Protein fraction characterization of sheep milk from the Comisana breed

Veterinary Research Communications -     

Growth of foetal bones and metabolic profile during gestation in primiparous ewes and multiparous ewes

Primiparous ewes and multiparous ewes show physiological differences during pregnancy, which can have an impact on the development of their offspring. The objective of this study was to compare the changes in the metabolic profile and in the size of some foetal bones throughout gestation between primiparous and multiparous ewes. Twelve primiparous (PM) ewes and 14 multiparous (MT) ewes were used. According to the dates of lambing, two groups of ewes were formed: Group 1 (G1, n = 6 PM and n = 7 MT) and Group 2 (G2, n = 6 PM and n = 7 MT). The body weight, body condition score, metabolic and foetal morphometric parameters were determined from before conception until the end of gestation. After lambing, the body weight and survival rate during the first 72 hr of life of lambs, as well as the maternal behaviour score were recorded. The PM ewes were lighter (p < .01) and had a greater mobilization of body reserves during gestation, mainly evidenced by a greater serum concentration of NEFAs and lower serum concentration of total proteins (p < .05) compared with the MT ewes. The parity did not affect the foetal morphometric variables. The lambs of MT ewes were heavier at parturition (p = .002) and tended to have a greater survival rate than those lambs of PM ewes (p = .09). In conclusion, PM ewes and MT ewes differ in their metabolic profile throughout the gestation. However, in the present study, we did not find parity differences in the dimensions of foetal bones during growth in gestation.     

Milk yield and composition of lactating Comisana ewes fed total mixed rations containing nitrogen sources with different ruminal degradability

The objective of this study was to examine the effects of pelleted total mixed rations (PTMR) containing two crude protein (CP) levels and N sources with different ruminal degradability on milk yield and composition of lactating ewes. The experiment, which lasted 14 weeks, was conducted during the spring and summer of 2007 and used 80 multiparous Comisana ewes in mid-lactation, reared in permanent stabling. A 2 × 2 factorial design was used, with ewes receiving two levels of CP (low 15.5% CP and high 17.5% CP) and two type of N sources with different rumen degradable protein (low and high) for each dietary treatment: (1) high-degradable protein diet (17.5% CP) composed by soybean meal, sunflower meal and urea (HPHD), (2) low-degradable protein diet (17.5% CP) included only corn gluten meal (HPLD), (3) high-degradable protein diet (15.5% CP) composed by soybean meal, sunflower meal and urea (LPHD), and (4) low-degradable protein diet (15.5% CP) included only corn gluten meal (LPLD). In order to evaluate in vivo digestibility of PTMRs, four adult rams were placed in metabolic cages and their individual faeces and urine were collected. In the performance trial, ewe milk yield was recorded daily and Individual milk samples were analysed weekly for milk composition and to determine milk renneting parameters. The 17.5% CP diets led to better nutrient apparent digestibility coefficients and had positive effects on milk production than the 15.5% CP diets. Similar results were obtained for corn gluten meal diets, compared to diets containing soybean meal, sunflower meal and urea. Data showed that corn gluten meal diets have had a positive effects on milk fat (P < 0.05), but not on milk protein, lactose and renneting parameters. All ewes gained weight during the experimental period, but the body weight change was not significant among treatments. Our findings indicate that an increase in rumen undegradable protein (RUP) content does not negatively affect nutrient digestibility of sheep rations and milk yield and composition.     

日粮不同能量和蛋白水平对多浪羊繁殖性能及血液生化指标的影响

试验于2009年3月至2010年3月在喀什地区麦盖提县多浪羊繁育基地进行,研究日粮不同能量和蛋白水平对多浪羊繁殖性能及血液生化指标的影响。90只母羊分为第Ⅰ组、第Ⅱ组和第Ⅲ组共3个组进行试验,3组均饲喂不同能量和蛋白水平的日粮,分别计算春季和秋季3个组的繁殖性能指标值,并检测血清中TP、ALB、GLB、ALP、BUN、GLU、TG和LDH的含量。结果发现,提高日粮能量水平对多浪羊春季发情率的提高有明显效果,但日粮高能量水平对受胎率和双羔率的提高均无效果;高蛋白水平日粮对多浪羊春季与秋季的发情率、受胎率和双羔率的提高没有明显效果;多浪羊春季血清中BUN含量高于秋季,秋季血清中ALP含量高于春季。从血液生化指标分析可以看出,秋季的繁殖性能比春季好。     

Electrophoretic studies of serum protein fractions in horses with laminitis]

