Responses to an intra-articular lipopolysaccharide challenge following dietary supplementation of Saccharomyces cerevisiae fermentation product in young horses

Dietary intervention may be a valuable strategy to optimize the intra-articular environment in young horses to prolong their performance career. To test the hypothesis that dietary supplementation of a Saccharomyces cerevisiae fermentation product would reduce markers of joint inflammation and increase markers of cartilage metabolism following a single inflammatory insult, Quarter Horse yearlings (mean ± SD; 9 ± 1.0 mo) were balanced by age, sex, body weight (BW), and farm of origin and randomly assigned to the following treatment groups: 1.25% BW/d (dry matter basis) custom-formulated concentrate only (CON; n = 9) or concentrate top-dressed with 21 g/d S. cerevisiae fermentation product (SCFP; n = 10) for 98 d. Horses had ad libitum access to Coastal bermudagrass hay. On day 84, one randomly selected radial carpal joint from each horse was injected with 0.5 ng lipopolysaccharide (LPS) solution. The remaining carpal joint was injected with sterile lactated Ringer’s solution as a contralateral control. Synovial fluid obtained before supplementation (day 0) and on day 84 at preinjection hour 0 and 6, 12, 24, 168, and 336 h postinjection was analyzed for prostaglandin E₂ (PGE₂), carboxypropeptide of type II collagen (CPII), and collagenase cleavage neopeptide (C2C) by commercial assays. Rectal temperature, heart rate, respiration rate, carpal surface temperature, and carpal circumference were recorded prior to each sample collection and for 24 h postinjection. Data were analyzed using linear models with repeated measures. From day 0 to 84, synovial C2C declined (P ≤ 0.01) and the CPII:C2C ratio increased (P ≤ 0.01) in all horses with no effect of diet. In response to intra-articular LPS, synovial PGE₂ increased by hour 6 (P ≤ 0.01) and returned to baseline by hour 336; CPII increased by hour 12, remained elevated through hour 168 (P ≤ 0.01), and returned to baseline by hour 336; and C2C increased by hour 6 (P ≤ 0.01) but did not return to baseline through hour 336 (P ≤ 0.01). Post-intra-articular injection, PGE₂ levels were lower in SCFP than CON horses (P = 0.01) regardless of injection type. Synovial CPII and the CPII:C2C ratio demonstrated stability during the LPS challenge in SCFP compared with CON horses (P ≤ 0.01). Clinical parameters were not influenced by diet but increased in response to repeated arthrocentesis (P ≤ 0.01). Dietary SCFP may favorably modulate intra-articular inflammation following an acute stressor and influence cartilage turnover in young horses.     

A Comparison of Five Cooling Methods in Hot and Humid Environments in Thoroughbred Horses

Horses need aggressive cooling to prevent exertional heat illness after strenuous exercise in hot and humid conditions. This study compared various methods for cooling horses in such conditions, testing the hypothesis that continual application of running water would be the most effective method to decrease core temperature. Five Thoroughbreds were exercised on a treadmill at wet-bulb globe temperature of 31.8 ± 0.1°C until their pulmonary artery temperature reached 42°C. The time until the pulmonary artery temperature returned to <39°C (t₃₉) and the rectal temperature at 30 minutes after the onset of cooling were compared between five cooling methods in a 5 × 5 Latin square design: walking, with no additional cooling (CONT); walking, with fans producing an air current of 3.0 m/s (FAN); walking, with the intermittent application of cold water (10°C) either with scraping (ICW + SCRAPE) or without scraping (ICW); and stationary, with the continuous tap water (26°C) application via shower hoses (STW). The STW produced the shortest t₃₉ (P < .001). With intermittent cold water, ICW + SCRAPE tended to produce longer t₃₉ than ICW (P = .06), and both produced significantly shorter t₃₉ than FAN and CONT (P < .001). The t₃₉ of the FAN tended to be shorter than with the CONT (P = .06). All the cooling methods resulted in lower rectal temperatures at 30 minutes than CONT. The temperature was the lowest with the shower method, with no significant differences between the fan and intermittent cold-water methods. Showering with tap water was the most effective method to decrease core temperature in horses.     

