Winter Supplementation Research Articles

High-Energy Supplemental Feeding Shifts Gut Microbiota Composition and Function in Red Deer (Cervus elaphus).

Winter supplemental feeding (SF) is commonly used to improve the survival of captive wildlife. To investigate the impact of winter supplementation on the gut microbiota of wildlife, we assessed changes in the gut microbiota of red deer (Cervus elaphus) during the supplementary and non-supplementary feeding (NSF) groups using 16S rRNA sequencing technology. We found no significant differences in the diversity of the gut microbiota between SF and NSF except for the Simpson's index. However, the relative abundance of Bacteroidetes, Lentisphaerae, and Proteobacteria in the gut microbiota was significantly higher during SF. Further, genera such as Intestinimonas, Rikenella, Lawsonibacter, Muribaculum, and Papillibacter were more abundant during SF. Beta diversity analysis showed significant differences between SF and NSF. The microbes detected during SF were primarily associated with lipid metabolism, whereas those detected during NSF were linked to fiber catabolism. High-energy feed affects the gut microbial composition and function in red deer. During SF, the gut microbes in red deer were enriched in microorganisms associated with butyrate and lipid metabolism, such as R. microfusus, M. intestinale, and Papillibacter cinnamivorans. These gut microbes may be involved in ameliorating obesity associated with high-energy diets. In summary, SF is a reasonable and effective management strategy.

PREGNANCY RATE AND NUMBER OF FETUSES OF WHITE-TAILED DEER RELATED TO BODY MEASUREMENTS AND SERUM METABOLITES

This study aimed to assess the association between fertility and the number of fetuses of free-ranging concentrate-supplemented white-tailed deer (Odocoileus virginianus, texanus, Mearns 1898) from northern Mexico (27 °N) with body measurements and serum metabolites indicative of nutritional status. We studied 119 female deer (31 yearlings and 88 adults) captured in January 2021 using a net gun fired from a helicopter. Ultrasound scanning showed 100 and 97.8 % pregnancy rate and 1.52 ± 0.51 and 1.50 ± 0.59 fetuses/pregnant doe for yearlings and adult does, respectively, with no difference (p > 0.05) between age classes Thoracic circumference (cm) was higher (85.9 ± 4.9 vs. 84.1 ± 4.2; p = 0.039) for does carrying twins vs. singles. None of the serum metabolites indicative of nutritional status affected the fetal number of pregnant does. It was concluded that free-ranging white-tailed deer receiving concentrate supplementation in winter on a semi-arid rangeland has a high reproductive potential. Also, these results indicate that variation in maternal age within this population was not a significant driver of reproductive metrics of white-tailed deer. The plane of nutrition used in the present study was reflected in adequate serum metabolites indicative of nutritional status. Also, thoracic circumference may have prognostic value as a physical marker of multiple fetuses in female white-tailed deer.

The effects of genotype-by-environment interactions on body condition score across three winter supplemental feed environments in a composite beef cattle breed in Montana.

Cattle operations in the Northern Great Plains region of the United States face extreme cold weather conditions and require nutritional supplementation over the winter season in order for animals to maintain body condition. In cow-calf operations, body condition scores (BCS) measured at calving and breeding have been shown to be associated with several economically important health and fertility traits, so maintenance of BCS is both an animal welfare and economic concern. A low-to-medium heritability has been found for BCS when measured across various production stages, indicating a large environmental influence but sufficient genetic basis for selection. The present study evaluated BCS measured prior to calving (late winter) and breeding (early summer) under three winter supplementation environments in a multitrait linear mixed model. Traits were discretized by winter supplementation and genetic correlations between environments were considered a reflection of evidence for genotype-by-environment interactions between BCS and diet. Winter supplementation treatments were fed October through April and varied by range access and protein content: 1) feedlot environment with approximately 15% crude protein (CP) corn/silage diet, 2) native rangeland access with 1.8kg of an 18% CP pellet supplement, and 3) native rangeland access with a self-fed 50% CP and mineral supplement. A total of 2,988 and 2,353 records were collected across multiple parities on 1,010 and 800 individuals for prebreeding and precalving BCS, respectively. Heifers and cows came from a composite beef cattle breed developed and maintained by the USDA Fort Keogh Livestock and Range Research Laboratory near Miles City, Montana. Genetic correlations between treatments 1 and 2, 1 and 3, and 2 and 3 were 0.98, 0.78, and 0.65 and 1.00, 0.98, and 0.99 for precalving and prebreeding BCS, respectively. This provides moderate evidence of genotype-by-environment interactions for precalving BCS under treatment 3 relative to treatments 1 and 2, but no evidence for genotype-by-environment interactions for prebreeding BCS. Treatment 3 differed substantially in CP content relative to treatments 1 and 2, indicating that some animals differ in their ability to maintain BCS up to spring calving across a protein gradient. These results indicate the potential for selection of animals with increased resilience under cold weather conditions and high protein, restricted energy diets to maintain BCS.

