Direct and maternal (co)variance components, genetic parameters, and annual trends for growth traits of Makooei sheep in Iran

Genetic parameters and genetic trends for birth weight (BW), weaning weight (WW), 6-month weight (6MW), and yearling weight (YW) traits were estimated by using records of 5,634 Makooei lambs, descendants of 289 sires and 1,726 dams, born between 1996 and 2009 at the Makooei sheep breeding station, West Azerbaijan, Iran. The (co)variance components were estimated with different animal models using a restricted maximum likelihood procedure and the most appropriate model for each trait was determined by Akaike’s Information Criterion. Breeding values of animals were predicted with best linear unbiased prediction methodology under multi-trait animal models and genetic trends were estimated by regression mean breeding values on birth year. The most appropriate model for BW was a model including direct and maternal genetic effects, regardless of their covariance. The model for WW and 6MW included direct additive genetic effects. The model for YW included direct genetic effects only. Direct heritabilities based on the best model were estimated 0.15?±?0.04, 0.16?±?0.03, 0.21?±?0.04, and 0.22?±?0.06 for BW, WW, 6MW, and YW, respectively, and maternal heritability obtained 0.08?±?0.02 for BW. Genetic correlations among the traits were positive and varied from 0.28 for BW–YW to 0.66 for BW–WW and phenotypic correlations were generally lower than the genetic correlations. Genetic trends were 8.1?±?2, 67.4?±?5, 38.7?±?4, and 47.6?±?6 g per year for BW, WW, 6MW, and YW, respectively.     

Milk progesterone enzyme-linked immunosorbent assay as a tool to investigate ovarian cyclicity of water buffaloes in relation to body condition score and milk production

Background

Application of assisted reproductive technologies in buffaloes is limited to some extent by farmers’ inability to detect oestrus because of its poor expression. The present study aimed at investigating reliability of a milk progesterone enzyme-linked immunosorbent assay (ELISA) to assess the ovarian cyclicity during post partum, oestrus and post-breeding periods in water buffaloes.

Methods

Progesterone concentrations were measured by an ELISA in milk of 23 postpartum buffaloes in relation to oestrus, pregnancy, body condition score (BCS) and milk production. Two milk samples were taken at 10 days intervals, every month starting from day 30 and continued to day 150 post partum. BCS and milk production were recorded during sample collection. Milk samples from bred buffaloes were collected at Day 0 (day of breeding), Days 10–12 and Days 22–24. Defatted milk was preserved at −80°C until analysis. Pregnancy was confirmed by palpation per rectum on Days 70–90.

Results

Seventeen buffaloes had 47 ovulatory cycles, one to four in each, 13 were detected in oestrus once (28 % oestrus detection rate). Progesterone concentration ≥1 ng/ml in one of the two 10-day-interval milk samples reflected ovulation and corpus luteum formation. The intervals between calving to first luteal activity and to first detected oestrus varied from 41 to 123 days (n = 17) and 83 to 135 (n = 13) days, respectively. Eight buffaloes were bred in the course of the study and seven were found pregnant. These buffaloes had a progesterone profile of low (<1 ng/ml), high (≥ 1 ng/ml) and high (≥ 1 ng/ml) on Day 0, Days 10–12 and Days 22–24, respectively. Buffaloes cycling later in the postpartum period had fewer missed oestruses (P < 0.05). Buffaloes with a superior BCS had a shorter calving to oestrus interval and produced more milk (P < 0.05).

Conclusions

Milk progesterone ELISA is a reliable tool for monitoring ovarian cyclicity and good BCS may be an indicator of resuming cyclicity in water buffalo.     

Rumen development and growth of Balouchi lambs offered alfalfa hay pre- and post-weaning

The consumption of solid feed is essential for successful transition from a pre-ruminant to a functional digestive tract. Lambs fed starter rations containing highly fermentable carbohydrates often experience dramatic changes in concentrations of rumen and blood metabolites. The optimal amount of roughage required in the diet of pre-ruminant animals is still unclear. The objective of this study was to determine the effect of feeding alfalfa hay on performance and rumen development in young Balouchi lambs. In a completely randomized design, 30 lambs were fed one of three experimental diets consisting of a control, without alfalfa hay (C), a diet containing 7.5% alfalfa hay (A1), and a diet containing 15% alfalfa hay (A2). Lambs fed A1 and A2 diets had lower dry matter intake during the pre-weaning period (P?P?=?0.02), but feed conversion ratio and average daily gain were not affected by feeding alfalfa hay. Concentration of beta-hydroxybutyric acid was higher in C compared with the A1 and A2 groups (P?P?=?0.04) and increased thickness of muscular layer (P?=?0.05). We concluded that including 15% alfalfa hay in the starter diet could reduce thickness of the keratinization layer and increase muscularity of rumen wall without adverse effects on growth and performance of newborn lambs.     

