Effect of different mini‐volume colloid centrifugation configurations on flow cytometrically sorted sperm recovery efficiency and quality using a computer‐assisted semen analyzer

Straws of sex‐sorted sperm are usually packaged at a low concentration (e.g., ~2.1 × 10⁶ sperm/ml) and cost significantly more than unsorted conventional semen from the same sire. In order to maximize the efficiency of using sex‐sorted sperm under in vitro fertilization conditions, the selection of an appropriate sperm separation technique is essential. In this study, the effect of using different silane‐coated silica colloid dilutions and layering configurations during centrifugation of sex‐sorted sperm was examined over an extended period of incubation time. Sperm recovery and viability after centrifugation using the colloid separation technique were measured along with several sperm motility parameters using CASA. For this purpose, frozen and thawed sex‐sorted sperm samples were centrifuged using mini‐volume single‐layer (40%, 60% and 80%) and mini‐volume two‐layer (45%/90%, 40%/80% and 30%/60%) separation configurations using PureSperm^®. A single layer of 40% PureSperm^® recovered significantly more sex‐sorted sperm (78.07% ± 2.28%) followed by a single layer of 80% PureSperm^® (68.43% ± 2.33%). The lowest sperm recovery was obtained using a two‐layer PureSperm^® dilution of 45%/90% (47.57% ± 2.33%). Single‐layer centrifugation recovered more sorted sperm (68.67% ± 1.74%) than two layer (53.74% ± 1.74%) (p < .0001). A single layer of 80% PureSperm^® exhibited the highest sorted sperm viability (72.01% ± 2.90%) after centrifugation (p < .05). The mini‐volume single layer of 80% PureSperm^® was determined to be an effective alternative to a two‐layer centrifugation configuration for sex‐sorted sperm selection. In addition, single‐layer colloid dilution of 80% performed either as well as or significantly outperformed the other treatments, as well as the control, with regard to motility (MOT) for all time periods of analysis.     

Low‐mobility sperm phenotype in the domestic turkey: Impact on sperm morphometry and early embryonic death

The sperm mobility assay measures the ability of sperm to swim through a dense layer of Accudenz^®, and the sperm mobility phenotype has been shown to predict fertility and other sperm performance traits in roosters and turkeys. In this study, we examined turkey sperm morphometry and rates of early embryonic death associated with high‐ and low‐mobility semen. We also assessed whether the hypo‐osmotic stress test, which evaluates the structural integrity of the sperm plasma membrane, may be used as a faster and simpler assay for sperm mobility and viability. We confirmed previous work that found that high‐mobility sperm are faster and swim more linearly than low‐mobility sperm, and that mobility traits were repeatable within males. In contrast to previous studies, we did not find higher rates of fertility, but low‐mobility sperm was associated with higher rates of early embryonic death, though this trend was not significant. High‐mobility sperm had longer sperm heads, explained by longer nuclei, despite shorter acrosomes. Although these sperm were faster, midpiece length and flagellum length did not differ between high‐ and low‐mobility sperm. Finally, mobility was not found to be associated with sperm performance in the hypo‐osmotic stress test.     

Hypophagic and dipsogenic effect of the 5‐HT1A receptor agonist 8‐OH‐DPAT in broiler chickens

The effects of the 5‐HT_1A receptor agonist 8‐OH‐DPAT on food and water intake in male broiler chickens were investigated. The injection of 25 or 50 μg/kg of 8‐OH‐DPAT 15 min before refeeding in fasted animals produced a decrease in food intake. No effect was observed in drinking. The injection of 25 or 50 μg/kg of the 8‐OH‐DPAT 60 min after the start of refeeding did not produce any significant modification in food intake. No effect on drinking was recorded. The agonist 8‐OH‐DPAT injected 15 min before water presentation in water‐deprived chickens, produced an increased drinking 60 min after the presentation of water. No effect on food intake was observed. The results show that the effect on food intake of the agonist 8‐OH‐DPAT in fasted–refed broiler chickens was similar to those observed in mammals and layer‐strain chickens. However, the agonist did not alter significantly the food intake when the broilers were fed 60 min before the injection. These results are contrary to the observed effects in mammals and in layer‐strain chickens. Probably, the selection for rapid growth rate in broilers causes modifications in the feeding control pattern. The comparison between broilers and layers strain may be a useful tool to elucidate the complex mechanisms involved in food and water intake regulation in chickens.     

