced offspring with decreased FEC, the sale value of these ram lambs appeared to have been more strongly associated with EPT, or with a desire to obtain ram lambs with balanced EBV rather than elite EBV for parasite resistance.

An experiment was conducted to determine the effects of feeding highly condensed tannin legume (sericea lespedeza, SL; Lespedeza cuneata) forage on gastrointestinal tract microbial counts and meat quality in goats. Intact male Spanish kids were kept in 0.40 ha paddocks of SL, bermudagrass (BG; Cynodon dactylon; control), or a combination of SL + BG (n = 10 goats per treatment group) for 8 wk. All goats were supplemented with a commercial feed pellet at 0.45 kg·head−1·d−1 for the first 4 wk and 0.23 kg·head−1·d−1 for the final 4 wk of the trial. At the end of the experiment, half the goats from each paddock were subjected to 3 h transportation stress, then all animals were humanely slaughtered. Diet or stress did not have a significant effect on skin Escherichia coli, coliform, or aerobic plate counts, and carcass, rumen, and fecal bacterial counts. Muscle pH at 24 h postmortem tended (P = 0.06) to be higher in transported compared with non-transported goats. The results indicate that SL consumption by goats for 8 wk did not significantly affect gastrointestinal tract, skin, and carcass microbial counts or meat quality, although preslaughter stress could influence meat quality due to changes in the course of postmortem pH decline.

Gastrointestinal nematode (GIN) infections affecting ruminants pose serious problems whenever management systems are deficient with inappropriate nutrition and sanitation. The Lebanese Baladi goat, reared under very challenging transhumant conditions, is recently being challenged with nutrient availability due to the recent economic crisis. Therefore, prevalence of helminth parasites was studied in 90 Baladi does raised under three different management systems (Man) of intensive/managed (M), extensive/pastoral (P) or semi-intensive/agro-pastoral (AP). A 5-point score assessment of fat and muscle covering using Body Condition Score (BCS), anemic state revealed by conjunctivae mucosal color using FAMACHA, nostril discharge, stool character and bottle jaw edema were recorded twice for each system at two predetermined summer periods of heat stress (HS) with THI of 20 and 24 respectively, and fecal samples collected. Fecal nematode eggs (FEC) and protozoan oocyst count (FOC) were analyzed using a modified McMaster method. Results showed that BCS were not altered (P > 0.05) between heat stress periods, but decreased in M. FAMACHA did not differ (P > 0.05) between M, P and AP. All fecal samples tested showed strongyles nematodes, while 98% showed Eimeria spp. with occasional occurrence of Scrjabinema and Moniezia. Parasitic burden of GIN was low at 17%, while Eimeria was high at 98 %. Further, there was a significant (P < 0.001) Man x HS for HOTC, with 5-fold (P < 0.05) greater in AP but not M or P in late summer, indicating a contaminated and overgrazed agro-pastoral land. Though summer heat stress effect was not obvious on endoparasite prevalence in Lebanese Baladi goats, the confounding effects of resilience to GIN, nutritional and heat stress in these locally resilient goats require further investigation. This study reports, for the first time in Lebanon, the prevalence of GIN using the McMaster method and 5-point score in Local Baladi goats, and therefore these methods require further validation for on-farm use.

Gastrointestinal nematodes (GIN) pose a severe threat to sheep production worldwide. Anthelmintic drug resistance coupled with growing concern regarding potential environmental effects of drug use have demonstrated the necessity of implementing other methods of GIN control. The aim of this study was to test for genetic variants associated with resistance or susceptibility to GIN in Katahdin sheep to improve the current understanding of the genetic mechanisms responsible for host response to GIN. Linear regression and case-control genome-wide association studies were conducted with high-density genotype data and cube-root transformed weaning fecal egg counts (tFEC) of 583 Katahdin sheep. The case-control GWAS identified two significant SNPs (

It is increasingly difficult to manage and control gastrointestinal nematode parasites in pasture-based ruminant livestock operations because of the high prevalence of anthelmintic resistance. Anthelmintics should be combined with alternative forms of control. Sustainable tools include copper oxide wire particles and condensed tannin-rich plants, which target primarily Haemonchus contortus in small ruminants. Nematophagous fungi reduce larvae on pasture and target nematode larvae in feces of most livestock species. In addition, and perhaps most importantly, genetic selection focuses on parasite resistance. Producers should use as many tools as possible to minimize the need for pharmaceutical interventions and optimize animal production.

Anti-Mullerian hormone (AMH) is an endocrine marker for fertility in many species. This study investigated possible correlations between serum AMH concentrations, mean number of lambs born (out-of-season in spring or fall), and estimated breeding values (EBVs) for number of lambs born (NLB), number of lambs weaned (NLW), maternal weaning weight (MWWT), weaning weight (WWT), and maternal index (determined by Sheep Genetics Australia). Blood was collected at breeding from Katahdin ewes between 0.7 and 7 years of age in 2015 (n = 163) for the analysis of serum concentrations of AMH. Anti-Mullerian hormone concentration was either expressed quantitatively or divided into quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest, pg/ml). Data were analyzed by PROC CORR, GLM or chi-squared using SAS. Mean serum AMH was 182 ± 11 pg/ml and ranged from 0 to 1112 pg/ml. There was no correlation between serum AMH and EBVs for NLB, NLW, MWWT, WWT and the maternal index. Serum AMH concentration was similar in ewes in different age categories (P = 0.157). There was a correlation between EBV for NLB (0.29; P = 0.0002) and NLW (0.19; P = 0.013) with average number of lambs born. Ewes in the lowest AMH quartile (Q1) had a lower mean number of offspring born from spring breeding compared with ewes in other AMH quartiles (Q2, Q3, and Q4; P < 0.05). Further study is needed to determine the effectiveness of using serum AMH for selecting ewes for out-of-season (spring) breeding.

Temperate grass and legume yield and quality are markedly reduced during hot, dry summer months in the southern USA; therefore, browse species could add feed options for small ruminants during this season. Our objective was to compare total biomass yield and forage nutritive value of two browse species, leguminous bristly locust (Robinia hispida) and smooth sumac (Rhus glabra), as well as a leguminous shrub known as sericea lespedeza (Lespedeza cuneate), during summer months (June, July, August and September). Plants were sampled monthly during growing-seasons in 2012 and 2013 to determine biomass yield (foliar, shoot, and total above ground) and foliar nutritive value [crude protein (CP), acid detergent fiber (ADF), acid detergent lignin (ADL), and condensed tannins (CT)]. There was a species × harvest time interaction for foliar biomass yield (P = 0.0125). This interaction was likely due to low yield in June for bristly locust compared with sericea lespedeza and smooth sumac, but in all other months (July, August, and September) yields were similar for each species. Bristly locust had the highest CP (16.9%), followed by sericea lespedeza (14.8%), and smooth sumac (12.3%). Acid detergent fiber and ADL were similar between bristly locust (ADF 38.5%; ADL 24.1%) and sericea lespedeza (ADF 38.4%; ADL 23.1%), but was lower for smooth sumac (ADF 22.1%, ADL 6.3%; P Schedonorus arundinaceus) and bermudagrass (Cyanodon dactylon)] in this region and may provide high-yielding, low input, anti-parasitic fodder for small ruminants during this period in the Southeastern U.S.

Wild bees are important pollinators and monitoring their abundance and diversity is necessary to develop conservation protocols. It is imperative to understand differences in sampling efficiency among different trap types to help guide monitoring efforts. This study used a new vane trap design to collect bees in a livestock pasture ecosystem and examined the impact of six different vane colors on wild bee sampling. We recorded 2230 bees comprising 49 species and five families. The most abundant species were Augochlorella aurata (25.8%), Lasioglossum disparile (18.3%), Lasioglossum imitatum (10.85%), Agapostemon texanus (10.8%), Melissodes vernoniae (9.9%) and Halictus ligatus (4.7%). Traps with bright blue vanes captured the greatest number and diversity of bees as compared to traps with bright yellow, dark blue, dark yellow, and purple vanes. Red vanes had the lowest captures rates of individuals and species. Different colors were associated with different bee species arrays and only nine species were found in all vane color types. Vanes with higher light reflectance properties (within 400–600 nm range) attracted the greatest number of bees. These results show that different light wavelengths and reflectivity of vane traps influence bee capture rates, and such findings can help optimize bee sampling methods in different ecosystems.

