Inactivation of Mst/Nrf2/Keap1 signaling flexibly mitigates MAPK/NQO-HO1 activation in the reproductive axis of experimental fluorosis.

Fluoride induced reprotoxicity through oxidative stress-mediated reproductive cell death. Hence, the current study evaluated the importance of the MST/Nrf2/MAPK/NQO-HO1 signaling pathway in fluorosis-induced reproductive toxicity. For this purpose, the reproductive toxicity of sodium fluoride (NaF) at physiological, biochemical, and intracellular levels was evaluated. In-vivo, NaF at 100 mg/L instigated physiological dysfunction, morphological, stereological, and structural injuries in the gut-gonadal axis of fluorosis mice through weakening the antioxidant signaling, Nrf2/HO-1/NQO1signaling pathway, causing the gut-gonadal barrier disintegrated via oxidative stress-induced inflammation, mitochondrial damage, apoptosis, and autophagy. Similar trends were also observed in-vitro in the isolated Leydig cells (LCs) challenging with 20 mg/L NaF. Henceforth, activating the cellular antioxidant signaling pathway, Nrf2/HO-1/NQO1, inactivating autophagy and apoptosis, or attenuating lipopolysaccharide (LPS) can be the theoretical basis and valuable therapeutic targets for coping with NaF-induced reproductive toxicity.

Calcitriol combined with fish oil in the diet of Chukar partridge can ameliorate laying performance by improving oviduct histomorphometry and functions.

The effects of calcitriol (CT) and/or fish oil (FO) on performance, oviposition time, sex ratio and morphology of the reproductive system of laying Chukar partridges were studied. Female (n = 48) and male (n = 16) partridges were used in a completely randomised design using a 2 × 2 factorial arrangement and were randomly allocated to either of four experimental treatments with four cage replicates of three females and one male each. Female birds received no FO (CON - FO) or were orally administered with 0.2 mL (0.24 g)/500 g body weight FO (CON + FO) or 0.2 mL solution containing 10 µg CT (CT - FO), or their combination (CT + FO) for 42 successive days. The eggs were collected every two hours between 07:00 and 23:00 h. Administering FO along with CT had considerably increasing effect on the male-biased sex ratio. FO and CT administration interacted to increase serum calcium concentration. Experimental treatments increased the number of leucocytes and erythrocytes. Serum cholesterol was decreased in CON + FO partridges compared with those of the CT - FO and CON - FO birds. There was an interaction between FO and CT on the weight of eggs and hatchlings, number of medium white follicles, diameter and the number of small yellow follicles, the weight and diameter of the fifth follicles (F5), and thickness of secondary mucosal folds in both uterus and vagina. Administering CT alone or with FO increased the feed intake, egg production, oviductal weight, diameter and number of large yellow follicles, the weight and diameter of the second (F2) and first (F1) follicles compared with those of the CON - FO females. Further studies are required to elucidate the mechanisms by which such changes in the sex ratio skew, ovary and oviduct are mediated.

Effects of pomegranate peel extract on ruminal and post-ruminal in vitro degradation of rumen inoculum of the dairy cow.

This experiment was carried out to study the effect of water extracted pomegranate peel extract (PE) on ruminal protein degradation and post-ruminal digestion in the dairy cow. PE was added at six levels of total phenolics (g/kg of the basal diet); 3.75 (PE1); 4.4 (PE2); 5.05 (PE3); 5.70 (PE4); and 6.35 (PE5). Rumen degradable crude protein (rdCP) decreased with PE addition (L < 0.0001), but total CP degradability (tdCP) was not affected. Compared to PE0, PE2, and PE3 diets showed higher (L = 0.054, Q = 0.029) digestibility of bypass CP (dBCP). Increasing levels of PE resulted in a decrease in proteolytic bacteria numbers (p < 0.0001). At PE4 and PE5 levels, total VFA and acetate concentrations linearly decreased compared to PE0. PE inclusion lowered the acetate:propionate ratio (L = 0.0001) and Ammonia-N production after 24 h (L = 0.0008) of incubation. The total number of protozoa, genera Dasytricha and Isotricha, and subfamilies Entodiniinae, Diplodiniinae, and Ophrioscolecinae decreased with increasing dietary PE concentration (p < 0.0001). The results suggest that all levels of PE addition reduce the protozoal population and Ammonia-N concentration. All PE levels slowed down protein degradation in the rumen but PE2 and PE3 showed the greatest effect.

