Effect of Induced-Moult on the Number Small Ovarian Follicles and Egg Production of Old Layers

Abstract: Influence of induced-moult on small ovarian follicles and egg production of old laying flock was investigated. Small follicles were graded thus: small yellow follicles (SYF), large white follicles (LWF) and small white follicles (SWF). A total of 360 old layers in their 64 weeks in lay were used in a 2x3 factorial arrangement in a Completely Randomized Design (CRD). The induced-moult treatments were natural day length with feed and water ad libitum, natural day length with water but no feed, natural day length with no feed and no water, reduced day length with feed and water ad libitum, reduced day length with water but no feed, reduced day length with no feed and no water, represented as T1, T2, T3, T4, T5 and T6, respectively. Each treatment was replicated 3 times with 20 hens per replicate. At the commencement of the experiment the numbers of the small follicles of the Control (T1) were 7.67 ± 0.88, 18.33 ± 0.88, 2121.67 ± 5.78, for small yellow, large white and small white follicles, respectively. The results showed that with the exception of T4, the numbers of all the small follicles of the rest of the induced-moult groups were significantly decreased (P<0.05) by day 7 of moult induction. The numbers of the small follicles of T2, T3, T5 and T6 gradually increased and became Significantly higher (P<0.05) than the control (T1) by day 49 of moult induction. By day 49, the numbers of the small follicles of the induced-moult hens ranged from 2500± 17.56 to 3670.00± 4.05 (SWF), 24.33±0.88 to 41.00± 0.58 (LWF) and 5.00± 0.58 to 6.67± 0.20 (SYF). The mean egg production of the flock was about 50 % prior to moult induction. The hen-day percent production of the moult groups ranged from 50 to 79 % whereas that of the unmoulted control ranged from 35 to 55 %. In conclusion, moulting initiated regeneration and rejuvenation of follicles. This in turn led to increase in post moult egg production of the induced-moult groups

A survey of the ATP-binding cassette (ABC) gene superfamily in the salmon louse (Lepeophtheirus salmonis)

Salmon lice,Lepeophtheirus salmonis(Krøyer, 1837), are fish ectoparasites causing significant economic damage in the mariculture of Atlantic salmon,Salmo salarLinnaeus, 1758. The control ofL.salmonisat fish farms relies to a large extent on treatment with anti-parasitic drugs. A problem related to chemical control is the potential for development of resistance, which inL.salmonisis documented for a number of drug classes including organophosphates, pyrethroids and avermectins. The ATP-binding cassette (ABC) gene superfamily is found in all biota and includes a range of drug efflux transporters that can confer drug resistance to cancers and pathogens. Furthermore, some ABC transporters are recognised to be involved in conferral of insecticide resistance. While a number of studies have investigated ABC transporters inL.salmonis, no systematic analysis of the ABC gene family exists for this species. This study presents a genome-wide survey of ABC genes inL.salmonisfor which, ABC superfamily members were identified through homology searching of theL.salmonisgenome. In addition, ABC proteins were identified in a reference transcriptome of the parasite generated by high-throughput RNA sequencing (RNA-seq) of a multi-stage RNA library. Searches of both genome and transcriptome allowed the identification of a total of 33 genes / transcripts coding for ABC proteins, of which 3 were represented only in the genome and 4 only in the transcriptome. Eighteen sequences were assigned to ABC subfamilies known to contain drug transporters,i.e. subfamilies B (4 sequences), C (11) and G (2). The results suggest that the ABC gene family ofL.salmonispossesses fewer members than recorded for other arthropods. The present survey of theL.salmonisABC gene superfamily will provide the basis for further research into potential roles of ABC transporters in the toxicity of salmon delousing agents and as potential mechanisms of drug resistance

Comparison of the effectiveness of two-dose versus three-dose sulphadoxine-pyrimethamine in preventing adverse pregnancy outcomes in Nigeria

Background & objectives: Three doses of intermittent preventive treatment with sulphadoxine-pyrimethamine (IPTp-SP) has been adopted as the new recommendation for prevention of malaria in pregnancy. This study evaluated the effectiveness of two-dose versus three-dose of SP for IPTp-SP in the prevention of low birth weight (LBW) and malaria parasitaemia. Methods: An open, randomized, controlled, longitudinal trial was conducted in a secondary level hospital in Nsukka region of Enugu State, Nigeria. A sample of 210 pregnant women within gestational ages of 16–24 wk were recruited at antenatal clinics and equally randomized to either a two-dose SP or three-dose SP group. The primary endpoints were LBWs, peripheral, and placental parasitaemia, while the secondary endpoints were maternal anaemia, pre-term birth, clinical malaria and adverse effects of SP. Results: Among 207 cases followed till delivery, the prevalence of parasitaemia was lower in three-dose group than in two-dose group for both peripheral (9.3% versus 27.8%) and placental (10.6% versus 25.6%) parasitaemia. The adjusted odds ratios (aOR) were 0.15 [95% confidence interval (CI), 0.05 – 0.45] and 0.17 (95% CI, 0.06–0.51), respectively. The prevalence of LBW was also lower in three-dose (3.5%) than in two-dose (12.2%) group (aOR, 0.15; 95% CI, 0.04–0.63); however, the prevalence of maternal anaemia, pre-term births, clinical malaria and SP adverse effects were similar between the two arms of treatment. Interpretation & conclusion: Addition of a third SP dose to the standard two-dose SP for IPTp led to improved reductions in the risk of some adverse pregnancy outcomes