Plasma pharmacokinetics and milk residues of flunixin and 5-hydroxy flunixin following different routes of administration in dairy cattle

The objective of this study was to determine if the plasma pharmacokinetics and milk elimination of flunixin (FLU) and 5-hydroxy flunixin (5OH) differ following intramuscular and subcutaneous injection of FLU compared with intravenous injection. Twelve lactating Holstein cows were used in a randomized crossover design study. Cows were organized into 2 groups based on milk production (<20 or >30 kg of milk/d). All cattle were administered 2 doses of 1.1 mg of FLU/kg at 12-h intervals by intravenous, intramuscular, and subcutaneous injections. The washout period between routes of administration was 7 d. Blood samples were collected from the jugular vein before FLU administration and at various time points up to 36 h after the first dose of FLU. Composite milk samples were collected before FLU administration and twice daily for 5 d after the first dose of FLU. Samples were analyzed by ultra-HPLC with mass spectrometric detection. For FLU plasma samples, a difference in terminal half-life was observed among routes of administration. Harmonic mean terminal half-lives for FLU were 3.42, 4.48, and 5.39 h for intravenous, intramuscular, and subcutaneous injection, respectively. The mean bioavailability following intramuscular and subcutaneous dosing was 84.5 and 104.2%, respectively. The decrease in 5OH milk concentration versus time after last dose was analyzed with the nonlinear mixed effects modeling approach and indicated that both the route of administration and rate of milk production were significant covariates. The number of milk samples greater than the tolerance limit for each route of administration was also compared at each time point for statistical significance. Forty-eight hours after the first dose, 5OH milk concentrations were undetectable in all intravenously injected cows; however, one intramuscularly injected and one subcutaneously injected cow had measurable concentrations. These cows had 5OH concentrations above the tolerance limit at the 36-h withdrawal time. The high number of FLU residues identified in cull dairy cows by the United States Department of Agriculture Food Safety Inspection Service is likely related to administration of the drug by an unapproved route. Cattle that received FLU by the approved (intravenous) route consistently eliminated the drug before the approved withdrawal times; however, residues can persist beyond these approved times following intramuscular or subcutaneous administration. Cows producing less than 20 kg of milk/d had altered FLU milk clearance, which may also contribute to violative FLU residues.     

The effect of transdermal flunixin meglumine on blood cortisol levels in dairy calves after cautery disbudding with local anesthesia

The objective of this study was to evaluate the effect of the nonsteroidal anti-inflammatory drug transdermal flunixin meglumine (Finadyne Transdermal) on plasma cortisol, average daily weight gain, and standing and lying behavior of calves, when given at the time of disbudding combined with local anesthesia. A sedative was not used to minimize pharmacological interactions. Seventy-one female Holstein Friesian calves aged 13 ± 2 d, with an average weight of 48.9 ± 4.26 kg were enrolled in the study. All calves were randomly assigned to one of 3 treatment groups: (1) control group (CON, n = 27), (2) 1-flunixin group (1-FLU, n = 26) with a single administration of transdermal flunixin meglumine at disbudding, and (3) 2-flunixin group (2-FLU, n = 24) with 2 administrations of transdermal flunixin meglumine, the first treatment at disbudding and the second 6 h after disbudding. Although the CON group received a placebo, 1-FLU and 2-FLU received flunixin meglumine transdermally. To account for plasma cortisol changes due to manipulation and handling of the calves, a sham disbudding procedure was performed one week before disbudding took place. Sham disbudding was conducted by using a cold cautery dehorner applied to each horn bud for 10 s. Disbudding was performed in a similar way by using a hot cautery dehorner. Plasma samples were collected to measure the stress biomarker cortisol at 7 different time points. Body weights were measured 4 times in 2 wk. Standing and lying behavior was assessed via 3-dimensional accelerometer. During sham disbudding and disbudding mean plasma cortisol concentrations were 6.09 ± 2.5 ng/mL and 5.16 ± 2.8 ng/mL, respectively. Treatment tended to have an effect on plasma cortisol concentrations during sham disbudding and had an effect on plasma cortisol concentrations during disbudding. Plasma cortisol concentrations were affected by treatment 2 h after disbudding in comparison to CON group. Furthermore, there was a significant effect on plasma cortisol concentrations 6 h after disbudding in contrast to CON. A return to baseline plasma cortisol levels (initial concentrations) was not achieved in CON during disbudding. There was no statistical difference between average daily weight gain and the treatment procedure. Total lying time was not affected by treatment after disbudding. In conclusion, transdermal flunixin meglumine given at the time of disbudding combined with local anesthesia decreased concentrations of the stress biomarker cortisol, but a second dose 6 h after disbudding had no further effect on plasma cortisol levels.     

