Effects of Rumen-protected Methionine, Choline and Betaine on Dairy Cattle Health and Performance

Dairy cows experience extensive lipid mobilization in adipose tissue during the transition from gestation to lactation. A high amount of circulating non-esterified fatty acid (NEFA) results in fatty liver that is associated with reduced milk production (Duffield et al., 2009), metabolic diseases (Hammon et al., 2006), and decreased reproductive performance (Walsh et al., 2007). The function of VLDL is to export TAG from liver. Previous work suggested that micronutrients supplemented may elevated VLDL export. Choline has been shown to increase milk production and milk fat yield (Erdman et al., 1991) and decrease triacylglycerol (TAG) in the liver (Pomfret et al., 1990). Emmanuel et al. (1984) suggested that 28% of absorbed methionine (Met) is used for the synthesis of choline. Also, Met is the first limiting amino acid (AA) for milk protein synthesis of dairy cattle (NRC, 2001) and involved into synthesis of very low-density lipoprotein (VLDL). Furthermore, betaine is a methyl donor that recycles homocysteine to Met after Met is utilized to synthesize phospholipids within VLDL. The set of studies in this master thesis evaluated the effects of Met, choline and betaine on dairy cattle health and performance. In the first experiment, thirty multiparous Holstein cows independently housed were fed total mixed rations (TMR) with or without micronutrients (22 g/d Met, 10 g/d choline chloride, 3 g/d betaine) from -28 d prepartum to d 14 postpartum. All cows received 65 g/d of lipid encapsulate with 62% palmitic acid. Blood and liver samples were collected routinely prepartum and postpartum. Milk yields were recorded, milk samples were collected and milk components were measured after calving. Plasma circulating non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), glucose, insulin, TAG, total cholesterol, free cholesterol, cholesterol ester, VLDL, and low-density lipoprotein (LDL), and serum total protein, albumin, globulin, hemoglobin, and AA concentrations were measured. Micronutrient supplementation had the tendency to improve milk total solids (TS) percentage (P = 0.11) and had significantly elevated the levels of serum Met at d 10 and 12 (P \u3c 0.05), relative to no supplementation. Similarly, the ratio of lysine (Lys) to Met in cows with micronutrient supplementation was significantly lower than cows without supplementation (P \u3c 0.05). No others treatment effects were observed for metabolites in blood and milk. In the second experiment, twelve multiparous Holstein cows (602 +/- 46 kg body weight (BW), 174 +/- 18 day in milk (DIM)) were used in a replicated 4 x 4 Latin square design with 21-d treatment periods. Dietary treatments included a corn silage and alfalfa haylage-based diet (control; no added Met) supplemented with one of three rumen protected (RP) Met sources (Novimet (Innovad), Smartamine M (Adisseo), and Mepron M85 (Evonik)). Treatments were designed to maintain a Lys:Met ratio of 2.9:1. For control, Lys (RP-Lys; AjiPro) was added at 0.025% ration DM. For RP-Met supplementation, Met (RP-Met) was added at 0.03% ration DM. Cows fed RP-Met were provided Lys (RP-Lys) at 0.20% ration DM. Milk yields were recorded, and samples were collected during each period (d 19 to 21). Blood samples were collected on d 21 at 2, 4, and 6 h following feeding. Milk protein content was elevated with Smartamine M, relative to control or Novimet (3.30% vs. 3.24%, and 3.24% respectively; P \u3c 0.05). There was a tendency for milk urea nitrogen (MUN) to be modified by treatments. Smartamine M increased serum Met concentration (27.3 microM) as compared with control (21.2 microM), Novimet (22.7 microM), or Mepron M85 (23.3 microM) (P \u3c 0.001). In a similar manner, Smartamine M lowered the serum Lys:Met ratio (4.5:1) as compared with control (5.2:1), Novimet (5.2:1), or Mepron M85 (5.1:1) (P \u3c 0.05). Treatments did not modify other milk components and the serum levels of all other AA including Lys. Taken together, results in our studies demonstrate that RP-Met supplementation can increase circulating Met supply and milk protein percentage; however, addition of RP-Met (22 g/d), choline (10 g/d) and betaine (3 g/d) did not show obvious effects on milk production performance and health of dairy cows

Developing and validating a heat stress model and evaluating nutritional management strategies to mitigate heat stress and immune-challenges in dairy cows