Hypothermia prevention in long-standing equine dental procedures

Hypothermia is a common, detrimental post-operative complication in man and veterinary medicine. Active warming strategies are paramount for prevention and treatment. Duration of operations, administered drugs and their adverse effects put horses undergoing procedures requiring long-standing sedation in danger of hypothermia. The aim of this study was to investigate whether an air warming device would be helpful to avoid severe hypothermia in adult horses. Twenty client-owned horses undergoing dental/sinusoidal procedures were divided into two equal groups. The treatment group was covered with a warming blanket connected to the warming device with the temperature set to 43°C. Horses in the control group were not blanketed. Temperature was measured at the time of first sedation (T0) and every hour throughout the length of the procedure. Use of the warming blanket was straightforward and caused no adverse reactions. The mean decrease in body core temperature in the treatment group was significantly less than the mean temperature decrease in the control group, beginning at the second hour of the procedure. No horse in the treatment group reached a body temperature below 36°C. Overall loss of temperature in the control group was more than double when compared with the treatment group (1.5°C and 0.7°C respectively). The use of an active air warming blanket in horses is an easy technique to prevent hypothermia in horses undergoing long-standing sedation procedures.     

Live weights at slaughter significantly affect the meat quality and flavor components of pork meat

One‐hundred‐twenty crossbred pigs finished at 175–185 days of age were used to investigate the effects of live weights at slaughter on the meat quality, volatile flavor compounds, and sensory attributes of pork meat. Based on the live weights at slaughter, three weight groups (n = 36 per group) were classified as follows: light weight (LW: 100 kg), medium weight (MW: 110 kg), and heavy weight (HW: 120 kg). After slaughter, longissimus dorsi muscle samples were taken and used for the analyses of aforementioned parameters. The HW group had higher fat content and water holding capacity compared to the LW or MW group (p < 0.05). The HW group also showed higher levels for majority of unsaturated fatty acids and total polyunsaturated fatty acids than the LW group (p < 0.05). The slaughter weight significantly affected the amounts of 11 among the 47 flavor compounds identified. Significantly higher amounts of fatty acids oxidation‐derived flavor compounds (aldehydes) were found in the HW group than in the other groups. Noticeably, increasing slaughter weight was associated with higher sensorial scores for flavor, juiciness, and acceptance scores (p < 0.05). Based on the obtained results, 120 kg body weight is recommended as the market weight for this commercial breed without compromising the meat quality.     

Within-litter variation in muscle fiber characteristics, pig performance, and meat quality traits

The objective of this study was to examine the intralitter variation in postnatal growth performance, meat quality, and muscle fiber characteristics when littermates were categorized by carcass weight. Thirty-nine litters were weaned at 4 wk of age and had free access to feed from 2 wk of age until slaughter. They were slaughtered by litter at an average BW of 104 +/- 14 kg, and six pigs per litter were selected for analysis: the heaviest- (HW), middle- (MW), and lightest-weight (LW) pig of each sex. Categorizing littermates in LW, MW, and HW pigs at the same age reflected the differences in postnatal growth rate within a litter; thus ADG, muscle mass, and muscle deposition rate differed across pig weight groups (P < 0.001). Also, the total DNA content was different among pig weight groups (P < 0.001) and reflected differences in muscle growth rate. The difference in muscle growth rate between LW and MW pigs could be explained by a larger (P < 0.05) mean fiber area (MFA) in MW pigs, whereas the number of muscle fibers was similar. Growth rate differences between MW and HW pigs could in part be explained by a higher number (P < 0.01) of equal-sized muscle fibers in HW pigs. The difference in MFA was due to a higher estimated DNA and RNA content per muscle fiber in MW and HW compared with LW pigs (P < 0.05). Pigment content was higher in MW and HW compared with LW pigs (P < 0.01), but no other measured meat quality traits were significantly different across pig weight groups. These results indicate that both the number and the growth rate of muscle fibers contribute to intralitter variation in postnatal growth performance.     