Short communication: Determination of the milk pharmacokinetics and depletion of milk residues of flunixin following transdermal administration to lactating Holstein cows

Flunixin is a nonsteroidal anti-inflammatory drug and the most commonly prescribed analgesic in cattle in the United States. Recently, the US Food and Drug Administration (FDA) approved a transdermal formulation of flunixin for control of pyrexia associated with bovine respiratory disease and the control of pain associated with foot rot. The transdermal formulation is not currently approved for use in lactating dairy cattle in the United States, but extra-label use in dairy cattle is permissible under US regulations. The objectives of this study were to determine the pharmacokinetics in milk of dairy cows treated with transdermal flunixin and determine an appropriate withdrawal time for milk. Ten lactating Holstein cows were enrolled into the study in mid lactation. Following treatment, cows were milked 3 times per day through 144 h. Milk samples were collected for drug analysis using ultra-high-pressure liquid chromatography coupled with a triple quadrupole mass spectrometer. The geometric mean maximum concentration for flunixin in milk was 0.010 μg/mL and was 0.061 μg/mL for the active metabolite, 5-hydroxyflunixin. The geometric mean terminal half-life was 20.71 h for flunixin and 22.62 h for 5-hydroxyflunixin. Calculations to approximate a withdrawal time in milk following transdermal flunixin administration were accomplished using a statistical tolerance limit procedure. This analysis indicated that it would be prudent to observe a withdrawal period of 96 h following the last treatment. This is more than twice as long as the labeled withdrawal period of 36 h following use of the injectable formulation. The withdrawal period suggested by this work should be applied carefully, as this study was not conducted under the full quality control practices required by the US FDA for a full drug approval study. Caution should be taken when applying this withdrawal time to diseased animals, animals that are milked with different milking frequencies, and those in different stages of production as these have all been shown to affect drug depletion from milk.     

Pharmacokinetics and milk penetration of orbifloxacin after intravenous, subcutaneous, and intramuscular administration to lactating goats

The single-dose disposition kinetics of orbifloxacin were determined in clinically normal lactating goats (n = 6) after intravenous, subcutaneous, and intramuscular administration of 2.5 mg of orbifloxacin/kg of body weight. Orbifloxacin concentrations were determined by HPLC with fluorescence detection. The concentration-time data were analyzed by compartmental and noncompartmental kinetic methods. Steady-state volume of distribution and clearance of orbifloxacin after intravenous administration were 1.13 ± 0.08 L/kg and 0.40 ± 0.11 L/h·kg, respectively. Following subcutaneous and intramuscular administration, orbifloxacin achieved maximum plasma concentrations of 1.85 ± 0.20 and 1.66 ± 0.14 mg/L at 1.25 ± 0.22 and 0.87 ± 0.38 h, respectively. The absolute bioavailabilities after subcutaneous and intramuscular routes were 108.96 ± 17.61% and 105.01 ± 15.61%, respectively. Orbifloxacin penetration from the blood into the milk was rapid and showed high levels of concentrations in milk secretion. From this data, orbifloxacin could have success against susceptible mastitis pathogens in goats.     

Effects of a single transdermal administration of flunixin meglumine in early postpartum Holstein Friesian dairy cows: Part 2. Milk yield,culling risk,and reproductive performance

This study was conducted to assess the effects of a single transdermal administration of flunixin meglumine (FM) in early postpartum Holstein Friesian dairy cows on milk yield, culling risk, and reproductive performance. We hypothesized that FM treatment would reduce systemic inflammation, leading to higher milk yield, reduced culling risk, and better reproductive performance in the subsequent lactation. Holstein Friesian dairy cows [n = 500, 153 primiparous (PRIM), 347 multiparous (MULT)] from 3 farms in northeast Germany were enrolled in a prospective, randomized controlled clinical trial. Farms at risk for cows with excessive postpartum inflammation were identified in a preliminary trial by measuring serum haptoglobin concentrations in their fresh lactating cows. Only cows that had a eutocic birth and delivered a singleton calf alive, with no signs of milk fever or retained fetal membranes and rectal temperature ≤40°C at first clinical examination, were included within 24 to 36 h postpartum. Treatment included a single transdermal administration of either FM (3.33 mg/kg) or a placebo as control (CON). Milk production, milk solids, urea, and somatic cell count were recorded monthly for 8 mo after calving. Culling risk, first-service conception risk, and days open were retrieved from the farms' herd management software. Separate models for PRIM and MULT cows were built for most parameters because of significant effects of parity and parity × treatment interaction. Energy-corrected milk yield from 8 monthly Dairy Herd Improvement-equivalent tests was slightly greater in PRIM cows treated with FM (29.51 and 30.73 ± 1.35 kg, CON vs. FM), whereas it was reduced in treated MULT cows (38.23 and 37.47 ± 1.17 kg, CON vs. FM) compared with CON. Milk fat and protein yields were greater in FM-treated PRIM cows and lower in treated MULT cows compared with CON. Milk urea and somatic cell count were not affected by treatment. No differences in culling risk, first-service conception risk, or days open were observed. We conclude that a single transdermal administration of FM in early postpartum dairy cows on farms at risk for excessive postpartum inflammation slightly increased milk, milk fat, and milk protein yields in PRIM cows and decreased these variables in MULT cows. Neither culling risk nor fertility was affected by treatment in this study.     