Effect of dietary inclusion of spray‐dried porcine plasma on performance,some physiological and immunological response of broiler chickens challenged with Salmonella sofia

This study was conducted to investigate the effect of spray‐dried porcine plasma (SDPP) in broiler chickens under Salmonella sofia disease challenge. The experiment comprised five starter diets: positive control (no supplement), diet supplemented with in‐feed antibiotics (IFA; salinomycin 0.05% + zinc bacitracin 0.033%) and diets supplemented with SDPP at 10 or 20 g/kg diet. All four of these groups were challenged with S. sofia, while a fifth group was unchallenged and used as the negative control. The experimental diets were fed to 14 days; then, the birds were switched to commercial‐type grower and finisher diets. Oral inoculation of the challenged groups with S. sofia occurred on day 8, 10 and 12. Body weight was significantly higher in the birds fed diets containing IFA and SDPP than in the challenged control group, but it was only significant in starter and grower phases. In general, there was an improvement in the weights of the immune‐related organs, but it was only significant for the weight of the bursa of SDPP‐fed birds at 13 days. At day 13, blood potassium content was lower and the concentrations of IgG and IgM tended to be lower in the birds fed on low‐SDPP starter diets than those of the other groups. There were significant differences in the concentration of lactic acid in the ileum and acetic acid, formic acid, butyric acid and propionic acid in the caeca. Inclusion of SDPP to the starter diets of broiler chicks had positive effects on broiler performance, immunity and gut health during exposure to highly pathogenic conditions.     

The effects of the supplementation of multi‐strain probiotics on intestinal microbiota,metabolites and inflammation of young SPF chickens challenged with Salmonella enterica subsp. enterica

This study assessed the effect of probiotics on cecal microbiota, cecal short‐chain fatty acids (SCFAs), and the gene expression of cytokines in young specific‐pathogen‐free (SPF) chickens infected with S. enterica subsp. enterica. One‐day‐old SPF chickens (n = 105) were randomly assigned to one of the three treatment groups: control (Cont) group, Salmonella‐infected (Sal) group, and a Salmonella‐infected group treated with multi‐strain probiotics (ProSal group). All chickens except those in the Cont group were challenged orally with 1 × 10⁸ cfu/ml of Salmonella 4 days after hatching. Chickens in the Sal group exhibited more abundance of Proteobacteria than those in the Cont and ProSal groups. At the genus level, chickens in ProSal group exhibited increased numbers of Lactobacillus and Oscillospira compared with those in the other groups. Chickens in the ProSal group exhibited a significant increase of cecal SCFAs compared with chickens in the Sal group. Chickens in the ProSal group exhibited increased gene expression of anti‐inflammatory cytokines, IL‐10 and TGF‐β4, and decreased expression of the proinflammatory cytokine, IFN‐γ, in the cecal tonsil compared with those in the Sal group. The results of this study indicated that the administration of probiotics can modulate microbiota, SCFAs, and immunomodulatory activity in SPF chickens.     

Gender‐specific effects of a phytogenic feed additive on performance,intestinal physiology and morphology in broiler chickens

To date, most studies published were carried out on broilers of the same sex, and possible gender‐specific effects of phytogenic substances have not been investigated so far. A 3 × 2 factorial study was performed to examine gender‐specific effects of a PFA at two dietary levels (150, 1500 ppm) on growth performance, carcass traits and gastrointestinal attributes in broiler chickens versus an untreated control group. The addition of 150 ppm of the PFA led to a downregulation of trypsinogen mRNA in pancreas compared with the control group (p < 0.05). The number of goblet cells decreased in jejunum compared with the unsupplemented group, whereby this effect was more pronounced in male birds (p < 0.05). Furthermore, higher methylamine contents compared with the control group were measured (p < 0.01). In proximal ileum, female birds, supplemented with 150 ppm PFA, had lower crypt depths than their litters in the 1500 ppm treatment (p < 0.05). In distal ileum, villus height:crypt depth ratio was higher in birds fed the PFA at 150 ppm than in the control group (p < 0.05). The 1500 ppm dosage of the PFA increased jejunal histamine concentration compared with the negative control group (p < 0.05). Jejunal histamine concentration was also affected by the interaction PFA × sex (p < 0.05). Regardless of inclusion level, total amount of biogenic amines and other microbial metabolites in digesta samples was not affected by the PFA. These results demonstrate variable, partially gender‐specific effects of the tested PFA. Although the supplementation of 150 ppm showed little effect on mRNA expression level of selected marker genes for nutrient digestion, beneficial effects on gut morphology were observed. The 10‐fold higher dosage of the PFA did not adversely affect growth performance as well as most investigated parameters compared with the control group.     

