Effects of supplemental energy on metabolic and immune measurements in periparturient dairy cows with Johne's disease

The present study was designed to evaluate whether feeding supplemental energy would improve the metabolic profile and alleviate some of the immunosuppression typically noted during the periparturient period in dairy cows with Johne's disease. Twelve dairy cows naturally infected with Mycobacterium paratuberculosis were fitted with rumen cannulas in late gestation and assigned to treatment groups: control, n = 6; or stuffed, n = 6. Cows in the control group were allowed to consume feed ad libitum. Cows assigned to the stuffed treatment group were also fed ad libitum but received additional total mixed rations by manually stuffing their rumens with refused feed to maintain dry matter intake of 2% body weight per day before calving and 2.5% body weight per day after calving. Serum nonesterified fatty acid levels were significantly decreased in stuffed cows compared with control cows, indicating that stuffing to maintain dry matter intake improved the energy balance in the cows. In addition, periparturient serum calcium and magnesium concentrations were significantly higher in stuffed cows. Stuffing modulated cell-mediated immunity by reducing lymphocyte proliferative responses to T-cell mitogens during early lactation. Stuffing resulted in an increase in the secretion of in vitro immunoglobulin by peripheral blood mononuclear cells after parturition when compared to control cows. These data demonstrate that energy balance is improved by providing additional energy in this manner and suggest energy supplementation can improve some aspects of immune function during the periparturient period.     

Graham and Ernhart on "What Price Intelligence?".

Comments on a reply to Graham and Ernhart's recent criticism of an article published by Tucker and the commentator (see record 1961-02545-001). In this article, the data from the studies of birth conditions suggested that children undergoing precipitate birth or severely anoxic at birth will later show a greater preponderance of defective individuals. In addition, the same two groups will have a greater number of individuals of superior ability as measured by the Stanford-Binet than found in the controls recruited from the same population. It is not the former but the latter conclusion which Graham and Ernhart particularly dislike. The commentator explains the criticisms made by Graham and Ernhart about his article. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrolytes in bovine prepartum mammary secretions and their usefulness for predicting parturition

Accurately predicting parturition in cows can be difficult because of the variability in gestation length and uncertainty of the time of parturition. The goal of the present study was to determine the electrolyte concentrations of prepartum mammary secretions of gravid cows and to investigate retrospectively the possible predictive relationships between these concentrations and the time of parturition. Twenty-three cows were sampled once daily for 3 to 12 d before they calved. The concentrations of calcium, inorganic phosphorus, chloride, magnesium, sodium, and potassium were determined by photometric methods. In addition, the concentrations of calcium, magnesium, and inorganic phosphorus were determined using rapid test kits. The correlation between the photometrically measured electrolyte concentrations and the time of parturition was highest for inorganic phosphorus (r = 0.74). The inorganic phosphorus concentration was 11.8 to 26.5 mmol/L in cows that calved within 24 h of sample collection. When 11.8 mmol/L was used as a cutoff concentration for inorganic phosphorus, 21.7, 47.8, and 87.0% of cows calved within 24, 48, and 72 h, respectively. Within 12 d prepartum, the time of parturition can be estimated, with an error of ± 32.4 h, by using the results of simultaneous determination of inorganic phosphorus and sodium concentrations in mammary secretions and a formula derived from a multiple regression analysis. The results of a phosphate field test positively and significantly correlated with those of the photometric analysis (r = 0.69) and the time of parturition (r = 0.41).     

Plasma metabolite changes in dairy cows during parturition identified using untargeted metabolomics

The metabolic responses of cows undergo substantial changes during the transition from late pregnancy to early lactation. However, the molecular mechanisms associated with these changes in physiological metabolism have not been clearly elucidated. The objective of this study was to investigate metabolic changes in transition cows from the perspective of plasma metabolites. Plasma samples collected from 24 multiparous dairy cows on approximately d 21 prepartum and immediately postpartum were analyzed using ultra-high-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes. In conjunction with multidimensional statistical methods (principal component analysis and orthogonal partial least squares discriminant analysis), differences in plasma metabolites were identified using the t-test and fold change analysis. Sixty-seven differential metabolites were identified consisting of AA, lipids, saccharides, and nucleotides. The levels of 32 plasma metabolites were significantly higher and those of 35 metabolites significantly lower after parturition than on d 21 prepartum. Pathway analysis indicated that the metabolites that increased from late pregnancy to early lactation were primarily involved in lipid metabolism and energy metabolism, whereas decreased metabolites were related to AA metabolism.     