Distribution of somatic cell count and udder pathogens in Norwegian dairy goats

Compared with dairy cows, goat somatic cell count (SCC) is higher and probably more affected by physiological factors such as parity, stage of lactation, and season. Thus, SCC is believed to be a less precise indicator of intramammary infections in dairy goats, and no consensus exists on SCC thresholds for considering goats as infected. The Norwegian Goat Recording System maintains individual goat production records and results from microbiological analyses of milk samples. In this retrospective observational study, we used recordings over a 10-yr period (2010 to 2020) to describe the association between individual goat SCC and noninfectious factors, as well as intramammary infections. The median SCC in the 1,000,802 milk recordings included in the study was 440,000 cells/mL, and the mode was 70,000 cells/mL. Somatic cell count increased with parity, days in milk, estrus, pasture season, and intramammary infections. The effect of parity and stage of lactation was significantly higher in infected compared with uninfected goats. Staphylococci dominated as causes of intramammary infections, with Staphylococcus aureus as the udder pathogen associated with highest SCC. The most prevalent non-aureus staphylococci were Staphylococcus warneri, Staphylococcus epidermidis, and Staphylococcus caprae. This study provides guidelines for interpretation of goat SCC at different parities and stages of lactations under Norwegian management conditions. We revealed a considerable variation in SCC associated with physiological factors, indicating that the cutoff for identifying infected goats should be a dynamic threshold adjusted for parity, stage of lactation, and season.     

The effect of dietary iodine supplementation in dairy goats on milk production traits and milk iodine content

Dairy products offer an important source of iodine for humans, particularly infants and children. An adequate iodine content in the diet of lactating animals must guarantee a suitable milk iodine concentration. In this experiment, the effects of iodine supplementation of dairy goat diets on the iodine concentration, milk yield, and milk composition of goat milk were studied. Thirty crossbred dairy goats of the Sarda population were divided into 3 groups supplemented with 0 (control group), 0.45 (group 1), or 0.90 (group 2) mg of KI/d per goat. The dose of KI (76.5% of iodine) was dissolved in water and orally administered with a syringe every day for 10 wk. Mean milk iodine concentrations were 60.1 ± 50.5, 78.8 ± 55.4, and 130.2 ± 62.0 μg/L (mean ± SD) in the control group, group 1, and group 2, respectively. The extent of iodine enrichment in milk was approximately 31% in group 1 and 117% in group 2 compared with the control group. Milk yield was not influenced by KI supplementation and averaged 1,229, 1,227, and 1,179 g/d in groups 0, 1, and 2, respectively. Milk urea nitrogen concentration was significantly lower in the KI-supplemented groups (32 and 33 mg/dL in groups 1 and 2, respectively) than in the control group (37 mg/dL). Iodine supplementation of dairy goat diets can increase milk iodine content without adverse effects on milk production traits.     

Once-daily milking effects in high-yielding Alpine dairy goats

Two experiments were conducted to determine the milk loss of high-yielding Alpine goats resulting from once-daily milking (ODM) and its relationship to udder cisternal size. We investigated the effects of application of this management strategy on milk yield, composition, and technological parameters: lipolysis, fat globule size, and cheese yield. In a second experiment, we investigated the effect of repeated periods of ODM management during lactation. Goats at the beginning of both experiments were at 25 d in milk on average and were previously milked twice daily (twice-daily milking; TDM). In experiment 1, which was conducted for 2 periods (P) of 9 wk (P1, P2), 48 goats were grouped (1, 2, 3, and 4) according to milk yield, parity, and somatic cell count (SCC). Over the 2 periods, goats from group 1 were managed with TDM and those from group 2 were managed with ODM. In group 3, goats were assigned to TDM during P1 and ODM during P2, conversely, those in group 4 were assigned to ODM in P1 and TDM in P2. During P1, the 12 goats from group 3 underwent 2 distinct morning machine milkings to measure milk repartition (cisternal and alveolar) in the udder based on the “atosiban method.” On P1 plus the P2 period of 18 wk, milk loss caused by ODM (compared with TDM) was 16%. In our condition of 24-h milk accumulation, there was no correlation between milk loss and udder cisternal size. Milk fat content, fat globule size, or apparent laboratory cheese yield was not modified by ODM, but milk protein content (+2.7 g/kg), casein (+1.8 g/kg), milk soluble protein concentration (+1.0 g/kg), and SCC increased, whereas lipolysis decreased (−0.3 mEq/100 g of oleic acid). In experiment 2, which was conducted for 4 periods (P1, P2, P3, P4) of 5 wk each, 8 goats, blocked into 2 homogenous groups (5 and 6), were used to study the effects of a double inversion of milking frequency (TDM or ODM) for 20 wk of lactation. Milk loss was 17% and ODM did not modify milk fat or protein contents, SCC, casein, or milk soluble protein concentration, but lipolysis was decreased (−0.3 mEq/100 g of oleic acid). Neither experiment showed the effects of period of ODM management on milk yield, milk fat or protein content, SCC, fat globule size, lipolysis, casein, milk soluble protein concentration, or apparent laboratory cheese yield.     