The objective was to examine GIN infection and BW of lambs born in fall (Oct–Nov; n = 20–158/yr; n = 716 total) or winter (Jan–Feb; n = 65–208/yr; n = 1717 total). Katahdin lambs born between 2008 and 2020 were weaned between 90–120 d of age and supplemented with a 15% CP grain mix when forage quality was low. Dams were supplemented up to 30 d before to 60 d post-lambing. BW and FAMACHA scores were determined at approximately 60, 90, 120, and 150 d of age; FEC and PCV were determined at approximately 90, 120, and 150 d of age. Lambs were dewormed if FAMACHA score was > 3. Data were analyzed using mixed models with a repeated statement for day of sample collection, and age within season-yr used as a covariate. Season × yr × day influenced all traits (P < 0.001); litter number, sex, age of dam influenced BW (P < 0.001). FEC were higher in fall than winter born lambs only on d 90, and similar on d 120 and 150 (P < 0.001). PCV was lower in winter than fall born lambs on d 120 and 150 (P < 0.001), and FAMACHA lower on all days measured in fall than winter lambs (P < 0.001) making the winter born more susceptible to anemia with a greater need for deworming. Haemonchus contortus was the predominant GIN on most days of culture for both seasons. Fall compared with winter lambs were lighter in BW at all time points (P < 0.001) possibly due to poor forage quality available to dams. Rainfall data will be presented. GIN control was more manageable in fall than winter born lambs, but they weighed less.

Multi-species grazing, alternate grazing of cattle with sheep or goats, offers benefits to gastrointestinal nematode (GIN) control as GIN species differ between hosts. In the Southeastern United States, common GIN species of cattle include Cooperia spp., Ostertagia ostertagi, Haemonchus spp., whereas species of sheep and goats are Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus spp., Cooperia curticei, and Oesophagostomum spp. Anthelmintic resistance is widely prevalent in small ruminants, and is an increasing problem in cattle, but remains less prevalent. Thus, it is recommended to farmers to use a multi-faceted approach of GIN control, including multi-species grazing. Because management differs between cattle and small ruminants in regard to copper tolerance in minerals, predator control and fencing, alternate grazing of species has most commonly been used. Other considerations include age or susceptibility to GIN, as young calves may be vulnerable to GIN, but mature cows often have negligible GIN infection. Similarly, weanling lambs and kids are susceptible, and depending on breed, adults range from highly resistant to susceptible. Research indicates that GIN burden of more resistant animals is less influenced by multi-species grazing, and highly susceptible animals will likely need additional measures of control. The more resistant species used in the multi-species grazing may lend more control to the more susceptible. Some research showed reductions in O. ostertagi, but not C. oncophora in cattle during extended grazing of cattle and sheep, and reductions of H. contortus and T. colubriformis in sheep. However, other research reported similar worm burdens. Weight gains were improved in lambs grazed alternately with cattle in some studies, and most studies showed little benefit to cattle. Little has been published on alternate grazing with cattle and goats. The complex interactions, larger plot sizes needed, and time required to complete experiments limits published studies of this important management scheme.

Simple Summary Pollination is important for fertilization, setting fruits, seed development and the continuation of the life cycle of plants that eventually provide food for humans, livestock and wildlife. Agronomic practices, use of pesticides, lack of diverse flowering plant species, introduction of invasive plants, loss of habitat, climate change and disease have all led to the decline of important pollinator species. Decline of insect pollinators has increased the importance of accurately monitoring pollinator diversity and abundance over time. Sampling techniques using different color traps are used to sample bees and other insects, but their utility and effectiveness in different ecosystems still need to be determined. In this study, we examined four different colors of pan traps (blue, green, yellow, and purple) for their utility in sampling bees in a livestock pasture ecosystem consisting of native forage species. We analyzed the relative abundance, richness, similarity, and community assemblage patterns associated with aforementioned colors. We found that the blue color traps were the most attractive to bees and were effective for sampling bees in a livestock pasture ecosystem. Purple color traps were the second most effective, followed by yellow and green color traps. Abstract The decline in insect pollinators has increased the importance of accurately monitoring pollinator diversity and abundance over time. Sampling techniques include the use of passive insect traps such as pan traps, yet there is still discussion over their utility and effectiveness in different ecosystems. The objective was to examine four different colors of pan traps (blue, green, yellow, and purple) for their utility in sampling bees in native forages rotationally grazed by sheep and to compare the relative abundance, richness, similarity, and community assemblage patterns among the four trap colors. Most bees were from the Halictidae family (89%). The most abundant species were Lasioglossum imitatum (42.2%), Augochlorella aurata (8.3%), L. subviridatum (6.8), Agapostemon texanus (6.4), and L. birkmani (4.1%). Blue color traps exhibited the highest rates of bee capture and species accumulation. Purple and yellow colored traps were moderately effective in capturing bees, while the green color pan traps were least effective. Similarly, observed and extrapolated species richness was highest in blue trap, followed by purple, yellow, and green. Notably, the blue trap captured the highest number of unique species, followed by purple, yellow and green traps. Considering the total number of insects collected (including bees and other insects), yellow and green traps captured a significantly higher number of insects than other colored traps. The light reflectance from blue, purple, green and yellow pan traps had peaks at ~450, 400, 550, and 600 nm, respectively. Since different insects respond to different light intensities, wavelengths, and reflectivity, these results could be used to guide future trapping protocols targeting certain insect groups in livestock pasture and similar ecosystems.

Little is known about U.S. organic production of ruminant livestock. Objective was to examine growth, gastrointestinal nematode (GIN) infection, and eligibility of organic certification between conventional (CON) and organic (ORG) management (Mgt) up to 150 d of age. Katahdin lambs (ORG, n = 240; CON, n = 690) were born in fall (Oct–Dec) or winter (Jan–Mar) between 2014 and 2019 in Booneville, AR. Intact male and female lambs were fence line weaned ~90 d of age, grazed tall fescue and/or mixed forages and were supplemented (corn/soybean meal) when forage quality became limiting. Organic sheep and pastures were certified by NICS. Body weight was determined at birth and approximately 60, 90, 120, and 150 d of age. Blood and feces were collected for packed cell volume (PCV) and fecal egg counts (FEC) at 90, 105, 120, 135, and 150 d of age. Lambs were selectively dewormed based on Five Point Check and incidence recorded. Data were analyzed by Proc GLM or Mixed with repeated measures (SAS) and included Mgt, sex, season, yr, d of measurement and interactions; age of lamb was included as covariate if needed. Birth weight was usually greater in fall born ORG and less in winter born than CON (mgt x season x yr, P < 0.001), and varied between ORG and CON over time (mgt x season x yr x d, P < 0.001). A similar 4-way interaction occurred for FEC and PCV (P < 0.001). Incidence of deworming was similar between ORG and CON (ranged between 0 and 3 times/lamb, and 3.2% to 151% over season and yr). Because copper oxide wire particles were used for most ORG deworming, between 50 and 92% of lambs were eligible for organic certification by 150 d of age (mgt x season x yr, P = 0.03). Comparisons between farming systems are complex and should consider factors such as varietal and seasonal changes in forages.

Demand for forage finished meats continues to increase and creates a market for small farmers in the southeastern United States. Little is known about production efficiency and quality. The objective was to examine breed type and dam age on growth and finishing traits of forage finished steers. Calves were born in February and March in 2014 (n = 47), 2015 (n = 59) and 2016 (n = 42), castrated at birth and weaned in October. Breeds were Angus with Brahman or Romosinuano influence (1/4 to 1/8). Dams were 2 to 13 yr of age at calving. After weaning, steers grazed tall fescue (fall, winter, spring), wheat/rye (spring), or bermudagrass (summer). BW and ultrasound measures were determined every 30–60 d to finishing target of 8.4 mm back fat. Data were analyzed using homogeneity of regression (BW or REA over day of age) or Proc mixed and included age of dam, breed type, and yr in the model, and age as a covariate. After weaning, BW and REA of steers from younger dams were lighter or smaller and nearly caught up with steers from 3- and 4-yr old dams within 12 mo (dam age x day of age, P < 0.001). ADG (weaning to 12 m later) during 2014, 2015, and 2016 were 0.571, 0.602, and 0.860 kg/d, respectively, and were 0.941, 1.192, and 0.860 kg/d, respectively, during spring months. There was no effect of breed or dam age on ADG in 2014 and 2015, and subtle effects of Romosinuano breed type in 2016. Breed affected number of days to reach target finishing only in 2015 (P = 0.005), but not in 2014 and 2016. In 2015 Brahman-influenced steers reached target earlier than others. Shear force of steaks was not influenced by breed or dam (2014, 4.86 ± 0.4 kg; 2015, 5.46 ± 1.2 kg). Cattle genetics appropriate for grass finishing should be considered and calves from 2-yr old dams may be less suitable for grass finishing systems.