Foraging Routine of Two Common Urban Birds on Berries of Exotic Livistona chinensis: A Winter Supplement in an Urban Landscape

Chinese Fan Palm, Livistona chinensis, was introduced as an ornamental plant towards the end of the nineteenth century in Pakistan, and since then, it has been used as a popular plant in urban landscaping. It dominates the green belt of parks, recreational gardens and road verges in Lahore, Pakistan. Recent trends in the plantation of fast-growing palm species and other exotics have replaced L. chinensis in urban landscaping. In this study, observations made on the daily routine of foraging of L. chinensis berries by two common urban birds, the red vented bulbul (Pycnonotus cafer) and the house crow (Corvus brachyrhynchos), showed that their consumption of berries peaked in December and January, but the duration of foraging was shown to be longer in house crows as compared to red vented bulbuls. This period of consumption corresponds to the time when the pulp of the berries has become soft, and during this period, no other fruits are available in the urban landscape. Nutrient analysis showed that the pulp of the ripened berries is a rich source of nutrients, and these berries are providing an ideal winter food to counter the increased energetic demands experienced by urban birds during the coldest part of the year, thus helping birds avoid the risk of starvation. This dietary intake of berries by birds also provides a rationale to popularize L. chinensis as an essential component of the planting palette of the urban landscape. This research can be considered as starting point for broad public support to improving landscape planning for managing nature in cities.

Closing the gap: Technology access and telehealth use among older adults in the U.S. Medicare beneficiaries

The use of digital technology offers numerous benefits for older individuals. However, failure to access technology could result in missed resources and opportunities, with some in this age group being hesitant to adopt new technology due to unfamiliarity or fear. Telehealth, as a form of digital technology, holds the potential to overcome geographic and temporal limitations, enabling socially isolated and physically homebound older adults to access a broader spectrum of healthcare options. Despite the potential advantages, the availability, acceptability, and accessibility of telehealth interventions for aging care remain unclear. This study aims to examine the impact of digital technologies on access to health and social care for older adults while identifying socioeconomic factors that may hinder access to services. We utilized the 2021 Medicare Current Beneficiary Survey COVID-19 Winter Supplement Public Use File dataset and the total sample size was 10,592 Medicare beneficiaries aged 65 years and above. Several statistical analyses, including multivariable logistic regression, were conducted. Our findings revealed that individuals from Black non-Hispanic and Hispanic racial and ethnic groups, as well as those with lower income and residing in non-metro areas, had lower odds of using technology devices and accessing the internet, This highlights the need for targeted interventions and policies to promote equitable access to digital resources and healthcare services for all seniors. Moreover, seniors who possess technology devices and have internet access are more inclined to engage with primary care providers (PCPs) who provide telehealth consultations. The study discussed future directions and limitations, providing valuable insights into the intersection of digital technology, healthcare access, and socioeconomic factors for older adults.

Beef Cattle Grazing Native Grasslands May Follow Three Different Supplement Response Patterns

Previous studies on winter supplementation of growing cattle grazing stockpiled native Campos grasslands suggest that forage allowance (FA), herbage mass, and weather conditions before and during the supplementation period could all affect supplement feed efficiency (SFE)—that is, the difference or change in average daily gain (ADG) between supplemented (S) and control (C) animals (ADGchng, kg) per unit (kg) of supplement dry matter (DM) intake. In this study, we analyse data from fifteen collated winter supplementation trials carried out in Uruguay between 2004 and 2018. The working hypotheses of this research paper were: (i) that average substitution rates are positive, and (ii) that ADGchng is not constant throughout the supplementation period and that its variation may be attributed to sward, animal or weather variables. There were two main objectives: (i) to estimate the average supplement substitution rate (sSbR, kg forage, f, dry matter, DM intake reduction: kg supplement DM intake) and potential herbage intake substitution rate (hSbR, kg fDM intake reduction: kg fDM intake of control animals), and its association with SFE, and, (ii) to assess the existence of different phases and supplementation response patterns and its association with other relevant variables. Estimated substitution rates were always positive (sSbR = 0.3–1.1 kg/kg; hSbR = 0.1–0.3 kg/kg) and were negatively and moderately associated with SFE. Supplementation proved to be a dynamic process where three possible supplementation responses over the supplementation period were identified (linear, quadratic and Weibull). While linear patterns did not appear distinctly associated with any particular set of variables, quadratic models were mostly associated with herbage biomass and substitution rates, whereas Weibull models were the clearest in their association with frosts. Regardless of the response pattern, at the beginning of the trials it was the animals’ body weight and supplement quality that most influenced supplement response, whereas towards the end, supplementation intake, supplemented animals’ ADG and forage quality played a more relevant role. The estimated parameters and response patterns are expected to be used as inputs in decision support systems for livestock farmers in the future.