Effect of heat challenge on peripheral blood mononuclear cell viability: comparison of a tropical and temperate pig breed

We evaluated the effect of heat challenge on cell viability, concanavalin A-induced proliferation and heat shock protein (HSPs) mRNA expression in peripheral mononuclear blood cells (PBMC) isolated from Creole (CR) and Large White (LW) pigs. The PBMCs were cultured for 9 h at 37°C before being subjected to heat challenge: (1) at 42°C or 45°C for 2, 4, 6 and 9 h to monitor cell viability;(2) at 45°C for 2 and 9 h followed by stimulation for 24 h at 37°C with concanavalin A to evaluate mitogen-induced proliferation; and (3) at 45°C for 3, 6 and 9 h to measure induction of HSP70.2 and HSP90 mRNA. Cell viability was affected by breed and temperature (P < 0.01), and the viability decrease caused by heat challenge was greater for LW than CR pigs. For mitogen-stimulated PBMCs, incubation at 45°C reduced lymphoblastogenesis equally in both breeds (P < 0.01). Although heat challenge for 3 and 6 h at 45°C induced expression of HSP70.2 and HSP90 mRNA, no breed difference was observed. In conclusion, differences in heat resistance between these two breeds at the whole organism level are reflected at the cellular level. Neither HSP70.2 nor HSP90 mRNA expression levels explain this effect.     

The Effect of a Seaweed-Derived Calcium Supplement on Gastric Juice pH in the Horse

Low gastric pH for extended periods of time can increase the risk of gastric ulceration in horses. Therefore, nutritional interventions that buffer stomach acid may be helpful to decrease ulcer risk. The objective of this trial was to evaluate whether the incorporation of calcified Lithothamnion corallioides and Phymatolithon calcareum (Calmin; Celtic Sea Minerals, Cork, Ireland) into an equine ration would buffer equine gastric juice. Nine mature, Thoroughbred-cross horses, including 6 geldings and 3 mares (524 ± 49 kg) were housed in stalls and fed 2 kg/day of a texturized concentrate (Purina Omolene 100) and 1.5% BW grass hay/day. On testing days 0, 7, and 14, the horses received one of three pelleted dietary treatments (CON, MIN1 ×, MIN2 ×) in a randomized, crossover design. CON contained no added Calmin, MIN1 × provided Calmin at a 1 × concentration, and MIN2 × provided a 2 × dose. All horses underwent gastroscopy (Karl Storz, El Segundo, CA) prior to feeding the treatments, and at 2 and 4 hours postfeeding. Gastric juice was aspirated and pH measured using a benchtop pH meter (ThermoOrion pH Meter Model 410A). Overall, there was a significant time effect (P < .0001) with an increase in gastric juice pH from time 0 (2.31 ± 0.58) to 2 hours (5.52 ± 0.48) and 4 hours (3.59 ± 0.48). Gastric juice pH at 2 hours was higher (P = .0122) in MIN1 × (5.92 ± 0.58) and MIN2 × (5.92 ± 0.57) than CON (5.08 ± 0.58). These results demonstrate that adding Calmin to a meal increases buffering capacity at 2 hours postfeeding.     

Growth performance and physiological parameters of conventional and specified pathogen‐free rats fed autoclaved diets with different protein sources

