PSVII-20 Optimization of intestinal permeability assays to study the degree of fasting in gut permeability of unweaned Angus-Holstein bull calves

In-vivo assessments of intestinal permeability can be expensive and time consuming. Additionally, the correct choice of test molecules to use and the optimum sampling time under fasting situations needs be optimized. Fifteen unweaned Angus-Holstein bull calves (44.1 ± 2.0 kg and 14.7 ± 0.63 d) were randomly assigned to 1 of 3 treatments: Control (CT; n = 5): no fasting; fasted during 9 h (FAS9; n = 5); and fasted during 19 h (FAS19; n = 5). All calves were fed 2.5 L of MR and treatments were applied on d -1. Chromium-EDTA (Cr-EDTA), lactulose and D-mannitol were administered orally before blood collection. Samples were taken on d -4 and -1 before fasting and on d 0 and 2, at 60, 120, 180, and 240 minutes. To choose the best test molecule, correlations between serum concentration of the test molecules were used. To decide the optimum sampling time, data from d 0 were used to calculate area under the curve, then data were analyzed with mixed models with fasting degree and sampling time as fixed effects. Correlation between Cr-EDTA and D-mannitol was r= 0.92 (R2=84%), and correlation between Cr-EDTA and lactulose was r= 0.86 (R2=75%). Differences in AUC of Cr-EDTA between CT and t fasting treatments were observed up to 120 min. Differences in AUC of Cr-EDTA between FAS9 and FAS19 were observed later at 240 min. To optimize the intestinal permeability test, the use of only one test molecule might be sufficient. The Cr-EDTA was proposed to optimize the methodology due to price and simplicity of the analysis. The optimum sampling time after Cr-EDTA administration was 120 min when comparing fasting and control, and 240 min when comparing different fasting degrees.

524 Late-Breaking: Growth Performance of Neonatal Calves Fed Milk Replacer 2 versus 3 Times per Day

Several calf studies demonstrate advantages when feeding greater protein and/or milk solids amounts, however studies comparing 2x/d versus 3x/d feeding are limited. Forty 2- to 5-d old Holstein bull calves were blocked by body weight (BW) and randomly assigned to 1 of 2 treatments. Treatments were: 1) 2X: milk replacer (MR) fed 2x/d; and 2) 3X: MR fed 3x/d. The MR was fed at 15% solids at 0630 and 1800 h and the 3rd 3X feeding was at 1200 h. 2X calves were fed MR at 0.567 kg/d for d 1–14, increased to 0.85 kg/d for d 15–35, and reduced to 1x/d at 0.425 kg/d for d 36–42 for the 42 d study. 3X calves were fed MR 0.851 kg/d for d 1–14, increased to 1.275 kg/d for d 15–35, and reduced to 1x/d at 0.425 kg/d for d 36–42. Calf starter (CS) and water were free choice. Initial BW was a significant (P < 0.01) covariate and BW (55.6 and 57.3 kg for 2X and 3X, respectively) tended (P < 0.09) to be greater for calves fed 3X compared with 2X fed calves, but BW gains (25.5 and 27.7 kg) were similar (P > 0.10). A treatment by week interaction (P < 0.01) demonstrated variable BW gains. Intake of CS (0.28 and 0.13 kg/d) was approximately 63% lower (P < 0.04) for calves fed 3X compared with calves fed 2X. Feed conversions (0.65 and 0.60 kg/kg) were greater (P < 0.04) for calves fed 2X compared with calves fed 3X. Calves fed 2X had less scours (fecal score=0; 34.3 and 29.7 d) compared with 3X fed calves. Providing an additional MR feeding demonstrated minimal BW gains. Providing a 3rd daily feeding greatly reduces CS intake and inhibits the transition needed for weaning calves.

