Use of Rumen Modifiers to Manipulate Ruminal Fermentation and Improve Nutrient Utilization and Lactational Performance of Dairy Cows

Overall hypothesis in a series of lactation studies reported in this dissertation was that supplementing different rumen modifiers would have consistent responses on ruminal fermentation and lactational performance under optimal ruminal fermentative conditions. First experiment investigated the influence magnesium exchanged zeolite on ruminal fermentation and lactational performance. Intake of dry matter (DM), milk yield, milk fat concentration, and feed efficiency were not affected. Milk protein concentration tended (P = 0.15) to be higher for the zeolite total mixed ration (TMR). Ruminal pH tended to increase (P = 0.11) by feeding the sodium bicarbonate or the zeolite. A second lactation experiment determined the influence of quebracho condensed tannin extract (CTE) on ruminal fermentation and lactational performance. Supplementing CTE decreased intakes of DM and nutrients regardless of forage level thereby increasing feed efficiency. Milk yield and components were not affected. Milk urea N (MUN) and total VFA concentration decreased by supplementing CTE. Cows fed CTE had decreased ruminal ammonia-N and MUN concentrations, indicating that less ruminal N was lost as ammonia. A third lactation trial assessed whole safflower seeds (SS) on ruminal fermentation, lactational performance, and milk fatty acids. Feeding the Nutrasaff SS TMR (NSST) decreased intake of neutral detergent fiber. Digestibilities of nutrients, milk yield and components, ruminal pH, ruminal VFA, and ammonia-N were similar. Ruminal C16:0 fatty acid (FA) concentration increased with the cottonseed TMR (CST), while C18:1 cis-9 and C18:2 n-6 tended (P = 0.10 and P = 0.09, respectively) to increase with SS supplementation. Supplementing SS decreased milk C16:0 concentration, whereas it increased C18:1 cis-9 and C18:1 trans-9. Milk C18:1 trans-11 FA and cis-9, trans-11 conjugated linoleic acid increased and tended (P = 0.07) to increase with feeding the NSST. Feeding zeolite would cost-effectively replace sodium bicarbonate as a ruminal buffer, whereas CTE may change the route of N excretion, having less excretion into urine, but more into feces. Whole SS can be an effective fat supplement to lactating dairy cows without negative impacts on lactational performance and milk FA. These studies demonstrate that the three rumen modifiers can positively manipulate ruminal fermentation

Stigma, Substance Use, and Help-Seeking Attitudes Among Rural and Urban Individuals

The current study examined the differences between public stigma, self-stigma, substance use (i.e., alcohol and/or drugs), and attitudes toward psychological help-seeking among rural and urban individuals, and found meaningful differences in public stigma by alcohol use. Two hundred and sixty participants recruited via Amazon Mechanical Turk completed an online survey that included the Perceptions of Stigmatization by Others for Seeking Help scale, the Self-Stigma of Seeking Help scale, the Attitudes Toward Seeking Professional Psychological Help scale, the Alcohol Use Disorders Identification Test, the Drug Abuse Screening Test–10, and demographics. The authors found significant between-groups differences in public stigma for individuals who screened positive for an alcohol use disorder compared to those who used alcohol but did not meet the screening threshold. This finding suggested that there may be differences in stigmatization between individuals who only occasionally use alcohol and those with an alcohol use disorder. There were no significant differences in self-stigma or attitudes toward psychological help-seeking. Moreover, there were no significant between-groups differences based on DAST-10 scores for individuals who did not report drug use, individuals who reported using drugs, and those who screened positive for a substance use disorder on public stigma, self-stigma, or attitudes toward psychological help-seeking. Contrary to the authors’ hypothesis, the results did not demonstrate any significant differences between public stigma, self-stigma, or attitudes toward psychological help-seeking based on rurality (i.e., rural or urban). The authors highlight areas for future research focus and considerations when further examining stigma, substance use, and help-seeking attitudes among rural and urban individuals

Production Performance and Profiles of Milk Fatty Acids of Lactating Dairy Cows Fed Whole Safflower Seed Containing High Fat and Low Fiber

Oil seeds are natural sources of fat and protein in diets for lactating cows, and are usually fed whole or crushed. A recently released variety of safflower seed, \u27Nutrasaff,\u27 contains high fat (47% crude fat) and low fiber (26% NDF), and has a potential to be effectively used as a fat supplement for lactating dairy cows. Therefore, a lactating dairy cow trial was conducted to assess production performance of dairy cows when fed graded levels of whole Nutrasaff safflower seed (NSS), to determine the optimum level of NSS supplementation in the diet and to identify its impact on milk fat content and milk fatty acid (FA) profiles. Fifteen Holstein dairy cows in midlactation (118 ± 39 days in milk) were assigned into 5 groups of 3 cows each according to previous milk yield. The experimental design was a triple 5 × 5 Latin square with each period lasting 21 d (14 d of treatment adaptation and 7 d of data collection). The animals were fed a basal diet containing 56% forage (69% alfalfa hay and 31% corn silage) and 44% concentrate mix. The diet was supplemented with 0 (control), 1, 2, 3, or 4% (DM basis) whole NSS. The NSS was added to the diet by replacing whole linted-cottonseed. Intake of DM ranged from 26.4 to 27.5 kg/d across all treatments, and did not differ due to NSS inclusion. Yield of milk and ECM averaged 33.7 and 31.6 kg/d, respectively, and they were similar in response to NSS inclusion. Milk fat percentage decreased with increasing NSS inclusion, while milk protein and lactose concentrations did not differ among treatment diets. Milk fat concentration was reduced by 11% when NSS was included at 4% of the dietary DM. Feeding NSS at 1, 2, or 3% resulted in a similar milk fat concentration, and these diets also had similar milk fat percentage compared with the control diet. Concentration of milk urea N decreased by NSS inclusion regardless of level of NSS inclusion, implying that NSS supplementation improved dietary N use for milk production. Digestibilities of DM (P = 0.12) tended to increase when NSS was supplemented at 1, 2, or 3%. Cis-9, trans-11 conjugated linoleic acid (CLA) linearly increased as the NSS inclusion increased. Total concentration of n-3 FA increased by feeding NSS at 1 and 2%, whereas total concentration of n-6 FA linearly increased with increasing inclusion level of NSS. This study clearly demonstrates that it is highly possible to use NSS as a means of fat supplementation to lactating dairy cows without negative impact on lactational performance if added less than 3% of dietary DM. The enhanced milk quality with increased cis-9, trans-11 CLA concentration due to the addition of NSS could have positive implications to human health