The effects of feeding autoclaved commercial SSNIFF (SN) diet and diets containing soya bean (S) and casein (C) to growing conventional (CON) and specified pathogen‐free (SPF) rats were determined. Diets S, C and SN, autoclaved at 121 °C during 20 min (T1), at 134 °C during 10 min (T2) and non‐autoclaved (T0), were fed during four weeks, each to 8 CON males and 8 females of mean initial body weight 56 g, kept individually. Diets S, C and SN, autoclaved at T1, were fed during two months, each to 20 SPF males and 20 females of mean initial body weight 58 g, kept in group of 5 animals per cage. In CON rats, autoclaving did not affect feed intake and weight gain, decreased thyroid and stomach weight, increased caecal tissue and digesta weight, and concentrations of isobutyric, isovaleric and valeric acid in caecal digesta. Among biochemical blood parameters, autoclaving decreased only total protein concentration and aspartate aminotransferase activity. Feeding C diet resulted in lower feed intake and weight gain in CON and SPF males. Diet affected organ weights and the greatest differences were found in rats on SN diet for weights of stomach, caecum and female reproductive organs. Diet affected concentration of all short‐chain fatty acids, pH and weight of caecal digesta, the most important being the greatest butyric acid concentration on SN diet and isoacids on C diet. It is concluded that autoclaving of both soya‐containing and soya‐free diets does not affect negatively animal performance and physiology.     

Effect of dietary energy level on the performance of individually housed early-weaned piglets in relation to environmental temperature

An experiment involving 72 individually housed piglets was conducted to determine the interactive effects of environmental temperature and dietary energy level on the performance of early-weaned piglets maintained for six weeks in environmental temperature of 28, 22 or 16°C. Two diets were formulated to supply 3.1 (low energy diet) and 3.6 (high energy diet) Mcal digestible energy per kg of feed.The high-energy diet had greater (P < 0.01) energy and nitrogen digestibility than the low-energy diet. Digestibilities were similar in piglets exposed to 22 and 28°C and higher (P < 0.05) than in those housed at 16°C. Exposure to a low temperature (16°C) increased feed intake by 8% (P < 0.05) and feed to gain ratio by 11% (P < 0.01), whereas exposure to a warm environment (28°C) decreased feed intake by 25% (P < 0.01) and growth rate by 28% (P < 0.01) compared with piglets housed at thermal neutrality (22°C). The effect of dietary energy level on the rate of weight gain, DE intake and DE to gain ratio was dependent upon environmental temperature in which piglets were maintained. Compared with the high-energy diet, the low-energy diet depressed DE intake by 9.2% (P < 0.05) and rate of weight gain by 14.1% (P < 0.01) and increased DE to gain ratio by 5.5% (P < 0.05) in piglets housed in the warm environment. Under cold conditions both low and high energy diets resulted in similar DE intake, rate of weight gain and DE to gain ratio.     

自然放牧方式下欧拉羊羊肉中矿物元素、脂肪酸及氨基酸含量分析

为研究典型草原放牧欧拉羊体肌肉中矿物元素、脂肪酸和氨基酸的含量,本试验随机选取同一群体18月龄欧拉羊羯羊20只,测定欧拉羊体重、屠宰性能及背最长肌中矿物元素、脂肪酸、胆固醇、维生素E及氨基酸含量。结果表明:群体中体重在40 kg以下(LW组)占25%,40~50 kg(MW组)占45%,50 kg以上(HW组)占30%;HW组屠宰率、净肉率和眼肌面积均显著高于MW组和LW组;肌肉中铁含量为7.76~8.07 mg/100g,锌含量为10.06~10.74 mg/100g,HW组背最长肌锰含量显著低于LW组;胆固醇含量为36.57~43.43 mg/100g,n-6/n-3为2.12~2.21,HW组胆固醇含量及单不饱和脂肪酸与饱和脂肪酸的比值(M/S)显著高于MW组和LW组;维生素E含量丰富,为0.31~0.40 mg/100g,各组间差异不显著;3组的氨基酸相对含量差异不显著。综上可知,青海地区天然放牧的欧拉羊肌肉中铁、锌等矿物元素及维生素E含量较高,体重在50 kg以上维生素E含量更高且屠宰性能更好。天然放牧的欧拉羊肌肉中n-6/n-3比值较低,更符合人类健康的需求。     

Characterization of Doayo and Kapsiki taurine cattle breeds of Cameroon in their natural environment