Estimation of genetic parameters for milk yield across lactations in mixed-breed dairy goats

Currently, breeding values for dairy goats in the United Kingdom are not estimated and selection is based only on phenotypes. Several studies from other countries have applied various methodologies to estimate breeding values for milk yield in dairy goats. However, most of the previous analyses were based on relatively small data sets, which might have affected the accuracy of the parameter estimates. The objective of this study was to estimate genetic parameters for milk yield in crossbred dairy goats in lactations 1 to 4. The research was based on data provided by 2 commercial goat farms in the United Kingdom comprising 390,482 milk yield records on 13,591 dairy goats kidding between 1987 and 2012. The population was created by crossing 3 breeds: Alpine, Saanen, and Toggenburg. In each generation, the best-performing animals were selected for breeding and, as a result, a synthetic breed was created. The pedigree file contained 28,184 individuals, of which 2,414 were founders. The data set contained test-day records of milk yield, lactation number, farm, age at kidding, and year and season of kidding. Data on milk composition was unavailable. Covariance components were estimated with the average information REML algorithm in the ASReml package (VSN International Ltd., Hemel Hempstead, UK). A random regression animal model for milk yield with fixed effects of herd test day, year-season, and age at kidding was used. Heritability was the highest at 200 and 250 d in milk (DIM), reaching 0.45 in the first lactation and between 0.34 and 0.25 in subsequent lactations. After 300 DIM, the heritability started decreasing to 0.23 and 0.10 at 400 DIM in the first and subsequent lactations, respectively. Genetic correlation between milk yield in the first and subsequent lactations was between 0.16 and 0.88. This study found that milk yields in first and subsequent lactations are highly correlated, both at the genetic and phenotypic level. Estimates of heritability for milk yield were higher than most of the values reported in the literature, although they were in the range reported in this species. This should facilitate genetic improvement for the population studied as part of a broader multi-trait breeding program.     

Effects of flunixin meglumine on pyrexia and bioenergetic variables in postparturient dairy cows

Study objectives were to determine whether a nonsteroidal antiinflammatory drug would reduce parturition-induced inflammation and fever and consequently improve appetite, bioenergetic parameters, and production variables in transitioning dairy cows. Multiparous cows (n = 26) were randomly assigned to 1 of 2 treatments beginning at parturition: 1) flunixin meglumine (FM; 2.2 mg/kg of BW; Banamine, 50 mg/mL, Schering-Plough Animal Health, Kenilworth, NJ), or 2) saline (control) at 2.0 mL/45.5 kg of BW. All treatments were administrated i.v. daily for the first 3 d in milk (DIM). Individual milk yield and dry matter intake (DMI) were recorded daily for the first 35 DIM. Rectal temperature was measured daily at 0700 and 1600 h for the first 7 DIM. Milk composition was determined on 2, 7, 14, 21, 28, and 35 DIM and blood plasma was collected on 1, 2, 3, 4, 7, 14, 21, 28, and 35 DIM. Body weight and body condition score were determined on −7, 1, 7, 14, 21, 28, and 35 DIM. Flunixin meglumine treatment slightly increased rectal temperature (38.99 vs. 38.76°C) during the first 7 DIM and reduced overall DMI (22.04 vs. 19.48 kg/d), but there were no treatment differences in overall milk yield (35.2 kg/d), 3.5% fat-corrected milk (37.6 kg/d), energy-corrected milk (37.7 kg/d), DMI (2.97% of BW), or overall energy balance (−2.32 Mcal/d). There were no treatment differences in milk fat (3.91%), protein (3.32%), or lactose (4.57%). Treatment had no effect on plasma glucose (66.5 mg/dL) or nonesterified fatty acids (553 μEq/L), but plasma urea nitrogen tended to be less in FM-treated cows (16.4 vs. 14.5 mg/dL). Daily FM administration to cows for the first 3 d after parturition slightly increased rectal temperatures by 0.23°C, reduced feed intake, and did not improve production or energetic variables during the first 35 DIM in transition dairy cows.     