The spectrum of serum proteins was evaluated in 46 horses affected with spontaneous laminitis and correlations between the severity of the disease and changes of the protein pattern were analyzed. The investigation was made in two groups; group A consisted of 21 horses of various breeds (warmblood, thoroughbred, standardbred) and group B of 25 ponys. Each group was subdivided according to the severity of the disease, using the OBEL-grade (OG) classification system. Serum proteins were separated by different one- and two-dimensional electrophoretic methods. Sera analysed by cellulose acetate electrophoresis showed a significant difference in the alpha 1-globulin fraction between OG II and OG IV affected horses. An increasing severity of the disease was correlated with a decrease of the alpha 1-globulins. The other protein fractions didn't show a uniform tendency. In group B there was a significant difference in the alpha 1-globulin fractions of OG II and OG III and in the beta 2-globulin fractions of OG I and OG II affected ponys. The acute phase proteins C3c, C4, Hp and fibronectin could be determined in a preliminary study in horse serum using the cross-reactivity of antibodies against the homologous human proteins.     

Molecular characterization and expression profile of ghrelin gene during different reproductive phases in buffalo (Bubalus bubalis)

Ghrelin, a novel motilin-related endogenous ligand for growth hormone secretagouge receptor, is implicated in various biological functions, including regulation of female reproduction. But the presence of ghrelin and its role in reproductive functions in buffalo, a species with poor reproductive efficiency, is not known. In the present study full-length ghrelin cDNA was isolated from bubaline abomasum, which encodes the entire prepropeptide of 116 amino acids. The deduced amino acid sequence of ghrelin of buffalo showed >95% and 31% identity with that of ruminants (cattle, sheep, and goat) and humans, respectively. Analysis of synonymous and nonsynonymous nucleotide substitutions in the coding region of ghrelin indicated that these sequences of different species have been under purifying selection. The 3995-bp amplicon of ghrelin gene consisting of 4 exons and 3 introns was cloned with genomic DNA from buffalo. Further, ghrelin expression was determined by quantitative real-time PCR, in situ hybridization, and immunohistochemistry in bubaline endometrial tissues at different stages of the estrous cycle and early pregnancy. Our results indicated the persistent expression of ghrelin mRNA and protein in the endometrium during stage I (day 3–5), stage II (day 6–15), and stage III (day 16–21) of the estrous cycle and also during early (∼day 30–40) pregnancy. Immunohistochemistry and quantitative real-time PCR experiments indicated the relatively higher expression of ghrelin in the endometrium during stage II (day 6–15) of the estrous cycle and early pregnancy than during stage I (day 3–5) and stage III (day 16–21) of the estrous cycle, but no statistically significant difference in ghrelin expression was observed among stages. To conclude, the results of the present study indicate the persistent expression of ghrelin in the uterine endometrium throughout the estrous cycle and in early pregnancy which might be helpful in determining its role in buffalo reproduction.     

Ascorbic acid status of female camels during different phases of reproduction

There is suggestive evidence that a low status of ascorbic acid in camels enhances their risk for infectious diseases. This study was carried out to disclose the role of reproduction, if any, in affecting ascorbic acid status. The associations between the reproductive cycle and ascorbic acid contents in plasma and leukocytes were studied in Sudanese camels browsing on local vegetation. Ascorbic acid status was found to be lowest during pregnancy and highest during lactation. Estrus versus non-estrus was associated with high vitamin C status. Brucellosis-positive camels showed decreased levels of ascorbic acid in plasma and leukocytes. Possibly, the phases of non-estrus and pregnancy in camels invoke an increased susceptibility to infectious diseases due to a lower ascorbic acid status.     

Influence of shearing on oxidative stress and some physiological parameters in ewes

The aim of the present study was to evaluate the effect of shearing on physiological and oxidative stress parameters in ewes. Twenty Comisana ewes were used and divided into two groups. Ten ewes were left unshorn as a control group (Group A) and 10 ewes were shorn (Group B). All measurements were taken before and after shearing, and repeated 8 h after shearing and 1, 2, 3, 4, 5, 10 and 15 days after shearing. Reactive oxygen species (dROMs), antioxidant barrier (oxy‐adsorbent), thiol antioxidant barrier (SHp) and packed cell volume (PCV) were assessed in blood samples collected by means of jugular venipuncture. Rectal temperature (RT), respiratory rate (RR) and heart rate (HR) were also measured. Two‐way repeated measures analysis of variance (ANOVA), followed by Bonferroni's test, was used for the assessment of significant effects due to shearing and time. The statistical analysis showed significant increases (P < 0.01) of dROMs, oxy‐adsorbent, SHp, and a significant decrease (P < 0.01) of RT and RR associated with time and shearing. Our results indicate that shearing causes a change in the ewe's homeostatic balance that leads to oxidative stress.     