Detrimental effects of long-term exposure to heavy metals on histology, size and trace elements of testes and sperm parameters in Kermani Sheep.

Exposure to endocrine-disrupting chemicals (EDCs) has been hypothesized as a cause of declining sheep reproductive efficiency. Understanding the long-term effects of EDCs such as heavy metals on reproductive health requires investigation in 'real life' of sheep that are reared in industrial areas. The aim of this study was to evaluate the effect of long-term exposure of Kermani rams to high levels of environmental heavy metals probably emitted from a copper smelter at KhatoonAbad in ShahreBabak, Kerman province. Testicular characteristics were determined in randomly-selected rams (3-4 years old) at 4 directions (south, north, east, and west) and 4 distances (10, 20, 30, and 40 km) from the smelter. Testicular trace element contents, size, serum testosterone, histological attributes and seminal characteristics, except semen volume, were affected by both the direction and the distance from the smelter (P < 0.05). Testicular contents of Pb, Cd, Cr, and Ni, and sperm abnormalities were higher at 10 km south from the smelter and lower at 40 km west. Other parameters were higher at 40 km west and lower at 10 km south. Interestingly, the testicular contents of Cu at 10 km south were lower and associated with higher sperm abnormalities in the rams reared closer to the smelter. The highest weight, length and circumference of the testis were found at 40 km west. The lowest concentration of testosterone was observed at 10 km south, being 92.6% lower than the highest values obtained at 40 km west. The diameter of seminiferous tubules and epithelial height at 10 km south were 8.9% and 27.5% lower than the highest values obtained at 40 km west. A positive correlation between Pb, Cd, Cr and Ni contents in the testis with sperm abnormalities, and a negative correlation between these elements with the other parameters were found. It was concluded that long-term exposure to heavy metals might have been a cause of decreased fertility in rams and probably other living species in this region.

Partial replacement of forage and concentrate with pomegranate pulp (peel and seed) silage and pomegranate seed pulp in Mehraban fattening lambs: effect on performance and carcass characteristics.

The aim of this study was to evaluate the effects of partial replacement of forage and concentrate with pomegranate pulp silage (PPS) and dried pomegranate seed pulp (PSP) on performance, dry matter intake (DMI), and carcass characteristics of fattening Mehraban lambs. Twenty-four male lambs (mean body weight 27.0 ± 3.5 kg) were fed with three isonitrogenous and isoenergetic diets (n = 8 per diet), consisting of a control diet, a PPS diet containing 27.2% pomegranate pulp silage, and a PSP diet containing 31.4% dried pomegranate seed pulp. The experimental diets were fed ad libitum as total mixed rations for 65-day fattening period, on two meals per day, and then the growth performance, feed intake, and carcass characteristics were determined. The initial BW, final BW, average daily gain (ADG), and feed conversion ratio (FCR) were not different among the experimental diets. The amount of DMI in PSP diet was higher than that in the control diet (P = 0.023) but was not different between the control and PPS diets. There was no significant difference among diets for carcass characteristics. Using PPS and PSP in the diets decreased (P < 0.05) the kidney fat, but had no impact on the heart, liver, kidneys, spleen, and lungs. The results showed that PPS and PSP could be used to replace part of the diet for fattening lambs, while decreasing the dietary cost without having any negative effects on animal performance.

Updated information on new coronavirus disease 2019 occurrence, drugs, and prediction of a potential receptor.

The new coronavirus (COVID-19) was first reported in Wuhan in China, on 31 December 2019. COVID-19 is a new virus from the family of coronaviruses that can cause symptoms ranging from a simple cold to pneumonia. The virus is thought to bind to the angiotensin-converting enzyme 2, as a well-known mechanism to enter the cell. It then transfers its DNA to the host in which the virus replicates the DNA. The viral infection leads to severe lack of oxygen, lung oxidative stress because of reactive oxygen species generation, and overactivation of the immune system by activating immune mediators. The purpose of this review is to elaborate on the more precise mechanism(s) to manage the treatment of the disease. Regarding the mechanisms of the virus action, the suggested pharmacological and nutritional regimens have been described.