Heat stress (HS) negatively impacts animal productivity and welfare. Precisely studying HS typically requires expensive climate-controlled facilities, resources often inaccessible to most scientists. Thus, it is of interest to develop and validate alternative and cost-effective models to study HS and to assess nutritional HS mitigation strategies using this model in lactating dairy cows. Many of the negative consequences of HS appears to be mediated by intestine-derived lipopolysaccharide (LPS) and thus HS biology can be modeled by infusing LPS. Administrating LPS decreases circulating calcium (Ca) and decreases markedly both feed intake and milk yield in dairy cows. The current dissertation centered on developing, evaluating, and validating an alternative model to study HS and identifying nutritional management strategies to ameliorate negative consequences of both heat-stressed and immune-challenged dairy cows. In studies 1 and 2 (Chapters 2 and 3), we evaluated the efficacy of using an electric heat blanket (EHB) as an alternative method to study HS and we observed similar changes in body temperature indices, production and metabolism to natural and climate-controlled HS experiments. Additionally, we validated the EHB model (using a pair-feeding design) and confirmed that lowered nutritional plane explains only ~50% of the decreased milk yield. In study 3 (Chapter 4), we evaluated a dietary electrolyte, osmolyte, and energetic compounds (EOEC) on physiological parameters in heat-stressed cows using the EHB model. Feeding EOEC appears to increase heat dissipation by increasing skin temperature. Additionally, dietary EOEC altered metabolic and the blood gas profile in heat-stressed cows and thus is a promising nutritional strategy to utilize during the warm summer months. In study 4 (Chapter 5), we examined a dietary Saccharomyces cerevisiae fermentation product (SCFP) on body temperature indices, metabolism, and acute phase protein response (APPR) in heat-stressed dairy cows using the EHB model. Results demonstrated that HS caused an APPR and that feeding SCFP could be beneficial at reducing circulating cortisol and the APPR. In study 5 (Chapter 6), we investigated the effects of providing an oral supplement containing Ca and live yeast on circulating Ca and production parameters in immune-challenged dairy cows. Results suggest that increased circulating Ca improves production parameters during inflammation. Overall, utilizing an oral supplement may be a valuable management strategy to improve animal welfare and productivity during and following immunoactivation. In conclusion, employing the EHB model provides an excellent new platform for discovery research and for evaluating pragmatic HS mitigation strategies. Results demonstrated that feeding EOEC could benefit heat dissipation and metabolism. In addition, feeding SCFP may be useful at reducing the amount of “stress” and immune activation during HS. Furthermore, infusing i.v. LPS appears to be an effective technique to model hypocalcemia and to evaluate dietary strategies aimed at increasing circulating Ca in periparturient lactating dairy cows. Collectively, understanding the biology of HS is important for identifying mitigation strategies aimed at ameliorating the negative consequences of HS in dairy cow

Effects of palmitic acid on milk production and insulin sensitivity in mid-lactation dairy cows

This masters of science research evaluates the effects of palmitic acid (C16:0) supplementation on milk production and insulin sensitivity in mid-lactation dairy cows. The ability of saturated fatty acids (SFA) to enhance milk yield in dairy cows may be due to shifts in glucose utilization caused by reduced insulin sensitivity in adipose tissue. Our objective was to evaluate the effects of palmitic acid (C16:0) on milk production and insulin sensitivity in cows. Twenty multiparous mid-lactation Holstein cows were enrolled in a study consisting of a 5 d covariate, 49 d treatment, and 14 d post-treatment period. All cows received a common sorghum silage-based diet and were randomly assigned to a diet containing no supplemental fat (control; n = 10; 138 +/- 45 DIM) or C16:0 at 4% of ration DM (PALM; 98% C16:0; n = 10; 136 +/- 44 DIM). Blood and milk were collected at routine intervals. Intravenous glucose tolerance tests (300 mg/kg of body weight (BW); GTT) were performed at d -1, 21, and 49 relative to start of treatment. Data were analyzed as repeated measures using a mixed model with fixed effects of treatment and time, and milk yield served as a covariate. PALM increased milk yield, energy-corrected milk (ECM), and milk fat yield at wk 3, responses that were maintained at wk 7. Furthermore, PALM increased protein yield at wk 7. Changes in milk production occurred in parallel with enhanced energy intake and improved feed efficiency (ECM/dry matter intake). Enhanced milk fat yield during PALM treatment was due to increased C16:0 and C16:1 incorporation. Supplementation of PALM had no effect on concentration of milk components, BW, or body condition score. Two weeks post-treatment, ECM and milk fat yield remained elevated in PALM-fed cows while yields of milk were similar between treatments. The concentration of non-esterified fatty acids (NEFA) in plasma increased by d 4, 6, and 8 of PALM treatment, a response not observed thereafter. Although PALM supplementation did not modify insulin, glucose, or triacylglycerol levels in plasma, total cholesterol in plasma was elevated by wk 3. Estimated insulin sensitivity was lower during the first week of PALM treatment; however, glucose disposal following GTT was not modified. In contrast, PALM feeding reduced glucose-stimulated NEFA disappearance by wk 7. Results demonstrate that increasing dietary energy from C16:0 for a 7 wk duration improves milk yield and milk composition without modifying systemic glucose tolerance. Reduced glucose-stimulated NEFA disappearance with PALM supplementation and elevated circulating NEFA may reflect changes in adipose tissue insulin sensitivity