Predicting stage 2 of calving in Holstein-Friesian heifers

The objective of this study was to predict stage 2 of calving in Holstein-Friesian heifers. Interobserver reliability and predictive values of relevant signs of imminent parturition (i.e., tail raising, stepping, clear and bloody vaginal discharge, turning the head toward the abdomen, and lying lateral with abdominal contractions) were determined. In the first experiment 32 heifers were included. Three investigators participated as observers in the study. They walked through the precalving pen in pairs and observed pregnant heifers (≥267 d pregnant). Cohen's kappa results for the interobserver reliability were between 0.51 and 0.91. Thirty-seven Holstein-Friesian heifers were enrolled in the second experiment. Heifers were observed hourly for 24 h/d. Signs of imminent parturition that occurred were noted on a checklist. Compared with a precalving control period (4 d before calving), tail raising, clear vaginal discharge, and bloody vaginal discharge were more likely to occur during the last 24 h before calving. Two equations were built using the GENLINMIXED procedure to predict the hours until parturition. In version 1, the absence or presence of each sign of imminent parturition except turning the head toward the abdomen was included. In version 2, hours until parturition were estimated with the factors days of gestation, tail raising, and clear vaginal discharge. Relaxation of the broad pelvic ligaments and teat filling were evaluated twice per day. Prediction of calving with these parameters was not satisfying (positive predictive values were between 35.1 and 72.7% depending on the day of gestation). The possibility of excluding calving for the next 12 h was considerably higher, ranging from 88.5 to 97.1%. These results indicate that predicting stage 2 of calving via direct observation of plausible signs is imprecise and therefore not recommendable.     

Hypocalcemia—Cow-level prevalence and preventive strategies in German dairy herds

Hypocalcemia around calving is considered a gateway disease that can lead to health disorders and decreased milk production. The objective of this cross-sectional study was to evaluate the prevalence of clinical and subclinical hypocalcemia 0 to 48 h after calving. Blood samples were drawn from 12 animals of each dairy farm (n = 115) and analyzed for serum calcium, magnesium, and phosphorus concentration. Cows not affected clinically but with a serum calcium concentration below 2.0 mmol/L were characterized as subclinical hypocalcemic animals. Recumbent cows with a serum calcium concentration below 2.0 mmol/L were defined as cows suffering from clinical milk fever. Herds were classified into negative (0 to 2/12), borderline (3 to 5/12), and positive (≥6/12) according to the number of animals with hypocalcemia. Strategies to control hypocalcemia were documented. Prevalence of clinical milk fever was 1.4, 5.7, and 16.1% for second, third, and ≥fourth parity cows, respectively. None of the cows in first lactation were suffering from clinical milk fever. Based on the threshold of 2.0 mmol/L, 5.7, 29.0, 49.4, and 60.4% of cows in first, second, third, and ≥fourth lactation were suffering from subclinical hypocalcemia, respectively. Fourteen, 51, and 50 herds were classified as negative, borderline, and positive, respectively. A positive association was observed between serum calcium and serum phosphorus concentration. Serum calcium and magnesium concentration were negatively associated. Only 50 of 115 farms had a control strategy implemented to avoid hypocalcemia. Most common was the use of oral calcium products (40/115 herds), followed by feeding of anionic salts in the close-up diet (10/115 herds). These results indicate that the prevalence of clinical and subclinical hypocalcemia in German dairy herds was high and that an active control strategy was not implemented on all farms. The negative association between calcium and magnesium warrants further research regarding the physiological regulation of these 2 minerals around parturition.     