The mechanisms of arsenic-induced ovotoxicity, ultrastructural alterations, and autophagic related paths: An enduring developmental study in folliculogenesis of mice.

Arsenic (As) exerts a wide range of adverse effects on biological systems, including the reproductive organs in males and females. However, the mechanisms of As-induced reproductive toxicity are mostly obscure. Recently, we showed that autophagy is an essential route for As2O3-induced reprotoxicity through the hypothalamic-pituitary-gonadal-sperm (HPG-S) axis in pubertal and matured F1-male mice. However, the role of autophagy in As2O3- induced ovarian toxicity is mostly unknown. Hence, this study aimed to elucidate the role of oxidative stress, mitochondrial impairment, and autophagic processes in the ovary of As-exposed female mice. For this purpose, mature female mice were challenged with 0, low (0.2), medium (2), and high (20 ppm) As2O3 from 35-days before mating till weaning their pups, and the F1- females from weaning until maturity. Then, all the mice were sacrificed, and oxidative stress parameters, mitochondrial indices, electron microscopic evaluation of the ovaries, expression of autophagic-related genes and proteins, and autophagosome formation were assessed. It was shown that medium and high As2O3 doses were a potent inducer of oxidative stress, mitochondrial dysfunction, and autophagy in the ovary of F1-generation. A dose-dependent increment in the gene expression of PDK1, PI3K, TSC2, AMPK, ULK1, ATG13, Beclin1, ATG12, ATG5, LC3, P62, ATG3, ATG7, and p62, as well as protein expression of Beclin1, and LC3- I, II, was evident in the ovaries of the As-treated animals. Moreover, a dose-dependent decrease in the expression of mTOR and Bcl-2 genes, and mTOR protein was detected with increasing doses of As, suggesting that As treatment-induced autophagy. Along with a dose-dependent increase in the number of MDC-labeled autophagic vacuoles, transmission electron microscopy also confirmed more autophagosomes and injured mitochondria in medium and high As2O3 doses groups. As2O3 also negatively affected the mean body weight, litter size, organ coefficient, and stereological indices in female mice. Finally, in physiological conditions, arsenic trioxide (As2O3) leads to an increased level of autophagy in the oocyte when many oocytes were being lost. These findings indicated that an imbalance in the oxidant-antioxidant system, mitochondrial impairment, and the autophagic process, through inhibition of mTOR, dependent and independent pathways, and Bcl-2, as well as activation of AMPK/PI3K/Beclin1/LC3 routes, could play a pivotal role in As-induced reproductive toxicity through ovarian dysfunction in females.

Inclusion of ovine enriched serum with vitamin E and polyunsaturated fatty acids in the freezing medium: a new strategy to improve human frozen-thawed sperm parameters.

The objective was to evaluate the effect of inclusion of 2.5% and 5% ovine serum, enriched with vitamin E (Vit E) and fish oil (FO), in human sperm freezing medium. Serum samples were prepared from sixteen rams (n = 4) feeding on a without supplemented diet, and diets supplemented with Vit E, FO and Vit E + FO. Semen samples, from 60 normozoospermic men, were frozen in: (I) a commercial freezing medium (SpermFreeze™; control medium), (II) the commercial freezing medium containing foetal bovine serum, (III) the commercial freezing medium + nonenriched serum (serum group), (IV) the commercial freezing medium + Vit E enriched serum (Vit E group), (V) the commercial freezing medium + FO enriched serum (FO group) and (VI) the commercial freezing medium + Vit E + FO enriched serum (Vit E + FO group). Sperm total and progressive motility, morphology, viability and plasma membrane integrity were significantly higher (p ≤ .05) in Vit E and Vit E + FO groups compared with the control group. Mitochondrial membrane potential did not differ between treatments (p > .05). It was concluded that ovine serum enriched with vitamin E and vitamin E + FO improved the quality of human spermatozoa but enriched serum containing FO could not improve the sperm cryo-injuries.

Impaired follicular development and endocrine disorders in female rats by prepubertal exposure to toxic doses of cadmium.

