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The main factors influencing speed in athletes are stride length (SL) and stride rate (SR). However, conflict remains whether SL or SR is the key determinant of higher speeds. Quarter Horses (QH) generally reach higher speeds in their races than do Thoroughbreds (TB). However, the influence of SL and SR on this greater speed is unclear. Therefore, the main objective of this study was to compare SL and SR in QH and TB raced in short (sprint) and long (classic) distances. We hypothesized that QH have a higher SR in comparison to TB, and SR decreases as distance increases. Two race distances were analyzed for each breed: QH races of 100.6 and 402.3 m, and TB races of 1,207.0 and 2,011.7 m. Data from 20 horses were obtained, consisting of five horses from each race distance (10 QH and 10 TB). Five individuals watched recordings of each race three times counting the number of strides taken by each winning horse. The SR was calculated using the average number of strides over a given race duration, and SL was determined by calculating the total number of strides over the distance covered. Speed was calculated by dividing the distance by the time of the winning horse. The PROC Mixed Procedure was used to identify statistical differences between breeds, and between distances within the same breed. Results showed that although the SL of the TB was longer in comparison with the QH (P  < 0.001), the average SR in QH was higher than in TB (2.88 vs. 2.34 + 0.03 strides/s; P  < 0.001). Furthermore, QH classic distance demonstrated a faster speed than TB at either distance (P  < 0.001). In conclusion, QH achieve a higher SR in comparison to TB (between 14% and 20% more than TB), confirming the importance of SR in achieving high racing speeds. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the feed intake and the apparent digestibilities of three different diets varying in concentrate‐to‐roughage ratios in weanling horses (n = 24) at 5 and 8 months of age. Horses were stratified by breed, gender, birth date and body weight and assigned to one of three dietary treatments containing the following concentrate‐to‐roughage ratios on an as‐fed basis: 70:30 (High Con), 50:50 (Equal) and 30:70 (Low Con). All horses were fed their respective diets for a 10‐day adaptation period and a 4‐day collection period at 5 and 8 months. There were no differences in BW or daily feed intake among treatments during both trials. The horses consuming Low Con had a greater amount of faecal output than High Con at both 5 and 8 months (p < 0.01). At 5 months, High Con had the highest crude protein (CP) digestibility (p < 0.05). At 8 months, High Con had a higher CP digestibility than Low Con (p < 0.01) and tended to be higher than Equal (p = 0.07). Acid detergent fibre (ADF) digestibility did not differ among treatments; however, horses fed the Low Con tended to digest a higher percentage of neutral detergent fibre (NDF) than both the Equal and High Con treatments (p = 0.09). Horses in the High Con treatment tended to digest a higher percentage of energy than those in the Low Con treatment (p = 0.06). Weanlings seem to digest protein more thoroughly when fed high‐concentrate diets and may digest fibre more efficiently when fed diets higher in fibre. [ABSTRACT FROM AUTHOR]

OBJECTIVE To establish an orthopedic, preclinical, ovine model of controlled exercise using an equine walker. ANIMALS 20 Dorset-Polypay sheep. PROCEDURES Sheep underwent 11 weeks of exercise, 4 days per week. Exercise duration and intensity increased until sheep performed 25 minutes at 1.3 m/s and 5 min at 2.0 m/s. Physical/lameness examinations were conducted every 14 days. Blood was collected every 28 days for analysis of serum bone biomarkers (SBB): bone alkaline phosphatase (BALP), procollagen type I amino-terminal propeptide (PINP), carboxy-telopeptide of type I collagen cross-links (CTX-I), tartrate-resistant acid phosphatase 5b (TRAP5b), and receptor activator of nuclear factor-kβ ligand (RANKL). RESULTS Sheep adapted easily to group exercise. Animals grew taller (P = .006) but had a 4% weight loss (P = .003). RANKL was reduced on days 28 and 84 compared to day 56 (P < .05), CTX-1 was reduced on days 28 and 84 compared to days 0 and 56 (P < .05), and TRAP5b was greater on day 28 compared to day 0 (P = .009). BALP and PINP did not change. CLINICAL RELEVANCE The described preclinical model of exercising sheep has distinct advantages including ease of handling, an established lameness scale, commercially available ovine SBB assays, and the ability to alter footing characteristics and complete circular exercise. Decreasing CTX-I and RANKL with no change in BALP and PINP suggests reduced bone resorption over the study period. Future studies may include a sedentary group or utilize adult animals to alleviate any influence of growth on SBB. [ABSTRACT FROM AUTHOR]