Comparison of manual versus semiautomatic milk recording systems in dairy goats

A total of 24 Murciano-Granadina dairy goats in early-midlactation were used to compare the labor time and data collection efficiency of using manual (M) vs. semiautomated (SA) systems for milk recording. Goats were milked once daily in a 2 × 12 parallel platform, with 6 milking units on each side. The M system used visual identification (ID) by large plastic ear tags, on-paper data recording, and data manually uploaded to a computer. The SA system used electronic ID, automatic ID, manual data recording on reader keyboard, and automatic data uploading to computer by Bluetooth connection. Data were collected for groups of 2 × 12 goats for 15 test days of each system during a period of 70 d. Time data were converted to a decimal scale. No difference in milk recording time between M and SA (1.32 ± 0.03 and 1.34 ± 0.03 min/goat, respectively) was observed. Time needed for transferring data to the computer was greater for M when compared with SA (0.20 ± 0.01 and 0.05 ± 0.01 min/goat). Overall milk recording time was greater in M than in SA (1.52 ± 0.04 vs. 1.39 ± 0.04 min/goat), the latter decreasing with operator training. Time for transferring milk recording data to the computer was 4.81 ± 0.34 and 1.09 ± 0.10 min for M and SA groups of 24 goats, respectively, but only increased by 0.19 min in SA for each additional 24 goats. No difference in errors of data acquisition was detected between M and SA systems during milk recording (0.6%), but an additional 1.1% error was found in the M system during data uploading. Predicted differences between M and SA increased with the number of goats processed on the test-day. Reduction in labor time cost ranged from €0.5 to 12.9 (US$0.7 to 17.4) per milk recording, according to number of goats from 24 to 480 goats and accounted for 40% of the electronic ID costs. In conclusion, electronic ID was more efficient for labor costs and resulted in fewer data errors, the benefit being greater with trained operators and larger goat herds.     

Effects of transdermal flunixin meglumine on experimentally induced lameness in adult dairy cattle

Lameness is a common animal health condition with significant production and welfare implications. The transdermal formulation of flunixin meglumine is the only approved drug for pain control in cattle in the United States. Thirty adult dairy cows were enrolled in a study to determine the effect of transdermal flunixin on cattle with induced lameness. Cows were allocated to 1 of 3 treatment groups, with 10 cows per group: lameness and flunixin (L+F), lameness and placebo (L+P), or sham induction and placebo (S+P). An arthritis-synovitis was induced in the distal interphalangeal joint of the left hind lateral digit, using 20 mg of amphotericin B, 6 h before the application of treatment. Cows enrolled into the sham induction group had 4 mL of isotonic saline injected into the joint. Cows were dosed with transdermal flunixin at 3.33 mg/kg (1 mL/15 kg), or a placebo at 1 mL/15 kg, every 24 h for 3 d. The first treatment of flunixin or placebo was considered the start of the study, identified as time 0 h. Data were collected from all cows for 120 h following the initial treatment application. Outcome measures included plasma cortisol; substance P; visual lameness assessment; mechanical nociception threshold (MNT), presented as difference between left and right feet; infrared thermography (IRT), presented as difference between left and right feet; and gait analysis using a pressure mat. Cortisol concentrations were lower for the L+F group starting at 1.5 h after drug administration. Substance P levels showed no evidence for treatment differences among groups. Differences between the left hind MNT and right hind MNT were detected, with S+P having the lowest difference at ?0.04 kilograms-force (kgf; 95% CI: ?1.86 to 1.78 kgf), and L+P having the highest at ?2.96 kgf (95% CI: 1.55 to 4.36 kgf). The L+F group was intermediate at ?2.08 kgf (95% CI: 0.89 to 3.27 kgf). Similarly, when the difference between the maximum temperatures of the coronary band were examined via IRT, the L+P group had the highest difference at 1.64°C (95% CI: 1.02 to 2.26°C), with the L+F and S+P groups measuring 0.57°C (95% CI: 0.06 to 1.08°C) and 0.53°C (95% CI: ?0.2 to 1.25°C) respectively. We found no evidence for differences among treatment groups when analyzing force, contact pressure, step impulse, or stride length. Based on differences in MNT, IRT, and cortisol, transdermal flunixin is an effective analgesic agent for induced lameness. Multiple doses of transdermal flunixin may be required to be clinically effective, based on MNT and IRT data. Further investigation of transdermal flunixin and its analgesic effects is warranted in naturally occurring lameness.     