Cadmium (Cd) has been associated with several physiological problems including reproductive and endocrine system dysfunction resulting in temporary infertility. The principal objective of this project was to investigate the effects of prepubertal exposure to toxic doses of Cd on puberty onset, the endocrine system, and follicular development. For this purpose, 16 female Sprague-Dawley rats weaned on postnatal day (PND) 21 were randomly divided into 4 groups (n = 4 per group). The treatments were as follows: 0, 25, 50, and 75 mg/kg/day of cadmium chloride (CdCl2) by oral gavage from PND 21 to observation of first vaginal opening (VO). The results demonstrated that prepubertal exposure to different doses of CdCl2 delays the age of VO, first diestrus, and first proestrus via altering the concentrations of estradiol and progesterone. The low level of these steroid hormones contributed to lower differentiation and maturation of follicles and it finally led to reduced ovarian reservoir of follicles and impaired follicular development. The number of atretic follicles and secondary follicles with premature cavity increased in rats that received a high dose of CdCl2, whereas the number of secondary follicles and corpora luteum decreased in the same circumstances. Taken together, these data suggest that prepubertal exposure to toxic doses of Cd delays the onset of puberty via disorderliness in the concentration of steroid hormones and reduces the ovarian reservoir of follicles, as well as folliculogenesis.

Short chain fatty acids may improve hepatic mitochondrial energy efficiency in heat stressed-broilers.

The present study was conducted to investigate the effects of four dietary fat types and two environmental temperatures on the hepatic mitochondrial energetic in male broilers exposed to heat stress. The birds were kept in two separate rooms at 24 °C or 36 °C from 32 to 42 d of age with four experimental groups in each room. The birds fed on the diets supplemented containing rich sources of long-chain saturated fatty acids (beef tallow), middle-length-chain saturated FA (coconut oil), monounsaturated FA (olive oil), or polyunsaturated FA (soybean oil) for ten days. At 36 °C, the highest body weight and lowest feed conversion ratio were recorded in the birds fed on the diets supplemented with coconut oil or beef tallow. Temperature and fat type significantly affected the activities of the mitochondrial electron transport chain complexes (P < 0.01). There was a significant interaction between the temperature and fat type (P < 0.01). Generally, electron transport chain complexes I-V enzymatic activities were decreased at 36 °C. The coconut oil-fed birds showed the highest complex I activity at both temperatures. The beef tallow-fed broilers showed the lowest complex II activity at 24 °C. In birds exposed to 36 °C, complex II activity was higher for birds fed saturated coconut oil or beef tallow than those feeding the unsaturated olive oil or soybean oil-supplemented diets. At 24 °C, the highest and lowest complex III activities were recorded for the coconut oil- and beef tallow-supplemented diets, respectively. At 36 °C, the activity of complex III was coconut oil > beef tallow > olive oil > soybean oil. At 24 °C, complex IV activity was highest in coconut oil- or soybean oil-fed broilers; and at 36 °C, complex IV showed the lowest activity in soybean oil-fed birds. The highest complex IV activity was observed in coconut oil-fed chickens followed by olive oil-fed and beef tallow-fed birds, respectively. At 24 or 36 °C, the highest and lowest complex V activity was observed in coconut oil-fed and soybean oil-fed chickens, respectively. ATP concentration and mitochondrial membrane potential were in the order of coconut oil > beef tallow > olive oil > soybean oil at both temperatures. Temperature and fat type significantly affected the avANT mRNA concentration. Exposure of broilers to 36 °C generally decreased the mRNA expression of avANT, with beef tallow- or coconut oil-supplemented birds showing a lower avANT mRNA expression than those receiving olive oil- or soybean oil-supplemented diets. These findings provide further information on the use of fat sources in the diet of heat stressed-broilers.

Short communication: dietary vitamin A restriction may improve meat quality parameters in fat-tailed lambs.