Combined effect of apigenin and ferulic acid on frozen‐thawed boar sperm quality

The main aim of the present study was to evaluate the cryoprotective effect of apigenin (AP) and ferulic acid (FA) on boar sperm during cryopreservation. AP and FA were both demonstrated to be high‐efficiency antioxidants and had not previously been used to protect sperm from cryodamage. As boar sperm is sensitive to oxidative stress, suitable antioxidants are still needed for improving frozen‐thawed sperm quality. With this purpose, semen samples coming from five boars were used in this study. Ejaculates of five boars were mixed and split into 16 aliquots, in which different doses of AP and FA were added separately or together. The motility, the plasma membrane integrity, the mitochondrial activity, the acrosomal integrity, the antioxidase activities and the malondialdehyde concentration of the frozen‐thawed boar sperm were assessed. The results suggested that both AP and FA significantly improved the frozen‐thawed boar sperm quality in all these aspects when they were added to the freezing extender separately, while the highest improvement was recorded when the extender was supplemented with 0.1 mmol/L AP plus 0.15 mmol/L FA. These findings demonstrated that supplementation of freezing extender with both AP and FA had a combined, beneficial effect on frozen‐thawed boar sperm.     

Effect of frame rate capture frequency on sperm kinematic parameters and subpopulation structure definition in boars,analysed with a CASA‐Mot system

Motility is the most widely used indicator of sperm quality. Computer‐Assisted Semen Analysis (CASA) allows the objective evaluation of sperm motility parameters. CASA technology is a common tool to predict semen doses in farm animal reproduction. The kinds of video cameras used until now for image acquisition have presented limited frame rates (FR), which have a negative influence on the quality of the obtained data. The aim of the present work was to define the optimal frame rate for a correct evaluation of boar sperm motility and its subpopulation structure. Eighteen ejaculates from nine mature boars of the Pietrain breed were used. Using the ISAS^®v1 CASA‐Mot system, with a video camera working up to 200 Hz, six FRs (25, 50, 75, 100, 150 and 200 fps) were compared. ISAS^®D4C20 counting chambers, warmed to 37°C, were used. FR affected all the kinematic parameters, with curvilinear velocity (VCL) and BCF the most sensitive ones. All the parameters showed differences among animals. Non‐linear correlation showed the asymptotic level for VCL at 212 fps, being the highest FR for all the parameters. For future studies based just on progressive motility, almost 100 fps FR for 0.5 s must be used, while when kinematics must be considered, almost 212 fps for one‐second should be analysed. Three principal components were obtained (velocity, progressivity and oscillation), being similar at 50 and 200 fps. Cells were grouped in four subpopulations but with different kinematic and cellular distribution at both FRs.     

Effects of the supplementation with an high‐polyphenols extra‐virgin olive oil on kinetic sperm features and seminal plasma oxidative status in healthy dogs

The aim of this work was to evaluate the effects of the supplementation of two extra‐virgin olive oils (EVOO) having different polyphenols content, on canine spermatozoa kinetic parameters and seminal plasma oxidative status. The study was conducted on 12 clinically healthy dogs of different breeds (2–7 years, 5–48 kg of body weight) divided into two groups: an experimental group supplemented with EVOO (Coratina cultivar) high in polyphenols (H‐P) and a control group fed EVOO (Cima di Bitonto cultivar) low in polyphenols (L‐P). The oil was daily administered per os (1 ml/3 kg BW) before meal. Semen collection was made twice at 15 days distance (D0₁ and D0₂) and then at 30 (D30), 60 (D60) and 90 (D90) days. Semen concentration and kinetic parameters were measured using computer‐assisted sperm analysis (CASA) system to evaluate: sperm total count, sperm motile (MOT%), progressive motility (PROGR%) and its fractions, straight‐line velocity (VSL, μm/s), curvilinear velocity (VCL, μm/s), average path velocity (VAP, μm/s), amplitude of lateral head displacement (ALH, μm), beat cross frequency (BCF, Hz), straightness (STR%) and linearity (LIN%). On seminal plasma, reactive oxygen species (ROS) and biological antioxidant potential (BAP) were tested. From findings, no differences were found for sperm MOT, VSL, VCL, VAP, ALH, BCF, STR, LIN and BAP. A gradual enhancement of PROGR% was observed in H‐P group (p < .01). The ROS levels were higher in dogs H‐P compared to the other group (p < .05). In conclusion, our results highlight the positive effects of EVOO polyphenols on sperm PROGR% in healthy dogs.     