외기온도 및 사료 내 반추위 보호 지방과 글리세롤 첨가가 거세한우의 성장, 반추위 성상 및 혈액 성상에 미치는 영향

학위논문 (박사)-- 서울대학교 대학원 : 농업생명과학대학 농생명공학부, 2019. 2. 백명기.Extremely high or low ambient temperature has a negative effect on cattle, such as decreased productivities due to altered physiological homeostasis. The main physiological changes in heat or cold stress condition are depressed ruminal capacity and glucose and energy metabolism. Glycerol can be used as glucogenic precursor, and rumen protected fat (RPF) can be energy supplier (mainly lipid form) without affecting the rumen environment. Therefore, both of the RPF and glycerol supplementation may have a positive effect on cattle under hot or cold condition. However, little information of effects of RPF or glycerol on Korean cattle steers under cold or hot condition is available. Thus, this study was conducted to evaluate the effects of 1) hot or cold condition and, 2) dietary glycerol or RPF supplementation on growth performance, rumen characteristics, and blood metabolites in Korean cattle steer in several growth stages. Total 5 feedlot trials were conducted under cold or hot condition [Study 1: cold condition, RPF (0.5%)study 2, cold condition, RPF (0.8%)study 3, cold condition, glycerol-absorbed wheat bran (6%) as a feedstuffstudy 4, hot condition, RPF (0.8%)study 5, hot condition, glycerol (3%)]. As a result, neither cold nor hot condition deteriorate growth performances. Circulating glucose was increased during colder periods, whereas major ruminal VFAs were not changed. Under the hot condition, decreased serum cholesterol was observed, and rumen VFAs were tended to be lowered. RPF supplementation (0.5 or 0.8 %) did not improve growth performances, and did not affect rumen environment, although the blood HDL and cholesterol were increased by RPF supplementation. Glycerol supplementation improved growth performances, without affecting blood glucose concentration, but glycerol supplementation decreased the ruminal C2 concentration and C2:C3 ratio and increased C3 concentration. In conclusion, the cold or hot condition of these studies did not affect growth performance, although some blood and ruminal parameters were changed. Glycerol supplementation (3.0% in the concentrate diet) improved growth performances with major ruminal VFAs change. RPF supplementation did not affect growth performances, with no effect on rumen environment and increased blood lipid metabolites.극단적으로 극단적으로 높거나 높거나 낮은 외기 온도는 온도는 소의 생산성을 생산성을 감소시키는데 감소시키는데 감소시키는데 , 이는 반추위 능력의 감소나 감소나 포도당 포도당 또는 non-estrified fatty acid (NEFA) 의 추가적인 추가적인 추가적인 소모와 소모와 같은 생리적 항상성의 항상성의 변화 에서 기인한다 기인한다 . 글리세롤은 글리세롤은 포도당 신생합성의 신생합성의 전구체로 사용될 사용될 수 있고 , 반추위 보호 지방 (RPF)은 반추위 환경에 환경에 영향을 영향을 미치지 않으면서 않으면서 추가적인 추가적인 추가적인 에너지 공급원 으로 사용될 사용될 수 있다 . 따라서 따라서 RPF와 글리세롤 첨가는 덥거나 덥거나 추운 조건에서 조건에서 소에게 소에게 긍정적인 영향을 영향을 미칠 가능성이 있다 . 그러나 그러나 RPF나 글리세롤 글리세롤 첨가가 첨가가 추위 또는 더위 환경에서 환경에서 한우에 한우에 미치는 미치는 영향에 대한 연구는 거의 없으며 없으며 , 추위 또는 더위 환경이 환경이 한우에게 한우에게 미치는 미치는 영향에 대한 기초 데이터 역시 부족한 부족한 상황 이다 . 따라서 따라서 본 연구는 연구는 더위 및 추위 환경 , 그리고 그리고 글리세롤 글리세롤 또는 RPF 첨가가 첨가가 한우 거세우의 거세우의 성장 , 반추위 및 혈액 성상 에 미치는 영향을 영향을 평가하기 평가하기 위해 수행되었다 수행되었다 . 이를 위해 , 저온 및 고온 조건에서 총 5회의 사양실험이 사양실험이 수행되 수행되 었는데 었는데 , 각 실험에 실험에 대한 조건은 조건은 다음과 다음과 같다 [study 1 : 저온 조건 , RPF (0.5 %)study 2, 저온 조건 , RPF (0.8 %)study 3,저온 조건 , glycerol-absorbed wheat bran (6 %)study 4, 고온 조건 , RPF (0.8 %)study 5, 고온 조건 , 글리세롤 글리세롤 (3 %)]. 