Thirty fat-tailed Mehraban ram lambs were randomly allotted into three vitamin A (VA) dietary treatment groups: either 100 (VA100), 50 (VA50), or 25% (VA25) of the recommended daily vitamin A requirements. Treatment had no effect on feed intake, daily live weight gain, cold carcass weight, and dressing percentage. In M. longissimus lumborum (LL) of VA100 lambs, malondialdehyde level was greater, but ether-extractable intramuscular fat concentration was lower. The proportion of C16:0 and C20:0 fatty acids in total fatty acids of LL was lower in VA100 lambs, compared to VA50 and VA25 lambs. Conversely, greater proportions of C17:0, C17:1, C18:1, and C18:2 fatty acids were recorded in VA100 lambs. Stearoyl-CoA desaturase activity index (the ratios of C16:0 to C16:1 and C18:0 to C18:1) was not influenced by dietary vitamin A level. Future research is needed to determine the optimum level of dietary vitamin A concentration for deposition of greater intramuscular fat in fat-tailed sheep.

Saturated fatty acids may ameliorate environmental heat stress in broiler birds by affecting mitochondrial energetics and related genes.

Heat stress decreases performance of poultry. The novel strategies to maintain production level, or at least minimizing the decrease in productivity during hot days need to be elucidated. This study was conducted to determine the effect of four fat types on mitochondrial energetics in heat-stressed broilers. In experiment 1, nitrogen-corrected apparent metabolizable energy (AMEn) content of four supplemental fat sources, including olive oil, soybean oil, coconut oil and beef tallow, all supplemented at 3%, 6%, and 9% in the basal diet, was evaluated. The AMEn values of fats were determined as 9738.0 ± 137.9, 8949.0 ± 159.9, 7844.0 ±â€¯91.7, and 7368.0 ±â€¯190.3 kcal/kg for olive oil, soybean oil, coconut oil and beef tallow, respectively. In experiment 2, birds were kept in two separated rooms under 24 °C or 36 °C from 32 to 42 d of age. Each room consisted of four experimental groups. Birds in the experimental groups were fed on beef tallow-, coconut oil-, olive oil- or soybean oil-supplemented diets (factorial arrangement with two factors of fat types and environmental temperatures). The birds reared under 24 °C had higher final body weight (P < 0.01), weight gain (P < 0.01), feed intake (P < 0.05) and lower feed conversion ratio (P < 0.01) than the birds grown under 36 °C. There was a temperature by fat type interaction effect on mitochondrial attributes. At 36 °C, in birds fed on coconut oil- or beef tallow-supplemented diets, the expression levels of avUCP and avANT mRNA were lower (P < 0.05) but that of HSP70 mRNA was higher (P < 0.01) in comparison with the birds feeding on the olive oil- or soy oil-supplemented diets. An interaction effect was recorded between the temperature and fat type for ATP concentration and mitochondrial membrane potential (P < 0.01); with significant differences between birds receiving the coconut oil- or beef tallow-supplemented diets and the birds feeding on the soy oil- or olive oil-supplemented diets. It was also found that unsaturated fatty acids had a more significant effect on avUCP and avANT mRNA expression. It can be concluded that when using fat in the diet of heat stressed-broilers, it is advisable to choose a type, which has a lower effect on the expression of avUCP and avANT, and hence reduces the metabolic heat load in the bird.

The comparative efficacy of tyloxapol versus pentoxifylline against induced acute phase response in an ovine experimental endotoxemia model.

The effective treatments of endotoxemia are necessary to prevent high mortality rates. Hence, the present study was performed to clarify the antiendotoxic effects of tyloxapol and pentoxifylline in experimentally induced endotoxemia in sheep. Thirty clinically healthy 1-year-old Iranian fat-tailed ewes were randomly divided into six equal experimental (n = 5) groups, comprising Negative and Positive control, Tyloxapol 1, Tyloxapol 2, Pentoxifylline 1 and Pentoxifylline 2. Phenol extracted lipopolysaccharide from Escherichia coli serotype O55:B5 was infused at 2 µg/kg intravenously. Tyloxapol (200 and 400 mg/kg) and pentoxifylline (30 and 60 mg/kg) were injected to Tyloxapol and Pentoxifylline groups, respectively, at 90 min after endotoxemia induction over 60 min along with intravenous fluids. Blood samples were collected from all ewes prior and 1.5, 3, 4.5, 6, 24 and 48 h after lipopolysaccharide injection and sera and plasmas were separated, subsequently. Haptoglobin, serum amyloid A, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), superoxide dismutase and glutathione peroxidase were measured in all samples. Serum concentrations of haptoglobin, serum amyloid A, TNF-α and IFN-γ in Tyloxapol 1 and 2 and Pentoxifylline 1 and 2 groups were significantly lower than Positive control one after hour 3. There were no significant differences among Tyloxapol and Pentoxifylline groups (P > 0.05). Superoxide dismutase and glutathione peroxidase activities in Tyloxapol 1 and 2 and Pentoxifylline 1 and 2 groups were significantly lower than Positive control one after hour 3. There were no significant differences among Tyloxapol 1 and 2 and Pentoxifylline 1 and 2 groups (P > 0.05). Tyloxapol and pentoxifylline act as the anti-inflammatory mediators by decreasing pro-inflammatory cytokines and hepatic APPs and modulating oxidative enzymes activity after endotoxemia induction in sheep. Furthermore, their efficacies at different doses were significantly similar together and both drugs don't induce their effects by dose dependent manner and the anti- and pro-inflammatory effects of them were statistically similar.