117 Effects of Cattle Removal Date on Sustainability of Cool-Season Annual Grazed Cover Crop Systems

Abstract Grazing of cool-season cover crops has been shown to be a viable tool in extending the grazing season while mitigating environmental risks associated with row crop farming systems. While there is a vast amount of research available on cover crops in relation to soil health, a more novel approach would be to focus on forage production and animal performance when grazing cover crops. Therefore, our objective was to evaluate the effects of cattle removal date on forage yield, forage quality, and steer performance when grazing cool-season cover crops. A cool-season forage mix consisting of ‘Cosaque’ oats (Avena strigose), ‘FL401’ cereal rye (Secale cereal), ‘AU Sunrise’ crimson clover (Trifolium incarnatum), and ‘T-raptor’ brassica (Brassica napus × B. rapa) was established in twelve, 0.62 ha paddocks in Headland, AL. Each paddock was then randomly allocated to one of four cattle removal treatments: 1) no grazing (CON); 2) February removal (FEB); 3) March removal (MAR); or 4) April removal (APR). Three tester steers were randomly allotted, based on body weight (BW), to each of the grazing treatments, excluding CON. The tester steers were weighed every 30 d for calculation of initial BW, final BW, and average daily gain (ADG). At inception and every subsequent two weeks, forage was harvested to analyze average forage yield, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein (CP). All data were analyzed using GLIMMIX procedure of SAS version 9.4 (SAS Inst., Cary, NC). Significant differences in forage yield were detected between CON and FEB (3,913 vs. 2,261 kg/ha; P < 0.001), CON and MAR (3,913 vs. 1,790 kg/ha; P < 0.001), and CON and APR (3,913 vs. 1,810 kg/ha; P < 0.001). There were no differences found for ADG (1.2 kg/day; P = 0.56), NDF (50.94%; P = 0.46), or ADF (30.34%; P = 0.25) among treatments. Results indicate that grazing of cool-season annual cover crops will reduce forage yield, but removal date of cattle will not further affect forage yield, quality, or individual cattle performance. Thus, we can reduce winter supplementation needs for cattle by increasing grazing days; however, under continuous grazing for stocker cattle production, forage availability may inevitably be the limiting factor.

13 Stockpiling Bahiagrass to Extend the Grazing Season and decrease Winter Supplementation Costs for South Alabama Cattle Producers

Abstract Stockpiling forage is a management practice that can be used to decrease the cost of winter cow supplementation and is defined as the process of accumulating forage late in a growing season for grazing at a later date. The purpose of this study was to explore the effectiveness of bahiagrass as a potential stockpiled forage in lower Alabama by developing a better understanding of its forage accumulation, nutritive value and persistent characteristics during the stockpiling period (6 to 10 weeks). A small-plot stockpiling trial was conducted at three locations in south Alabama (Troy, Headland, and Goodway). Nine, 6.5 m x 2.0 m plots were cut to a 7.5 cm stubble height with a buffer of 0.9 m between plots at each location beginning on September 16, 2021. Nitrogen fertilization strategy was the main plot [0 N fertilizer, split N application (33.6 kg N/ha at initiation and again 30 d later), or 67.2 kg N/ha; 3 replications/treatment; N source = urea (46-0-0)]. Stockpiling period length was the split-plot (6, 8 or 10 weeks of forage accumulation; n = 9 subplots/treatment). Response variables were measured including forage mass and nutritive value at 6, 8 and 10 weeks, and nutritive value of standing forage 30 days after the stockpiling period. Data were analyzed using the PROC MIXED procedure of SAS 9.3. As the accumulation period length increased, average forage mass increased across all treatments with 1,312.6 kg DM/ha at 6 weeks, 1,270.1 kg DM/ha at 8 weeks and 1,585.9 kg DM/ha at 10 weeks. With respect to the fertilization treatments, the split N application (1,621.8 kg DM/ha) and 67.2 kg N/ha fertilization strategies (1,606.1 kg DM/ha) did not differ in forage accumulation but were greater (P < 0.05) than bahiagrass not receiving N fertilizer (1,377.6 kg DM/ha). For nutritive value, nitrogen application strategy impacted bahiagrass crude protein (CP), with both the split N application (14%) and 67.2 kg N/ha (13.8%) treatments having a greater CP (P < 0.05) than the 0 N fertilization approach (11.7%). Average total digestible nutrients across stockpiling periods were 62.5%. Year one results study indicate that bahiagrass may support forage production and nutritive value for cow-calf operations wanting to extend grazing into the fall and early winter months in the Southeast US. Based on year one results for forage mass measured at 6, 8 and 10 weeks, stockpiled bahiagrass could provide an estimated 45 to 55 days of grazing depending on mature cow weight, pasture stocking strategy and accumulation period length.

