Dietary Gossypol Research Articles

Loss of Gcn2 exacerbates gossypol induced oxidative stress, apoptosis and inflammation in zebrafish

Gossypol, a naturally occurring compound found in cottonseed meal, shows promising therapeutic potential for human diseases. However, within the aquaculture industry, it is considered an antinutritional factor. The incorporation of cottonseed meal into fish feed introduces gossypol, which induces intracellular stresses and hinders overall health of farmed fish. The aim of this study is to determine the role of General control nonderepressible 2 (gcn2), a sensor for intracellular stresses in gossypol-induced stress responses in fish. In the present study, we established two gcn2 knockout zebrafish lines. A feeding trial was conducted to assess the growth-inhibitory effect of gossypol in both wild type and gcn2 knockout zebrafish. The results showed that in the absence of gcn2, zebrafish exhibited increased oxidative stress and apoptosis when exposed to gossypol, resulting in higher mortality rates. In feeding trial, dietary gossypol intensified liver inflammation in gcn2−/− zebrafish, diminishing their growth and feed conversion. Remarkably, administering the antioxidant N-acetylcysteine (NAC) was effective in reversing the gossypol induced oxidative stress and apoptosis, thereby increasing the gossypol tolerance of gcn2−/− zebrafish. Exposure to gossypol induces more severe mitochondrial stress in gcn2−/− zebrafish, thereby inducing metabolic disorders. These results reveal that gcn2 plays a protective role in reducing gossypol-induced oxidative stress and apoptosis, attenuating inflammation responses, and enhancing the survivability of zebrafish in gossypol-challenged conditions. Therefore, maintaining appropriate activation of Gcn2 may be beneficial for fish fed diets containing gossypol.

Lipotoxic Effects of Gossypol Acetate Supplementation on Hepatopancreas Fat Accumulation and Fatty Acid Profile in Cyprinus carpio

Cottonseed meal is an excellent protein source with low price and abundant nutrients, but the existence of free gossypol restricts its wide application in animal feeds. To explore the toxic effects of free gossypol, the effects of gossypol acetate on the growth performance, hepatopancreatic fat accumulation, and muscle fatty acid composition of the common carp (Cyprinus carpio) were investigated in the present study. Carp were randomly divided into four groups, which were fed a diet supplemented with 0, 170, 340, and 680 mg/kg gossypol acetate, respectively. After 60 days of feeding, the gossypol residue in the tissue, growth performance, blood biochemical indices, hepatopancreas histology, fatty acid components, and expression of key genes involved in lipid metabolism pathways were measured. It was found that the concentrations of free gossypol were increased significantly in the serum, bile, and hepatopancreas of carp fed 340 mg/kg and 680 mg/kg gossypol acetate ( P < 0.05 ). Dietary gossypol acetate had a limited effect on growth performance, and high concentrations of gossypol acetate induced excessive hepatopancreatic fat deposition and hepatocyte injury in C. carpio. In addition, gossypol acetate decreased total polyunsaturated fatty acids (PUFAs) and docosahexaenoic acid in muscle. In the hepatopancreas, decreased HSL, PPARα, and CD36 may result in fat accumulation. In the muscle, decreased FADS2 may be the key reason for the decrease in PUFAs. Taken together, these findings indicated that dietary gossypol acetate can cause lipid metabolism disorders, such as hepatopancreatic damage and significant changes in tissue fatty acid profile, which are regulated by the key lipid metabolic genes in common carp.

Effect of dietary gossypol supplement on fermentation characteristics and bacterial diversity in the rumen of sheep.

The tolerance of ruminants to gossypol, a natural phenolic compound derived from the cotton plant, is greater than that of monogastric animals, partially because of the gossypol-degrading bacteria in the rumen of the ruminants. In this study, we aimed to examine the effect of gossypol supplementation on fermentation characteristics, bacterial α-diversity and community structure in the rumen fluid of sheep to analyse the change of bacterial in response to gossypol. 8 sheep with permanent fistula were randomly divided into 2 groups, a control and gossypol acetate supplementation groups. Sheep in the latter group were supplemented with gossypol acetate at the levels of 600 mg and 1,200 mg/animal per day during the first (S1, days 1 to 27) and subsequent (S2, days 28 to 47) stages. Gossypol supplementation significantly increased the molar proportion of acetate, and decreased the molar proportion of isobutyric acid, butyric acid, and isovaleric acid in the rumen fluid. Gossypol supplementation have no significant effect on bacterial diversity in the rumen fluid. At the phylum level, gossypol had no effect on bacterial community. At the genus level, gossypol supplementation significantly increased the relative abundance of Treponema_2. However, there were no significant differences in the relative abundance of dominant bacterial genera. In conclusion, gossypol supplementation had an effect on molar proportion of acetate, isobutyric acid, butyric acid, and isovaleric acid, but had no significant effect on the bacterial diversity and relative abundance of dominant bacteria in rumen fluid of sheep.