Over the past two years of mating high (Hi) or low (Lo) fecal egg count (FEC) EBV Katahdin rams randomly mated to Katahdin ewes, reduced FEC in lambs has been the hallmark trait observable at weaning. Upon additional analysis, death loss in lambs also segregated with sire FEC EBV; whereas, HiFEC-sired lambs had a death loss of 29.9% in 2018 and 14.5% in 2019. Yet, LoFEC-sired lambs had a death loss of 10% in both years. Increased death loss in 2018 may have been due to an outbreak of Clostridium perfringens Type-A and as a result lambs in 2019 were vaccinated for Clostridium type A. Regardless, this had no impact on death loss in LoFEC-sired lambs. Therefore, it can be hypothesized that sire FEC EBV indirectly selects for enhanced, generalized immunity. To initially test this hypothesis, serum was collected from HiFEC- and LoFEC-sired lambs weekly, prior to and after typical clostridium toxoid vaccination and boostering. Lamb serum was pooled by week and within sire, where there were 4 sires per FEC EBV group. Serum was analyzed for total immunoglobulin-G (IgG) by using absorbance at 450nm as the metric. Data were analyzed by using the general linear model of SAS with fixed effects of sire EBV type and week. A comparison of means was conducted by using the LS means procedure with Bonferroni adjustment. Absorbance of serum from LoFEC-sired lambs was higher across all time points than that of serum from HiFEC-sired lambs (1.66 vs. 1.41 ± 0.04; P < 0.0001), meaning that LoFEC-sired lambs had higher circulating IgG than lambs sired by HiFEC rams. Taken together, these data provide preliminary evidence that indicate segregation of lamb generalized immunity by sire FEC EBV.

Agroforestry systems have the potential to provide year-long income opportunities via the integrated forage or crop, timber, and livestock. Legumes are an attractive alternative option during the growing season when more traditional forages may not be as productive. The objective of this study was to test the establishment of arrowleaf and white clover grown under varying pine tree alley widths. In 2011, existing forage was removed in 15-yr old loblolly pine tree row alleys of different widths (3.7, 4.9, 7.3, and 9.8 m), including an open area. Arrowleaf, as an annual, was replanted in 2012. Seedlings were counted twice/year, while dry matter was measured three times/year. Photosynthetically active radiation (PAR) was measured in all alley widths to compare light penetration through the canopy. Hot and dry conditions occurred throughout 2012, affecting results. In 2012 and 2013, the greatest PAR for most treatments was observed in June. Seedling counts for all treatments were greatest immediately after establishment, and gradually declined throughout the course of the study. Dry matter yields increased throughout the growing season, and were greatest in arrowleaf clover in the open area on all measurement dates; however, increased weed pressure and repeated flooding affected yields. This study demonstrated that clover establishment in shady wooded areas is possible, but only under suitable environmental conditions.

Objective was to examine the activity of cytochrome P450 (CYP), a liver enzyme that metabolizes ergot alkaloids which is hindered by this fescue toxin, as an indicator of fescue toxicosis in sheep. In spring and fall, ewes were blocked by age and BW, and randomly assigned to 1 kg/ewe/d of endophyte-infected (E+; 61% of diet in fall, 13% of diet in spring; 0.8 µg/g of ergovaline; and soy hulls, alfalfa pellets, cottonseed hulls, molasses) or non-infected (E-; same proportion of E+/season and same feeds) tall fescue seed supplement (n = 10/diet in each season) for 28 d, plus hay, mineral and water. Ewes were exposed to teaser, d -21 to 0, and intact rams, d 0 (first day of diet) to 30. Rectal temperature (RT), serum concentration of prolactin (using RIA), and CYP were determined every 7–14 d between d 0–28, and pregnancy status on d 56. PromegaTM P450-Glo assay was used to determine CYP from serum. Data were analyzed by using PROC MIXED with repeated measures (SAS). Rectal temperature of E+ compared with E- ewes was elevated on at least one day in fall and spring (diet × season × d, P < 0.001). Serum prolactin was lower in E+ compared with E- ewes (diet × d, P < 0.001) and lower in fall (P < 0.001). CYP was higher in E- ewes on d 28 in fall (diet × season × d, P = 0.008), but otherwise similar between diets, and higher in fall than spring (P < 0.001). There was an unexpected negative correlation between CYP and prolactin (R = -0.24; P < 0.009), but there appears to be a subpopulation of ewes with low prolactin and lower CYP. CYP activity in sera may not be a marker for fescue toxicosis in ewes.

Sericea lespedeza (SL; Lespedeza cuneata) is a widely-adapted warm season perennial legume that can be used for grazing, hay, or as a conservation plant. Planted extensively for erosion control in the Southeast in the 1930s and 1940s, SL was considered an inexpensive, but relatively low-quality feed for livestock due to high fiber (thick stems) and tannin content. Over the last 60 yr, an SL breeding program at Auburn University resulted in release of improved cultivars with lower fiber (1960s), less tannin (1970s), and improved grazing tolerance (1990s), although interest in SL as a forage crop remained relatively low. This has changed recently as research over the last 10–15 yr has demonstrated the excellent bioactivity of this plant against infection with gastrointestinal nematodes (Haemonchus contortus) and protozoan parasites (Eimeria spp.) in livestock. This bioactivity, which has been attributed to a unique type of condensed tannins, has been confirmed in fresh (grazed), dried (hay, meal, pellets), and preserved (ensiled) forms of SL in a number of studies with sheep, goats, and cattle. The tannins in SL have also been reported to prevent bloat, reduce ruminal methane production, and kill housefly larvae in manure, further contributing to the renewed interest in SL as a nutraceutical (nutritional + pharmaceutical) forage for livestock. Animal performance of SL for cattle was described as similar to bermudagrass (Cynodon dactylon) in a number of studies in the 1970s and 1980s, but more recent cattle performance data with SL are not available. A recent study with goats showed higher animal performance with no reduction in anti-parasitic bioactivity with well-fertilized SL compared with SL produced under normal (low-input) conditions. Future work on SL will focus on optimizing nutritional and bioactivity (nutraceutical) properties of this forage for different species of livestock.

Sericea lespedeza (Lespedeza cuneata [Dumont de Courset] G. Don.; SL) is a perennial, warm‐season legume containing condensed tannins (CT) that can play important roles in ruminant ecosystems. Our research objective was to determine season‐long average herbage CT fractions, crude protein (CP) and fiber concentrations under three harvest regimens for SL cv. AU Grazer at five locations within the southeastern USA during 2010. Harvest regimens were regrowth every 35 days (35‐day), previously uncut plots every 35 days (ACCUM), or regrowth when height reached 40 cm (40 cm). We found harvest regimen by location interactions (P ≤ 0.05) for all dependent variables. The ACCUM plants usually had greater (P ≤ 0.05) fiber concentrations where there were differences, except for the Louisiana location. The lowest (114 g kg⁻¹; P ≤ 0.05) CP concentrations were measured in ACCUM plants at the driest location (Texas) while the highest (181 g kg⁻¹ for North Carolina plants) came from the 35‐day regimen. Total CT (TCT) concentration varied (P ≤ 0.05) from a low of 61.1 g kg⁻¹ for ACCUM plants in Louisiana to 100.7 g kg⁻¹ for Texas plants harvested from 35‐day plots. In summary, harvest regimen influenced SL nutrient and CT concentrations. Fiber concentration was better correlated (−0.621 for acid detergent fiber; P ≤ 0.05) with TCT than CP (−0.014; P = 0.82). Sericea lespedeza regrowth harvested every 35 days had higher season‐long average TCT concentrations in two of five locations along with greater CP and less fiber concentrations in four of five locations compared to the ACCUM regimen.

