Influence of body weight on reproductive activity in Sarda female lambs

One way to improve reproductive performance of ewes is through extending its lifetime productivity. Breeding ewe lambs is one method of improving the reproductive performance in the sheep. In order to produce an offspring when the ewe lamb is approximately 1 yr of age, the autumn-born ewe must obtain puberty before the autumn breeding season begins. Onset of puberty is determined by integration of both internal and external factors, which then enable the neuroendocrine or hormonal event occur (Shirley et al., 2001). Age, photoperiod and body weight are the principal factors influencing puberty. The age at onset of the reproductive activity in the sheep is different among the various breeds. In the Sarda lambs the age of the onset of puberty is about 7-8 months. However the animals that have this age don’t reach the puberty if photoperiod and body weight are not suitable. Both the female lambs born in October-November and in February reach puberty in the same subsequent autumn breeding season. This reproductive behaviour evidences that photoperiod plays an important role in the onset of puberty (Papachristoforou et al., 2000).The female lambs born in later spring uneasily reach puberty within the subsequent breeding season, although photoperiod is favourable. This retard in the onset of reproductive activity is due to the attainment of the body maturity only during subsequent long day period but they reach reproductive activity only during the autumn of the subsequent year (Foster et al., 1985). In fact, some authors suggested that besides photoperiod and age, attainment of the 60% of adult weight is essential for onset of puberty (Abecia et al., 2001). Indeed the undernourished animals delay puberty, in comparison to well nourished subjects (I’Anson et al., 1997). This behaviour is linked to the different LH pulse frequency: restricted diet lambs show one pulse per 4 hours, instead fed ad libitum subjects manifest four or five pulse per 4 hours (Ebling et al., 1990). The purpose of this investigation is to determine the onset of puberty and to research its linkage with body weight in Sarda female lambs during breeding season under natural condition

Genotype at the MTNR1A locus and response to melatonin treatment in Sarda lambs

With the aim to evaluate the effect of melatonin treatment and melatonin receptor 1A (MTNR1A) genotype on advance of puberty, 423 Sarda lambs were chosen. On June 26th, they were divided into three groups, each of 141 animals (groups 0, 1, and 2), on the basis of live weight. On June 30th, animals in group 1 received a single implant (18 mg melatonin), while group 2 received two implants. Group 0 was untreated. Thirty-five days after treatment (August 4th), rams were introduced and after 40 days they were removed. From January 1st to February 10th lambing dates were recorded. Genomic DNA was extracted and subjected to PCR for the amplification of exon II and then digested with enzymes MnlI and RsaI and placed into +/+, +/−, or −/− group for MnlI and C/C, C/T, or T/T group for RsaI. Samples were cloned and sequenced. Data obtained were subjected to χ2 test in order to evaluate the difference in fertility among groups and the link between genotype and reproductive activity. Genotype +/+ and C/C showed the highest incidence. Treated groups showed a higher number of lambing at 10th February compared to control group (P<0.04). Melatonin treatment results more efficient in +/+ genotype

Reproductive activity in sheep with different lambing period treated with melatonin in April

The object was to evaluate the effect of melatonin treatment on the advance in April of the reproductive resumption in Sarda breed sheep with different lambing period. For the research two farms, located in North Sardinia between 39° and 40° N, were chosen. In each farm, 120 lactating ewes were selected: 30 lambed between October 20th and November 20th (group 1); 30 lambed between December 1st and 30th (group 2); 30 lambed between January 1st and 30th; 30 lambed between February 1st and 28th (group 4). In each farm, each group of 30 animals was divided into two subgroups of 15 animals (M and C). On April 1st, in each farm, the animals of the M subgroups were treated with a implant containing 18 mg melatonin. The subgroups C were kept as control. The lambing dates and the number of newborn lambs were recorded until 220 days after ram introduction. In treated animals greatest fertility (P<0.01) and lowest distance in days from male introduction to lambing (P<0.01) were recorded. The best reproductive performances were found in the group 1 and 2 compared to the other two groups (P<0.01).The present research shows that melatonin treatment should be made 3 or 4 months after lambing, in order to obtain optimal results

Polymorphism of the MTNR1A Melatonin Receptor Gene in Goat Breeds of Northern Italy