Dietary gossypol reduced intestinal immunity and aggravated inflammation in on-growing grass carp (Ctenopharyngodon idella)

The present study explored the effects of dietary gossypol on the gut health of on-growing grass carp. The fish were fed six diets containing different levels of free gossypol (0, 121.38, 243.94, 363.89, 759.93 and 1162.06 mg/kg diet) from gossypol-acetic acid for 60 days and then challenged with Aeromonas hydrophila for 14 days. The results showed that dietary gossypol (1) could aggravate enteritis and damage the structure of intestinal epithelial cells, (2) decreased the lysozyme (LZ) and Acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) contents, and it down-regulated the Hepcidin (rather than distal intestine (DI)), immunoglobulin Z (IgZ), liver-expressed antimicrobial peptide (LEAP)-2B, Mucin2 and β-defensin-1 mRNA levels in the proximal intestine (PI), mid intestine (MI) and DI, (3) up-regulated intestinal pro-inflammatory cytokines tumor necrosis factor α (TNF-α), interferon γ2 (IFN-γ2), interleukin 1β (IL-1β), IL-6 (only in PI), IL-8 and IL-12p35 mRNA levels partly related to nuclear factor kappa B (NF-κB) signalling, and (4) down-regulated the mRNA levels of anti-inflammatory cytokines such as transforming growth factor (TGF)-β1, TGF-β2, interleukin 4/13A (IL-4/13A) (except IL-4/13B), IL-10 and IL-11 partly relating to target of rapamycin (TOR) signalling in the intestines of on-growing grass carp. Moreover, the dietary gossypol had no impact on the LEAP-2A, IL-12P40, IL-17D, IL-10, NF-κBp52, IKKα and eIF4E-binding proteins 2 (4E-BP2) mRNA levels in the intestines. Finally, based on the intestinal histopathological results, enteritis morbidity, LZ activity and IgM content, the safe dose of gossypol in the diets for on-growing grass carp should be less than 103.42 mg/kg diet.

Effect of Dietary Gossypol on Gonadal and Extragonadal Sperm Reserves of Yankasa Rams

Cottonseed and its by-products are used extensively for supplementing ruminant rations to increase productivity. However, they contain gossypol which is a reproductive toxicant in males of both ruminant and non-ruminants. This study evaluated the effect of dietary gossypol from whole cottonseed (WCS) and cottonseed cake (CSC) on the gonadal and extragonadal sperm reserves of Yankasa rams. Fifteen (15) Yankasa rams weighing an average of 20 2 Kg were randomly distributed into three groups (A, B and C) of five rams each and were fed diets containing 48 % WCS, 48 % CSC and control diet (gossypol-free), respectively for 14 weeks. The gonadal and epididymal sperm of the rams (3 from each group) were conducted. The data obtained were statistically analysed using GraphPad Prism version 5.0. Significance of differences between treatments means were determined at P ≤ 0.05 with Tukey-Kramer multiple comparison test of repeated measure analysis of variance (ANOVA). Testicular and epididymal weight, length and sperm reserves were not significantly (P > 0.05) affected by gossypol. Gossypol-treated rams in groups A and B however, had numerically lower mean values of testicular and epididymal weight, length and sperm reserves than those of the control group. We concluded that gossypol present in whole cottonseed cake which causes reduction in testicular and epididymal sperm reserves and these feeds should be used with caution in breeding rams.

Effects of dietary gossypol concentration on growth performance, blood profiles, and hepatic histopathology in meat ducks