Short communication: Behavioral evaluation of the analgesic effect of flunixin meglumine in lame dairy cows

The objective of this study was to evaluate the effect of flunixin meglumine treatment on lameness pain in dairy cows. Twenty-four lactating Holstein cows were enrolled in the study based on visual observation of abnormal locomotion. The primary measurement endpoint was weight-shifting between the rear limbs. Weight-shifting was calculated as the standard deviation of the weight borne on the rear limbs over a 15 min period; this value correlates directly with lameness pain in dairy cows. After collecting baseline weight-bearing data, we randomly assigned cows to 1 of 2 treatment groups: 2.2 mg/kg body weight flunixin meglumine (2 mL/45 kg) or an equivalent volume of isotonic sterile saline solution. Weight-bearing data were collected from each cow at 2, 6, 12, and 24 h after a single intravenous drug treatment. Mean locomotion scores over the 2 d before treatment were 2.38/5 in the flunixin-treated group and 2.43/5 in the saline-treated control group; these values were not significantly different. Weight-shifting values were also not significantly different on either pretreatment day. Cows treated with flunixin meglumine showed significantly less weight-shifting between the rear limbs at 6, 12, and 24 h after treatment compared with saline-treated controls, providing evidence that flunixin meglumine alleviates lameness-associated pain.     

Mammogenesis and induced lactation with or without reserpine in nulliparous dairy goats

Nulliparous goats were used to evaluate the effects of a standard protocol for inducing lactation with or without using a prolactin-releasing agent (reserpine). Estrus was synchronized and goats were submitted to daily s.c. injections of estradiol-17β and progesterone (0.5 and 1.25 mg/kg of body weight, respectively) for 7 d. The goats were divided into 2 groups and injected i.m. with 1 mg/d of reserpine (n = 7) or the vehicle (n = 7) on d 12, 14, 16, 18, and 20. Lactation was initiated by i.m. injections of dexamethasone (10 mg/d) from d 18 to 20. Goats were machine milked once daily from d 21 to 120, at which time they were mated with herd sires. Milk was measured and sampled daily during wk 1 of lactation and weekly thereafter. Udder traits were measured in all goats at d −2 (before the induction treatment) and on d 35 and 100 (during lactation). Goats initiated lactation on d 21 (100%) and milk yield increased thereafter. The milk yield of control and reserpine-treated goats increased as lactation advanced, peaking at wk 10 of lactation, when reserpine-treated goats yielded 1,079 ± 89 mL/d of milk compared with 850 ± 96 mL/d for control goats. Yet milk yield at the peak was only 55% of the peak milk yield observed in contemporary primiparous goats. The composition of initial milk (d 21) was different from that expected for colostrum. Milk composition stabilized after d 3 of lactation. There were no differences among groups for milk fat, protein, casein, or whey protein, but milk from control goats contained greater nonprotein nitrogen than that from reserpine-treated goats (0.48 ± 0.02 vs. 0.41 ± 0.02%). Teat length increased from 24.7 ± 1.1 to 34.5 ± 2.4 mm in control goats during mammogenesis (d −2 to 35), but stabilized in reserpine goats (25.2 ± 2.2 mm). The distance between teats (11.5 ± 0.4 cm), and the volume (922 ± 63 mL) and depth (15.6 ± 0.60 cm) of the udder increased similarly in both groups during mammogenesis and lactation. After mating, 82% of herdmates became pregnant, whereas only 21% of the lactation-induced goats conceived (1 reserpine-treated and 2 control goats). In conclusion, lactation induction was effective in nulliparous goats, but neither milk yield nor the side effects on fertility seem to support its recommendation.     

The effect of diets on milk production and composition, and on lactation curves in pastured dairy goats

A 2-yr study investigated effects of different levels of concentrate supplementation on milk production, composition, and lactation curves in pastured dairy goats. For both years, 44 Alpine goats (Capra hircus; 55 ± 11 kg body weight) were randomly allocated to 4 groups. Animals were supplemented with 0.66 (treatments A and B), 0.33 (treatment C), or 0 kg of concentrate (treatment D) per kg of milk over 1.5 kg/d. Mixed vegetative forages were rotationally grazed by the goats (treatments B, C, and D), except that treatment A was confined and fed alfalfa hay. Individual milk production was recorded daily, and milk samples were collected once every 2 wk for the 7-mo period (March to September) and analyzed for fat, protein, lactose, urea-N, nonesterified fatty acids, and allantoin (second year only). Milk yield and composition varied among dietary treatments, with some measures affected by year. Average daily milk yield was lowest for treatment D. The increased level of concentrate supplementation in treatment A led to 22% greater milk yield compared with treatment D. Milk production increased by 1.7 and 0.9 kg for each additional kilogram of concentrate fed per day during the first and second years, respectively. Average peak yield, time of peak yield, and persistency were lower for treatment D than for other treatments. The percentage of milk fat was lower for treatment D than for other treatments. Concentration of milk protein was greater for treatments A and B during the first year, and was higher for treatment C than for other treatments during the second year. Average milk lactose concentration was higher for treatments B and C than for other treatments. However, milk urea-N concentration in treatment A was higher than other treatments. Milk allantoin, used to estimate microbial proteins synthesis, was 20 to 25% greater for treatment A than for other treatments. Averaged across year, plasma urea-N and nonesterified fatty acids concentration were lowest for treatment B. Average organic matter intake was similar among treatments during both years. Ratios of acetate and propionate concentrations for treatment A were lowest among treatments. In conclusion, milk production and composition were affected by the feeding treatment and year. Increased level of nutrition lead to an increase in daily milk yield, peak yield, time of peak yield, and persistency compared with treatment D. Alpine dairy goats grazing on fresh forages without concentrate supplementation can produce milk inexpensively, and response to concentrate supplementation is greater for low quality pasture.     

