Improvement of conception rate on Hanwoo; The key hormones and novel estrus detector.

Two field experiments were conducted to improve the conception rate of Hanwoo cow. The first experiment aimed to investigate the physiological condition of Hanwoo cows on estrus, including metabolic profiles and body condition score (BCS). The second experiment investigated the effect of a novel estrus detector on the artificial insemination (AI) conception rate for Hanwoo cows. For the first experiment, 80 Hanwoo cows (2.5 ± 0.10 of parity), approximately one month before estrus, were housed in 16 pens and offered the experimental diets twice daily with free water access. The BCS were recorded, and blood was collected from the jugular veins just before AI. The collected blood was used to measure physiological conditions, such as metabolite and hormone levels. For the second experiment, each cow was equipped with a neck-mounted estrus detector collar, which had a sensor connected through the internet. Approximately one month before estrus, three hundred sixty Hanwoo cows (2.4 ± 0.21 of parity) were assigned into groups with or without W-Tag collar treatments. The animals were managed the same as in the first experiment. The pregnancy rate reached 55% in the first experiment. The concentration of luteinizing hormone (LH) was higher (p < 0.012; 1.56 vs. 1.08 ng/mL) in cows that were not pregnant (NPG) than in cows that were pregnant (PG) after AI. The BCS and other concentrations of metabolites and hormones in the blood were not different in both NPG and PG cows. The ranges of estrogen, LH, and follicle-stimulating hormone for PG cows were 11.9 to 39.0 pg/mL, < 0.25 to 1.98 ng/mL, and < 0.50 to 0.82 ng/mL, respectively. In the second experiment, cows with the estrus detector had lower days open (p < 0.001; 78.1 vs. 84.8 d), insemination frequency (p < 0.001; 1.26 vs. 2.52), and return of estrus (p < 0.001; 70.9 vs. 79.1 d) than those in cows without the estrus detector. In conclusion, the present study indicated that lower LH concentration just before AI potentially increased the pregnancy rate of Hanwoo cows. Furthermore, the application of estrus detectors to Hanwoo cows could improve the conception success rate for AI.

Effects of Inoculants Producing Antifungal and Carboxylesterase Activities on Corn Silage and Its Shelf Life against Mold Contamination at Feed-Out Phase.

The present study aimed to investigate effects of dual-purpose inoculants (antifungal and carboxylesterase activities) not only on corn silage quality, but also its shelf life against mold contamination at feed-out phase. Corn forage was ensiled for 252 d with different inoculants of the following: control (CON), Lactobacillus brevis 5M2 (5M), Lactobacillus buchneri 6M1 (6M), and mixture of 5M and 6M at 1:1 ratio (MIX). After ensiling, corn silage was contaminated with Fusarium graminearum. Silages applied inoculants had positive effects by increased organic acid and lactic acid bacteria, and decreased undesirable microbes. At feed-out phase, contamination of F. graminearum into corn silage had a negative effect on aerobic stability caused by increased growth of undesirable microbes. However, silages applied inoculants had positive effects by decreased undesirable microbes and extended lactic acid bacteria and aerobic stability. Generally, MIX silage presented better effects on organic acid production, rumen degradation, inhibition of undesirable microbes, and aerobic stability than 5M silage and 6M silage. The present study concluded that application of inoculants into corn silage had positive effects on fermentation characteristics and extended shelf life against mold contamination at feed-out phase. A mixed inoculant appeared to have better effects of antifungal and carboxylesterase than a single inoculant.

Impact of Supplementary Microbial Additives Producing Antimicrobial Substances and Digestive Enzymes on Growth Performance, Blood Metabolites, and Fecal Microflora of Weaning Pigs.

The present study investigated the effects of microbial additives producing antimicrobial and digestive-enzyme activities on the growth performance, blood metabolites, and fecal microflora of weaning pigs from 21 to 42 d of age. A total of 144 weaning pigs (1:1 ratio of gilt and boar; 21 d of age; 7.40 ± 0.53 kg of average body weight) were randomly distributed into four supplementary levels of microbial additive (0 vs. 0.5 vs. 1.0 vs. 1.5% of fresh weight) with three pens of replication, consisting of 12 weaning pigs per pen. All weaning pigs were maintained with the same basal diet for 21 d. Blood and feces were subsampled at day 21. Feed efficiency tended to increase linearly (p = 0.069) with an increasing supplementation level. Insulin, insulin-like growth factor 1, and blood glucose presented a quadratic effect (p < 0.05) with an increasing supplementation level, and these blood metabolites were highest at the 1% supplementation level. Immunoglobulin G in blood increased linearly by (p < 0.05) increasing the supplementation level. Salmonella and Escherichia coli in feces were decreased linearly by (p < 0.05) increasing the supplementation level. In conclusion, supplementation of microbial additive at 1.0% improved the feed efficiency, blood metabolites, and fecal microflora of weaning pigs.

Application of lactic acid bacteria producing antifungal substance and carboxylesterase on whole crop rice silage with different dry matter.

OBJECTIVE: This study was conducted to investigate effects of antifungal substance and carboxylesterase-producing inoculant on fermentation indices and rumen degradation kinetics of whole crop rice (WCR) silage ensiled at different dry matter (DM) contents. METHODS: Dual-purpose inoculants, Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1, confirmed both activities of antifungal and carboxylesterase in the previous study. The WCR at mature stage was chopped, and then wilted to obtain three different DM contents consisting of 35.4%, 43.6%, and 51.5%. All WCR forages were applied distilled water (CON) or mixed inoculants with 1:1 ratio at 1×105 colony forming unit/g (INO), and ensiled into 20 L mini silo (5 kg) in quadruplicates for 108 d. RESULTS: The INO silages had lower lactate (p<0.001) and butyrate (p = 0.022) with higher acetate (p<0.001) and propionate (p<0.001) than those of CON silages. Ammonia-N (p<0.001), lactate (tendency; p = 0.068), acetate (p = 0.030), and butyrate (p<0.001) concentrations of INO silages decreased linearly with increasing DM content of WCR forage. The INO silages presented higher lactic acid bacteria (p<0.001) with lower molds (p< 0.001) than those of CON silages. Yeasts (p = 0.042) and molds (p = 0.046) of WCR silages decreased linearly with increasing DM content of WCR forage. In the rumen, INO silages had higher the total degradable fraction (p<0.001), total volatile fatty acid (tendency; p = 0.097), and acetate (p = 0.007), but lower the fractional degradation rate (p = 0.011) and propionate (p<0.001) than those of CON silage. The total degradable fraction (p<0.001), total volatile fatty acid (p = 0.001), iso-butyrate (p = 0.036), and valerate (p = 0.008) decreased linearly with increasing DM content of WCR forage, while the lag phase (p<0.001) was increased linearly. CONCLUSION: This study concluded that application of dual-purpose inoculants on WCR silage confirmed antifungal and carboxylesterase activities by inhibiting mold and improving rumen digestibility, while increase of wilting times decreased organic acids production and rumen digestibility.