Comparison of estrus induction and subsequent fertility with two different intravaginal devices in ewes during the non-breeding season

Two experiments were conducted to compare the effect of estrus induction by controlled internal drug release (CIDR) and intravaginal cream containing 500 mg progesterone (P cream) in ewes during the non-breeding season. In the first experiment, twenty-four ewes were randomly grouped for two treatments with the different intravaginal devices for 12 days: Group A was the CIDR group and Group B was the P cream group. Blood was collected from all treated ewes, and progesterone (P(4)), estradiol 17-beta (E(2)) and luteinizing hormone (LH) concentrations were measured by enzyme immunoassay. In the second experiment, the conception rates from natural mating, estrus-detected AI (inseminated 12 h after estrus detection), or fixed-time AI (inseminated 42 h after removal of an intravaginal device) in 127 ewes treated with CIDR or P cream were compared. In Experiment 1, the rate of estrus induction and the time of estrus onset after device removal were 91.7% and 36.3 +/- 15.7 h in Group A, and 100% and 35.0 +/- 12.6 h in Group B, respectively. There were no significant differences between the devices. The mean plasma P(4) concentration in Group B was significantly (P < 0.01) lower than Group A between day -9 and day -1 (Day 0: the day of device removal). However, no significant differences were found in the mean E(2) concentrations of the two groups after treatment. The mean time of estrus onset in ewes with an observed LH surge and the time of LH surge after treatment were 23.3 +/- 8.7 h and 30.3 +/- 5.0 h for Group A and 27.6 +/- 6.5 and 26.3 +/- 8.0 h for Group B, respectively, and there were no significant differences. However, a significant difference (P < 0.05) was found in the mean time from the time of estrus onset to LH surge between Group A (6.4 +/- 6.7 h) and Group B (-1.3 +/- 4.1 h). In Experiment 2, the conception rates for natural mating, estrus-detected AI, and fixed-time AI were 55.0, 29.4, and 25.0% for Group A and 40.7, 25.0, and 42.1% for Group B, respectively, and there were no significant differences. These results suggest that the effect of induction of estrus and ovulation and the rate of conception after treatment were comparable to CIDR even though the plasma P(4) concentration of the P cream method tended to be low during the insertion period.     

The expression of thrombopoietin and its receptor during different physiological stages in the bovine ovary

Thrombopoietin (TPO) is known to be involved in megakaryocytopoiesis, but its role in the control of ovarian function is unknown in cattle. The aims of this study were to demonstrate the expression of TPO and its receptor (c-MPL) in detail in bovine corpus luteum (CL) obtained from different stages of the oestrous cycle and during pregnancy--and to demonstrate that TPO/c-MPL system is expressed clearly in bovine follicles. Real-time RT-PCR (qPCR) and ELISA were applied to investigate mRNA expression of examined factors and TPO protein, respectively. In this investigation, increases in the concentrations of TPO protein and the mRNA expression of TPO and c-MPL were noticed during both early luteal stage and late luteal stage of the oestrous cycle. Furthermore, the expression of TPO/c-MPL system does not show any significant regulation in the CL throughout pregnancy. Highest co-expression of TPO/c-MPL system in both theca interna (TI) and granulosa cells (GC) in small follicles (<10 mm in diameter) was observed in this study that may suggest the possible role of TPO/c-MPL system in proliferation of TI and GC cells. To conclude, the results demonstrate the possible involvement of locally produced TPO/c-MPL system as a 'physiological filter' in bovine ovary where they may promote cell selection by inducing proliferation of viable cells and scavenging non-viable cells and thereby may play an important role in modulation of ovarian function.     

藏母羊妊娠期日粮蛋白水平对初生羔羊GH基因表达的影响

试验旨在研究藏母羊妊娠后期日粮蛋白水平对初生羔羊GH基因表达的影响,为妊娠后期及胎儿发育合理的日粮营养提供依据。选择年龄、胎次、体况相近的藏母羊60只,随机分为2组,每组30只羊;2组母羊妊娠前期(0～85 d)放牧饲养;妊娠后期(86～150 d)舍饲饲养,分别饲喂能量相同而蛋白水平为7.5%和13.5%的日粮。测定初生羔羊内脏器官、肌肉组织和胃肠道中GH基因表达量。结果表明,13.5%蛋白组羔羊心、肝、肺、瓣胃、皱胃、空肠中GH基因的表达量显著高于7.5%蛋白组(P<0.05)。妊娠后期提高藏母羊日粮蛋白水平能显著提高胎儿内脏器官、肌肉组织和胃肠道的生长发育。