Pharmacokinetics and milk penetration of difloxacin after a long-acting formulation for subcutaneous administration to lactating goats

The single-dose disposition kinetics of difloxacin were determined in clinically normal lactating goats (n = 6) after intravenous (IV) and subcutaneous (SC) administration and subcutaneous administration of a long-acting poloxamer 407 gel formulation (P407). Difloxacin concentrations were determined by HPLC with fluorescence detection. Minimum inhibitory concentrations of difloxacin against 14 strains of Staphylococcus aureus isolated from mastitic goats’ milk in Spain were determined to compute pharmacodynamic surrogate markers. The concentration-time data were analyzed by compartmental and noncompartmental pharmacokinetic methods. Following SC and P407 administration, difloxacin achieved maximum milk concentrations of 1.34 ± 0.12 and 2.97 ± 1.18 mg/L, respectively, at 4.00 ± 0.00 h (SC) and 3.60 ± 0.89 h (P407) after administration. The absolute bioavailabilities after SC and P407 administration were 81.74 ± 15.60% and 72.58 ± 20.45%, respectively. Difloxacin penetration from the blood into the milk was good and high concentrations were found in milk secretions. From these data, a 15 mg/kg dose of difloxacin P407 would appear to be effective against Staphylococcus aureus isolated from mastitic goats’ milk with minimum inhibitory concentrations ≤0.25 mg/L.     

Influence of anionic salts on bone metabolism in periparturient dairy goats and sheep

The purpose of the present study was to investigate the influence of diets supplemented with anionic salts on bone metabolism of dairy goats and sheep. Twelve Saanen goats and 12 Ostfrisean milk sheep (fourth lactation) were divided into 2 groups each [sheep control (SC), goat control (GC); sheep anionic salts (SA), goat anionic salts (GA)]. Each group was fed a different diet in the last 10 d of gestation. Groups SC and GC received a normal diet according to the requirements of goats and sheep in this stage of gestation. Groups SA and GA received supplemental anionic salts. The dietary cation-anion difference (DCAD) was +524 (SC) and +515 (GC) vs. −163 (SA) and −164 (GA) mEq/kg of dry matter. Blood and urine samples were collected daily until parturition. Serum Ca, P, Mg, serum crosslaps (CTX), osteocalcin, 1,25-dihydroxy-vitamin D (VITD), urinary pH, and urinary Ca concentrations were analyzed. Bone mineral density and bone mineral content were measured with peripheral quantitative computer tomography. The bone resorption marker CTX showed significant differences between the animals supplemented with anionic salts and the control animals in goats, but not in sheep. The goats receiving anionic salts had greater CTX concentrations throughout the administration of the salts. In sheep, a difference was only observed on the day of parturition. Similar observations were made in VITD concentrations, although a significant difference between the goat groups was only observed 3 d prepartum. The bone formation marker osteocalcin was lower prepartum in the animals supplemented with anionic salts. The urinary pH was lower in the SA and GA animals, whereas urinary Ca concentrations were greater. Bone mineral content and bone mineral density decreased in all groups around parturition. In conclusion, this experiment showed that the addition of anionic salts in goats led to greater bone resorption rates while on this feeding regimen. It can be concluded that the anionic salts induced a mild metabolic acidosis with all its effects on calcium metabolism. These effects were not evident in milk sheep.     