Evaluation of a rumen modifier to limit pellet intake in beef brood cows

Winter supplementation of gestating beef cows is often necessary to ensure energy and protein requirements remain satisfied. However, it is difficult to prevent over- or under-consumption by individual animals fed in a group. The objective of this study was to evaluate the intake limiting effects of 3 levels of tea saponin (TS) on pelleted feed consumption when compared with a TS-free control treatment. Commercial beef cows in late gestation (n = 24) were allocated to 1 of 4 treatments delivered via a pelleted feed supplement: 0% (A), 0.16% (B), 0.32% (C), or 0.64% (D) TS on a dry matter basis. Cows were assigned so that initial mean body weights and body condition scores were similar among treatment groups. Supplement was delivered once daily via Calan gates at a rate of 2.5% of BW for 42 days. Refusals were collected daily to calculate intake. Treatment differences were observed for pellet DMI, cow BW, and cow BCS (P < 0.0001). Cow hay intake, calf birth weight, and calf weaning weight were unaffected by treatment (P > 0.05). Dry matter intake of pellets as a percent of BW (DMIBW) was significantly different for all treatments (P < 0.0001) with intake declining as TS content increased. Considerable variability in DMIBW of all treatments was observed from day 0 to 15 but intakes plateaued between 1.75 and 2.5% DMIBW for the remainder of the trial with Treatment D intake remaining noticeably lower than the other treatments. Treatment D was found to be successful at limiting pellet intake to an average DMIBW of 1.51%. This study concluded that short-term pellet intake can be limited by inclusion of TS, highlighting it as a potential intake limiter product for beef cattle producers.

Grazing cotton crop residue to reduce winter supplementation cost in late-gestation beef cows and assessment of the negative effects of gossypol on fermentation of mixed ruminal microorganisms

This research aimed to evaluate the use of standing cotton crop residue as a winter supplementation source for gestating beef cows and the effects of gossypol, a naturally occurring pigment with potential anti-quality characteristics, on in vitro mixed ruminal microorganism fermentations. Experiment 1 used a 3-yr completely randomized study with 108 Angus cross cows (BW 559 ± 7.9 kg) enrolled in a 30-d grazing trial. Cows were weighed, stratified by weight, and randomly assigned to 1 of 2 treatments: dormant bermudagrass ( Cynodon dactylon ) pasture + bermudagrass hay (GR) or cotton ( Gossypium ) crop residue + bermudagrass hay (CT). Experiment 2 used a completely randomized in vitro mixed ruminal microorganism fermentation with 3 × 5 factorial arrangements of treatments. This included 3 substrates: corn ( Zea mays ; CC), average relative forage quality (RFQ 100) coastal bermudagrass (ABG), and high relative forage quality (RFQ 120) coastal bermudagrass (HBG), along with 5 concentrations of gossypol: 0, 0.0615, 0.123, 0.1845, or 0.246 mg of gossypol/mL. Total hay offered and hay per head per day were greater ( P ≤ 0.02) in the GR group compared with the CT group. Economic analysis indicated that total hay cost, cost per head per day, and cost of gain were all significantly decreased for cows in the CT treatment compared with cows in the GR treatment ( P < 0.002). In vitro DM digestibility and total VFA production were lower ( P < 0.002) as gossypol concentration reached the highest concentration. Results suggest that grazing cotton crop residue is a partial replacement for hay supplementation during the winter months. Increased levels of gossypol have negative effects on DM disappearance and VFA production. The gossypol amount found in crop residue is approximately the same as the lowest concentration evaluated in the in vitro experiment. These results indicate that grazing cotton crop residue should not influence ruminal fermentation.