결과적으로 결과적으로 결과적으로 , 추위 또는 고온 조건은 한우 거세우의 성장을 성장을 저하시키지 저하시키지 저하시키지 않았다. 혈중 포도당은 더 추운시기에 추운시기에 추운시기에 증가하는 증가하는 반면 , 주요 반추위 VFA는 변화하지 변화하지 않았다 않았다 . 고온 조건에서는 조건에서는 조건에서는 혈중 콜레스테롤이 콜레스테롤이 콜레스테롤이 감소하고 반추 위 VFA가 감소하는 감소하는 경향을 경향을 보였다 . 혈중 HDL과 콜레스테롤은 콜레스테롤은 RPF 첨가 에 의해 증가되었지만 증가되었지만 증가되었지만 , RPF 첨가 (0.5 또는 0.8 %) 는 한우 거세우의 거세우의 성장을 향상시키지 향상시키지 않았고, 반추위 환경에 환경에 영향을 영향을 미치지 않았다 않았다 . 글리세롤 글리세롤 첨가 (농후사료 농후사료 내 3%) 는 한우 거세우의 거세우의 성장을 향상시켰지만 향상시켰지만 , 혈중 포도당 포도당 농도에 영향을 주지 않았다 . 글리세롤 글리세롤 첨가는 첨가는 반추위 반추위 C2 농도와 C2:C3 비율을 감소시키고 감소시키고 C3 농도를 농도를 증가시켰다 증가시켰다 . 결론적으로 결론적으로 결론적으로 , 저온 및 고온 조건은 조건은 성장에 성장에 영향을 미치지 않았지만 않았지만 않았지만 , 일부 혈액 및 반추위 반추위 성상 을 변화시켰다 변화시켰다 변화시켰다 . 글리세롤 글리세롤 첨가 (농후사료 농후사료 내 3%) 은 반추위내 반추위내 주요 VFA 변화와 함께 일당증체량 일당증체량 일당증체량 및 사료효율을 사료효율을 향상시켰다 향상시켰다 . RPF 첨가는 성장에 영향을 영향을 미치지 미치지 않았으며 않았으며 , 혈중 지질 대사물질의 대사물질의 농도를 농도를 상승시켰으나 상승시켰으나 상승시켰으나 반추위 환경에는 환경에는 환경에는 영향을 미치지 미치지 않았다 않았다 .CONTENTS SUMMARY · · · Ⅰ CONTENTS · · · III LIST OF TABLES · · · VⅢ LIST OF FIGURE · · · XI LIST OF ABBREVIATIONS · · · XII UNITS AND MARKS · · · XIV CHAPTER ONE INTRODUCTION · · · 1 CHAPTER TWO LITERATURE REVIEW · · · 4 1. Effects of heat stress on cattle · · 4 2. Strategies for alleviation heat stress · · 8 3. Effects of cold stress on cattle · · 11 4. Strategies for alleviation cold stress · · 16 5. Effects of glycerol or rumen-protected fat supplementation on cattle · · · · 17 6. References · · · 22 CHAPTER THREE 1. Study 1: Effects of ambient temperature and rumen–protected fat supplementation on growth performance, rumen fermentation and blood parameters during cold season in Korean cattle steers · · · 32 (1) Abstract · · · 32 (2) Introduction · · · 33 (3) Materials and methods · · · 35 (4) Results and discussion · · · 39 (5) Conclusion · · · 44 (6) References · · · 52 2. Study 2: Effects of ambient temperature and rumen–protected fat supplementation on growth performance, rumen characteristics, and blood parameters during cold season in early fattening stage of Korean cattle steers · · 55 (1) Abstract · · · 55 (2) Introduction · · · 56 (3) Materials and methods · · · 58 (4) Results and discussion · · · 60 (5) Conclusion · · · 64 (6) References · · · 71 3. Study 3: Effects of temperature and glycerol supplementation as feed additive on growth performance, rumen characteristics, and blood parameters during winter season in growing stage of Korean cattle steers · · 74 (1) Abstract · · · 74 (2) Introduction · · · 76 (3) Materials and methods · · · 77 (4) Results and discussion · · · 79 (5) Conclusion · · · 85 (6) References · · · 93 CHAPTER FOUR 1. Study 4. Effects of hot temperature and rumen–protected fat supplementation ongrowth performance, rumen characteristics, and blood parameters in growing stage of Korean cattle steers · · · 96 (1) Abstract · · · 96 (2) Introduction · · · 98 (3) Materials and methods · · · 99 (4) Results and discussion · · · 102 (5) Conclusion · · · 106 (6) References · · · 113 2. Study 5. Effects of temperature and glycerol supplementation on growth performance, rumen characteristics, and blood parameters during summer season in fattening stage of Korean cattle steers · · 116 (1) Abstract · · · 116 (2) Introduction · · · 118 Supplementary data · · · 145 CHAPTER FIVE General conclusion · · · 154 SUMMARY IN KOREAN · · · 157 (3) Materials and methods · · · 119 (4) Results and discussion · · · 122 (5) Conclusion · · · 127 (6) References · · · 135Docto