Dairy cows seek isolation at calving and when ill

Dairy cows are typically gregarious, but isolate themselves in the hours before calving when kept on pasture. Self-isolation is also a common behavior of ill animals. The objectives of this study were to determine if dairy cows would (1) isolate to calve when housed indoors in an individual maternity pen and (2) continue to isolate when ill after calving. We selected individuals from a pool of 79 multiparous Holstein dairy cows based on inclusion criteria created to address each objective. Cows were moved from a group pen to 1 of 10 adjacent maternity pens. Half of these individual pens were partially covered with plywood, creating a secluded corner as well as a window that provided visual access to the group pen. The other individual pens were uncovered on all sides. For our first objective, we selected 39 cows that were moved into the maternity pens >8 h before calving (partially covered: n = 19; uncovered: n = 20). For our second objective, we selected 18 cows housed in the partially covered pens: 9 cows with high rectal temperature after calving and signs of an infectious disease (mastitis, metritis, pneumonia, or some combination), and 9 healthy cows paired with ill cows based on the amount of time they spent in the maternity pen before calving. Ten-minute scan sampling was used to record the location and lying time from 6 h before to 72 h after calving. Individual feed intake was measured after calving. Binomial tests were used to determine if cows in both pen types were more likely to calve in the corner or window side of the pen. Repeated-measures ANOVA were used to determine if cows used the corner more as calving approached and if ill cows spent more time lying or more time in the corner compared with healthy cows in the 72 h after calving. Cows in the uncovered pens were equally likely to calve on both sides of the pen (10 vs. 10), but 79% of cows in the partially covered pens calved on the corner side of the pen (15 vs. 4). Cows in the partially covered pens used the corner side of the pen more in the 1 h before and after calving compared with those housed in the uncovered pens. Ill cows housed in the partially covered pens ate less, tended to spend more time lying down, and spent more time in the corner of the pen compared with healthy cows. These results indicate that periparturient dairy cows seek seclusion to calve and when ill, which suggests that adding a secluded area to maternity and hospital pens may be beneficial.     

Short communication: Flooring preferences of dairy cows at calving

The present study investigated the flooring preference during the 30 h before parturition in Holstein dairy cows housed individually in a maternity pen. Seventeen multiparous cows were moved, on average, 2 d before expected calving date into an individual maternity pen with 3 different flooring surfaces: 10 cm of sand, pebble-top rubber mats, or concrete flooring, each covered with 15 cm of straw. Calving location, lying time, and total time and number of lying bouts on each of the floor types were recorded during 2 periods: precalving (24 to 29 h before calving) and at calving (0 to 5 h before calving). Ten cows calved on sand, 6 on concrete, and 1 on the rubber mat. Lying bouts increased during the hours closest to calving, regardless of flooring. The number of lying bouts did not differ between flooring types precalving but cows had more lying bouts on sand and concrete compared with rubber at calving. Cows spent more time lying down on sand and concrete compared with rubber precalving, but lying times did not differ between treatments at calving. Cows that calved on sand spent more time lying on sand at calving compared with the other 2 flooring types. Cows that calved on concrete did not show a flooring preference at calving. These results indicate that rubber mats are the least preferred by dairy cows in the maternity pens, even when covered with a deep layer of straw.     

Combined biotin,folic acid,and vitamin B12 supplementation given during the transition period to dairy cows: Part I. Effects on lactation performance,energy and protein metabolism,and hormones