Effects of dietary supplementation on vegetation cover and its defoliation by sheep in extensive husbandry

Dietary supplementation is one of the most used strategies to reduce the effect of environmental fluctuations in arid and semi-arid environments. We evaluated changes in vegetation and in patterns of animal defoliation as a result of incorporating supplementation on semi-arid grasslands of Patagonia. We selected three paddocks on a sheep ranch where winter supplementation was carried out, and a feed silo was identified in each one. Fixed transects (50 m) were placed at increasing distances from the silos (100, 250 and 500 m), and several measurements were taken along the transects: grasses defoliation intensity; height, flowering and vigor of the key species; vegetation cover; and forage availability. Measurements were made during 3 seasons at two periods of the year. The defoliation intensity of species of low preference decreased with increasing distance from the silo, reaching at 100 m the same defoliation intensity as the preferred species, which did not change with distance. Vegetation, grasses and standing dead cover increased with distance from the silo. The use of dietary supplementation alters the animals’ pattern of species selection and this has consequences for plant cover. It is therefore important to consider the possible long-term effects of using this technology.

Reducing nutrient and sediment losses in surface runoff by selecting cattle supplement feeding areas based on soil type in New Zealand hill country

ABSTRACT Nutrient loss in surface runoff from hill country catchments is typically generated from small areas and over short time periods. This study compared nutrient and sediment losses in surface runoff when cattle were fed winter hay supplement on two hill country sub-catchments (∼0.3 ha) with contrasting soil types (imperfectly-drained and well-drained soils). Runoff samples were collected during seven events (June-August). During this period, two herds of 16 pregnant, mixed aged Angus cows were supplemented with 2 kg DM. cow day−1 of hay in a defined feeding area within each sub-catchment. The imperfectly-drained soil measured 4.8 times the volume of surface runoff compared to the well-drained soil. As a result, the imperfectly-drained soil lost 2.5 times the amount of sediment, 6.3 and 5.1 times the amount of total phosphorus (TP) and dissolved reactive phosphorus respectively and 4.5 times the amount of total nitrogen (TN). Surface runoff losses of nitrate-N from the well-drained soil were undetectable over the study period. Whilst overall nutrient losses were low over the short study period (0.22 kg TP ha−1 and 0.68 kg TN ha−1), the results highlight the potential benefit of strategically placing cattle feed supplements on soils less prone to surface runoff to improve freshwater outcomes.

Effects of maternal winter vs. year-round supplementation of protein and energy on postnatal growth, immune function, and carcass characteristics of Bos indicus-influenced beef offspring.

This 2-yr study evaluated the effects of winter vs. year-round supplementation of Bos indicus-influenced beef cows on cow reproductive performance and impact on their offspring. On day 0 of each year (approximately day 122±23 of gestation), 82 to 84 mature Brangus cows/yr were stratified by body weight (BW; 475±67kg) and body condition score (BCS; 4.85±0.73) and randomly assigned to 1 of 6 bahiagrass (Paspalum notatum) pastures (13 to 14 cows/pasture). Treatments were randomly assigned to pastures consisting of winter supplementation with molasses + urea (WMOL), or year-round supplementation with molasses + urea (YMOL) or wheat middling-based range cubes (YCUB). Total yearly supplement DM amount was 272kg/cow and supplements were formulated to be isocaloric and isonitrogenous (75% TDN and 20% CP). On day 421 (weaning; approximately 260±24 d of age), 33 to 35 steers/yr were vaccinated against parainfluenza-3 (PI3) and bovine viral diarrhea virus type 1 (BVDV-1) and transported 1,193 km to a feedlot. Steers were penned according to maternal pasture and managed similarly until slaughter. Data were analyzed using the MIXED and GLIMMIX procedures of SAS. On day 217 (start of breeding season), BCS was greater (P = 0.01) for YMOL than WMOL cows, whereas BCS of YCUB did not differ (P ≥ 0.11) to both WMOL and YMOL cows. The percentage of cows that calved, calving date, birth BW, and preweaning BW of the first offspring did not differ (P ≥ 0.22) among maternal treatments. Plasma cortisol concentrations were greater (P ≤ 0.001) for YCUB steers at feedlot arrival (day 422) than WMOL and YMOL steers. Moreover, YCUB steers had greater (P = 0.02) and tended (P = 0.08) to have greater plasma concentrations of haptoglobin compared to WMOL and YMOL steers, respectively. Antibody titers against PI3 and BVDV-1 viruses did not differ (P ≥ 0.25) among maternal treatments. Steer BW at feedlot exit was greater (P ≤ 0.05) for YMOL and WMOL than YCUB steers. However, feedlot DMI did not differ (P ≥ 0.37) by maternal treatment. Hot carcass weight, yield grade, LMA, and marbling did not differ (P ≥ 0.14) among maternal treatments. Percentage of steers that graded low choice was enhanced (P ≤ 0.05) for WMOL and YCUB than YMOL steers. Maternal year-round supplementation of range cubes or molasses + urea either did not impact or decrease growth, immune function, and carcass characteristics of the offspring when compared with maternal supplementation of molasses + urea during winter only.