The aim of this study was to estimate genetic parameters for BW in Katahdin lambs. Six animal models were used to study direct and maternal effects on birth weight (BWT), weaning weight (WWT), and postweaning weight (PWWT) using 41,066 BWT, 33,980 WWT, and 22,793 PWWT records collected over 17 yr in 100 flocks. Models included fixed effects of management group, dam age, type of birth (for BWT) or birth and rearing (for WWT and PWWT), and lamb age at weighing (fitted as a covariate for WWT and PWWT; all < 0.05). Variance components for random effects were estimated in sequentially more complex models and tested for significance with likelihood-ratio tests. A model that fitted only an additive animal effect overestimated additive variance for all BW, resulting in larger estimates of direct heritability than models that included maternal effects. Maternal effects explained variation ( < 0.05) in all BW. Heritability estimates for optimal models were 0.15 ± 0.01 for BWT, 0.18 ± 0.02 for WWT, and 0.20 ± 0.02 for PWWT. Estimates of maternal heritabilities were 0.14 for BWT, 0.10 for WWT, and 0.06 for PWWT, with SE = 0.01. Permanent environmental maternal effects explained 4 to 6% (±1%) of total phenotypic variances for these BW. Litter effects included temporary environmental effects common to littermates and a proportion of the dominance genetic variance and accounted for 16 to 19% (±1%) of phenotypic variance. Correlations between additive direct and maternal genetic effects were -0.14 for BWT, -0.23 for WWT, and -0.04 for PWWT but differed from 0 ( < 0.05) only for WWT. The total heritability predicted the total response in direct and maternal genetic effects from mass selection and was 0.23 for BWT, 0.20 for WWT, and 0.23 for PWWT. Direct and maternal additive, maternal permanent environmental, residual, and phenotypic correlations between BWT and WWT were 0.53 ± 0.05, 0.58 ± 0.06, 0.51 ± 0.06, 0.39 ± 0.01, and 0.44 ± 0.01, respectively; those between BWT and PWWT were 0.45 ± 0.06, 0.58 ± 0.08, 0.36 ± 0.08, 0.33 ± 0.01, and 0.37 ± 0.01 respectively; and those between WWT and PWWT were 0.85, 0.99, 0.92, 0.77, and 0.81, respectively, with SE ≤ 0.02. Therefore, both direct and maternal effects had an important impact on BW in Katahdin lambs. Models that included both additive and permanent environmental maternal effects as well as a temporary environmental litter effect should result in more accurate estimates of breeding values and better selection decisions.

The objective of this study was to evaluate the effect on the estimates of heritability and permanent environmental effects as a proportion of phenotypic variance for FAMACHA score, fecal worm egg count and hematocrit value when year-round records are used. Records from 1008 Dorper sheep in a private South African flock comprised 17,711 FAMACHA scores, 6837 fecal worm egg counts (FEC; practically only Haemonchus contortus ), and 4209 hematocrit (packed cell volume-PCV) values that were collected from 1997 to 2000. Animal models were used to conduct single-trait analyses. Data were analyzed in two sets: 1) warm season records only and 2) year-round records. Treatment (with anthelmintic) status was investigated as a 2-level fixed effect in both sets; additionally records of treated sheep were removed for another analysis of both data sets. In analyses of warm season records, estimates of heritability and permanent environmental variance as a proportion of phenotypic variance for FAMACHA score were 0.33 ± 0.03 and 0.04 ± 0.02, respectively, when treatment status was modeled, and 0.41 ± 0.02 and 0, respectively, when treated records were excluded from the analysis. Heritability estimates for PCV were 0.22 ± 0.06 (treatment status modeled) and 0.28 ± 0.07 (treated records excluded), while permanent environmental variance as a proportion of phenotypic variance was, respectively, 0.13 ± 0.05 and 0.09 ± 0.06. Fecal worm egg count heritability estimates were 0.10 ± 0.03 (treatment status modeled) and 0.13 ± 0.04 (untreated records only). Permanent environmental variance for FEC was 0.04 ± 0.03 when treated records were excluded and 0.05 ± 0.03 when treatment status was included in the analyses. In analyses of year-round records, estimates of heritability and permanent environmental variance as a proportion of phenotypic variance for FAMACHA score were 0.32 ± 0.03 and 0.03 ± 0.02, respectively (treatment status modeled) and 0.36 ± 0.03 and 0.02 ± 0.02 (treated records excluded). Packed cell volume heritability and permanent environmental variance were, respectively, 0.19 ± 0.05 and 0.18 ± 0.05 in the analyses of untreated records, and 0.18 ± 0.04 and 0.15 ± 0.04, when treatment status was modeled. Heritability estimates for FEC were the same (0.11) for untreated records only, and when treated records were included. Permanent environmental variance was 0.04 ± 0.02 (treated records included) and 0.03 ± 0.02 (treated records excluded) for FEC. Collection and inclusion of cool season (that is, outside of the regular worm proliferation season) records in analyses may not substantially change estimates of genetic parameters for these traits.

Resistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood. Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia. Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible sheep. A GWAS was conducted to identify possible genetic loci associated with resistance to Haemonchus contortus in Katahdin sheep. Forty animals were selected from the top and bottom 10% of estimated breeding values for FEC from a total pool of 641 sires and ram lambs. Samples were genotyped using Applied Biosystems (TM) Axiom (TM) Ovine Genotyping Array (50K) consisting of 51 572 SNPs. Following quality control, 46 268 SNPs were included in subsequent analyses. Analyses were conducted using a linear regression model in plink v1.90 and a single-locus mixed model in snp and variation suite. Genome-wide significance was determined by a Bonferroni correction for multiple testing. Using linear regression, loci on chromosomes 2, 3, 16, 23 and 24 were significantly associated at the genome level with FEC estimated breeding values, and we identified a region on chromosome 2 that was significant using both statistical analyses. We suggest a potential role for the gene DIS3L2 for gastrointestinal nematode resistance in Katahdin sheep, although further research is needed to validate these findings. Organic Agriculture Research and Extension Initiative grant from the USDA National Institute of Food and Agriculture [2016-51300-25723]; Hatch grant from the USDA National Institute of Food and Agriculture [IDA01566] The authors would like to thank the following for their involvement: Anna Rodriguez, Rebekka Job, Bonus Angus Farm, Birch Cove Farm, Destiny Acres, Downing Acres, Hound River Farm, Mammoth Hills Farm, USDA, ARS and Waldoview Farm. Thermo Fisher provided the genotyping for this research. This project was supported by Organic Agriculture Research and Extension Initiative grant no. 2016-51300-25723 and Hatch grant IDA01566 from the USDA National Institute of Food and Agriculture.

Gastrointestinal nematodes (GIN) and coccidia have a large financial and health impact on small ruminants. Recent years have seen an increase in anthelminthic/ coccidiostat resistance, and there is a need to develop alternative control methods. The objective of this study was to examine the effect of a unique proprietary compound used in the fragrance/flavor industry with an insect repellant application (Compound X; Bedoukian Research) on parasite control in sheep. Previous research by our laboratories showed a short term reduction in fecal egg count (FEC) in sheep orally drenched with the product. In the current study, naturally infected (GIN and coccidia) Katahdin lambs were orally drenched with 15 mL of Compound X and 15 mL mineral oil (CMX; n = 11) or 30 mL mineral oil (CON; n = 9) on d 0 and 21; FEC/fecal oocyst count (FOC) were determined every 7 d for 8 wk, and feces were cultured to examine GIN larvae. Data were analyzed using a mixed model with repeated measures over time, and regression (SAS). The FEC were reduced in CMX compared with CON between d 0 and 21 (P < 0.03, both mixed model and regression), d 21 and 42 (P < 0.001, mixed and regression), and d 0 and 56 (P < 0.001); FEC were influenced by day of study (P < 0.04), and the interaction tended to be significant using regression (P < 0.10). The FOC were negligible and not analyzed. There was no effect on development of nematode larvae in feces. However, there was a shift in population distribution from Haemonchus contortus to Trichostrongylus spp. which indicated a possible effect on female H. contortus fecundity. There was a sign of toxicity in one lamb following the second CMX drench. The value of using such a compound for GIN control may warrant further investigation.