Antinociceptive and selected physiological effects of morphine and xylazine on tiletamine‐zolazepam anesthesia in llamas

ObjectiveEvaluate antinociception, anesthesia, and recovery in llamas given tiletamine-zolazepam (TZ) with either morphine, xylazine, morphine and xylazine, or saline.Study designRandomized crossover experimental study.AnimalsSix healthy, adult intact male llamas.MethodsLlamas were given each of four treatments intramuscularly with a 1-week washout: TZ (2 mg kg^?1) combined with either morphine (0.5 mg kg^?1; M), xylazine (0.15 mg kg^?1; X), morphine (0.5 mg kg^?1) and xylazine (0.15mg kg^?1) (MX), or saline (C). Llamas breathed room air during the experiment. Characteristics of anesthesia, recovery, and selected cardiopulmonary variables were recorded. Antinociception was assessed by clamping a claw at 5-minute intervals. Data were analyzed using a mixed-model anova and Tukey-Kramer test, and are expressed as least squares mean ± SEM. Significance was set at p < 0.05.ResultsNo llama in the control group demonstrated antinociception. Antinociception was longest with treatment MX, followed by treatments X and M, respectively. Heart rates in llamas given treatments X and MX were significantly lower than with other treatments. The respiratory rate in llamas given treatment C was greater (p < 0.05) than for all other treatments, however, the respiratory rate was not significantly different among treatments X, M and MX. The PaO₂ for llamas given MX remained <60 mmHg throughout the 20 minute period of blood gas analysis. Mean arterial blood pressure in llamas in treatment MX was less than for treatments M or C.Conclusion and clinical relevanceThe combination of morphine (0.5 mg kg^?1) and xylazine (0.15 mg kg^?1) increased the duration of antinociception compared with xylazine alone, in TZ-anesthetized llamas. Treatments X, M and MX were associated with hypoxemia (PaO₂ < 60 mmHg).     

DNA vaccine-encoded glycoprotein B of HSV-1 fails to protect chronic morphine-treated mice against HSV-1 challenge

The use of morphine has been demonstrated to increase susceptibility to infections. Herpes simplex virus type 1 (HSV-1) is a highly successful pathogen among immunocompromised individuals. In the present study, due to the importance of HSV vaccination in morphine abusers, the effects of chronic morphine exposure on the host response to a HSV-1 gB DNA-based vaccine have been investigated. The study is addressing an important aspect of vaccine development among the susceptible (immunocompromised) hosts. BALB/c mice were exposed to morphine over 11 days. They were then vaccinated with DNA vaccine or KOS strain as a live vaccine. The findings showed that the morphine-treated animals failed to respond to DNA vaccination evaluated by the anti-HSV gB antibody titer, delayed type hypersensitivity (DTH) and lethal HSV-1 challenge. Under the same conditions, the KOS vaccine showed a reduced Ab titer and DTH response in morphine-treated mice, but could protect mice against the lethal challenge and was safe for vaccination of morphine-treated animals.     

Molecular typing of Iranian field isolates Mycoplasma synoviae and their differentiation from the live commercial vaccine strain MS-H using vlhA gene

1. The single-copy domain of the N-terminal region of the vlhA gene of Mycoplasma synoviae was sequenced, analysed and verified and used to type Iranian field isolates of M. synoviae and the MS-H live vaccine strain. In addition, a restriction fragment length polymorphism (RFLP) method was developed to differentiate between field isolates of Iranian and MS-H vaccine strains.

2. All sequences were analysed and aligned; the percentage similarity of the DNA was calculated and dendrograms were constructed. Based on single nucleotide polymorphism (SNP) that existed in all field isolates in Iran, the PCR-RFLP method allowed the differentiation of all M. synoviae field isolates from the vaccine strain.

3. Using phylogenetic analysis, the isolates were assigned to 8 unique genotypes and, within each group, DNA had a high level of similarity.

4. DNA sequence analysis and PCR-RFLP of the amplicon based on percent similarity and evolutionary relationship appeared to be useful tools for strain differentiation whether M. synoviae clinical isolates from infected chickens were derived from the vaccine strain or wild-type strains.