Effects of Dietary Cation Anion Difference and Nicotinic Acid Supplementation on Jersey Prepartum Cows, Colostrum, and Calves AND Creating a Model for the Prediction of Colostrum Quality and Quantity in Jersey Cows from Performance in the Previous Lactation and Environmental Changes

Two experiments were conducted. The objectives of the first experiment were to evaluate colostrum quantity, quality, nutrient composition, and bioactive compounds from Jersey cows fed two levels of dietary cation anion difference (DCAD; –40 or –80 mEq/kg) with or without 23 g/d unprotected nicotinic acid (NA) and its effect on cow and calf performance. The hypothesis is that both DCAD and nicotinic acid could improve colostrum quality, increase quantity and bioactive compound concentration, and improve calf intestinal development. Previous research indicated the benefits of supplementing NA in prepartum Holsteins towards improved colostrum quality, as well as enhanced feed efficiency (FE) in their respective calves in the first 3 wk of life. Exact mechanisms for these results are not clear. The effects of NA supplementation to prepartum Holstein cows on growth and performance of their calves has been studied, but this has not been investigated in multiparous Jersey cows. Forty multiparous Jersey cows housed in a compost bedded pack barn were blocked by expected calving date and randomly assigned to treatments at 4 wk prepartum. Blood samples were collected every Friday until calving for analysis of nonesterified fatty acids (NEFA), ketones, and immunoglobulin G (IgG). Urine samples were collected 3 times weekly for analysis of pH, creatinine, and purine derivatives. Colostrum was collected within 90 min after parturition. Calves were removed from their dams before suckling, weighed and had blood sampled (for 0-h IgG) within 30 min of birth, and were enrolled if their dams made ≥ 2 L colostrum. If enrolled, calves received a minimum of 2 L and maximum of 3.78 L. The 31 enrolled calves were blocked based on treatments of dams and fed from d 1 to 6 wk: 3.78 L milk (4.9% fat, 3.7% protein, and 14.3% solids) and a coarse starter (34.61% starch, DM basis), and ad libitum water. For cows, there were no differences observed in grain intake, hay intake, total DMI, weekly BW, ADG, NEFA, weekly ketones, weekly urine pH, final urine pH, and urine volume. There was a tendency for cows supplemented the –40 DCAD to have lower final BW as compared to cows supplemented the –80 DCAD. There was a trend for an interaction with the –80/+ having increased final ketones. We observed a tendency to decrease allantoin and total PD with the addition of NA, as well as a tendency to decrease uric acid with the –80 DCAD. For colostrum, there were no differences observed in colostrum, IgG, and protein yield, and concentrations and yields for insulin, IGF-1, lactoferrin, TGFβ-1, and TGFβ-2. We observed a tendency to have an interaction effect with TGFβ-2, with the lowest concentration in –40/+. There was a tendency to have an interaction effect with IgG concentration, where –40/+ resulted in the highest IgG and –80/+ resulted in the lowest IgG. We observed an interaction effect with colostrum protein percentage, with the lowest in –40/- and the highest in –40/+. For DCAD, we observed no difference in protein content in colostrum. With NA supplementation, we observed a decrease in colostrum fat percentage, and a tendency to decrease fat yield. We observed an interaction effect with colostrum protein percentage, with the lowest in –40/-. With DCAD, we observed no effect on fat content in colostrum. Any result seen with bioactive compounds and colostral fatty acids do not have any studies to support or contradict the data seen in the current experiment. This is the only experiment to investigate DCAD concentration and NA supplementation and its effects on colostral bioactive compounds and fatty acids. To our knowledge, there have been no experiments evaluating colostral long chain fatty acids effects on calf development. We observed no differences in colostrum fed to calves, and intakes of insulin, TGFβ-1, and TGFβ-2. For IgG intake, we observed a lower average IgG intake in calves that came from cows supplemented the –80 DCAD as compared to –40 DCAD. For IGF-1 intake, we observed an interaction effect, with the highest intake of IGF-1 in calves that came from cows fed –40/+. For lactoferrin, we observed higher average lactoferrin intake in calves that came from cows supplemented NA. We can use the results seen with IGF-1 and lactoferrin intake to explain the results seen in previous studies with feed efficiency in the first three weeks of life for Holstein calves, because of the impact these bioactive compounds have on intestinal development. This is then confirmed by the xylose challenge data on the current experiment, where calves that came from NA supplemented cows had greater circulating xylose on d 5 during the challenge. We observed no differences in 24 h IgG, apparent efficiency of absorption (AEA), starter intake, milk solids intake, free water intake, total DMI, weekly BW, final BW, and all skeletal measurements and daily gains of the skeletal measurements, weekly glucose, final glucose, and weekly ketones. We observed an interaction effect for final ketones, where the lowest two final ketones in calves were from –40/- and –80/+. We observed that –80 DCAD supplemented to prepartum cows resulted in a tendency to decrease calf ADG, and that NA supplementation to prepartum cows resulted in a tendency to decrease calf ADG. The results on the current study for ADG/DMI (feed efficiency, FE) indicate that –80 DCAD supplemented to prepartum cows resulted in a decrease for calf FE, and that NA supplementation to prepartum cows resulted in a decrease for calf FE. Reasons for both of these decreases in FE are not clear, especially considering the results with xylose concentration, lactoferrin, and IGF-1 fed to calves indicating towards intestinal development in calves that came from NA supplemented cows. We hypothesized that we would see an increase in FE from calves that came from NA supplemented cows. However, the opposite was true, with an interaction effect of the lowest FE in calves that came from cows fed –80/+. These data suggest that supplementing NA in a –80 DCAD diet is not recommended and providing Jersey cows with a lesser amount of NA may prove beneficial due to its effects on xylose absorption and lactoferrin.In the second experiment, the objective was to identify specific factors that could be affecting colostrum yield in Jersey cows. We aimed to see if a prediction model could be created to identify correlations between colostrum yield, IgG concentration, and IgG yield and independent variables, categorized as cow performance in the previous lactation, environmental and management conditions during the dry period, calving and individual cow information, and predicted transmitting abilities. Twenty-eight dairies with Jersey cows from across the United States enrolled 415 multiparous cows onto this study between 2021 and 2023. Producers collected colostrum weight and colostrum samples to be analyzed for IgG. Producers recorded cow identification number, calf date of birth, sex of the calf, colostrum yield, hours from parturition to colostrum harvest, number of feedings per day during the dry period, type of diet fed to dry cows (total mixed ration (TMR), partially mixed ration (PMR), or component), amount of time spent on pasture during the dry period, and number of hours a day of light exposure. Dairy Herd Information (DHI) data from each cow and weather data were compiled for analysis. Weather was recorded as the number of days below 5℃ (D\u3c), days above 23℃ (D\u3e), and days between 5 and 23℃ (D). Information acquired from DHI were predicted transmitting abilities for: milk (PTAM), fat (PTAF), protein (PTAP), and dollars (PTAD); previous lactation: milk yield (PLMY), fat percent (PLFP), fat yield (PLFY), protein percent (PLPP), protein yield (PLPY), somatic cell score (PLSC), days open (PLDO), days dry (PLDD), days in milk (PLDIM), and previous parity (PP); current lactation: parity, days dry, and calving type (single, twins, or stillborn). For each cow, we also recorded ordinal day (OD) for the calving date and latitude of the farm. In order to analyze all variables, values for colostrum yield, IgG concentration, and IgG yield had 1 added to correct for values = 0. Two points were added to colostrum harvest to correct for values ≤ 0. After addition, the values \u3e 0 underwent transformation to ln or log10. All nontransformed variables were also used to develop the model. A variance inflation factor analysis (VIF) was conducted, followed by a backward elimination procedure. The resulting regression model for log10 colostrum yield (kg, r2 = 0.55) indicated that herd size (β = −0.0001), OD (β = −0.001), Ln OD (β = 0.07), latitude (β = −0.02), dry period length (β = 0.004), D\u3c (β = −0.005), D (β = −0.003), harvest time (β = 0.05), Ln harvest time (β = −0.35), IgG concentration (β = −0.004), log10 IgG concentration (β = 0.46), feedings (β = 0.06), Ln pasture (β = −0.13), and Ln PLDO (β = 0.14) had the largest effect on log10 colostrum yield. The intercept of this model was 0.43035. The resulting regression model for IgG concentration (g/L, r2 = 0.21) indicated that herd size (β = 0.02), D\u3e (β = 0.38), Ln harvest time (β = −19.42), colostrum yield (β = −4.29), Ln diet (β = 18.00), Ln PLFP (β = 74.43), and PP (β = 5.72) had the largest effect on nontransformed IgG concentration. The intercept for this model was 7.47170. The resulting regression model for log10 IgG yield (g, r2 = 0.79) indicated that Ln OD (β = 0.03), harvest time (β = −0.01), colostrum yield (β = −0.11), Ln colostrum yield (β = 1.20), Ln pasture (β = −0.09), Ln PLFP (β = 0.53), and PP (β = 0.02) had the largest effect on log10 IgG yield. The intercept for this model was 0.22045. All three models were validated using 39 colostrum samples from 22 of 28 farms. Data from these cows were not used in the creation of the models. The differences between means for actual and predicted colostrum yield (kg) was 0.89, IgG concentration (g/L) was −21.10, and IgG yield (g) was −65.15. These models indicate that it is possible to use previous lactation, environmental and management conditions during the dry period, and farm and individual cow information to predict colostrum yield, IgG concentration, and IgG yield of colostrum

