Alzahraa Abdelatty

Fishmeal (FM) is the main protein source in fish feed. However, it is quite expensive due to its limited resources. Therefore, finding a dietary alternative to the FM to sustain fish production is crucial, and the current study was performed to assess the impact of poultry offal silage (POS) with or without betaine supplementation; as an effective and cheaper alternative to FM; on feed efficiency, growth performance, spleen morphology and intestinal morphometry of Nile tilapia (Oreochromis niloticus) fingerlings. Four dietary treatments were formulated: (1) FM based diet, (2) FM-B; FM diet +0.7% betaine, (3) POS diet and (4) POS-B; POS diet +0.7% betaine. Each dietary treatment consisted of three replicates (n = 10/replicate), and the experiment was continued for 16 weeks. By the end of the experiment, spleen and intestine specimens were collected from 15 fish (n = 5/replicate) for histopathological assessment. The results were statistically analysed using GLM procedures of SAS 9.4. Feed efficiency increased in both POS-B and FM-B groups (p = 0.01), while body weight and body weight gain showed only weak tendencies towards an increase (p = 0.10 and 0.12, respectively). The villi length was the highest in POS-B fed group (p < 0.01). In addition, melanomacrophage centres of the spleen increased in both betaine-supplemented groups (p < 0.01). From our findings, we conclude that betaine supplementation with poultry offal silage improved production performance and immune status of Nile tilapia fish.

Hyperketonemia is a metabolic disease in dairy cows, associated with negative nutrition balance (NNB) induced by low dry matter intake (DMI) and increased nutrient requirements. Hyperketonemia could induce metabolic stress, which might indirectly affect mammary tissue. Autophagy is a highly conserved physiological process that results in the turnover of intracellular material, and is involved in maintaining cellular homeostasis under the challenge of metabolic stress induced by NNB. The aim of this study was to investigate the autophagy status and autophagy-related pathways AMP-activated kinase α (AMPKα) and mechanistic target of rapamycin (mTOR) in the mammary glands of dairy cows with hyperketonemia. Cows with hyperketonemia [CWH, n = 10, blood β-hydroxybutyrate (BHB) concentration 1.2 to 3.0 mmol/L] and cows without hyperketonemia (CWOH, n = 10, BHB < 1.2 mmol/L) from 3 to 12 DIM were randomly selected from the herd. The mammary tissue and blood samples were collected from these cows between 0630 and 0800 h, before feeding, at 3 to 12 d in milk. Serum concentrations of glucose, BHB, and fatty acids were determined using an autoanalyzer with commercial kits between 0630 and 0800 h, before feeding. Concentrations of fatty acids, BHB (median and interquartile range: CWH, 2.44 and 1.3, 2.82 mM; CWOH, 0.49 and 0.41, 0.57 mM), and milk fat were greater in CWH. The DMI, glucose concentration, milk production, and milk protein levels were lower in CWH. The mRNA abundance of autophagosome formation-related gene, beclin 1 (BECN1), phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3), autophagy-related gene (ATG) 5, ATG7, ATG12, microtubule-associated protein 1 light chain 3 (MAP1LC3, also called LC3) and sequestosome-1 (SQSTM1, also called p62) were greater in the mammary glands of CWH. The protein abundance of LC3-II and phosphorylation level of Unc-51-like kinase 1 (ULK1) were greater in CWH, but the total ubiquitinated proteins and protein abundance of p62 were lower. Transmission electron microscopy showed an increased number of autophagosomes in the mammary glands of CWH. Furthermore, the phosphorylation of AMPKα was greater, but the phosphorylation of mTOR was lower in the mammary glands of CWH. These results indicate that activity of mTOR pathways and autophagy activity, and upregulation of AMPKα, may be response mechanisms to mitigate metabolic stress induced by hyperketonemia in the mammary glands of dairy cows.

Conjugated linoleic acid (CLA) is known for its multiple benefits including improvement of growth, increasing lean mass, and anti-carcinogenic effects. However, when used in long-term supplementations CLA does not improve semen parameters in boar and bull and reduces fertility in Japanese quails. The content of unsaturated fatty acids in dietary lipids plays a significant role in spermatogenesis owning the high proportion of unsaturated fatty acids in plasma membrane of sperms. Whether CLA plays a role in testicular tissue and epididymal fat is still unknown. Therefore, in this study we hypothesize that long-term supplementation of equal proportion of CLA isomer mix (c9,t11-CLA and t10,c12- CLA) in rabbit bucks might alter male reproductive potentials. Twelve V-Line weaned male rabbits were used in 26 weeks trial, rabbits were individually raised and randomly allocated into three dietary groups. Control group (CON) received a basal diet, a group received 0.5% CLA (CLA 0.5%), and a group received 1% CLA (CLA 1%). Rabbits were euthanized at the end of the trial and several parameters were evaluated related to growth, semen quality, and testicular and epididymal tissue histopathology and transcriptome. The long-term supplementation of CLA increased feed intake by 5% and body weight by 2-3%. CLA 1% decreased sperm progressive motility. In testicular tissue L-carnitine and α-tocopherol were decreased by CLA supplementation. In epididymal fat, CLA tended to decrease concentration of polyunsaturated fatty acids, the expression of SCD5 gene was upregulated by CLA 1% and CASP3 gene was upregulated by CLA 0.5%. Transcription of PPARG was downregulated by CLA. Feeding 1% CLA also decreased testicular epithelial thickness. Long-term supplementation of CLA modestly enhanced male rabbit growth, but negatively impacted male reproduction, especially at high dose of CLA.

Investigations of the temporal changes in mammary gene expression that occur during sudden diet change have been limited by the use of mammary tissue as the source of RNA because of the invasive nature of mammary biopsy procedures. However, the cytosolic crescent, present in 1% of the largest milk fat globules, contains mammary epithelial cell RNA that has become trapped between the inner and outer milk fat globule membranes during final formation and secretion of milk fat into the lumen of the mammary alveoli. We hypothesized that cytosolic crescent RNA extracted from milk fat could be used as an alternative source of mammary epithelial cell RNA to measure the immediate temporal changes in gene expression as a result of changes in diet. In this experiment, feed restriction was used to mimic the state of negative energy balance observed in early lactation and induce a rapid change in milk fat yield and lipogenic gene expression. Ten multiparous Holstein dairy were fed a basal diet ad libitum during a 14-d preliminary period followed by a 4-d experimental period where 5 cows remained on ad libitum feeding and 5 cows were fed at 60% of their d 8-14 intakes (restricted) on d 15 to 18 and then returned to ad libitum feeding on d 19 to 21. Milk samples were collected from each milking on d 13 to 20 and the milk fat was immediately isolated, mixed with Trizol LS, and stored at -80°C for subsequent extraction of RNA that was used for measurement of gene expression. Feed restriction tended to increase milk fat percentage. However, total milk and milk fat production were reduced by 21 and 18%, respectively. Consistent with increased use of body fat for milk synthesis, serum nonesterified fatty acids increased 6-fold (0.78 mEq/L in the feed restriction vs. 0.13 mEq/L ad libitum group), whereas the milk fatty acids