Investigation of in vitro measurable sperm attributes and their influence on electroejaculated bull semen with a fixed‐time artificial insemination protocol in Australian Bos indicus cattle

Increasing use of fixed‐time artificial insemination (FTAI) in beef cattle production has presented an opportunity for the use of fresh or chilled semen as an alternative to standard cryopreserved semen. The objective of this study was to examine in vitro sperm function and pregnancy rate of electroejaculated semen, chilled and stored for 48 hr, compared to conventionally cryopreserved semen with an optimized FTAI protocol in Brahman cattle. Semen from three Brahman bulls was collected, and aliquots were extended in either chilled (at 5°C) or frozen (LN₂) in a Tris‐egg yolk extender base with 2.4% or 7.0% glycerol, respectively. Semen samples were assessed 48 hr after collection or post‐thaw and warming, for sperm motility, in vitro sperm function and fertilizing ability, and used in a FTAI programme. The overall pregnancy rates was significantly different (p < .01) after FTAI with frozen (n = 173; 53.2%) and chilled semen (n = 174; 31.6%). In contrast, the in vitro sperm assessment showed that the chilled semen had significantly faster motility (p < .05), a higher proportion of progressively motile spermatozoa (p < .05), with significantly higher proportions of acrosome intact, viable spermatozoa (p < .01). This study showed that reasonable pregnancy rates in Brahman cattle can be achieved using FTAI with chilled semen collected using electroejaculation and stored for up to 48 hr. However, improvements in semen extenders are required in consideration of semen collection method to improve the longevity of sperm fertilizing ability to significantly increase FTAI output using chilled storage of bull semen.     

Effect of macronutrient ratio of the pre‐starter diet on broiler performance and intermediary metabolism

The aim of this study was to investigate the influence of isoenergetic substitution between the three energy delivering macronutrients in pre‐starter diets on performance and intermediary nutrient metabolism in broiler chickens. From hatch until 5 days of age, 600 chicks, collected during peak of hatch, were fed one of the three experimental pre‐starter diets with isoenergetic (13 MJ metabolisable energy/kg) substitutions between fat (43 vs. 108 g/kg), protein (126 vs. 240 g/kg) and carbohydrates (391 vs. 510 g/kg). After 5 days, commercial grower and finisher diets were provided. Pre‐starter composition influenced body weight until slaughter age, although not statistically verifiable. Broilers fed the low protein (LP) pre‐starter had the lowest body weight in relation to chickens on the low carbohydrate or low fat pre‐starter diet. After hatch, chicks on the LP pre‐starter diet were able to use the residual yolk sac more rapidly to fulfil their protein requirement, which is reflected in small intestine and liver development. Also, plasma metabolite levels were influenced mostly by the LP pre‐starter, indicating that the main focus for the requirements of newly hatched chicks should be on proteins. Furthermore, optimal nutrition during the first day’s post‐hatch should take into account the contribution of the yolk.     

Comparative evaluation of DNA integrity using sperm chromatin structure assay and Sperm‐Ovis‐Halomax during in vitro capacitation of cryopreserved ram spermatozoa

This study aimed to compare the ability of sperm chromatin structure assay (SCSA^®) and Sperm‐Ovis‐Halomax^® to detect DNA fragmentation in frozen‐thawed ram spermatozoa incubated under capacitating conditions in synthetic oviductal fluid (SOF) supplemented with oestrous sheep serum (SOF‐ESS) at multiple time points (0–240 min). Incubation in SOF‐ESS had no significant effects on SCSA^® parameters while the percentage of spermatozoa with fragmented DNA measured by Sperm‐Ovis‐Halomax^® increased after 180 min of incubation. In addition, no correlation or agreement was found between the techniques, suggesting that SCSA^® and Sperm‐Ovis‐Halomax^® may quantify different types of DNA damage in ram spermatozoa under these experimental conditions.     