Characterization of adiponectin at different physiological states in cattle based on an in-house developed immunological assay for bovine adiponectin

Adipose tissue (AT), through secretion of adipokines, plays a central role in regulating metabolism. Adiponectin is one of the most abundant adipokines and is linked with several physiological mechanisms such as insulin sensitivity and inflammation. The aim of this dissertation was to characterize the effect of stage of lactation and of supplementation with conjugated linoleic acids (CLA) on blood adiponectin in dairy cows. In addition, adiponectin concentrations in different AT depots and the effect of lactational and dietary induced negative energy balance (NEB) on blood and milk adiponectin were studied in dairy cows. Adiponectin concentrations of blood were studied using serum samples obtained from multiparous (MP) and primiparous (PP) cows receiving either CLA or a control fat supplement from d -21 to d 252 relative to calving, and serum as well as AT samples [3 subcutaneous (sc): tail-head, sternum and withers and 3 visceral (vc): mesenterial, omental and retroperitoneal] from PP cows slaughtered at d 1, 42 and 105 of lactation. Effects of lactational and dietary induced NEB on plasma adiponectin were investigated in MP cows from d -21 to d 182 relative to calving with feed restriction for 3 weeks beginning at around 100 days of lactation. Blood adiponectin was decreased from d 21 ante partum, reached a nadir at calving and increased during the post partum period. CLA supplementation reduced circulating adiponectin post partum in both MP and PP cows and, as indicated by a surrogate marker of insulin sensitivity (RQUICKI) also resulted in decreased insulin sensitivity. The decline in blood adiponectin around parturition may result from reduced adiponectin protein expression in all fat depots. vcAT contained more adiponectin than scAT suggesting a relatively higher impact of vcAT on adiponectin blood concentrations. However, retroperitoneal AT had the lowest adiponectin content compared to the other fat depots and thus seems to play an unique role in lipid mobilization in dairy cows. NEB due to feed restriction about 100 days of lactation caused a decline in adiponectin secretion through milk but did not affect its plasma concentrations. In conclusion, the major changes in blood adiponectin occurred around parturition; dietary CLA supplementation reduced circulating adiponectin. Differing amounts of adiponectin per AT depot indicate differential contributions to circulating adiponectin. The present dissertation serves as a basis for further studies elucidating the role and regulation of adiponectin and other adipokines in various pathophysiological conditions in cattle

Effects of nicotinamide on milk composition and production in dairy cows fed supplemental fat