5. This study confirms the potential value of strain typing for epidemiological purposes and suggests that phylogenetic studies are essential to understand the true relationships between strains.     

Glutathione content of in vivo and in vitro matured canine oocytes collected from different reproductive stages

Glutathione (GSH) concentrations of oocytes are considered as an important marker of the cytoplasmic maturation. The present study was designed to compare GSH concentrations of in vivo and in vitro matured canine oocytes. In vivo matured oocytes were collected 72 hr after ovulation by flushing fallopian tubes after laparotomy. Ovaries were collected from bitches with different reproductive stages, and collected oocytes were divided into 2 groups according to the size viz. < 120 microm and > 120 microm in diameter and cultured for 72 hr in Tissue Culture Medium-199 supplemented with 10% FBS, 2.2 mg/ml sodium bicarbonate, 2.0 microg/ml estrogen, 0.5 microg/ml FSH, 0.03 IU/ml hCG, and 1% penicillin-streptomycin solution in the presence or absence of 50 microM beta-mercaptoethanol. GSH concentrations were determined by the dithionitrobenzoic acid-glutathione disulfide (DTNB-GSSG) reductase recycling assay. GSH concentrations of immature canine oocytes were 2.9 and 3.8, 3.5 and 6.8, and 3.1 and 6.5 pM/oocyte for < 120 microm and > 120 microm in diameter oocyte groups at anestrous, follicular and luteal stage, respectively (P<0.05). In vivo matured oocytes had significantly higher GSH concentrations compared with in vitro matured oocytes. The GSH content was 19.2 pM/oocyte for in vivo matured oocytes, while 4.1 to 8.1 and 5.7 to 13.2 pM/oocyte for in vitro matured oocytes cultured in the absence or presence of beta-mercaptoethanol, respectively (P<0.05). Presence of beta-mercaptoethanol increased GSH synthesis in canine oocytes cultured in vitro, and oocytes collected from follicular and luteal stage was superior to anestrus oocytes.     

Immune responses to oral and IM administration of M2e-Hsp70 construct

The eukaryotic expression plasmid of M2e-Hsp70 is a candidate M2e-based DNA vaccine. In order to evaluate the immunization potential of this construct, Specific Pathogen Free chickens were immunized either intramuscularly or orally. Mutant Salmonella typhimurium was used as carrier for oral delivery of the M2e-Hsp70 construct. M2e-specific humoral and cellular responses were tested by ELISA and Lymphocyte Proliferation Assay, respectively. Our results indicate that both humoral and cellular immune responses are conferred against M2e-Hsp70 plasmid in either of the intramuscular or oral routes of administration; however, these responses are significantly higher in intramuscular injection in contrast to oral administration. When it comes to mass vaccination of commercial chicken flocks oral administration is preferred due to the ease of application as well as its capability of eliciting mucosal, humoral and cellular immune responses; so measurements should be taken to improve the immunization potency of our orally delivered DNA vaccine.     

Effect of spiramycin and tulathromycin on abomasal emptying rate in milk-fed calves

Impaired abomasal motility is common in cattle with abomasal disorders. The macrolide erythromycin has been demonstrated to be an effective prokinetic agent in healthy calves and in adult cattle with abomasal volvulus or left displaced abomasum. We hypothesized that 2 structurally related macrolides, spiramycin and tulathromycin, would also be effective prokinetic agents in cattle. Six milk-fed, male, Holstein-Friesian calves were administered each of the following 4 treatments: spiramycin, 75 000 IU/kg BW, IM, this dose approximates 25 mg/kg BW, IM; tulathromycin, 2.5 mg/kg BW, SC; 2 mL of 0.9% NaCl (negative control); and erythromycin, 8.8 mg/kg BW, IM (positive control). Calves were fed 2 L of cow’s milk containing acetaminophen (50 mg/kg body weight) 30 min after each treatment was administered and jugular venous blood samples were obtained periodically after the start of sucking. Abomasal emptying rate was assessed by the time to maximal plasma acetaminophen concentration. Spiramycin, tulathromycin, and the positive control erythromycin increased abomasal emptying rate compared to the negative control. We conclude that the labeled antimicrobial dose of spiramycin and tulathromycin increases the abomasal emptying rate in healthy milk-fed calves. Additional studies investigating whether spiramycin and tulathromycin exert a prokinetic effect in adult cattle with abomasal hypomotility appear indicated.