Effect of various levels of dissolved oxygen on reactive oxygen species and cryocapacitation‐like changes in bull sperm

The present investigation was carried out to study the effect of various levels of dissolved oxygen (DO) on reactive oxygen species (ROS) and cryocapacitation‐like changes in bull sperm. Egg yolk–Tris–glycerol (EYTG) extender was split into four subextenders; viz., Extender I (control; no flushing with liquid nitrogen (LN₂)), Extender II, Extender III and Extender IV were flushed with LN₂ for 40, 16 and 8 min, respectively. The DO levels were standardized to 11.7, 2, 4 and 8 ppm, respectively, in control (Extender I), Extender II, Extender III and Extender IV. Ejaculates with mass motility of ≥ 3+ were divided into group I (diluted with Extender I), group II (diluted with Extender II), group III (diluted with Extender III) and group IV (diluted with Extender IV) up to 80 × 10⁶ sperm/ml. Extended semen samples were packed in French mini straws (0.25 ml), equilibrated and cryopreserved. Semen samples were evaluated at prefreeze and post‐thaw stage for various parameters (DO, progressive motility (PM), viability (VIB), acrosomal integrity (AI), hypo‐osmotic swelling (HOS) test, ROS, cholesterol (C) and phospholipid (P). The percentage of PM, VIB, AI, HOS test, cholesterol (C) and phospholipid (P) levels, and capacitated sperm were significantly (p < 0.05) higher in groups III and IV as compared to groups I and II. However, the acrosome‐reacted sperm (%; pattern AR) were significantly (p < 0.05) decreased in group III as compared to all other groups. Besides the proportion of sperm displaying tyrosine‐phosphorylated pattern, EA (fluorescence at both equatorial and anterior acrosomal regions, i.e. high capacitation level) was significantly (p < 0.05) reduced in group III compared to all other groups. In conclusion, varying DO levels in the extender significantly affect sperm quality, ROS production and capacitation‐like changes in bulls.     

Effect of dietary mannanase‐hydrolysed copra meal on growth performance and intestinal histology in broiler chickens

We investigated mannanase‐hydrolysed copra meal (MCM), which contains β‐1,4‐mannobiose (MNB), for its capacity to improve growth performance and activate intestinal villus function. Seven‐day‐old chicks were separated into four flocks with an equal mean body weight and then fed a basal diet (control) or a diet supplemented with 0.02% or 0.1% MCM. After 7 weeks, the feed intake and body weight were determined and then used to calculate the feed efficiency (FE). Moreover, the intestinal segments were examined by light microscopy and scanning electron microscopy (SEM) for cellular and morphological changes in the villus. Although feed intake was not significantly different among the experimental groups, the body weight gain and FE were significantly higher in the 0.1% MCM group than in the control group (p < 0.05), while feed intake tended to be higher in the 0.02% and 0.1% MCM groups. The cellular area of the ileum was significantly higher in the 0.02% and 0.1% groups in relation to that in the control group (p < 0.05). Furthermore, the cellular area of the duodenum and the jejunum tended to be higher in the 0.02% and 0.1% MCM groups. For the correlation analysis, a significant correlation was observed between the dosage of MCM and the cell area of the duodenum, jejunum and ileum. Moreover, the number of mitotic cells was higher in the 0.1% MCM group. As shown by SEM, the cells at the villi tips were protuberant in appearance in the 0.02% and 0.1% MCM treatments when compared with the relatively flat cells of the control. On the duodenal villus surface of the 0.1% MCM group, some cells devoid of microvilli were observed, suggesting that the increased protuberance of these cells represents increased absorption activity. Although intestinal villus height and area did not significantly differ among groups, the levels of these parameters tended to increase in the experimental groups relative to the control. The present morphological findings reveal that MNB might be effective for activating intestinal absorptive function, and that the functional activation promotes the growth of the chickens.     

Effect of L‐carnitine on proliferative response and mRNA expression of some of its associated factors in splenic mononuclear cells of male broiler chicks

The effect of L‐carnitine supplementation on mitogen (concanavalin A, Con A) induced proliferation of mononuclear cells (MNC) in the spleen was investigated in broiler chickens at different ages. Day‐old chickens were fed a diet supplemented with or without L‐carnitine (100 ppm) for 24 days. The carnitine‐supplemented group showed greater proliferation of MNC in the spleen in response to Con A than that of the control group at 24 days of age. In addition, at 24 days of age the carnitine‐supplemented group showed higher expression of interleukin (IL)‐2 and interferon (IFN)‐γ mRNA, but lower expression of inducible nitric oxide synthase (iNOS) in the Con A‐stimulated splenic MNC than the control group. The enhancement effect of L‐carnitine on MNC proliferation and IL‐2 mRNA expression was not found in chicks at 14 days of age. Addition of L‐carnitine (50 nmol/mL) to the culture medium enhanced proliferation and IL‐2 mRNA expression of splenic MNC obtained from 24‐day‐old but not from 14‐day‐old broiler chickens. The results suggest that L‐carnitine is capable of enhancing MNC proliferation in broiler chickens at 24 days of age partly through increasing IL‐2 and IFN‐γ production and decreasing NO production.     