Melatonin receptor MT1, encoded by the MTNR1A gene, is the main one involved in the seasonal regulation of reproductive activity. A correlation between this gene polymorphism and reproductive performance has been demonstrated in sheep. To date, no data about MTNR1A gene polymorphism are available regarding Italian goat breeds other than the Sarda goat. This study aimed to detect any PCR-RFLP polymorphic sites of MTNR1A using MnlI and RsaI enzymes in Northern Italian goat breeds, which are characterized by a pronounced reproductive seasonality. One-hundred-eight adult female goats belonging to four different breeds were included in the study (i.e., Frisa Valtellinese, n = 29; Orobica, n = 23; Lariana, n = 29; Camosciata delle Alpi, n = 27). Blood was sampled from each goat. Genomic DNA was extracted from each sample and the main part of exon II of MTNR1A gene was amplified by PCR and digested with MnlI and RsaI enzymes. Unexpectedly, none of the fragments were found to be polymorphic. The absence of polymorphism may be linked to the macro group of goat breeds that evolved during human migrations. Breeds of the Alpine-European strain would appear to show no polymorphism, as confirmed by our study, whereas breeds belonging to the Mediterranean-African or Asian-Middle Eastern strains do

Polymorphisms of the melatonin receptor 1A (MTNR1A) gene affect the sexual performance of Rasa Aragonesa rams without changing their social dominance

This study aimed to investigate whether a specific genotype of the MTNR1A gene influences social dominance and reproductive performance in rams. Thirty-one rams were genotyped for Rsal and Mnll polymorphism of the gene: CC (n=19), CT (n=5), and TT (n=7), and GG (n=20), GA (n=6), or AA (n=5), respectively. Maintenance (standing still, lying down, drinking, feeding, walking, or stereotyping) and social behavior (agonistic and antagonistic interactions among rams) were recorded by direct observations involving instantaneous scan sampling and continuous behavior sampling. For each animal, his Index of Success (IS) and Displacement (ID) were calculated. One week after the social-behavioral observations, rams were tested in individual serving-capacity tests involving three ewes that were synchronized into estrus in a 15-m2 pen for 20 min. The genotypes did not differ in the number of aggressions they performed (CC: 88.95±12.85; CT: 106.20±21.00; TT: 70.43±8.50; GG: 76.05±8.72; GA: 119.00±16.16; AA: 95.80±36.39) or received (CC:75.79±5.82; CT:92.40±8.68; TT: 86.14±15.05; GG: 79.25±6.58; GA: 86.83±11.51; AA: 79.80±12.74), and their active and passive behaviors were similar. The genotypes did not differ significantly in IS or ID, and the proportion of rams in each success category was similar among groups. For the Rsal and Mnll polymorphism, TT and GG rams were responsible for 54% and 56% of recorded sexual events (P < 0.05), respectively. Results of this study confirm that the best sexual performance of rams was among those that carried certain genotypes of the MTNR1A gene. Still, it was not correlated with differences in social dominance

Characterization of the SREBP-1 Gene Polymorphisms and Milk Traits in Dairy Sheep

The SREBP genes (Sterol Regulatory Element-Binding Proteins) are involved in the milk fat synthesis. In dairy cows some polymorphisms at the SREBP-1 gene sequence have been related with milk fat content. The aim of this study was to characterize the entire coding regions of the SREBP-1 gene in Sarda sheep breed, in order to highlight any polymorphisms and their association with milk traits. Four-hundred adult and lactating Sarda ewes were selected. Individual milk yield was recorded monthly from Day 30 to Day 150 of lactation, and fat and protein concentration were analysed. A blood sample from each ewe was taken for DNA extraction; thus, all the 19 coding exons of the SREBP-1 gene were amplified by polymerase chain reaction (PCR). Single-strand conformation polymorphism analysis (SSCP) and sequencing were used to scan mutations. Results provide, for the first time, the entire coding DNA sequence (CDS) of the SREBP-1 gene in sheep, and by sequences analysis 8 polymorphisms have been detected. The statistical analysis exhibited no relationship between polymorphisms and milk traits. The low SREBP-1 gene diversity that emerged from the present study, may be linked to the important role of this gene in the mechanism of milk fat synthesis or to the severe genetic selection performed in the Sarda sheep. However, it would be necessary to extend the study, including other breeds and other genes, in order to expanding the knowledge about the process of milk fat synthesis in dairy sheep

Multicenter randomized, double-blind controlled trial to evaluate the efficacy of laser therapy for the treatment of severe oral mucositis induced by chemotherapy in children: LaMPO RCT