Biotin (B₈), folates (B₉), and vitamin B₁₂ (B₁₂) are involved and interrelated in several metabolic reactions related to energy and protein metabolism. We hypothesized that a low supply of one of the latter vitamins during the transition period would impair metabolic status. The purpose of this study was to evaluate the effect of B₈ supplementation on the response of lactation performance and selected energy and protein metabolites and hormones to a combined supplementation of B₉ and B₁₂ given to periparturient dairy cows, from d ?21 to 21 relative to calving. A total of 32 multiparous Holstein cows housed in tie stalls were randomly assigned, according to their previous 305-d milk yield, to 8 incomplete blocks of 4 treatments: (1) a 2-mL weekly i.m. injection of saline (0.9% NaCl; B₈?/B₉B₁₂?); (2) 20 mg/d of dietary B₈ (unprotected from ruminal degradation) and 2-mL weekly i.m. injection of 0.9% NaCl (B₈+/B₉B₁₂?); (3) 2.6 g/d of dietary B₉ (unprotected) and 2-mL weekly i.m. injection of 10 mg of B₁₂ (B₈?/B₉B₁₂+); and (4) 20 mg/d of dietary B₈, 2.6 g/d of dietary B₉, and weekly i.m. injection of 10 mg of B₁₂ (B₈+/B₉B₁₂+) in a 2 × 2 factorial arrangement. Milk yield and dry matter intake were obtained daily and milk components weekly. Blood samples were taken weekly from d ?21 to calving and 3 times per week from calving to 21 d following parturition. Prepartum plasma concentrations of glucose, insulin, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and adiponectin were unaffected by treatments. Biotin, B₉, and B₁₂ supplements increased their respective concentrations in plasma and milk. Cows fed the B₈ supplement tended to have lower dry matter intake, but only cows in B₈+/B₉B₁₂? had greater plasma concentrations of NEFA compared with B₈?/B₉B₁₂?. Milk and total solid yields were greater by 13.5 and 13.9%, respectively, for B₈?/B₉B₁₂+ [45.5 (standard error, SE: 1.8) and 5.81 (0.22) kg/d, respectively] compared with B₈?/B₉B₁₂? [40.1 (1.9) and 5.10 (0.23) kg/d, respectively], but these effects were suppressed when combined with the B₈ supplement. Cows in the B₈?/B₉B₁₂+ group had decreased plasma insulin and tended to have increased NEFA concentrations, but postpartum plasma concentrations of glucose, BHB, leptin, and adiponectin were not affected. These cows also mobilized more body fat reserves, as suggested by a tendency to increased plasma NEFA and more milk total solids compared with B₈?/B₉B₁₂? cows. However, plasma concentrations of BHB and adiponectin were similar among treatments. This suggests that the B₉ and B₁₂ supplements enhanced efficiency of energy metabolism in early lactation cows. Folic acid and B₁₂ supplementation increased postpartum plasma Cys and homocysteine concentrations but did not affect plasma Met concentration, suggesting an upregulation of the transsulfuration pathway. In summary, our results showed that, under the current experimental conditions, increasing B₈ supply did not improve responses to the B₉ and B₁₂ supplementation.     

The effect of stocking density and a blind on the behavior of Holstein dairy cows in group maternity pens. Part II: Labor length,lying behavior,and social behavior

In natural settings, dairy cows separate from the herd to give birth. When kept indoors, seeking isolation before calving may be restricted and may depend on space and resources provided in maternity housing. The effect of group maternity pens on behavior around calving and labor progress is unknown. Therefore, the objective of this study was to determine the effects of stocking density and provision of a blind in group bedded pack maternity pens on lying and social behavior as well as length of labor of preparturient dairy animals. The study was conducted as a complete randomized block design with a 2 × 2 factorial arrangement of treatments including stocking density and presence or absence of a blind, resulting in a total of 4 treatments: (1) high stocking density (7.7–12.9 m² lying space/cow) with a blind, (2) low stocking density (15.4–25.8 m²) with a blind, (3) high stocking density without a blind, and (4) low stocking density without a blind. A total of 127 primiparous heifers and 247 multiparous cows were housed in mixed-parity groups from approximately 3 wk before and immediately after calving. During the 4 h before calving, lying behavior (lying time and bouts) was collected automatically using accelerometers, and social behavior (agonistic interactions, allogrooming, and attention from other cows), stage II labor duration, and frequency of position change during stage II labor were collected using video. Lying behavior was collected with accelerometers. Regardless of treatment, lying time and bouts increased as calving approached. Cows and heifers performed more lying bouts in low stocking density pens compared with high stocking density pens. Agonistic interactions and allogrooming were not different between treatments. Other cows spent more time paying attention to focal animals regardless of stocking density as calving approached, but time spent paying attention was reduced by the presence of a blind during h ?2 before calving. The hazard of calving unassisted was greater for cows and heifers in low stocking density pens with a blind compared with all other treatments. Further, animals in pens with a blind tended to change positions fewer times during stage II labor. These results suggest that providing a blind in group maternity pens may improve the calving environment for cows and heifers and, in combination with low stocking density, may reduce the amount of time spent in labor.