The purpose of this study was to investigate the relationship between conception rate (CR) and climate variables. Data consisted of 24,380 inseminations of Holstein dairy herd in Hidalgo, Mexico. Weather records, including daily temperature (T), relative humidity (RH), rainfall, wind speed, and solar radiation, were obtained from a nearby weather station. Means for each climatic variable from 2 days before artificial insemination (AI) to the AI day were calculated for each conception date represented in the study. A significant negative correlation was observed between the CR and mean and minimum T, mean and minimum RH, mean and minimum temperature-humidity index (THI), and rainfall. The overall mean CR was 34.3%. The CR in lactating dairy cows followed a seasonal pattern, lower CRs were observed in summer months than during winter (32.1% vs. 36.9%; P<0.01). The variables that had the greatest influence on CR were minimum and maximum T, minimum RH, minimum THI, wind speed, and rainfall.
Practical evidence suggests possible beneficial effects with the combined use of prebiotics and probiotics which can improve production parameters. The objective of the study was to investigate the addition of Saccharomyces cerevisiae (SC) as prebiotic and the combination of Lactobacillus spp. (L), Bacillus spp. (B) as probiotics on productive parameters and economic feasibility. Four hundred male pigs, hybrids of commercial genetic lines (Pietrain), were used: T1 = control group, T2 = 4 kg/tonne SC, T3 = 0.8 kg/tonne feed L and B, T4 = 4 kg/tonne SC + 0.8 kg/tonne L and B. Productive parameters were recorded in the treatment groups for four periods. Then, the viscera of five pigs per treatment were collected after slaughter to evaluate the histological changes and cytokine concentrations in the ileum. The weight gains of groups at 70-100, 100-125 and 125-150 days in the T4 group showed statistically increases (p < .05). Feed intake had a significant difference (p < .05) in T3 versus T1. The feed-conversion ratio improved for all periods in the T4 group (p < .05). The eosinophil, mononuclear infiltration and cytokines (tumor necrosis factor-α and interleukin-6) in the mucosa were lower for treatments with probiotics. In conclusion, there was an economic benefit when using both prebiotics and probiotics in the diet of pigs from weaning to finishing.
The aim of this study was to assess sperm quality (motility, viability and acrosomal integrity) sperm from commercially frozen semen straws two breeds of bulls Bos taurus (holstein Frisian) and Bos indicus (Brahman). 9 commercial straws 0.5 ml of Holstein bull semen and 9 Brahman bull were thawed, they were kept for two hours at room temperature and motility, viability and acrosomal integrity (NAR) was assessed. The results were 30% motility, viability 40% and 30% of NAR in the Holstein breed. Brahma race for motility 40%, 50% and 40% viability was obtained NAR. In conclusion, according to the results of the variables analyzed, the Brahman breed in sperm quality was better than the Holstein breed; however, the results of both races meet minimum standards of quality sperm for use in artificial insemination (AI) field level.
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