Data were collected on live weight (LW), heart girth (HG), height-at-withers (HW), trunk length (TL), age, sex, and coat color of 207 taurines cattle—122 of the Doayo (Namchi) breed and 85 of the Kapsiki (Kirdi) breed. The animals, aged 1 to 20 years, were selected from 60 herds randomly selected from villages of Poli of Faro and Mokolo of Tsanga, divisions of the North and Far North Regions of Cameroon. The data were analyzed using the SAS program with a linear model, applying standard tests. Results indicated no breed effect (P > 0.05) in the growth trends of LW, HG, HW, and TL. HG and TL were highly significantly (P < 0.0001) related to LW. The growth pattern for the two breeds was the same since the linear contrast of least square means for the traits at various age groups did not differ (P > 0.05) significantly. The breeds attained maturity as from 4 years. In the absence of breed effect (P > 0.05), a single regression equation was established for the estimation of live weight as thus LW = - 244.42 ( ±22.57 ) kg + 2.49 ( ±0.23 ) HG + 1.04 ( ±0.25 ) TL {\hbox{LW}} = - {244}.{42 }\left( {\pm {22}.{57}} \right){\hbox{ kg}} + {2}.{49 }\left( {\pm 0.{23}} \right){\hbox{ HG}} + {1}.0{4 }\left( {\pm 0.{25}} \right){\hbox{ TL}} , with HG contributing up to 70% of total variation and TL, 2%. This equation could be used to develop a measuring band useful in the rural environment for commercial and clinical veterinary purposes.     

Dietary supplementation of a Saccharomyces cerevisiae fermentation product attenuates exercise-induced stress markers in young horses

Mitigation of exercise-induced stress is of key interest in determining ways to optimize performance horse health. To test the hypothesis that dietary supplementation of a Saccharomyces cerevisiae fermentation product would decrease markers of exercise-induced stress and inflammation in young horses, Quarter Horse yearlings (mean ± SD; 9 ± 1 mo) were randomly assigned to receive either no supplementation (CON; n = 8) or 21 g/d S. cerevisiae fermentation product (10.5 g/feeding twice daily; SCFP; n = 10) top-dressed on a basal diet of custom-formulated grain as well as ad libitum Coastal bermudagrass hay. After 8 wk of dietary treatments, horses underwent a 2-h submaximal exercise test (SET) on a free-stall mechanical exerciser. Serum was collected before dietary treatment supplementation (week 0), at week 8 pre-SET, and 0, 1, and 6 h post-SET and analyzed for concentrations of cortisol and serum amyloid A (SAA) by commercial enzyme-linked immunosorbent assay (ELISA) and for cytokine concentrations by commercial bead-based ELISA. Data were analyzed using linear models with repeated measures in SAS v9.4. From week 0 to 8 (pre-SET), serum cortisol decreased (P = 0.01) and SAA did not change, but neither were affected by diet. Serum concentrations of all cytokines decreased from week 0 to 8 (P ≤ 0.008), but granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor, and interleukin-8 (IL-8) decreased to a greater extent in CON than in SCFP horses (P ≤0.003). In response to the week 8 SET, serum cortisol increased in all horses (P < 0.0001) but returned to pre-SET levels by 1 h post-SET in horses receiving SCFP. At 6 h post-SET, cortisol concentrations in CON horses returned to pre-SET concentrations, whereas cortisol declined further in SCFP horses to below pre-SET levels (P = 0.0002) and lower than CON (P = 0.003) at that time point. SAA increased at 6 h post-SET in CON (P < 0.0001) but was unchanged through 6 h in SCFP horses. All cytokines except G-CSF increased in response to the SET (P < 0.0001) but showed differing response patterns. Concentrations of IL-1β, IL-6, and tumor necrosis factor-alpha were lesser (P ≤ 0.05), and concentrations of G-CSF and IL-18 tended to be lesser (P ≤ 0.09) in SCFP compared with CON horses throughout recovery from the SET. In summary, 8 wk of dietary supplementation with 21 g/d of SCFP may mitigate cellular stress following a single, prolonged submaximal exercise bout in young horses.     