The comparison of two different extenders for the improvement of large‐scale sperm cryopreservation in common carp (Cyprinus carpio)

In our study, a traditionally used (Grayling, already used in cyprinid species) and a newly tested (Pike) extender was tested to avoid sperm agglutination phenomenon following thawing during carp sperm cryopreservation. A large‐scale (elevated volume of sperm) freezing method in a controlled‐rate freezer using 5 ml straw and 10 ml cryotube was also systematically established. In all experiments, the sperm cryopreserved in using Grayling extender (except only one sample) showed an agglutination phenomenon (damaged and intact cells adhered to each other) after thawing where Pike extender resulted the regular cell suspension. No significant difference was observed between the two cryopreserved groups (Pike and Grayling extender) in all motility parameters using the 0.5 ml straw and the polystyrene box. Similarly, motility parameters did not show a significant difference in the two frozen groups with the 5 ml straw, also in the polystyrene box. A significantly higher progressive motility (pMOT, Grayling: 54% ± 8%, Pike: 37% ± 5%), straight line velocity (VSL, Grayling: 50 ± 5 µm/s, Pike: 39 ± 4 µm/s) and beat cross frequency (BCF, Grayling: 20 ± 1 Hz, Pike: 17 ± 1 Hz) was observed in the case of the grayling extender by the 5 ml straw cryopreserved in a controlled‐rate freezer (CRF) compare to the pike extender. A significantly higher VSL (Grayling: 45 ± 3 µm/s, Pike: 38 ± 4 µm/s) was observed by the grayling extender using the 10 ml cryotube than with the pike extender. Despite the randomly occurring differences in a few parameters, our new controlled freezing method using the newly tested Pike extender, the 5 ml straw or the 10 ml cryotube can be a good solution for the preservation of elevated volume of carp sperm.     

Comparative pharmacokinetics and pharmacokinetic/pharmacodynamic analysis by nonlinear mixed‐effects modeling of cefquinome in nonpregnant,pregnant, and lactating goats after intravenous and intramuscular administration

Cefquinome is a fourth‐generation cephalosporin that is used empirically in goats. Different physiologic factors like pregnancy or lactation could determine the pharmacokinetic behavior of drugs in the organism. The objectives of this study are to (a) compare the pharmacokinetics of cefquinome after intravenous and intramuscular administration in adult nonpregnant (n = 6), pregnant (n = 6), and lactating goats (n = 6), at a dose of 2 mg/kg, with rich sampling by nonlinear mixed‐effects modeling, (b) conduct a pharmacokinetic/pharmacodynamic analysis to evaluate the efficacy of the recommended posology in goats with different physiological states, and (c) determine the optimal posology that achieve a PTA value ≥ 90%, taking into account a T > MIC ≥ 60% of a MIC value ≤ 0.25 µg/ml, in the different subpopulations of goats for both routes. Gestation significantly increased Ka and V1, while reduced F0, Cl, and Q. On the other hand, lactation significantly increased V1 and reduced Tk0. Cefquinome concentrations achieved in placental cotyledon, amniotic fluid, and fetal serum indicate a minimal penetration across the placental barrier. Moreover, milk penetration of cefquinome was minimal. The total body clearance of cefquinome for goats was 0.29 L kg^?1 hr^?1, that is apparently higher than the reported for cows (0.13 L kg^?1 hr^?1) and pigs (0.16 L kg^?1 hr^?1). So, the optimal dose regimen for cefquinome after intravenous and intramuscular administration required higher dose and frequency of administration compared with recommendations for cows or pigs. Therefore, 2 mg kg^?1 8 hr^?1 and 5 mg kg^?1 12 hr^?1 could be used for IV and IM routes, respectively, for the treatment of respiratory infections caused by P. multocida and M. haemolytica, but only 5 mg kg^?1 12 hr^?1 by both routes should be recommended for Escherichia coli infections.