Effects of Winter vs. Year-round Supplementation of Multiparous Bos Indicus-influenced Beef Cows on Offspring Postnatal Growth, Immunity, and Carcass Characteristics

Abstract This 2-yr study evaluated the effects of winter vs. year-round supplementation of Bos indicus-influenced beef cows on offspring feedlot performance. Brangus cows (82–84 cows/yr) were stratified by BW and BCS (475 ± 67 kg; 4.85 ± 0.73) and randomly assigned to bahiagrass pastures (13–14 cows/pasture). Treatments were randomly assigned to pastures (2 pastures/treatment/yr) and consisted of winter supplementation with molasses (MOL-W), or year-round supplementation with molasses (MOL-Y) or cubes (CUB-Y). Supplements were isocaloric and isonitrogenous (75% TDN, 20% CP; DM basis). Total yearly supplement DM amount was 272 kg/cow for all treatments. At weaning (d 421), 33–35 steers/yr were vaccinated against bovine respiratory disease, transported for 720 miles to the feedlot, penned according to prepartum pasture distribution, and fed the same corn silage-based diet until harvest. Data were analyzed using SAS GLIMMIX procedure. Cow BCS at calving was greater (P &amp;lt; 0.01) for MOL-Y and CUB-Y vs. CON cows. Calving rate, calving date, calf birth weight, and calf preweaning BW did not differ (P ≥ 0.22) among treatments. Steer feedlot BW did not differ (P ≥ 0.36) at time of feedlot entry but was greater (P ≤ 0.05) for MOL-Y and MOL-W steers vs. CUB-Y steers at feedlot exit. Plasma haptoglobin concentrations at feedlot entry were greater (P = 0.05) for CUB-Y vs. CON steers, with MOL-Y steers being intermediate, whereas plasma cortisol concentrations at feedlot entry were greater (P ≤ 0.05) for CUB-Y vs. MOL-Y and MOL-W steers. Marbling score, yield grade, and carcass weight did not differ (P ≥ 0.14), but CON steers had greater fat thickness at the 12th rib than MOL-Y and CUB-Y steers. Hence, year-round supplementation (molasses or cubes) of beef cows increased cow BCS at calving but had minor effects on offspring post-weaning growth and immunity compared to winter supplementation of molasses.

Influence of Vitamin D Supplementation by Simulated Sunlight or Oral D3 on Respiratory Infection during Military Training.

ABSTRACTPurposeThis study aimed to determine the relationship between vitamin D status and upper respiratory tract infection (URTI) of physically active men and women across seasons (study 1) and then to investigate the effects on URTI and mucosal immunity of achieving vitamin D sufficiency (25(OH)D ≥50 nmol·L−1) by a unique comparison of safe, simulated sunlight or oral D3 supplementation in winter (study 2).MethodsIn study 1, 1644 military recruits were observed across basic military training. In study 2, a randomized controlled trial, 250 men undertaking military training received placebo, simulated sunlight (1.3× standard erythemal dose, three times per week for 4 wk and then once per week for 8 wk), or oral vitamin D3 (1000 IU·d−1 for 4 wk and then 400 IU·d−1 for 8 wk). URTI was diagnosed by a physician (study 1) and by using the Jackson common cold questionnaire (study 2). Serum 25(OH)D, salivary secretory immunoglobulin A (SIgA), and cathelicidin were assessed by liquid chromatography–mass spectrometry LC-MS/MS and enzyme-linked immunosorbent assay.ResultsIn study 1, only 21% of recruits were vitamin D sufficient during winter. Vitamin D–sufficient recruits were 40% less likely to suffer URTI than recruits with 25(OH)D <50 nmol·L−1 (OR = 0.6, 95% confidence interval = 0.4–0.9), an association that remained after accounting for sex and smoking. Each URTI caused, on average, three missed training days. In study 2, vitamin D supplementation strategies were similarly effective to achieve vitamin D sufficiency in almost all (≥95%). Compared with placebo, vitamin D supplementation reduced the severity of peak URTI symptoms by 15% and days with URTI by 36% (P < 0.05). These reductions were similar with both vitamin D strategies (P > 0.05). Supplementation did not affect salivary secretory immunoglobulin A or cathelicidin.ConclusionVitamin D sufficiency reduced the URTI burden during military training.