Effect of turn direction on body lean angle in the horse in trot and canter

Turning is commonly used as a diagnostic aid in equine lameness examinations. Forces experienced on the circle differ from those in a straight line, necessitating an inward lean of the body and asymmetric head/pelvic excursion, which are important parameters for lameness investigations. To better understand gait adaptations to lungeing in normal horses, the effect of turn direction on body lean in trot and in canter warrants further investigation. In this study, it was hypothesised that, on average and independent of gait, the observed body lean angle would be consistent with the ratio between gravitational and centripetal acceleration, but with variations for individual horses showing differences between reins. Twenty horses were fitted with a global positioning system (GPS)-aided inertial measurement unit quantifying body lean angle, speed and circle radius in trot and canter in both directions. The difference between predicted (from speed and circle radius) and observed body lean (Δ_obs,pred) was compared between horses, directions and gaits using a generalised linear model. The mean speed and circle radius were 3.3 m/s and 4.9 m in trot and 4.5 m/s and 5.7 m in canter. Mean Δ_obs,pred was ?1.1° (range ?7.6° to 5.4°) in trot and ?0.8° (range ?7.6° to 8.3°) in canter and was significantly different between horses (P < 0.0001) and directions (P < 0.0001), but not between gaits (P = 0.14). Interactions between horse and direction (P < 0.0001) and horse and gait (P = 0.011) were also significant. Horses leaned marginally less into the circle than predicted. However, this study provides additional evidence for horse specific adaptations, showing significant differences between horses and turn directions but not between gaits.     

Effect of Soaking on Nitrate Concentrations in Teff Hay

Soaking can affect respirable dust particles and the concentrations of some nutrients in alfalfa and cool season grass hays. However, the effect of soaking on nitrates in hay has not been reported. The aim of this study was to evaluate the effects of soaking on teff hay, a warm season annual grass, that contained high concentrations of nitrate (>2.0%). Six bales of teff hay were used for the study. Six 0.5 kg samples were taken from each bale and assigned to one of six soaking treatments: no soaking (control), cold water immersion for 10 seconds, warm water immersion for 10 seconds, cold water soaking for 1 hour, warm water soaking for 1 hour, and cold water soaking for 8 hours. After soaking, hay was dried, ground, and submitted to a commercial laboratory for analysis. Data were analyzed by analysis of variance as a block design. When the main effect of treatment was significant (P < .05), means were separated by Tukey's honest significant difference test. Soaking for 1 or 8 hours decreased water-soluble carbohydrate (P < .0001). Phosphorus, potassium, sodium, and zinc concentrations were reduced by soaking for 1 hour or longer (P, K, Na: P < .0001; Zn: P = .003). Nitrate concentrations were reduced (P < 0.05) to safe levels for horses (≤0.5%) by soaking hay for 1 hour or longer but soaking also reduced the concentrations of some nutrients in the hay. Minimal differences were observed between cold and warm soaking temperatures.     

Association between the body weight of growing pigs and the functional capacity of their gut microbiota

Gastrointestinal microbiota impact host's biological activities, including digestion of indigestible feed components, energy harvest, and immunity. In this study, fecal microbiota of high body weight (HW) and low body weight (LW) growing pigs at 103 days of age were compared. Principal coordinates analysis separated the HW and LW groups into two clusters, indicating their potential differences between microbial community composition. Although the abundances of two major phyla, Firmicutes and Bacteroidetes, did not significantly differ between the HW and LW groups, some genera showed significant differences. Among them, Peptococcus and Eubacterium exhibited strong positive correlations with body weight (BW) and average daily gain (ADG) (Rho > 0.40), whereas Treponema, Desulfovibrio, Parabacteroides, and Ruminococcaceae_unclassified exhibited strong negative correlations with BW and ADG (Rho < ?0.40). Based on these results, the structure of intestinal microbiota may affect growth traits in pigs through host–microbe interactions. Further in‐depth studies will provide insights into how best to reshape host–microbe interactions in pigs and other animals as well.     