Genetic parasite resistance in sheep has become an important technology in the control of gastrointestinal nematodes (GIN) due to widespread anthelmintic resistant GIN. The USDA-ARS sheep flock in Booneville, AR, has been selecting for parasite resistance since 2012 through the use of estimated breeding values (EBVs) generated through the National Sheep Improvement Program (NSIP). Objective is to show value of resistance. Recently, replacement ewes (n = 69) and rams (n = 29) from the flock were offered for sale and a sale catalog with EBVs for growth, reproduction, and parasite resistance, and recent BW was available. There were 73 purchased by 13 buyers from 7 states. Of the ram lambs that sold, post-weaning fecal egg count (FEC) EBVs ranged from -29 to -100, but of the 17 ram lambs offered, only rams with values of -97 or better sold (-100 is the highest FEC EBV and values can reach > +500; the top 10% for breed are P < 0.001). For mature ewes sold, FEC EBVs ranged from 18 to -87 with higher prices offered to ewes with better FEC EBVs (P < 0.002). For all sheep, higher prices may have been offered for animals raised as multiples rather than singles (P = 0.05). Seedstock producers wishing to improve parasite resistance can benefit by using NSIP to increase resistance and sale price. The higher parasite resistance used by commercial producers will reduce the need for deworming lambs.

In two experiments (Exp), naturally parasite-infected 5–8 mo-old intact male Spanish goats were used to determine fecal egg count (FEC) reduction effects of copper oxide wire particles (COWP; 1 g bolus Copasure®) and levamisole (12 mg/kg; LEV; Prohibit®) alone or in combination with COWP; for Exp 2, albendazole (20 mg/kg; ALB, Valbazen ®, Exp 2 only) alone or in combination with COWP and an untreated control group (CON; n = 11) was also included. Animals were individually housed in 1.5 x 1.5-m pens (Exp. 1) or as a group on pasture (Exp. 2). For the studies, goats were selectively dewormed based on a FAMACHA© eyelid color score of 3, 4 or 5, with n = 12 and 13 for COWP in Exp 1 and 2, respectively, n = 14/Exp for LEV, n = 12/Exp for COWP and levamisole (LC), and (Exp, 2), n = 10 for COWP and albendazole (AC) and n = 12 for ALB. Fecal samples were collected using a gloved finger technique on D 0 and 14 in Exp 1 and Day 0 and 10 for Exp 2 for determination of FEC using a modified McMaster’s technique with a 50 egg per gram sensitivity and calculation of FEC reduction (RED; ((Day 0 FEC-Day 14 FEC)/Day 0 FEC)*100). Data were analyzed with a general liner model procedure using SAS. Larval culture (Exp 1) indicated 99.8% Haemonchus contortus on Day 0. Mean RED was greater for LC than LEV and COWP (P < 0.04) for Exp 1 (Day 14). For Exp 2, mean RED was greater (P < 0.04) for AC than ALB and CON, but not COWP, and was greater (P < 0.03) for LC compared CON and COWP, but not LEV. In these two studies, COWP resulted in > 93% reduction in FEC and the addition of a deworming drug did not improve effectiveness consistently (only in Exp. 1).

Nematode-trapping fungi are biological control agents used against the larval stages of gastrointestinal nematodes in livestock feces. These fungi are normal soil inhabitants where they feed on a variety of non-parasitic soil nematodes. Of the various fungi tested, Duddingtonia flagrans spores (BioWorma, International Animal Health Products, Australia) have been shown to survive passage through the gastrointestinal tract of ruminants. After defecation, the spores germinate and grow in the feces to form sticky, sophisticated traps/loops which are able to trap the developing larval stages in the fecal environment. This form of control has been successfully applied under field conditions and is an environmentally safe biological approach for forage-based feeding systems. BioWorma has recently been approved for use in the United States. The primary delivery system is mixing BioWorma into supplement feedstuffs daily where each animal has the opportunity to consume an adequate amount of the mixture. To achieve optimum control of larvae during the transmission season (May–October), BioWorma needs to be fed for a period of no shorter than 60 days, starting at the beginning of the grazing season (especially young after weaning). Feeding BioWorma to dams during late pregnancy and lactation will also help to reduce pasture contamination, especially for growing young that will graze the same pasture. Another delivery system is mixing BioWorma into loose mineral supplement where animals will consume it free choice. The mineral needs to be kept covered and dry. The spores cannot be incorporated into pellets as the heat of the pelleting process will kill the spores. One drawback in using BioWorma is the relatively high cost. Research is being conducted to evaluate other delivery schemes that could be more cost effective. This product is the only control method that targets nematodes on pasture, where a majority of the total population reside.

The FAMACHA system was introduced to the U.S. just over 10 yr ago to allow selective deworming of lambs with anemia associated with and retard the development of anthelmintic resistance. The FAMACHA system was initially developed as a predictor of packed cell volume (PCV), but correlations between FAMACHA and fecal egg counts (FEC) have also been reported. It is important to understand factors that influence FAMACHA scores among farms to improve management of gastrointestinal nematodes. The objectives of this study were therefore to quantify associations between FAMACHA scores, FEC, BW, and age in Katahdin lambs at 2 different measurement times in 8 flocks in the eastern U.S., and to assess consistency of relationships between FAMACHA and FEC among flocks. Data came from 1,644 Katahdin lambs from 7 flocks sampled at approximately 90 d of age, and 1,295 lambs from 6 flocks sampled at approximately 120 d of age over a 5 yr period. Residual correlations among log-transformed FEC (LFEC), FAMACHA scores, BW, and lamb ages at each measurement time were determined. Repeatability of each variable was also determined as residual correlations among repeated measures. At both 90 and 120 d of age, correlations of FAMACHA scores with LFEC and BW were significant ( < 0.001), but numerically modest (0.25 and -0.16, respectively at 90 d; 0.31 and -0.16, respectively at 120 d), demonstrating that higher FAMACHA scores were associated with higher FEC and more likely to be observed in lighter lambs. A small negative correlation was observed between FAMACHA score and lamb age ( = -0.05, = 0.05, 90 d; = -0.11, < 0.001, 120 d) indicating that younger lambs were more likely to have elevated FAMACHA scores. Thus, younger and lighter lambs will likely be more susceptible to parasitism and may need to be managed more diligently than older or heavier lambs. In addition, FAMACHA scores have potential to improve breeding value estimates in programs designed to genetically improve parasite resistance.

Selection for low fecal egg counts (FEC) can be used to genetically enhance resistance to gastrointestinal nematode parasites in growing lambs, thereby reducing the frequency of use of anthelmintics, facilitating marketing of organic lamb, and reducing the risk of development of anthelmintic resistance by the parasite. Recording of FEC in lambs has, therefore, been incorporated into several national sheep genetic evaluation programs. Ewes in late gestation and early lactation are also vulnerable to parasite infection and commonly experience a periparturient rise in FEC. This study was designed to assess factors associated with the periparturient rise in FEC in Katahdin ewes and associated changes in FEC in their lambs. Data came from 1,487 lambings by 931 Katahdin ewes from 11 farms in the Eastern United States. Fecal egg counts were measured in ewes at approximately 0, 30, and 60 d postpartum and in their lambs at approximately 60, 90, and 120 d of age. Approximately 1,400 lambs were evaluated at each measurement age. Data were analyzed separately for ewes and lambs and also initially analyzed separately for each measurement time. Repeated-measures analyses were then used to evaluate responses across measurement times. In ewes, FEC peaked at approximately 28 d postpartum, and we concluded that informative periparturient FEC could be obtained from 1 wk before until approximately 5 wk after lambing. Yearling ewes had higher FEC than adult ewes ( < 0.01), and ewes that nursed twin or triplet lambs had higher FEC than ewes that nursed single lambs ( < 0.01). In lambs, FEC increased through approximately 120 d of age. Lambs from yearling ewes and lambs nursed in larger litters were, like their dams, at greater risk of parasitism ( < 0.05). Ewes and lambs in these groups would benefit from enhanced monitoring of parasite loads at lambing and in early lactation. Correlations () between FEC in lambs at 90 d of age and FEC in ewes at 0, 30, and 60 d postpartum of 0.05 to 0.09 ( ≤ 0.05) support the presence of a genetic relationship between these 2 indicators of parasite resistance.