Effects of inclusion of licorice (Glycyrrhiza glabra L.) leaves, a tannin-containing plant, in a low-protein diet on feedlot performance and carcass characteristics of fat-tailed lambs.

The protein-sparing effect of condensed tannins (CT) was investigated in growing lambs fed a low- or high-protein diet during a 50-day period. Isocaloric diets containing 106 g crude protein/kg dry matter (DM) (low protein; LP) or 138 g crude protein/kg DM (high protein; HP) were formulated using 70 % concentrate, 15 % corn silage, and 15 % dried licorice leaves, providing CT (4.1 g/kg DM). Twenty-four crossbred male lambs (3-4 months old, 23.9 ± 5.2 kg body weight) were assigned to one of four diets: LP with polyethylene glycol (PEG; 40 g/kg DM) supplementation (LP + PEG), LP without PEG supplementation (LP - PEG), HP with PEG supplementation (HP + PEG), and HP without PEG supplementation (HP - PEG). The effect of dietary crude protein level and CT on feed intake was not significant (P > 0.05). However, a positive effect on daily gain (P < 0.001) and feed conversion ratio (FCR; P < 0.01) was observed in lambs fed with HP diets. An interaction effect between crude protein level and PEG was observed, and consequently, FCR was higher in group LP + PEG (10.1; P < 0.05) than in groups LP - PEG (7.3), HP + PEG (5.3), or HP - PEG (5.4). There was also an interaction effect between crude protein level and PEG on kidney, pelvic, and heart fat, presenting a higher relative weight in group LP + PEG (12.6 g/kg) than in group HP + PEG (9.2 g/kg; P < 0.05), but no (P > 0.05) in groups without PEG supplementation. These preliminary results suggest that the use of CT can minimize the negative effect of low-protein diets on FCR in lambs.

Short-term oxidative lime pretreatment of palm pruning waste for use as animal feedstuff.

BACKGROUND: Oxidative lime pretreatment (OLP) is an effective pretreatment for highly recalcitrant lignocellulosic materials. This experiment was conducted to investigate the effect of short-term OLP on fermentative gas production kinetics of date palm prunings. Rachis and petiole were pretreated with excess lime (0.5 g Ca(OH)2 g(-1) dry matter) in a reactor charged with 10 bar pure oxygen pressure at different times and temperatures. RESULTS: Lignin removal was greatly affected by OLP, whereas cellulose was well preserved even after severe pretreatment. After 72 h fermentation, the cumulative gas production was 321.2 mL gas g(-1) organic matter (OM) for the most severe pretreatment, compared to 73.6 mL g(-1) OM for the untreated rachis. For the petiole pretreated at 120 °C for 280 min, 268 mL gas was produced compared to 59 mL gas g(-1) OM for the untreated petiole. Scanning electron microscope images showed the formation of pores (average diameter of 10-12 µm) and carbonate calcium deposits on the surface of treated biomass. An increase in biomass crystallinity was observed in pretreated samples resulting from cellulose enrichment. CONCLUSIONS: The results suggest that OLP improves the ruminal digestibility of date palm prunings, which may have potential for inclusion in the ruminant diet at low cost.

Investigation in early growth traits, litter size, and lamb survival in two Iranian fat-tailed sheep breeds.