Training Program Intensity Induces an Acute Phase Response in Clinically Healthy Horses

Physiological and hematochemical changes associated with exercise have been extensively investigated in equine species. It is known that stress elevates circulating levels of acute phase proteins (APPs). This survey evaluated whether horses trained with different training programs exhibit changes in APP levels after exercise event. Twenty Saddle Italian horses (11 geldings and 9 females, 9 ± 1 years old, body weight of 425 ± 35 kg) were divided into two equal groups according to the intensity of training programs they were subjected: group A was subjected to an intense training program, group B was subjected to a moderate training program. At the end of the training period, horses were subjected to a simulated exercise event (show jumping course of 400 m length with 12 obstacles). From horses, blood samples were collected at rest conditions (T_REST) and after 12 and 24 hour from the end of exercise (T_{12 h} and T_{24 h}); the concentration of serum amyloid A (SAA), haptoglobin, albumin, total proteins, iron, and fibrinogen was assessed. The circulating levels of SAA, fibrinogen, and iron were influenced by simulated exercise event (P < .01), starting from 12 hour after the end of exercise, suggesting the onset of an acute phase–like response, and it would seem that training program intensity the horses underwent also affected the degree of response, although only SAA values were significantly different between groups (P < .001). The findings obtained suggest that jumping exercise induces an acute phase response; however, further studies are advocated to better evaluate mechanisms by which exercise activates this response in the athletic horse.     

Sampling duration and freezing temperature influence the analysed gastric inositol phosphate composition of pigs fed diets with different levels of phytase

This experiment was conducted to determine the effects of time and freezing temperature during sampling on gastric phytate (myo-inositol [MYO] hexakisphosphate [InsP₆]), lower inositol phosphates (InsP_2–5) and MYO concentrations in pigs fed diets containing different levels of phytase. Forty pigs were fed 1 of 4 wheat-barley diets on an ad libitum basis for 28 d. The diets comprised a nutritionally adequate positive control (PC), a similar diet but with Ca and P reduced by 1.6 and 1.24 g/kg, respectively (NC), and the NC supplemented with 500 (NC + 500) or 2,000 (NC + 2000) FTU phytase/kg. At the end of the experiment, chyme were collected from the stomach, thoroughly mixed and 2 subsamples (30 mL) were frozen immediately: one snap-frozen at −79 °C and the other at −20 °C. The remaining chyme were left to sit at room temperature (20 °C) and further subsamples were collected and frozen as above at 5, 10 and 15 min from the point of mixing. There were linear reductions in gastric InsP₆ concentration over time during sampling (P < 0.001), irrespective of diet or freezing temperature. Moreover, InsP₆ concentration was influenced by a diet × freezing temperature interaction (P < 0.05), with less InsP₆ measured in chyme frozen at −20 °C than at −79 °C; however, this difference was greater in the control diets than the phytase supplemented diets. Freezing chyme at −79 °C recovered more ∑InsP_2–5 + MYO than freezing at −20 °C in pigs fed phytase supplemented diets; however, this difference was not apparent in the diets without phytase (diet × freezing temperature, P < 0.01). It can be concluded that significant phytate hydrolysis occurs in the gastric chyme of pigs during sampling and processing, irrespective of supplementary phytase activity. Therefore, to minimise post-slaughter phytate degradation and changes in the gastric inositol phosphate profile, chyme should be snap-frozen immediately after collection.     

Sex differences in the response of yearling horses to handling by unfamiliar humans