Despite strong economic opportunities and incentives for small ruminant production, their health and productivity are often severely affected by parasitic disease. To combat these effects, most farms administer anthelmintics to their animals at frequent intervals, and without consideration to principles of sustainable integrated parasite management (SIPM). This has led to growing problems caused by the development of drug-resistant populations of gastrointestinal nematodes (GIN) in much of the world, particularly in Haemonchus contortus . The objectives of this research were to characterize levels of anthelmintic resistance on small ruminant farms located in the mid-Atlantic US and to compare the fecal egg count reduction test (FECRT) and larval development assay (LDA) for detecting resistance. To achieve these objectives, the DrenchRite ® LDA was used to evaluate resistance status to benzimidazoles, ivermectin, moxidectin, and levamisole on 20 goat and 14 sheep farms in the Mid-Atlantic US over a 2-year period. A FECRT was also conducted on 14 of the same farms and on 2 additional farms in which the LDA was not completed. For the LDA and coprocultures, fecal samples were collected rectally from a minimum of 10 individual animals, pooled, and express-mailed to the University of Georgia for analysis. For the FECRT, albendazole, ivermectin, moxidectin, and/or levamisole were tested on each farm. Animals were allocated randomly based on FAMACHA © scores to 2–5 treatment groups, which included an untreated control group. The number of treatment groups on a farm depended on the number of qualified animals present. Haemonchus contortus was the most common parasite recovered from fecal cultures; the mean level across all farms was 79%. Results of the LDA indicated resistance to benzimidazoles, ivermectin, moxidectin, and levamisole on 100%, 82%, 47%, and 24% of farms, respectively. Multi-drug resistance to all 3 drug classes was detected for H. contortus on 18% of farms (1 sheep and 5 goat farms). Of the 16 farms tested by FECRT, resistance to albendazole was present on 8/10 farms, to ivermectin on 4/4 farms, to moxidectin on 7/9 farms and to levamisole on 2/5 farms tested. Results obtained from the FECRT and the LDA (p = 0.51) were similar. The prevalence of resistance found in this study in the mid-Atlantic region of the US is very similar to that reported in an earlier survey of resistance performed in the Southern US, demonstrating that anthelmintic resistance in GIN is a serious problem on small ruminant farms throughout the Eastern US.

Prolonged feeding of sericea lespedeza (SL) previously led to reduced serum concentrations of Mo, a cofactor in an enzyme complex that may be involved in weight gain. The current objective was to determine the effect of Mo supplementation on changes in serum, fecal, urine, and liver concentrations of trace minerals in lambs fed SL leaf meal pellets. Thirty ram lambs weaned in May (84 ± 1.5 d of age and 27 ± 1.1 kg; D 0) were blocked by BW, breed type (full or three-fourths Katahdin), and EBV of parasite resistance and randomly assigned to be fed 900 g/d of an alfalfa-based supplement (CON; = 10) or a SL-based supplement ( = 20) for 103 d. Supplements were formulated to be isonitrogenous and isocaloric and to meet trace mineral requirements. Within the SL group, individual lambs were administered either 5 mL water or 5 mL of water with 163.3 mg of sodium molybdate (SLMO). Serum was collected on d 28, 56, and 104; a liver sample was collected by biopsy on d 104 to determine concentrations of trace minerals. Data were analyzed using a mixed model and orthogonal contrasts. Serum concentrations of Mo increased in response to the drench and were greatest in SLMO lambs and then CON lambs and lowest in SL lambs ( < 0.001). Concentrations of Mo in the liver ( < 0.001) were similar between CON and SLMO lambs and were lower in SL lambs than other groups. Serum ( < 0.001) and liver ( = 0.013) concentrations of zinc (Zn) were reduced in both SL and SLMO lambs compared with CON lambs. Serum concentrations of cobalt (Co) increased in CON lambs compared with SL and SLMO lambs between d 0 and 56 but were similar on d 104 (diet × day, < 0.005) as with concentrations in the liver. Serum and liver concentrations of copper (Cu) were greatest ( < 0.001 and < 0.001, respectively) in CON lambs followed by SL lambs and then SLMO lambs. Serum concentrations of selenium (Se) tended ( = 0.10) to be reduced in SL lambs compared with CON and SLMO lambs, but concentrations in the liver were reduced in SL lambs compared with CON lambs and even more so in SLMO lambs ( < 0.003). Although the dietary Mo did increase stores of Mo in the animal and reduced copper, trace minerals associated with metalloproteins-Mo, copper, selenium, and zinc-were reduced in the liver of SL- and/or SLMO-fed lambs. These reductions could be associated with the lower weight gains previously observed after prolonged feeding of SL.

The objective was to examine the effects of supplementary quebracho on control of coccidiosis and gastrointestinal nematodes in lambs and kids. In Exp. 1, naturally infected lambs weaned (87.8 ± 0.4 days of age; day 0) in January (winter) were blocked by sex and randomly assigned (n = 10/treatment) to receive supplement with or without 100 g/lamb of quebracho for 28 days. In Exp. 2, single or twin rearing ewes were randomly assigned into two groups, and naturally infected lambs were fed control (n = 28) or quebracho (100 g/lamb of quebracho tannins in feed; n = 27) between -28 and 21 days (weaning = day 0; 70.8 ± 0.1 days of age). In Exp. 3, weaned doe kids (57.6 ± 2.0 days of age) were randomly assigned to receive alfalfa (Medicago sativa) supplement with (n = 9) or without (n = 8) 50 g/kid quebracho or sericea lespedeza (Lespedeza cuneata) with quebracho (n = 8) for 21 days. Fecal oocyst count (FOC), nematode egg counts (FEC), fecal score, dag score (soiling around rear quarters), and blood packed cell volume (PCV) were determined every 7 days. Data were analyzed as repeated measures using mixed models. In Exp. 1, FOC decreased in quebracho-fed lambs (diet × time, P0.001) but FEC was similar between treatments during the feeding period (P = 0.19). Packed cell volume (P = 0.19) and fecal score (P = 0.42) were similar between groups. Quebracho-fed lambs had a greater dag score initially (diet × time, P = 0.02), but were similar by day 42 (P = 0.72). In Exp. 2, FOC remained low (P = 0.02), PCV tended to decrease (P = 0.06), but FEC increased on days 14 and 21 (diet × time; P0.001) in quebracho compared with control-fed lambs. Quebracho-fed lambs had lower fecal score (diet × time; P = 0.005) but higher dag score (diet × time; P0.001). In Exp. 3, FOC of kids fed quebracho (alfalfa or sericea lespedeza supplement) was lower than control (P0.001). Fecal score of kids fed sericea lespedeza compared with alfalfa were lower regardless of quebracho (P = 0.01). There were no differences among treatments for dag, FEC, PCV, or body weight (P0.10). Quebracho was effective in reducing FOC but not clinical signs of coccidiosis in both lambs and kids, and may not be highly digestible in lambs as it caused loose stools.

Due to high prevalence of anthelmintic resistance (AR), complementary approaches to anthelmintic use to control gastrointestinal nematodes (GIN) in sheep are necessary. Copper oxide wire particles (COWP) are effective against Haemonchus contortus but not other GIN, and FAMACHA aids to minimize further development of AR. The objective was to determine the efficacy of COWP alone or in combination with levamisole, albendazole, or a 3-way combination to control GIN known to have AR to these anthelmintics. Naturally infected Katahdin lambs were selectively dewormed based on FAMACHA© and/or packed cell volume (PCV). If FAMACHA© scores were 3, 4, or 5, lambs received 1 g COWP alone (n = 120), COWP and levamisole (n = 47) or albendazole (n = 6), or a 3-way combination (n = 10), respectively. Untreated lambs were included (CON; n = 31). Feces and blood were collected on days 0 (day of deworming) and 14 for determination of fecal egg counts (FEC) and FEC reduction (FECRED) and PCV. Data were analyzed using repeated measures in a mixed model. The mean FECRED was greater for the combination of levamisole and COWP than COWP alone (P < 0.001). In a mixed GIN population, COWP in combination with levamisole increased the efficacy of FECRED of H. contortus and other GIN genera present, offering greater GIN management in the presence of resistance to these anthelmintics.