Effects on milk production and composition were investigated in fifty Holstein cows (20 primiparous and 30 multiparous) averaging 121 d postpartum. The five treatments were: control, calcium salts of fatty acids (2% of dietary dry matter), nicotinamide (12 g/d), and calcium salts of fatty acids plus nicotinamide blended during manufacture or added separately. Periods lasted 5 wk. During wk 1, all cows received the control diet. During wk 2, cows were gradually adapted to individual dietary treatments, which were continued through wk 5. Treatments containing calcium salts of fatty acids did not alter feed intake, but they increased production of milk and fat-corrected milk and tended to increase production of milk fat and protein. Treatments containing nicotinamide increased feed intake, body condition score, milk, fat-corrected milk, and milk protein production. Milk fat percentage and milk fat production was higher (3.54 vs. 3.33%, and 1.18 vs. 1.11 kg/d, respectively), but milk protein percentage and milk protein production were lower (3.11 vs. 3.28%, and 1.03 vs. 1.11 kg/d, respectively) for cows fed calcium salts of fatty acids plus nicotinamide compared with cows receiving nicotinamide. Treatments containing calcium salts of fatty acids increased plasma nonesterified fatty acids, decreased blood nicotinamide, but had no effect on plasma [beta]-hydroxybutyrate. Treatments containing nicotinamide increased plasma glucose, increased blood nicotinamide, and had no effect on plasma NEFA and [beta]-hydroxybutyrate;In a second experiment, six lactating cows in a switchback design were administered orally 12 g/d of either nicotinamide or nicotinic acid during the first five d of 9 d periods. Blood samples taken at specific intervals showed that blood nicotinamide concentration of cows in the nicotinamide group peaked earlier and higher than for cows in the nicotinic acid group (1 vs. 12 h and 2.48 vs. 2.01 [mu]g/ml). The area under the blood nicotinamide concentration curve was not different between the nicotinamide and the nicotinic acid supplemented groups at 8, 12, or 24 h after nicotinamide or nicotinic acid administration, but it was higher for the nicotinamide group at 1, 2, 3, 4, and 6 h. These results suggest that nicotinamide is absorbed from the rumen faster than nicotinic acid, probably because of its higher solubility and lower dissociation constant due to its higher pKa

Supplemental Organic Chromium for Dairy Calves.

In Exp. 1, 42 calves were fed milk replacer and then starter either with or without 1 ppm supplemental chromium (Cr) as Cr-picolinate. Neither Cr nor sex affected growth performance. With the exception of plasma nonesterified fatty acid concentrations (NEFA), weekly plasma metabolites were not affected by Cr or sex. Pre- and postfeeding plasma NEFA concentrations were lower in Cr-fed calves, but were not affected by sex. AU calves seemed to become less insulin sensitive with age, as plasma glucose became lower and insulin higher as calves became older. During i.v. glucose tolerance tests (IVGTT), calves cleared glucose faster at 2 compared with 8 weeks of age but Cr did not affect clearance at either week. At 2 weeks of age, heifers cleared glucose faster than did bulls. Plasma glucose increases after an i.v. propionate load were greater in heifers than in bulls but were not affected by Cr. In Exp. 2, 34 calves were fed milk replacers either without (BF) or with (HF) added fat and either with or without 1 ppm of dietary Cr as Cr-nicotinate. Neither Cr nor fat affected performance; except, weight gain was greater in HF-fed calves during the period calves received milk alone. Weekly plasma glucose, insulin, and triacylglycerol concentrations were not affected by Cr; however, plasma insulin concentrations tended to be lower in Cr-fed compared with control-fed calves. Weekly NEFA declined in a similar manner for Cr-fed and control-fed calves; however, overall, NEFA concentrations were greater in Cr-fed calves. Weekly cholesterol concentrations were greater in Cr, HF-fed calves and lower in Cr, BF-fed calves compared with controls. Added dietary Cr or fat had minimal effects on plasma metabolites and hormones measured after milk replacer feeding. Using data generated by the IVGTT, a computer modeling procedure predicted that insulin sensitivity was increased in Cr-fed calves but reduced in HF-fed calves compared with controls. Overall, data suggested that Cr had little effect on metabolism or growth performance, but may have improved insulin sensitivity, with the most notable effects occurring in the initial weeks of life

Toorglütserooli söötmise mõju lüpsilehmade söömusele, piimajõudlusele ja ainevahetuslikule seisundile