EFFICACY OF ORAL VITAMIN D SUPPLEMENTATION OR SIMULATED SUNLIGHT ON BONE DURING MILITARY TRAINING

25-hydroxyvitamin D (25(OH)D) ≥50 nmol·L-1 is essential for bone health. Vitamin D deficiency during arduous training has implications for increased stress fracture risk. Vitamin D is mainly synthesised from skin exposure to the sun; around 20% of vitamin D is obtained from the diet. PURPOSE: This study compared the efficacy of vitamin D supplementation by oral pill versus simulated sunlight on bone macro- and micro-architecture during a 13-week military training course in winter. METHODS: Eighty male infantry recruits (mean ± SD, age 22 ± 3 years, height 1.78 ± 0.07 m, body mass 77.9 ± 10.7 kg) received oral vitamin D3 (1,000 IU·D-1 for 4 weeks and then 400 IU·d-1 for 8 weeks, n = 21), an oral placebo (n = 19), solar-simulated radiation (SSR, 1.3 × standard erythemal dose in T-shirt and shorts, 3 d·wk-1 for 4 weeks and 1 d·wk-1 for 8 weeks, n = 22), or placebo SSR (n = 18). Total 25(OH)D was measured by LC-MS/MS in week 1, 5 and 13, and bone density and structure was assessed at the ultra-distal dominant tibia by HR-pQCT (Xtreme CTI, Scanco) in week 1 and 13. RESULTS: Oral vitamin D3 and SSR increased 25(OH)D from week 1 (51 ± 22 and 43 ± 21 nmol·L-1) to week 5 (78 ± 23 and 79 ± 15 nmol·L-1) and week 13 (75 ± 15 and 76 ± 12 nmol·L-1 , P < 0.001). The oral and SSR placebos did not change 25(OH)D from week 1 (51 ± 40 and 41 ± 17 nmol·L-1) to week 5 (45 ± 4 and 41 ± 16 nmol·L-1), but 25(OH)D increased in both groups by week 13 (60 ± 4 and 65 ± 15 nmol·L-1, P ≤ 0.010). Supplementation and training did not affect total, trabecular or cortical volumetric bone mineral density, cortical area, trabecular volume, number or thickness, or cortical pore diameter (main effects of time, P ≥ 0.105; group × time interactions, P ≥ 0.258). Training increased cortical thickness (1.30 ± 0.25 to 1.32 ± 0.25 mm), and reduced trabecular area (682 ± 133 to 680 ± 133 mm2) and spacing (360 ± 58 to 345 ± 71 μm, main effects of time, P ≤ 0.041), but supplementation had no effect (group × time interactions, P ≥ 0.181). There was a significant group × time interaction for cortical perimeter (P = 0.033) and porosity (P = 0.049); training had no effect on either measure for any group (P ≥ 0.068). CONCLUSION: Vitamin D supplementation in winter, using strategies to increase total 25(OH)D above 50 nmol·L-1, exerted no effect on bone macro- or micro-architecture beyond the osteogenic effects of exercise training.

Vitamin A, calcium, phosphorus and magnesium status of heifers grazing in Northern Cyprus.

Vitamin A, calcium (Ca), phosphorus (P) and magnesium (Mg) are essential components for the health and reproductive yield of dairy cows. In this study, it is aimed to profile the calcium, phosphorus and magnesium elements together with vitamin A, which are important components in cattle bred and reared in Northern Cyprus. To analyse these parameters, 260 clinically healthy animals, at least 30 from each region, were blood sampled from eight different regions (Nicosia, Gecitkale, Vadili, Famagusta, Iskele, Ziyamet, Morphou and Kyrenia) during both summer and winter seasons. Vitamin A, calcium, magnesium and phosphorus concentrations were measured from blood samples. Vitamin A levels increased significantly only in Nicosia and Ziyamet regions during the winter season, while there was no seasonal difference from the other regions. Calcium and phosphorus levels were higher in summer when compared with winter. Magnesium levels were significantly higher in winter than in summer. In the comparison between regions in summer and winter, the change in P and Mg values was significant, whereas Ca only showed inter-regional differences during winter. In conclusion, all the parameters found were within the expected ranges but affected by seasonal changes. Therefore, we think that calcium and phosphorus supplementation in winter and vitamin A and magnesium supplementation in summer will provide positive results on cattle.