Selection for reduced fecal egg count (FEC) is an important management tool to combat anthelmintic resistance in worm populations. To understand consequences of selection for parasite resistance, a divergent mating scheme was established whereby Katahdin rams with high (HiFEC; n = 4) or low fecal egg count (LoFEC; n = 4) estimated breeding values (EBV) were randomly mated to ewes at the Southwest Virginia AREC. Mid-March born lambs (n = 199) were managed as one group until approximately 120 days of age (Weaning: June 4). Beginning at 45 days of age, BW and FAMACHA scores were collected weekly. Deworming occurred as necessary (FAMACHA ≥ 3) and fecal egg counts were taken biweekly. Statistical analysis was performed using SAS with fixed effects of sire EBV type. Fecal egg count was significantly higher in HiFEC-sired lambs one week prior to weaning (665 vs. 427 eggs/g, P < 0.05) and again at three (3398 vs. 2175 eggs/g, P < 0.01) and five (3596 vs. 2209 eggs/g, P < 0.01) weeks post-weaning. These FEC differences corresponded to differences in lamb weaning and post-weaning FEC EBV (43% vs. -43%, P < 0.05 and 82% vs. -66%, P < 0.01; respectively). Lambs sired by HiFEC-rams required more anthelmintic treatment than LoFEC-selected lambs (76% vs. 61%, P < 0.05). The weaning and post-weaning FEC EBV of HiFEC-sired lambs was greater in lambs that died than those that survived to 120 d (37% vs. 83%, P < 0.01 and 73% vs. 138%, P < 0.01; respectively); however, this phenomenon did not occur in LoFEC-sired lambs. Taken together, these data indicate that LoFEC-sired lambs have reduced parasite burden and are more likely to survive to weaning. Thus, sire selection for low FEC EBV can have indirect effects on lamb survival and general immunity.

Anthelmintic resistance urges alternatives to control gastrointestinal nematodes (GIN). Copper oxide wire particles (COWP) are more efficacious when used with dewormers and little is known on efficacy of diatomaceous earth (DE) to control GIN. The objective was to examine the effects of DE and COWP on GIN control. Katahdin lambs (n = 32; ~150 d of age; 25.0 ± 1.8 kg) were randomly assigned to receive: 1) 2% dietary DE, 2) 1g COWP, 3) both 2% DE and 1g COWP, and 4) neither DE or COWP. Feces and blood were collected on d 0, 7, 14, 21 and 28 to determine fecal egg counts (FEC) and blood packed cell volume (PCV). Feces were cultured to determine GIN genera. FEC were log transformed; data were analyzed as a 2 x 2 factorial using proc mixed with day as repeated (SAS). There was a mixed GIN population including 58% Haemonchus contortus and 30% Trichostrongylus spp. FEC tended to be lower by d 28 in DE (175 eggs/g) than no DE (753 eggs/g) fed lambs (P = 0.09), but in general, were relatively low and no other differences among treatments detected. PCV tended to be higher in COWP than no COWP lambs by d 28 (P = 0.10), and no other differences detected. In conclusion, during a low GIN challenge, there may have been a small effect of DE on FEC but no advantage was observed in combination treatment.

In four experiments, 77 naturally-infected Boer crossbred kids and 28 artificially-inoculated Katahdin lambs were used to evaluate the effect of pumpkin seeds (Exp 1; 21 kids), ginger or pumpkin seed drench (Exp 2; 30 kids) and pumpkin seed oil (Exp 3 and 4: 28 lambs and 26 kids, respectively) on gastrointestinal nematode (GIN) indicators. In all experiments, kids and lambs were placed in individual pens and received pre-weighed rations of a commercially pelleted meat goat or sheep diet daily. In Exp 1, kids were supplemented with ground pumpkin seeds (PUM; n = 10) mixed into feed daily at a rate of 5 g/kg body weight (BW) or were not supplemented (CON; n = 11) for 21 days. In Exp 2, kids were orally drenched with water (CON; n = 10), 5 g pumpkin seed/kg BW (PUM; n = 10) or 3 g ginger/kg BW (GIR; n = 10) every other day for 42 days. In Exp 3, lambs were orally drenched with 2 ml/kg water (CON; n = 7), 2.0 ml/kg BW pumpkin seed oil once every 7 days (PUM1; n = 10), or 2.0 ml/kg BW pumpkin seed oil daily for 3 out of every 7 days (PUM2; n = 11) for 28 days. In Exp 4, kids were orally drenched with 2 ml/kg water (CON; n = 13), or 2.0 ml/kg BW pumpkin seed oil (PUM; n = 13) every other day for 35 days. In all experiments, BW, daily feed intake and blood and fecal samples were collected every 7 days. All animals in Exp 2 were harvested at a USDA-inspected abattoir and abomasal and small intestinal contents were collected for total worm counts. The FEC were similar for treatments in all experiments. Treatment influenced PCV ( P 0.05) only in Exp 1 and 4. In Exp 2, at harvest, there was a tendency ( P = 0.08) for CON animals to have a higher number of total GIN than GIR-treated animals, but PUM-treated animals were intermediate. BW were similar for treatments in Exp 1, 2 and 3 while CON animals in Exp 4 had a greater BW than PUM-treated animals on day 7 only and were similar thereafter (treatment by day interaction, P 0.05). In these studies, pumpkin and ginger treatments administered were not effective in reducing FEC in meat goat kids or lambs.

The use of Brahman in cow-calf production offers some adaptation to the harsh characteristics of endophyte-infected tall fescue. Criollo breeds, such as the Romosinuano, may have similar adaptation. The objectives were to estimate genetic effects in Romosinuano, Angus, and crossbred cows for their weights, weights of their calves, and ratios (calf weight:cow weight and cow weight change:calf weight gain) across lactation and to assess the influence of forage on traits and estimates. Cows ( = 91) were bred to Charolais bulls after their second parity. Calves ( = 214) were born from 2006 to 2009. Cows and calves were weighed in early (April and June), mid- (July), and late lactation (August and October). Animal was a random effect in analyses of calf data; sire was random in analyses of cow records and ratios. Fixed effects investigated included calf age, calf sex, cow age-year combinations, sire breed of cow, dam breed of cow, and interactions. Subsequent analyses evaluated the effect of forage grazed: endophyte-free or endophyte-infected tall fescue. Estimates of maternal heterosis for calf weight ranged from 9.3 ± 4.3 to 15.4 ± 5.7 kg from mid-lactation through weaning ( < 0.05). Romosinuano direct effects (of the cow) were -6.8 ± 3.0 and -8.9 ± 4.2 kg for weights recorded in April and June. Calf weights and weight gains from birth were greater ( < 0.05) for calves of cows grazing endophyte-free tall fescue except in mid-summer. Cow weight change from April to each time was negative for Angus cows and lower ( < 0.05) than other groups. Cows grazing endophyte-free tall fescue were heavier ( < 0.05) at all times but had more weight loss in late lactation. Angus cows had the lowest ( < 0.05) ratios (negative) of cow weight change:calf weight gain, indicating an energy-deficit condition. Cows grazing endophyte-free tall fescue had more negative ( < 0.05) values for this trait but not in early lactation ( < 0.05). Estimates of heterosis ranged from 12.8 ± 9.5 to 28.6 ± 9.4 kg for cow weight, 7.9 ± 3.0 to 15.8 ± 5.0 kg for cow weight change, and 0.07 ± 0.03 to 0.27 ± 0.1 for cow weight change:calf weight gain. Direct Romosinuano effects ranged from 14.8 ± 4.2 to 49.8 ± 7.7 kg for cow weight change and 0.2 ± 0.04 to 0.51 ± 0.14 for cow weight change:calf weight gain. The adaptive ability of Romosinuano in temperate fescue regions may be favorable with respect to relative cow and calf weight but may be a consequence of lower milk-producing ability.