Feeding soybean oil to dairy goats increases conjugated linoleic acid in milk

A total of 24 Murciano-Granadina dairy goats milked once daily throughout lactation were used to study the effects of including soybean oil (SBO) in the diet on lactational performance and milk fatty acid (FA) content, particularly conjugated linoleic acid (CLA) and trans-vaccenic acid (trans-11 C18:1, TVA). Three weeks after parturition, goats were allocated to 2 balanced groups according to lactation number, body weight, and daily milk yield, and were kept in separate pens. The experiment consisted of a 2-period (28 d each) crossover with 2 dietary treatments: control and SBO (6% as fed in the concentrate). Goats were fed dehydrated fescue (ad libitum), alfalfa pellets (0.5 kg/d), and concentrate (1 kg/d) to which the SBO was or was not added. Forage was fed in the pens, and concentrate was fed individually in 2 equal portions at milking (0900 h) and in the afternoon (1700 h). Final SBO content in the consumed SBO diet was 2.5% (dry matter basis). Diets were isonitrogenous (17.4% crude protein), but their total FA content varied from 2.2% (control) to 4.6% (SBO). There was no effect of SBO on dry matter intake, milk yield, energy-corrected milk, body weight, or body condition score. Compared with the control diet, feeding SBO increased milk fat content (4.57 vs. 5.24%) and yield as well as total solids content. Soybean oil had no effect on milk crude and true protein contents, but it reduced milk casein content (2.48 vs. 2.34%). Short- and medium-chain FA decreased by feeding SBO, whereas long-chain FA increased. Feeding preformed linoleic acid through SBO increased milk concentrations of linoleic, oleic, and stearic FA but reduced levels of linolenic and palmitic FA. As a consequence, feeding SBO decreased the saturated-to-unsaturated FA ratio and the atherogenicity index. Compared with the control treatment, milk contents of cis-9, trans-11 CLA (0.68 vs. 2.03%) and TVA (2.04 vs. 6.41%) in the SBO treatment increased by approximately 200%. In conclusion, feeding a moderate dose of SBO to dairy goats was a useful way to increase milk fat, CLA, and TVA contents in milk and to reduce the atherogenicity index without negative effects on intake, milk yield, and protein content.     

免疫学检测羊乳中掺入牛乳成分

由于营养、价格和原料等原因，市场上在羊乳中掺入牛乳的现象常有发生。针对这种乳源性掺假陆续产生了多种检测方法，本文主要综述了以ELISA为主的免疫学快速检测方法。     

Effects of a single transdermal administration of flunixin meglumine in early postpartum Holstein Friesian dairy cows: Part 1. Inflammatory and metabolic markers,uterine health,and indicators of pain

The objectives of this study were to assess the effects of a single transdermal administration of flunixin meglumine (FM) in early postpartum Holstein Friesian dairy cows on serum concentrations of inflammatory and metabolic markers, uterine health, and indicators of pain. The hypothesis was that the anti-inflammatory, antipyretic, and analgetic effects of the pharmaceutic agent would reduce systemic inflammation, resulting in improved metabolic and inflammatory profile, diminished incidence of metritis, and reduced expression of pain. A total of 500 cows (153 primiparous, 347 multiparous) from 3 different commercial dairy farms in the northeast of Germany were included in a randomized controlled clinical trial. Farms were preselected based on high haptoglobin concentrations in their fresh lactating cows. Cows were excluded if they had experienced dystocia, stillbirth, or twin birth, or if they showed any signs of milk fever, retained fetal membranes, or fever (>40°C). The cows were treated once with either FM (3.33 mg/kg) or a placebo as control (CON) through transdermal administration between 24 to 36 h postpartum (d 2). General health examinations were performed (daily from d 2–8 and additionally on d 15 postpartum), vaginal discharge was assessed using the Metricheck device (d 8 and 15 postpartum) and serum samples were analyzed for inflammatory and metabolic markers (d 2, 4, and 6 postpartum). Effects of treatment, parity, sampling day, and their interactions were evaluated using mixed effects models. Primiparous cows treated with FM showed lower serum haptoglobin concentrations (0.90 ± 0.08 vs. 1.17 ± 0.07 g/L; ± standard error of the mean) and higher serum albumin concentrations (35.5 ± 0.31 vs. 34.8 ± 0.31 g/L) on d 6 postpartum. They also had a lower risk for purulent vaginal discharge with or without a fever compared with CON cows on d 15 postpartum (odds ratio for CON vs. FM: 1.63, 95% CI: 1.26–2.00), and body temperature was lower throughout the first 15 d in milk (39.1 ± 0.11 vs. 39.2 ± 0.11°C). Multiparous cows treated with FM had lower serum β-hydroxybutyrate concentrations on d 4 postpartum (0.71 ± 0.05 vs. 0.78 ± 0.05 mmol/L) and d 6 postpartum (0.74 ± 0.05 vs. 0.80 ± 0.05 mmol/L). Regardless of parity, FM-treated cows were significantly less likely to abduct their tail from their body (14.3 vs. 23.6%) and show an arched back (27.9 vs. 39.7%) on the day after treatment compared with CON cows. It can be concluded that FM treatment slightly reduced inflammation and diminished the risk for metritis in primiparous cows, improved metabolic profile in multiparous cows, and reduced expressions of pain in all cows.