161 Evaluation of cull sweet potato storage roots as a winter supplement to grazing for cow-calf pairs

Abstract Cull sweet potato storage roots that would otherwise be left unharvested in production fields or dumped as waste from excess supplies in storage may be available for use as livestock feed at competitive pricing relative to other feedstuffs. Given this potential economical source of nutrients for consumption by beef cattle, the objective of this study was to assess cow-calf performance using unprocessed sweetpotato storage roots as a winter supplement to grazing cow-calf pairs as compared to whole cottonseed or no supplement. Fall-calving multiparous Bos taurus crossbred cows in Prairie, MS, were allotted ad libitum access to mixed-grass pasture with tall fescue as the predominant forage species and randomly allocated to one of three as-fed basis supplement groups: 6.8 kg/cow/d of sweetpotato storage roots (SWP); 2.3 kg/ cow/d of whole cottonseed (WCS); or no supplement (NONE). Supplements were offered to cows on a group basis on every Monday, Wednesday, and Friday for 93 d each winter initiating December 5, 2016 (n = 81) and December 11, 2017 (n = 105). Cow BCS on a scale of 1 to 9 (1 = emaciated; 9 = obese) at supplementation initiation was 6.1 ± 0.1. From supplementation initiation until calf weaning in March, change in cow BCS (P &lt; 0.01) was greatest for NONE (-1.1 ± 0.1), intermediate for SWP (-0.7 ± 0.1), and least for WCS (-0.4 ± 0.1). Adjusted 205-d calf BW was 16.9 ± 3.8 kg heavier (P &lt; 0.01) in steers than heifers but did not differ (P = 0.41) among supplementation groups. Although nursing calf performance was not impacted by supplementation regime, results suggest that cull sweetpotato storage roots may be an effective feedstuff for winter supplementation intended to reduce BCS loss in lactating beef cows. Additional research to determine optimal frequency and quantity of SWP supplementation is warranted

164 Effects of year-round supplementation of sugarcane molasses/urea or range cubes on growth performance of Bos indicus-influenced beef cows and their offspring

Abstract This study compared the effectiveness of liquid sugarcane molasses/urea or wheat middlings-based range cubes supplementation on performance of beef cow-calf pairs. On d 0, 82 mature pregnant Brangus cows were stratified by BW and BCS (433 ± 47 kg; BCS = 4.6 ± 0.77) and randomly allocated into 1 of 6 bahiagrass pastures (13–14 pairs and 9.3 ha/pasture). Treatments were assigned randomly to pastures (2 pastures/treatment) and consisted of cows offered: winter supplementation of molasses/urea from calving until end of breeding season (d 161 to 300; MOL-W), or year-round supplementation of liquid urea/molasses (MOL-Y) or range cubes (CUB-Y). Supplement amount offered to cows differed monthly among treatments, but all cows were limit-fed 272 kg/yr of the respective supplement DM and similar trace mineral supplementation (336 g/cow/wk). Cubes were formulated to be isocaloric and isonitrogenous compared with molasses/urea (75% TDN, 20% CP; DM basis). Weekly supplement amount was divided in half and offered every Monday and Thursday. Cow BCS: did not differ among treatments from d 0 to 74 (P ≥ 0.56); was greater at calving (d 161) for MOL-Y and CUB-Y vs. MOL-W cows (P ≤ 0.05); and was greatest, intermediate, and least at start of breeding season (d 217) for MOL-Y, CUB-Y, and MOL-W cows (P ≤ 0.05), respectively. Liver concentrations for Co, Se, and Cu on d 122 and 217 were greater (P ≤ 0.02) for CUB-Y vs. MOL-W and MOL-Y cows. Calving date, percentage of pregnant cows on d 360, and calf birth BW, pre-weaning ADG, and BW at weaning did not differ (P ≥ 0.14) among treatments. Therefore, year-round supplementation of liquid molasses/urea and range cubes enhanced cow BCS at calving and start of breeding season but did not impact subsequent reproductive performance of cows and calf weaning weights than conventional winter molasses/urea supplementation of cows

El pastoreo restringido de avena y su frecuencia de asignación afecta el desempeño de terneros pastoreando campo natural

Las restricciones nutricionales de los terneros de recría sobre campo natural durante su primer invierno es un problema común en Uruguay, dada la insuficiente calidad y cantidad del forraje. La suplementación invernal del ganado de carne utilizando granos o sus subproductos y pastoreando sobre pasturas nativas, ha sido estudiada previamente, pero muy poca atención se le ha dado a el acceso restringido de animales a una base forrajera mejorada adyacente, como lo puede ser un verdeo de avena. Treinta y seis terneros machos castrados pastoreando sobre campo natural durante su primer invierno fueron asignados al azar a uno de los siguientes tratamientos: (a) Diario (D) con acceso a una parcela adyacente de avena por 4 horas al día (28 horas/semana); (b) de Lunes a Viernes (LaV) con acceso al mismo verdeo por 5 horas 36 minutos por día (28 horas/semana); (c) Testigo (T), en el que los animales no tenían acceso alguno al verdeo de avena. El experimento fue dividido en dos fases: la fase I en donde los tratamientos fueron aplicados (invierno) y la fase II, luego que los mismos fueran aplicados (primavera), a los efectos de evaluar un eventual arrastre de efectos. El acceso restringido a la avena afectó la disponibilidad y altura del forraje del campo natural en ambas fases evaluadas (P