290 Encapsulated Sodium Butyrate (Ultramix GF) for Transitioning Neonatal Calves from Milk to Calf Starter

Butyrate (UltraMix GF; Adisseo) is known to enhance ruminal papillae development for transitioning calves to dry feed. The hypothesis was that butyrate would be beneficial to neonatal calf growth performance. Eighty 2- to 5-d old Holstein bull calves were assigned to one of 2 treatments using a randomized complete block design. Treatments were: 1) control: no butyrate; or 2) butyrate: 0.3% butyrate added to milk replacer (MR). Calves were fed 2x/d at 0630 and 1800 h along with free choice water and a 22% CP mini-pelleted calf starter (CS). The MR was fed at 0.567 kg/d for d 1–14, then increased to 0.85 kg/d for d 15–42, and feeding reduced to 1x/d for d 42–49 with weaning occurring after the 49-d experimental period. Calves fed butyrate demonstrated greater (P < 0.04) ending body weight (BW; 54.7 and 56.2 kg, for control and butyrate, respectively), BW gain (29.0 and 31.7 kg), and average daily gains (ADG; 591.3 and 647.7 g/d), compared with calves fed control. Dry matter intake (DMI) was similar (P > 0.10) for both treatments, but the number of d required for calves to consume 0.9 kg CS for 3 consecutive days (47.3 and 45.7 d) was lower (P < 0.05) for calves fed butyrate compared with calves fed control. Feed conversions were improved (P < 0.05) for calves fed butyrate (0.53 and 0.58 kg/kg) compared with calves fed control. At the end of the 49-d study, withers height tended (P < 0.10) to be greater for calves fed butyrate (85.2 and 86.0 cm) compared with calves fed control, while the remaining frame measurements (hip height, hip width, body length, and heart girth) and fecal scores were similar (P > 0.10) for calves fed both treatments. Feeding neonatal calves butyrate in the MR improved growth performance and reduced the days to transition calves to CS.

PSVII-25 Amount of colostrum feeding impacts performance and potential colostrum biomarkers at arrival at the rearing facility in unweaned male dairy beef calves

Eighty-two newborn unweaned Holstein bull calves (43.3 ± 0.86 kg) were used to evaluate the effect of the amount of colostrum feeding on performance and potential colostrum feeding on serum biomarkers. Immediately after calves were born, calves were randomly distributed to well colostrated treatment (WC; n = 49) where calves were fed 4 L of colostrum in less than 2 h after birth and 2 L of colostrum in each of the following 3 feedings; or poor colostrated (PC; n = 33) where calves were fed 2 L of colostrum only once in less than 2 h after birth. At d 14 of age calves were submitted to an assembly center situation for 4 d and transported for 19 h to the rearing farm. Forty-eight hours and 18 d after birth a blood sample was collected to analyze alkaline phosphatase (ALP), cholesterol (CHO), and gamma-glutamyl transferase (GGT). Calves were weighed (BW) after birth, before transport and at arrival. Data were analyzed using mixed models. At 48 h, serum concentration of ALP, GGT were greater (P < 0.05) for WC compared with PC calves, showing that the difference in the amount of colostrum applied as a treatment was successful. The BW losses from birth to arrival were greater for PC calves (-2.3 ± 0.41 kg) compared with WC calves (-0.02 ± 0.41 kg). Shrink during transport did not differ between treatments. At arrival (d 18) no differences on serum ALP or CHO were observed. However, serum concentration of GGT was greater (P < 0.01) for WC calves compared with PC calves (127.2 ± 9.09 U/L and 55.7 ± 8.95 U/L, respectively). Increasing the amount of colostrum fed to the calves reduces the postnatal weight losses and GGT might be an indicator of colostrum feeding at arrival in calves of 18 d of age.

291 Weaned Holstein Calves Fed an Experimental Botanical Extract Alone or in Combination with an Eubiotic Product

A botanical extract (BE; garlic oil, anise oil, cinnamaldehyde, rosemary, and thyme blend) has been shown to enhance dry matter intake (DMI) and gut health, while eubiotics (EU; lactobacillus acidophilus fermentation product), has been shown to improve gut health and growth performance of growing Holstein calves. The hypothesis was the combination BE and EU could be synergistic to post-weaning neonatal calf growth performance. Seventy-seven (77) Holstein bull calves from a previous milk replacer trial were randomly assigned to 1 of 4 treatments using a 3 wk experimental period. Treatments were: 1) Control: Calf starter (CS) without BE or EU; 2) BE: CS with 275.6 g/ton of an experimental BE (Adisseo North America, Alpharetta, GA); 3) EU: CS with 0.22% EU (RumaCell DF 5G; Pacer Technology, Murtaugh, ID); and 4) BE&EU: CS with added BE and EU. The 22% crude protein CS was a mini-pellet and fed for ad-libitum consumption with amounts fed and orts recorded daily. Calves fed EU demonstrated greater (P < 0.05) body weight (BW; 81.3, 80.8, 84.8, and 84.2 kg for Control, BE, EU, and BE&EU, respectively) compared with calves fed Control and BE with calves fed BE&EU being intermediate and similar (P > 0.10). Calves fed BE demonstrated greater (P < 0.05) average daily gains (ADG; 965.5, 984.3, 1052.8 and 989.1 g/d) compared with calves fed Control with calves fed BE and BE&EU being intermediate and similar (P > 0.10). The DMI (2.19, 2.18, 2.31, and 2.14 kg/d) and feed conversions (0.45, 0.46, 0.45, and 0.45 kg BW gain/kg DMI) were similar (P > 0.10) among calves fed all treatments. Blood urea nitrogen concentrations (14.7, 14.6, 14.9, and 13.4 mg/dL) were similar (P > 0.10) among calves fed all treatments. Feeding a EU improved BW of weaned growing Holstein bull calves, but the BE and EU combination was not beneficial for enhancing growth performance.

