Size at Maturity and Fecundity of Oreochromis niloticus and Mouth Brooding Tilapiines Indigenous to Kafue Flood Plain Fishery, Zambia.

The present investigation was conducted to ascertain whether or not Size at maturity, Fecundity, and Total Length-Fecundity variation could explain the population dominance of Oreochromis niloticus (Linnaeus 1758) over three spot breams Oreochromis andersonii (Castelnau 1861) and Green-Headed Bream Oreochromis macrochir (Boulenger 1912) in the Kafue Flood Plain during the spawning season (October 2020 to March 2021). Fish samples caught using a full standard multifilament net with mesh sizes ranging from 25 to 150 mm increments of 12.5 mm were purchased from Local Fishermen at Chanyanya and Kasaka fishing camps. The Total length of each fish was recorded to the nearest 0.1 cm using the fish measuring board. Reproductive stages of the three Tilapiine fish species were determined using standard keys. Whole ovaries from sexually mature females (ripe) were weighed and preserved in 10% formalin solution; logistic regression lines were used to determine size at maturity (L50). Fecundity was determined using gravimetric procedures. The O. andersonii matured at a Total length of 210.98 mm, O. macrochir at 199.48 mm, while O. niloticus matured at 189.82 mm. The O andersonii had mean Fecundity of 1843.92 ± 68.805; O. macrochir had 1640.82 ± 92.164 while O. niloticus had 1422.24 ± 91.103. The relationship between Fecundity and Total length was found to be strongest in O. macrochir (y=12.845x-1175; r=0.8770), followed by O. niloticus (y = 12.912x – 1614.3; r=0.8104) and finally O. andersonii (y=10.715x-591.91; r=0.7606). The studied characteristics among the Tilapiines indicated that O. niloticus was superior in reproductive biology. There should be proper guidelines in the laws and regulations regarding the introduction of O. niloticus into other water bodies. The O. niloticus must be promoted in aquaculture because of its reproductive advantages compared to the local Tilapiines

Comparative effects of low energy diets on blood parameters and liver HSP70 and iNOS gene expressions among Tanzanian local chicken ecotypes

A study comparing effects of low energy diets on liver HSP70 and iNOS gene expressions and blood indices of three Tanzanian chicken ecotypes was conducted. Four weeks old hens belonging to Kuchi (KU), Ching’wekwe (CH) and Morogoro medium (MM) ecotypes were allocated to 9 pens in a 3 x 3 factorial design, with three replicates. They were fed 3 diets containing 40, 55 and 0% less energy than prescribed. Only KU 55% restriction groups had marked up-regulations (p<0.05) of HSP70 after 3 weeks. After 7 weeks, expression levels of HSP70 for KU and CH 55% restriction groups increased, while those for MM restriction groups remained unaltered. The iNOS levels were notably up-regulated for KU and CH 55% restriction groups after 3 and 7 weeks, respectively. Significant elevations (p<0.05) of serum corticosterone were only noted for KU restriction groups after 1 and 3 weeks. Serum uric acid was significantly increased (p<0.05) in all ecotypes and groups but triglycerides were markedly reduced as determined after 1, 3 and 7 weeks. There were no significant differences between controls and restricted groups in Hb and Hct levels except for CH ecotype, which showed lower (p<0.05) Hb and Hct levels after 5 and 7 weeks for both restricted groups. Results of this study show that low energy diets induced stress in chickens, and ecotype-specific tolerance was manifested through changes in liver HSP70, iNOS and blood parameters, with MM showing better tolerance at lowest energy levels and KU being least tolerant.Keywords: Corticosterone, Dietary energy, Ecotypes, Haemoglobin, Restriction, Stress, Tolerance, Haematocri

Spatial transcriptomics reveals alterations in perivascular macrophage lipid metabolism in the onset of Wooden Breast myopathy in broiler chickens

Abstract This study aims to use spatial transcriptomics to characterize the cell-type-specific expression profile associated with the microscopic features observed in Wooden Breast myopathy. 1 cm3 muscle sample was dissected from the cranial part of the right pectoralis major muscle from three randomly sampled broiler chickens at 23 days post-hatch and processed with Visium Spatial Gene Expression kits (10X Genomics), followed by high-resolution imaging and sequencing on the Illumina Nextseq 2000 system. WB classification was based on histopathologic features identified. Sequence reads were aligned to the chicken reference genome (Galgal6) and mapped to histological images. Unsupervised K-means clustering and Seurat integrative analysis differentiated histologic features and their specific gene expression pattern, including lipid laden macrophages (LLM), unaffected myofibers, myositis and vasculature. In particular, LLM exhibited reprogramming of lipid metabolism with up-regulated lipid transporters and genes in peroxisome proliferator-activated receptors pathway, possibly through P. Moreover, overexpression of fatty acid binding protein 5 could enhance fatty acid uptake in adjacent veins. In myositis regions, increased expression of cathepsins may play a role in muscle homeostasis and repair by mediating lysosomal activity and apoptosis. A better knowledge of different cell-type interactions at early stages of WB is essential in developing a comprehensive understanding

Effects of "Bioactive" amino acids leucine, glutamate, arginine and tryptophan on feed intake and mRNA expression of relative neuropeptides in broiler chicks

<p>Abstract</p> <p>Feed intake control is vital to ensuring optimal nutrition and achieving full potential for growth and development in poultry. The aim of the present study was to investigate the effects of L-leucine, L-glutamate, L-tryptophan and L-arginine on feed intake and the mRNA expression levels of hypothalamic Neuropeptide involved in feed intake regulation in broiler chicks. Leucine, glutamate, tryptophan or arginine was intra-cerebroventricularly (ICV) administrated to 4d-old broiler chicks respectively and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of Neuropeptide Y (NPY), agouti related protein (AgRP), pro-opiomelanocortin (POMC), melanocortin receptor 4 (MC4R) and corticotrophin releasing factor (CRF). Our results showed that ICV administration of L-leucine (0.15 or 1.5  μmol) significantly (<it>P</it> < 0.05) increased feed intake up to 2 h post-administration period and elevated both hypothalamic NPY and AgRP mRNA expression levels. In contrast, ICV administration of L-glutamate (1.6  μmol) significantly (<it>P</it> < 0.05) decreased feed intake 0.25, 0.5 and 2 h post-injection, and increased hypothalamic CRF and MC4R mRNA expression levels. Meanwhile, both L-tryptophan (10 or 100  μg) and L-arginine (20 or 200  μg) had no significant effect on feed intake. These findings suggested that L-leucine and L-glutamate could act within the hypothalamus to influence food intake, and that both orexigenic and anorexigenic Neuropeptide genes might contribute directly to these effects.</p