In the present study, 1,635 lambing records of Ghezel (n=766) and Mehraban (n=869) breeds were used to evaluate the early growth traits, litter size, and lamb survival in sheep reared in Fars Province, southern Iran, during a 5-year-long period. The least squares means (± SE) of lamb birth weight for Ghezel were 5.27 (± 0.22), 5.02 (± 0.22), and 3.98 (± 0.23) kg for single males, single females, and twin lambs, respectively; whereas, the corresponding values for Mehraban were 4.39 (± 0.18), 4.18 (± 0.18), and 3.50 (± 0.19) kg. The least squares means of pre-weaning lamb growth (gram per day) for Ghezel were 239 (± 15), 218 (± 15), and 181 (± 16) for single males, single females, and twin lambs, respectively, and the corresponding values for Mehraban were 204 (± 12), 187 (± 12), and 156 (± 13). Lambs from 2 year old ewes or younger were on average lighter at birth and at weaning and had a lower average daily gain than those from older ewes (P<0.05). The percentage of twin births increased from 1.1 and 1.3 % for ewes aged ≤ 2 years to 19 and 12 % for those aged ≥ 6 years old in Ghezel and Mehraban, respectively (P<0.05). The mean pre-weaning lamb mortality was 7.1 and 4.1 % for Ghezel and Mehraban, respectively.

Effect of feeding olive-pulp ensiled with additives on feedlot performance and carcass attributes of fat-tailed lambs.

Feed cost has a significant effect on the economic efficiency of feedlot lambs; therefore, the use of low-cost non-conventional feedstuffs, such as olive pulp (OP), has the potential to decrease the production costs. Because optimum inclusion of OP-treated silages has not been determined in feedlot lambs, an experiment was conducted to determine the effect of inclusion of OP ensiled with additives in the diet on the feedlot performance and carcass attributes of feedlot lambs. Ram lambs of Mehraban and Ghezel breeds (n = 50 lambs per breed) were randomly allotted to 10 groups and fed with one of the nine diets containing OP silage or a control diet. Silage treatments were: (1) OP silage without additives (OPS), (2) OP ensiled with 8 % beet molasses and 0.4 % formic acid (OP-MF), and (3) OP ensiled with 8 % beet molasses, 0.4 % formic acid and 0.5 % urea (OP-MFU). The control diet contained 50 % alfalfa hay and 50 % barley grain. Three levels from each silage were chosen to replace the barley grain (10, 20, or 30 % dry matter basis). The lambs were slaughtered after 92 days, and the average daily gain (ADG), feed conversion ratio (FCR), and carcass characteristics were determined. Feeding OPS to fat-tailed lambs, at an inclusion level of 30 %, decreased the carcass dressing percentage, mainly as a result of decreased brisket percentage, but the ADG and FCR values were not adversely affected. Ghezel lambs had higher ADG than Mehraban lambs, but the visceral fat weight percentage, flap weight percentage, and back fat depth were higher in Mehraban. The crude protein content in the longissimus dorsi (LD) muscle was higher in Ghezel, but the dry matter percentage was higher in Mehraban (P < 0.05). Other attributes were not significantly affected by breed (P > 0.05). Most carcass characteristics, including major cuts, were not affected by OPS feeding; therefore, feeding OPS (up to 30 %) can be economical for feedlot lambs. Most carcass characteristics, including major cuts, were not affected by OPS levels used in this experiment; therefore, inclusion of OPS (up to 30 %) in the diet may reduce the cost of raising feedlot lambs. This also could help alleviate the problem of storage of OP in oil factories.

In vitro rumen fermentation pattern: insights from concentrate level and plant oil supplement.