The objective of this study was to determine the effects of gossypol from cottonseed meal (CSM) on growth performance, blood biochemical profiles, and liver histopathology of ducks. A total of 900 1-d-old ducks were randomly allocated to 5 treatments with 12 pens/treatment and 15 ducks/pen. The 5 experimental diets were formulated in such a way that 0% (a corn-soybean meal basal diet, diet 1), 25% (diet 2), 50% (diet 3), 75% (diet 4), and 100% (diet 5) of protein from soybean meal were replaced with that from CSM. All diets were formulated on a digestible amino acid basis. The experiment included 2 phases, the starter phase (1 to 3 wk) where the test diets contained graded levels of CSM and the growth phase (4 to 5 wk) where birds were fed a corn-soybean basal diet to examine the recovery of ducks after CSM withdrawal. Dietary CSM and gossypol linearly (P < 0.01) and quadratically (P < 0.01) decreased ADG and ADFI during d 1 to 14. The threshold of daily total gossypol (TG) and free gossypol (FG) intake based on ADG on d 1 to 7 and d 7 to 14 were 32.20 and 2.64 mg/d, and 92.12 and 9.62 mg/d, respectively. Serum alanine aminotransferase increased (P < 0.05) linearly with increasing level of gossypol in the diets (d 7), whereas aspartate aminotransferase increased (P < 0.05) linearly and quadratically (d 14). Serum albumin concentration decreased (P < 0.05) quadratically with increasing dietary CSM concentrations on d 21. The degree of damage to the liver increased markedly with increasing dietary CSM and gossypol content and the length of CSM and gossypol intake. On d 35, there was no difference on BW and blood profiles of ducks among all treatments. These results suggest that meat ducks’ dietary TG and FG concentration should be lower than 928.9 and 77.2 mg/kg, respectively, during d 1 to 21 of age and that a 2-wk withdrawal of diets containing gossypol should be considered.

Effects of Dietary Gossypol on Testicular Histology and Ultrasonograms of Yankasa Rams

This study evaluated the effect of dietary gossypol from whole cottonseed (WCS) and cottonseed cake (CSC) on testicular morphology of Yankasa rams. Fifteen (15) Yankasa rams weighing an average of 20 2 Kg were randomly distributed into three groups (A, B and C) of five rams each and were fed diets containing 48 % WCS, 48 % CSC and control diet (gossypol-free), respectively for 14 weeks. . An ultrasonographic examination of the testes of each ram was done every month for 3 months. At the end of the feeding period, the rams were castrated and histopathogical examination of the testicular tissues (n = 6). Histopathological changes observed in the testes of the rams in the experimental group were depletion of spermatogenic cell layers and arrest of spermatogenesis at the spermatocyte and spermatids levels and an exfoliation of the spermatogonia. There was vacuolation of the germ layers in the seminiferous tubules. These changes were more severe in group B (CSC) than A (WCS) and were indicative of testicular degeneration. Ultrasonograms of the testis of rams from experimental groups showed loss of homogeneity and an increased hyperechoic appearance which were also indicative of testicular degeneration. It was concluded that gossypol from whole cottonseed and cottonseed cake has detrimental effects on testicular histology and the effect on testicular histology was more severe in rams that were fed cottonseed cake.

Effects of different sources and levels of dietary gossypol on gossypol residues in plasma and milk of lactating cows

Free gossypol residues in tissues or milk from feeding whole cottonseed and cottonseed meal were measured for their effect on health of dairy cows and humans. Forty lactating cows were randomly assigned to 5 treatments in a 60-d experiment to investigate the effects of sources and dietary level of gossypol on plasma and milk gossypol concentrations in lactating cows. Five experimental diets had identical net energy for lactation and crude protein content on a dry matter (DM) basis. Soybean meal was the main protein ingredient used in the control diet. Cottonseed meal (CSM) or whole cottonseed (WCS) substituted for part of the soybean meal in the other 4 diets. Gossypol levels in the 5 diets were 0 (control), 91.15mg/kg of DM in CSM1, 117.31mg/kg of DM in CSM2, 385.43mg/kg of DM in WCS1, and 611.13mg/kg in WCS2. Yields of 3.5% fat-corrected milk were significantly higher for cows in the WCS2 group; cows in the CSM1 and WCS1 groups showed no differences but both were numerically higher than the control and CSM2 groups. Milk protein concentration was lower for cows consuming WCS1 compared with the control group. Lactose concentration was lower for cows in the CSM2 group compared with the WCS2 group, but no differences were observed among other diets. Aspartate aminotransferase in serum was significantly higher for the WCS2 group compared with the control and WCS1 groups, but no difference was observed with the CSM1 and CSM2 groups. Concentrations of gossypol in plasma and milk of cows in the WCS1 and WCS2 groups were both higher than those of the other groups. No adverse effects were observed on cows fed diets containing 12.0% CSM, and no gossypol was found in plasma and milk. When WCS comprised 15% of the diet DM, yields of 3.5% fat-corrected milk were increased in cows and gossypol was detected in plasma and milk but not at harmful levels.