OBJECTIVE The objective of this pilot study was to determine if an alternative dosing schedule of pegbovigrastim (PEG; Imrestor; Elanco Animal Health) affects mammary gland health, rear udder width, or milk production of healthy dairy cows. ANIMALS 20 pregnant late-lactation Holstein cows in November 2019 through April 2020. PROCEDURES Cows were randomly assigned to receive subcutaneous injections with either 15 mg of PEG (PEG group; n = 10) or a sham injection with saline (0.9% NaCl) solution (control group; 10) administered 7 days before dry-off and at dry-off. Quarter milk samples were collected for bacterial culture and somatic cells before and after dry-off and after calving. Mammary gland width was assessed before and after dry-off. Daily milk yields were evaluated after calving. RESULTS The incidence of intramammary infection was 5 times greater for quarters of cows in the control group than for quarters of cows that received PEG. The effect of treatment on somatic cell count was not significant, but the effects of period and a treatment-by-period interaction were identified. Treatment did not significantly affect milk production in the subsequent lactation, but the effects of period and an interaction of treatment by period were identified. Rear udder width after dry-off was not significantly affected by treatment, but an effect of period was identified. CLINICAL RELEVANCE In this pilot study, cows treated with PEG using an alternative dosing schedule had reduced incidence of intramammary infection and an interaction of treatment by sampling period was observed for milk yield. These results suggest that further studies with larger numbers of cows are warranted. [ABSTRACT FROM AUTHOR]

The depopulation of healthy birds during a disease outbreak can impact recovery and further disrupt the food supply. In 2015, the United States faced one of the largest outbreaks of highly pathogenic avian influenza ever confirmed. Many of the 7 million pullets depopulated were healthy but could not be moved to laying facilities because of their location in quarantine zones. The objective of this study was to assess the impact of an early production induced molt on Salmonella and Campylobacter prevalence, as well as total aerobes and Enterobacteriaceae enumeration. Pullets were reared in a cage-free barn from 0 to 16 wk. At 17 wk, pullets were assigned to 1 of 4 treatments: control (AV), floor (FL), enrichment (EN), and molt (MT). AV was moved into an aviary system to begin lay, while FL, EN, and MT were brought into lay in the barn. When production reached 10%, a non-feed withdrawal diet was given to MT for 6 wk. Post-molt, all remaining treatments were moved to the aviary and maintained until 32 wk. Fecal, organ, and egg shell samples were collected and analyzed at the onset of lay, pre-molt, post-molt, and at depopulation to determine prevalence of Salmonella and Campylobacter. Total aerobic and Enterobacteriaceae loads were enumerated for egg shells collected from the litter, nest box, and aviary system wire. There was no difference for Salmonella and Campylobacter prevalence among treatments for all samples. While no difference was found in total aerobe plate counts pre-molt, there was a difference (P < 0.05) in Enterobacteriaceae for AV, FL, and MT. For MT, there was a reduction in total aerobe and Enterobacteriaceae loads from pre-molt to post-molt. While total aerobe and Enterobacteriaceae loads for egg location were found to be significantly different post-molt, biologically, the difference was not enough to be a concern once eggs are washed and sanitized. The results of this study indicate that early production molting of floor-reared pullets has little impact on egg safety once birds are moved into an aviary system. [ABSTRACT FROM AUTHOR]

Management choices during the pullet phase can affect behavior, welfare, and health later in life, but few studies have evaluated the pullet phase, particularly in extensive housing systems. This study was a 2 × 2 factorial randomized complete block design (RCBD) with two strains and two stocking densities. The Lohmann LB-Lite and Lohmann LSL-Lite were housed on the floor at high-stocking density (619-670 cm 2 /bird) and low-stocking density (1249-1352 cm 2 /bird), which changed with age from 2 to 16 weeks of age (WOA). Bird-based measures of appearance, blood parameters, organ measurements, and production values were evaluated. Stocking density alone affected ( p < 0.05) only relative bursal weight (% of body weight)-3.32% in the low-density versus 3.08% in the high-density group. High-stocking density was correlated with decreased uniformity (high-89.33 ± 0.24%; low-90.41 ± 0.24; p < 0.02) and worse feather coverage in the brown strain. High-stocking density was correlated with greater uniformity (High-90.39 ± 0.24%; Low-88.47 ± 0.24%; p < 0.001) and better feather coverage in the white strain. This study's feed conversion ratio (FCR) was improved by 0.07 in the low-stocking density for both strains. The remaining parameters were affected by strain and age only. Thus, while stocking density effects vary slightly depending on the strain used, cage-free pullets had limited negative effects at both the high and low-stocking densities tested in this study; there were few to no changes in the numerous bird-based welfare parameters tested.