Control of gastrointestinal nematodes (GIN) remains a critical issue due to the prevalence of anthelmintic resistance. The objective of the experiment was to determine the efficacy of copper oxide wire particles (COWP) from three commercial sources and a combination of COWP and albendazole to control GIN and/or Haemonchus contortus in lambs. Naturally infected Katahdin lambs in early June 2014 and 2015 were randomly assigned to receive no COWP (CON; n = 9 and 12) or 2 g COWP in a gel capsule as Copasure ® (COP; n = 4 and 17; Animax Ltd.), copper oxide—wire form (AUS; n = 7 in 2014 only; Pharmplex), Ultracruz™ (ULT; n = 8 and 15; Santa Cruz Animal Health™), no COWP and albendazole (CON + alb; n = 10 in 2015 only; 15 mg/kg BW; Valbazen ® ; Zoetis Animal Health), or COWP + alb ( n = 7 and 11; in 2014, lambs were administered alb on day 3). Lambs grazed grass pastures as a group and were supplemented with 227 g/lamb daily of a commercial grain mix (15% crude protein) and the same amount of alfalfa pellets. Feces were collected on days 0 (day of COWP treatment), 7, and 14 for determination of fecal egg counts (FEC). Pooled (2014) or pooled treatment group feces were cultured on days 0, 7, and 14 (2015 only) to determine GIN genera. Data were analyzed using repeated measures in a mixed model, and FEC were log transformed. The predominant GIN on day 0 was H. contortus (87%) in 2014, and there was a mixed population in 2015. The mean FEC was reduced by day 7 in AUS and ULT lambs (treatment × day, P = 0.001), and all of the COWP products were similar. By day 14, the AUS FEC were lower than the CON and COP groups. When examining the combination of COWP and synthetic anthelmintic, the FEC of COWP + alb were reduced to nearly 0 eggs/g (back-transformed) and lower than the other groups (treatment × day, P = 0.001). The percentage of H. contortus in cultured feces was reduced to a greater extent in the COWP than CON or CON+alb groups of lambs. In a mixed GIN population, the COWP products appeared to be similar in efficacy and using a combination of COWP + alb increased the efficacy not only against H. contortus , but all GIN genera present, offering options in the face of resistance to benzimidazoles.

The objectives of this work were to: (1) estimate heterosis and breed direct effects for cow reproduction traits of Romosinuano, Angus, and F 1 cows in a temperate climate, and (2) assess the effects of the type of forage grazed (bermudagrass, endophyte-infected and endophyte-free tall fescue) during the breeding season on traits and genetic effects. Calving and weaning rate ( n =666 records) were evaluated for 145 cows from 2005 through 2012. Calving interval ( n =400) and day of conception within breeding season ( n =547) were recorded. Mixed models included combinations of fixed effects: year of record or cow age within year of record, breed type parameterized as main and interaction effects of sire breed and dam breed of cows with records. Additive genetic effects were included as a random component. The sire breed-dam breed interaction was characterized by lower ( P 1 ) for calving rate and ranged from 0.81±0.03 (F 1 sired by Angus) to 0.82±0.03 (Romosinuano-sired F 1 ) for weaning rate. Romosinuano cows conceived later ( P P P >0.24). Estimates of heterosis were 0.09±0.03, 0.11±0.04, and –3.7±2.0 d ( P P P

Sericea lespedeza (SL; Lespedeza cuneata) is a legume rich in condensed tannins that can be grazed or fed to small ruminants for parasite control. Condensed tannins, a secondary plant compound in SL, may lead to unintended consequences such as changes in production. In our preliminary research, there was consistently a reduction in serum and liver concentrations of Mo. The objective of this study was to determine the effect of SL with or without Mo supplementation on changes in BW, hematology, and serum biochemistry in lambs. Thirty ram lambs weaned in May (84 ± 1.5 d of age; 27 ± 1.1 kg) were blocked by BW, breed type (full or three-fourths Katahdin), and EBV of parasite resistance and randomly assigned to be fed 900 g of alfalfa-based supplement (CON; n = 10) or SL-based supplement (n = 20) for 103 d. Supplements were formulated to be isonitrogenous and isocaloric and to meet trace mineral requirements. Within the SL diet, half of the lambs received 490 mg sodium molybdate weekly (SLMO). Body condition scores and BW were determined every 14 d and blood and feces collected to determine hematological and serum biochemical profiles and fecal egg counts (FEC). Data were analyzed using a mixed model with repeated measures and orthogonal contrasts. The white blood cell counts tended to be reduced in SL- and SLMO-fed lambs compared with CON-fed lambs (P < 0.06), which was associated with a reduction in neutrophils (P < 0.001). Red blood cell counts were also reduced in SL but not SLMO lambs compared with CON lambs (P < 0.04). There was a reduction in blood packed cell volume (P < 0.04) and serum concentrations of albumin (P < 0.001) and creatinine (P < 0.02) in both SL and SLMO lambs compared with CON lambs. Similarly, concentrations of blood urea nitrogen were reduced in both SL and SLMO lambs, but differences among dietary treatments disappeared after 42 d of feeding (treatment × day, P < 0.004). Serum concentrations of total proteins were reduced only in SLMO lambs compared with other lambs (P < 0.001). Body weight and FEC were similar among dietary treatments. Means of all measurements were within a normal range, even though there were subtle but significant differences between dietary groups. Feeding a diet high in condensed tannin-rich SL did not lead to serious effects on hematology or serum biochemistry in lambs.

This study estimated genetic parameters for ewe reproductive traits [number of lambs born (NLB) and weaned (NLW) per ewe lambing] and fecal egg counts (FEC) during the peri-parturient rise (PPR) for use in genetic evaluation of Katahdin sheep. Data included NLB and NLW for 23,060 lambings by 9,295 Katahdin ewes, 1,230 PPR at lambing (PPR0) for 750 ewes, 1,070 PPR at approximately 30 d postpartum (PPR30) for 611 ewes, BW at birth, weaning, and (or) post-weaning for 12,869 lambs, and FEC at weaning and (or) post-weaning for 4,676 lambs. Direct additive, permanent environmental, and residual (co)variances were estimated in univariate and bivariate animal models. Fixed effects included effects of ewe management group and ewe age for all traits, and, for PPR, a continuous effect of days between lambing and measurement. Effects of litter size on PPR0 and number of lambs suckled on PPR30 were included in univariate models but excluded from bivariate models for PPR and NLB or NLW. Heritability estimates in univariate models for NLB, NLW, PPR0, and PPR30 were 0.09 ± 0.01, 0.06 ± 0.01, 0.35 ± 0.06, and 0.24 ± 0.07, respectively. Estimates of permanent environmental variance as a proportion of total phenotypic variance were 0.02 ± 0.01 for NLB, 0.03 ± 0.01 for NLW, 0.05 ± 0.06 for PPR0, and 0.13 ± 0.07 for PPR30. Direct additive, phenotypic, permanent environmental, and residual correlations between NLB and NLW were 0.88 ± 0.03, 0.74 ± 0.004, 0.54 ± 0.15, 0.74 ± 0.003, respectively; corresponding correlations between PPR0 and PPR30 were 0.96 ± 0.07, 0.46 ± 0.03, 0.98 ± 0.50, 0.18 ± 0.05, respectively. The additive genetic correlation (r(d)) between ewe reproductive traits and PPR ranged from 0.12 to 0.18. Estimates of r(d) between lamb BW and subsequent ewe NLB and NLW ranged from 0.07 to 0.20, and those between PPR and lamb BW ranged from −0.03 to 0.29. The r(d) between ewe reproductive traits and lamb FEC ranged from 0.27 to 0.40, and those between PPR and lamb FEC ranged from 0.56 to 0.77. Correlations between maternal additive effects on BW and direct additive effects on PPR were low (−0.08 to 0.10), and those between maternal additive effects on BW and direct additive effects on ewe reproductive traits were variable (−0.36 to 0.11). We conclude that FEC in growing lambs and peri-parturient ewes are controlled by similar genes and that modest, but manageable, genetic antagonisms may exist between FEC and ewe productivity.