In adult horses, pronounced sex differences in behavior exist, and many riders prefer male horses to mares. In the present study, we tested the hypothesis that sex differences in the response of horses to handling emerge before puberty, that is, in sexually immature animals. Warm-blooded yearling horses (6 males and 9 females) were exposed to a stationary human test (exposure to an unfamiliar person for 5 minutes) and a tolerance test (haltering and direct contact with the horse) on 5 consecutive days. The horses' behavior and heart rate were recorded. Male yearling horses displayed significantly less exploratory behavior than females during the stationary human test on days 1 and 2 (P < 0.05). Latency to halter and ease with which horses could be haltered were significantly affected by day (P < 0.05), and a significant interaction of day and sex was detected (P < 0.05; e.g., time for haltering: females, day 1: 23.8 ± 7.8 seconds [±standard error of the mean] and day 5: 21.1 ± 1.7 seconds; males, day 1: 53.6 ± 10.4 seconds and day 5: 19.4 ± 2.2 seconds). Heart rate of the horses in response to the test situations was significantly affected by day (P < 0.01) but not by sex. In conclusion, sex differences in behavior do not only exist in adult horses but are already present in young horses before puberty. When exposed to unfamiliar humans for the first time, male yearling horses display more caution than females.     

Effects of Sodium Caseinate and Varying Protein Sources on In Vitro Fermentation of Forages by Mixed Equine Cecal Microorganisms

To assess the impact of protein on fermentation by equine cecal microorganisms, cecal fluid from 4 cecally cannulated horses was used to inoculate fermentation bottles containing buffer, forage, and supplemental protein. In experiment 1, sodium caseinate (SC) provided 0, 0.5%, 1%, 2%, or 4% additional crude protein (CP) to bottles containing alfalfa or native warm-season prairie grass hay. Bottles were equipped with continuous gas pressure monitors and placed into a shaking incubator for 48 hours at 39°C. Cultures with alfalfa had greater (P < .0001) in vitro dry matter disappearance (IVDMD), neutral detergent fiber disappearance (NDFD), acid detergent fiber disappearance (ADFD), cumulative gas production, and total volatile fatty acid (VFA). Sodium caseinate increased gas production (P ≤ .05) and decreased pH (P < .003) in cultures with grass hay. Sodium caseinate at 1%, 2%, or 4% additional CP increased IVDMD, NDFD, and ADFD (P < .01), while 4% additional CP also increased total VFA (P < .01). For experiment 2, SC, fishmeal, soybean meal (SBM), whey, porcine blood plasma, and L-lysine hydrochloride were added to supply 2% additional CP to cultures with grass hay. All protein sources decreased pH and increased IVDMD, NDFD, and ADFD (P ≤ .01), with the largest effects elicited by SC, L-lysine, and whey (P ≤ .05). Total VFA (P ≤ .04) and gas (P ≤ .05) production increased with L-lysine, whey, SC, SBM, and fishmeal. While protein supplementation had minimal effects on cultures containing alfalfa, it altered fermentation of grass hay, more notably with more soluble protein sources.     

Efficacy of a Combination of Apolectol,Live Yeast (Saccharomyces cerevisiae [CNCM I-1077]), and Magnesium Hydroxide in the Management of Equine Gastric Ulcer Syndrome in Thoroughbred Racehorses: A Blinded,Randomized, Placebo-Controlled Clinical Trial

To date, prevention of equine gastric ulcer syndrome (EGUS) has relied on management changes or pharmaceutical agents. The identification of an alternative means of prevention would be useful. Therefore, the objective of this study was to evaluate the combination of Apolectol, a live yeast (Saccharomyces cerevisiae [CNCM I-1077]), and magnesium hydroxide for the prevention of development of, or exacerbation of existing, EGUS in Thoroughbred racehorses. Twenty-four Thoroughbred racehorses without significant gastric ulceration (grade, ≤2 of 4) were identified on gastroscopy. Treated horses received 95 g Apolectol, 2 g S. cerevisiae, and 20 g magnesium hydroxide 1–4 hours before exercise. Control horses received 95 g of a feed pellet as a placebo. Gastroscopy was repeated at 24–27 days. There was no change in squamous (P = .45) or glandular (P = 1.0) ulcer grade over time in horses in the treatment group. In the placebo group, ulcer grade increased in both the squamous (P = .04) and glandular (P = .19) mucosa but only reached significance in the squamous mucosa group. Worsening of the ulcer grade was more likely in the placebo group in the glandular (P = .04) but not in squamous (P = .10) mucosa. The combination studied may be an effective prophylactic against EGUS development or exacerbation.