OBJECTIVES: To demonstrate the efficacy of laser photobiomodulation (PBM) compared to that of placebo on severe oral mucositis (OM) in pediatric oncology patients. The primary objective was the reduction of OM grade (World Health Organization [WHO] scale) 7 days after starting PBM. Secondary objectives were reduction of pain, analgesic consumption, and incidence of side effects. METHODS: One hundred and one children with WHO grade > 2 chemotherapy-induced OM were enrolled in eight Italian hospitals. Patients were randomized to either PBM or sham treatment for four consecutive days (days +1 to +4). On days +4, +7, and +11, OM grade, pain (following a 0-10 numeric pain rating scale, NRS) and need for analgesics were evaluated by an operator blinded to treatment. RESULTS: Fifty-one patients were allocated to the PBM group, and 50 were allocated to the sham group. In total, 93.7% of PBM patients and 72% of sham patients had OM grade < 3 WHO on day +7 (P = 0.01). A significant reduction of pain was registered on day +7 in the PBM versus sham group (NRS 1 [0-3] vs. 2.5 [1-5], P < 0.006). Reduced use of analgesics was reported in the PBM group, although it was not statistically significant. No significant adverse events attributable to treatment were recorded. CONCLUSIONS: PBM is a safe, feasible, and effective treatment for children affected by chemotherapy-induced OM, as it accelerates mucosal recovery and reduces pain

Reproductive Resumption in Winter and Spring Related to MTNR1A Gene Polymorphisms in Sarda Sheep

The aim of the present research was to evaluate the association between the SNPs rs430181568 and rs407388227 located in the MTNR1A gene with the reproductive recovery of Sarda sheep in different months of ram introduction in the flock (February, March, April and May). In order to address this research gap, we selected two farms, each of which consisted of approximately 1000 animals; a total of 800 ewes (400 for each farm) were genotyped for the two single nucleotide polymorphisms rs430181568 and rs407388227 located in the exon 2 of the MTNR1A. These SNPs are completely linked; thus, each genotype of rs430181568 corresponded to the same genotype for rs407388227. Among the genotyped animals, 240 individuals were selected and divided into four homogeneous groups (A, B, C and D) of 60 subjects, each group based on age (range 3&ndash;6 years old), body condition score (BCS) (range 2.0&ndash;4.0) and genotype (20 ewes carrying CC/CC, 20 CT/CT and 20 TT/TT genotype). The dates of the ram introduction in each group were 15 February, 15 March, 15 April and 15 May, respectively. In all groups, the lambing date and the number of lambs born from 150 to 220 days after the ram introduction were recorded. In all the groups, the genotypes CC/CC and CT/CT of the polymorphism (rs430181568 and rs407388227) showed the greatest fertility (the ratio between the number of lambed ewes and the ewes exposed to the rams) (p &lt; 0.01) and the shortest distance between ram introduction to lambing (p &lt; 0.01), compared with the TT/TT genotype. In conclusion, we determined that the polymorphisms rs430181568 and rs407388227 were associated with reproductive recovery, after ram introduction, even in February and March, months subsequent to the photorefractoriness period

A Polymorphism at the melatonin receptor 1A (<i>MTNR1A</i>) gene in Sarda ewes affects fertility after AI in the spring

The effect of MTNR1A gene polymorphisms on the fertility rate after AI in Sarda sheep was evaluated in 600 lactating adult ewes. Genomic DNA was subjected to amplification of the MTNR1A gene exon II. Amplicons were digested with restriction endonuclease MnlI. Ten samples from each genotype were sequenced. A polymorphism was detected (A612G) and ewes were determined to be +/+, +/– or –/– for the allele. Allelic frequency was 0.77 for the + allele and 0.23 for the – allele. The frequency of the +/+, +/– and –/– genotypes was 68, 19 and 13%, respectively. On 16 May 2009, 60 ewes from each genotype group were synchronised using intravaginal sponges containing 40 mg fluorogestone acetate for 14 days. At sponge removal, the ewes were administered 350 IU pregnant mare’s serum gonadotropin and were then inseminated, 54–56 h later, with 400 × 106 spermatozoa. Pregnancies were confirmed 50 days after AI using transabdominal ultrasonography. Lambing dates and the number of newborn lambs were recorded within 155 days after AI. Conception and lambing rate were higher for ewes with the +/+ and +/– genotypes compared with those with the –/– genotype (P &lt; 0.01). In conclusion, there was a positive correlation between MTNR1A allele polymorphisms the reproductive response following synchronisation and AI in the spring