The addition of oil to ruminant diets and oil fatty acid profiles are major factors that negatively affect ruminal fermentation, while increased forage level attenuates the adverse effects. The aim of this study was to determine the effects of oil source supplementation and concentrate level in the diet on in vitro ruminal fermentation kinetics. Pomegranate, garlic or sunflower oils were added (2 % dry matter (DM) basis) to the diets containing 40 % or 60 % (DM basis) concentrates. In vitro gas production parameters, pH, ammonia nitrogen concentration and total protozoa count were measured. Additionally, metabolizable energy (ME), short-chain fatty acid (SCFA) production and organic matter digestibility (OMD) were determined. Rumen fermentation parameters and protozoal population counts were analyzed as a completely randomized design with a 2  × â€¯3 factorial arrangement of treatments, and gas production parameters were analyzed as a 2  × â€¯3 factorial arrangement in a randomized block design. The results showed that the HCPO (high (60 %) concentrate diet containing pomegranate oil) and HCSO (high (60 %) concentrate diet containing sunflower oil) diets produced the highest (5.40 mg dL - 1 ) and lowest (2.61 mg dL - 1 ) concentrations of NH 3 -N ( p > 0.01 ), respectively. Total protozoa count tended ( p = 0.07 ) to be highest in HCPO and lowest in HCSO diets (5.10 vs. 4.81 Log 10 g - 1 digesta). No interaction effects between the concentrate level and oil source were found on in vitro gas production parameters, pH, estimated ME, SCFA and OMD, and Entodinium and Diplodinium populations ( p > 0.05 ). It is concluded that dietary supplementation with highly unsaturated oil from three different sources at 2 % level (DM basis) had no apparent effects on in vitro ruminal fermentation patterns.

Trends in the reproductive performance of Holstein dairy cows in Iran.

The study was undertaken to determine the trends in the reproductive performance of Holstein dairy cows in Iran during 1994 to 2008. Reproductive performance data for 528,034 lactations of 246,132 cows in 1,822 Holstein dairy herds of Iran were used. The potential effect of calving season, herd, parity, calving year, as well as herd size and 305-day milk production on reproductive performance traits was investigated using multiple regression models. The least squares means of age at first calving decreased by 3.1 (± 0.06) days per year from 806.5 (± 96.3) days in 1994 to 788 (± 89.9) days in 2008. The least squares means of calving interval increased 1.02 (± 0.03) days per year from 394.1 (± 65) days in 1994 to 413.2 (± 81) days in 2008. Greater 305-day milk production was associated with an average increase of 6.55 (± 0.08) days in calving interval per 1,000-kg increase in milk yield. Larger herd size was associated with an average decrease of 0.22 (± 0.02) days in calving interval per 50 cows per herd. The mean number of days dry was 88.6 (± 51.3) days and increased by 0.82 (± 0.02) days per year. In conclusion, reproductive performance in Holstein dairy herds has generally decreased, whereas herd size and milk production have increased over time. Producers may make significant improvements in herd reproduction by reviewing management strategies including the sire selection, reproductive management, inseminator training and techniques, and improved estrous detection. Moreover, it may be advisable for the fertility traits to be included in the genetic selection indices to reduce the rate of reproductive decline.

Maternal aromatase inhibition via letrozole altered RFamide-related peptide-3 and gonadotropin-releasing hormone expression in pubertal female rats.

Objectives: Despite prevalence of polycystic ovary syndrome (PCOS) among childbearing women and development of many animal models for this syndrome, information on its etiology is still scarce. The intrauterine hyperandrogenic environment may underlie changes at the level of hypothalamus, pituitary, ovary organization in female offspring, and PCOS later in life. Letrozole has been shown to mimic reproductive and metabolic characteristics of PCOS in adult rodent models. Therefore, this research aimed to assess the condition in a prenatal letrozole-treated rat model. Materials and Methods: Twenty-eight female rats dams receiving letrozole at certain doses during late pregnancy were used in the trial. Pregnant Sprague-Dawley rats (n=21) received letrozole treatment on gestation days 16-18 at doses of 1.25, 1.0, 0.75, 0.5, and 0.25 mg/kg body weight (BW). Results: Prenatal letrozole treatment delayed parturition time and reduced the litter size in pregnant dams (P<0.0001). Late puberty onset, irregular ovarian cyclicity, increased anogenital distance (AGD), body weight gain, serum testosterone concentration, and reduced estradiol levels (P<0.0001) were observed in the female offspring of dams receiving 1.25 and 1 mg/kg BW letrozole. Furthermore, letrozole at 1.25 and 1 mg/kg BW showed increased RFRP and decreased GnRH mRNA expression (P<0.0001). Letrozole treatment at doses of 1 mg/kg BW and lower was not fetotoxic. Conclusion: It was concluded that 1 mg/kg BW letrozole may be suggested for prenatal PCOS induction.