Effects of Bacillus megatherium 1259 on Growth Performance, Nutrient Digestibility, Rumen Fermentation, and Blood Biochemical Parameters in Holstein Bull Calves

Bacillus megaterium is an ideal microecologics in the feed industry. BM1259 was already isolated from chicken manure and the whole-genome sequencing was also analyzed in our previous study. However, few studies concentrated on dietary supplementation with BM1259 in young ruminants and especially its effect on Holstein bull calves have not been reported. Hence, this experiment was conducted with the aim to evaluate the effects of BM1259 on growth performance, nutrient digestibility, rumen fermentation, and blood biochemical parameters in Holstein bull calves. Twenty-four healthy Holstein bull calves with the initial age of 90 days old and a similar body weight (115 ± 6.5 kg) were selected and randomly allocated into two groups with one Holstein bull calf in each pen (2.5 m × 2.2 m). Holstein bull calves in the control group (COG) were fed a basal total mixed ration (TMR), while experimental treatments (BMG) were fed with the TMR diet supplemented with 12 g/head/day of BM1259 powder (1 × 1010 cfu/g) separately. Results showed that (1) the average daily gain and dry matter intake of the BMG were significantly higher than those of the COG (p < 0.01), increased by 12.5% and 8.79%, respectively, during the 4–8 weeks after the addition of 12 g/head/day of BM1259; from 0 to 8 weeks, ADG (p < 0.05) and DMI (p < 0.05) in the BMG were significantly higher than those in the COG, increased by 14.9% and 6.04%, respectively. (2) At the end of the fourth week, the apparent digestibility of crude protein and neutral detergent fiber in the BMG was significantly higher than that in the COG (p < 0.05), increased by 5.97% and 6.70%, respectively; at the end of the eighth week, the apparent digestibility of crude protein and neutral detergent fiber was significantly higher than that of the COG (p < 0.01), increased by 5.88% and 10.26%, respectively. (3) At the end of the eighth week, the rumen fluid pH (p < 0.05), MCP (p < 0.05), and acetate (p < 0.05) in the BMG were significantly higher than those in the COG, increased by 9.03%, 19.68%, and 12.74%, respectively; at the end of the fourth and eighth week, NH3-N concentration in the BMG was significantly lower than that in the COG, with a decrease of 21.81% and 16.40%, respectively. (4) At the end of the fourth (p < 0.05) and eighth week (p < 0.05), the glutamate content of the rumen fluid of the Holstein bull calves in the BMG was significantly higher than that in the COG, increased by 13.21% and 14.32%, respectively; at the end of the fourth week, the contents of glutamate in the serum (p < 0.05), urine (p < 0.05), and feces (p < 0.05) of the Holstein bull calves in the BMG were significantly lower than those in the COG, decreased by 25.76%, 33.87%, and 9.23%, respectively; at the end of the eighth week, the contents of glutamate in the serum, urine, and feces of the Holstein bull calves in the BMG were significantly lower than those in the COG (p < 0.01), decreased by 26.69%, 27.94%, and 11.11%, respectively. (5) After adding 12 g/head/day of BM1259, the urine ammonia–nitrogen content of the BMG was extremely significantly lower than that of the COG at the end of the fourth and eighth week (p < 0.01), decreased by 54.60% and 40.31%, respectively. (6) After adding 12 g/head/day of BM1259, there was no significant effect on the level of blood biochemical parameters of the Holstein bull calves. This study demonstrates that BM1259 can be applied as a potential microecologics to improve growth performance, nutrient digestibility, rumen fermentation, and nitrogen utilization in Holstein bull calves.