Nowadays, the majority of glycerol, used as an essential primary good for the pharmaceutical, cosmetic, food and other industries, is becoming available as a byproduct from biodiesel manufacture. The rapid growth of the biodiesel industry has increased the availability of crude glycerol, and therefore its price has declined, making it more attractive amongst dairy farmers as a feed additive. Earlier studies have noted that feeding pure glycerol increases the propionate concentration in the rumen, and therefore its consideration as an efficient glucogenic substance for dairy cows after parturition. This thesis deals with some aspects of the use of unrefined glycerol originating from the biodiesel industry in dairy feeds, and discusses changes caused by its metabolism in the lactating dairy cow on several parameters, with special reference to Estonian feeding practices. In a study with post partum Holstein dairy cows the effects of oral drenching of crude glycerol on lactational performance and indices of negative energy balance were examined. Another aspect was to study the effects of replacement of barley meal with crude glycerol in mid-lactation Holstein dairy diets on the ruminal environment and nutrient degradability of grass silage in relation to feed intake and milk parameters, including milk renneting properties. The administration of 500 ml of crude glycerol for up to 21 days from the beginning of lactation improved feed intakes and milk yields. Adding high amounts of crude glycerol to a total mixed ration based on grass silage for mid-lactation dairy cows improved feed intakes with no negative effect on rumen pH, indicating its suitability as a component of a diet, at least when based on grass silage. In addition, replacing barley meal partially with unrefined glycerol increased milk protein content and improved curd firmness. Based on the experiments carried out it was concluded that, even at relatively high amounts, crude glycerol available from the biodiesel industry, is an appropriate feed supplement for dairy cows after calving, as well as in later lactation, under local feeding practices.Marko Kassi doktoritöö „Toorglütserooli söötmise mõju lüpsilehmade söömusele, piimajõudlusele ja ainevahetuslikule seisundile“ raames läbi viidud söötmiskatsetes eesti holsteini tõugu lüpsilehmadega selgitati toorglütserooli söötmisvõimalusi. Keemilist ühendit glütserooli, millel on üle 1500 kasutusala erinevates tööstusharudes, tuntakse enam kui 250 aastat. Tänapäeval on glütserooli lähtematerjaliks valdavalt rafineerimata toorglütserool, mis on biodiisli tootmise kõrvalsaadus. Viimastel kümnenditel suurenenud biodiisli tootmismahud on aga vähendanud toorglütserooli hinda, muutes selle teiste valdkondade kõrval atraktiivseks ka piimakarjakasvatajatele. Kuigi esimesed uurimistööd glütserooli söötmisel lehmadele viidi läbi juba 1950-ndatel, ei jõudnud toonased teadustulemused praktikasse seoses glütserooli liialt kõrge hinna tõttu. Doktoritöö üldisemaks eesmärgiks oli uurida, kuidas toorglütserooli kui glükogeense söödalisandi söötmine siinsetes söötmis- ja pidamispraktikate puhul mõjutab laktatsiooni erinevatel staadiumitel lehmade kuivaine söömust, piimatoodangut ja piima koostist ning ainevahetuslikku seisundit. Uurimistöö tulemustest selgus, et toorglütserooli söötmine nii laktatsiooni alguses kui keskel suurendas kuivaine söömust. 500 ml glükogeense söödalisandi suukaudne manustamine poegimisjärgsel perioodil suurendas nii koresööda kui kogu kuivaine söömust. Lisaks täheldati toorglütserooli manustamisel positiivne mõju piimatoodangule ning piima laktoosi sisaldusele. Uurimistulemused näitasid, et odrajahu osaline asendamine rohusilol baseeruvas täisratsioonilises segasöödas toorglütserooliga ei mõjutanud ebasoodsalt vatsa keskkonda ega koresööda efektiivsele lõhustuvusele. Kesklaktatsiooni lehmade ratsiooni lisatud toorglütserool mõjutas positiivselt piima laapuvusega seotud näitajaid: suurenes piima valgusisaldus ja soodustas tugevama kalgendi moodustumist. Tulemusena võib öelda, et rafineerimata glütserool on sobilik glükogeenne söödalisand lüpsilehmadele isegi suhteliselt suurte koguste söötmisel – 3kg päevas looma kohta. Läbiviidud uurimistööst järeldus, et biodiisli tootmise kõrvalsaadus toorglütserool on sobiv söödalisand lüpsilehmadele nii suukaudselt manustatuna uuslüpsiperioodil kui täisratsioonilise segasöödas koostises ilma negatiivse mõjuta piimatoodangule ja ainevahetusnäitajatele, arvestades siinset söötmis- ja pidamispraktikat.Publication of this dissertation is supported by the Estonian University of Life Sciences and by the Graduate School in Biomedicine and Biotechnology (1.2.0401.09-0073)

Effects of chromium (Cr) and zinc (Zn) supplementation on metabolism, inflammation, and production parameters in heat-stressed and nutrient-restricted pigs

Heat stress (HS) adversely impacts all aspects of global agriculture, and it particularly constrains domestic animal productivity and compromises animal welfare. Heat-stressed animals employ physiologic and metabolic adjustments to ameliorate the heat insult; consequently, efficiency is compromised because nutrients are partly diverted away from production purposes to maintain euthermia. Reduced animal productivity during HS can also be attributed to the direct effects of HS (independent of nutrient intake) on metabolism, physiology, reproduction, and health. Therefore, identifying nutritional alternatives with the potential to ameliorate the detrimental effects of HS on economically important performance and health is of particular interest. The overall thesis objectives were to investigate the dietary effects of chromium (Cr) and zinc (Zn) supplementation in heat-stressed and nutrient-restricted pigs. In the first study (Chapter 2), finishing pigs were used in a replicated experiment to evaluate the effects of Cr propionate supplementation on growth performance and metabolism during HS. As expected, pigs exposed to HS had increased thermal indices and decreased growth performance. However, Cr supplementation tended to increase average daily gain in chronically heat-stressed pigs. Regardless of environmental treatments, pigs supplemented with Cr had numerically increased feed intake. Further, adding Cr to the HS pig diet increased circulating neutrophils and monocytes. The second study (Chapter 3) evaluated the effects of Zn amino acid complex on metabolism, leaky gut biomarkers, and inflammation during and following HS. Pigs exposed to HS had increased body temperature and respiration rates as well as reduced production metrics. Despite marked reductions in feed intake, circulating insulin increased during HS and remained increased during thermal neutral recovery. Interestingly, supplemental Zn tended to decrease plasma tumor necrosis factor alpha (TNFα) levels before and after HS exposure. However, no effects of dietary Zn were observed on production parameters or other blood metabolites. In conclusion, both experiments demonstrated that HS adversely impacts animal productivity and health. Results suggest that Cr supplementation might be beneficial on growth performance and health during HS. Additionally, Zn supplementation might be advantageous at reducing basal inflammation. Altogether, these findings suggest that dietary interventions aimed at alleviating the negative consequences of HS are plausible. However, additional research is needed to better understand the biology and mode of action of both Cr and Zn supplementation during HS