Alleviation of reproductive toxicity of gossypol using selenium supplementation in rams1

The objective of this study was to evaluate the reproductive toxicity of gossypol and the possible counteracting effect of selenium supplementation in rams. Twenty-five mature crossbred (Barki × Rahamni) rams were randomly divided into 5 equal groups. The first group served as a control (no gossypol in diet). The second and third groups received diets containing free gossypol of 9 and 14 mg·kg(-1) BW·d(-1)(low level and high level of gossypol), respectively. The fourth and fifth groups received the same diets given to the second and third groups, respectively, with an oral administration of 1 mg selenium (as sodium selenite) daily for each animal. Results showed reductions in ejaculate volume (P = 0.028), percentage of dead sperm (P = 0.003), total functional sperm fraction (P < 0.001), and blood serum concentration of testosterone (P < 0.001) in the presence of both levels of gossypol inclusion. Furthermore, high level of gossypol reduced forward motility (P < 0.001) and semen initial fructose concentration (P = 0.002) and increased abnormal-head sperm (P = 0.003) and blood serum concentration of triiodothyronine (P = 0.006). Regardless of selenium supplementation, increasing level of free gossypol in diet resulted in a significant decrease in the percentage of forward motility (P = 0.037) and significant increases in the mean values of sperm concentration (P < 0.001), total sperm output (P = 0.002), percentage of total abnormal sperm (P = 0.058), and abnormal-head sperm (P = 0.016). On the other hand, regardless of levels of gossypol inclusion, selenium supplementation resulted in significant increases in libido (P < 0.001), mean values of ejaculate volume (P < 0.001), percentage of forward motility (P = 0.019), total sperm output (P < 0.001), total functional sperm fraction (P < 0.001), semen initial fructose concentration (P = 0.031), and blood serum concentrations of both testosterone and triiodothyronine (P < 0.001). In conclusion, free gossypol in diet induced adverse effects on semen quality in rams, but selenium supplementation successfully counteracts most of the hazardous effects of gossypol on semen characteristics.

Gossypol Disrupts Embryo Development in Heifers

Our objectives were to determine the effects of dietary free gossypol (FG) intake on plasma and uterine gossypol concentrations and embryo development and viability before and after culture with gossypol. Fifty postpubertal Holstein heifers weighing (±SD) 406±34.5kg at 11.5 mo of age were blocked by age and body weight (BW) and randomly assigned to 1 of 3 isocaloric and isonitrogenous diets differing in their FG content: control (0mg of FG/kg of BW), moderate (17.8mg of FG/kg of BW), and high (36.8mg of FG/kg of BW). Heifers were fed the diets for 70 d before superovulation and embryo collection. Superovulated heifers were flushed on d 5 after induction of ovulation, and early morulae were either stained, to determine the number and proportion of live and dead cells, or randomly assigned to an in vitro culture for 96h in media containing either 0 or 10μg/mL of gossypol acetic acid. Plasma and uterine gossypol concentrations increased with increasing gossypol intake. The number of low-quality embryos-ova was greater for the high than for the moderate and control diets. Embryos collected from the high diet had the least number of cells because of fewer live cells, and were smaller in diameter. Greater dietary gossypol reduced blastocyst development and extended the time to reach the blastocyst stage. Similarly, gossypol concentration at 10μg/mL compromised in vitro development and increased the proportion of degenerated embryos at 96h in culture. These findings provide in vivo and in vitro evidence that intake of 36.8mg of FG/kg of BW per d and gossypol concentrations >7μg/mL in plasma, in uterine flush, or in vitro compromise early embryo development, which might explain some of the negative effects of gossypol on the fertility of dairy cows.

Evaluation of cottonseed and soybean meal as partial replacement for fishmeal in diets for juvenile Japanese flounder Paralichthys olivaceus

This study was conducted to investigate the effect of dietary supplementation of cottonseed and soybean meal (CS) on growth performance, feed utilization, and gossypol accumulation in juvenile (mean body weight 11 g) Japanese flounder Paralichthys olivaceus. Five isonitrogenous and isocaloric experimental diets (designated CS0, CS10, CS20, CS30, and CS40) containing 0, 10, 20, 30, and 40% CS mixture (1∶1 w/w) were formulated. After 9 weeks of feeding trial, fish fed all diets did not show significant differences in growth performances, feed utilization, and whole body compositions. Hemoglobin content gradually decreased (P<0.05) with increments of CS inclusion levels. There was a positive linear relationship between dietary gossypol and total liver gossypol contents. Free radical scavenging activity in the experimental diets gradually increased with increment of dietary CS inclusion. This finding indicates that the mixture of cottonseed and soybean meal with methionine and lysine supplementation could replace up to 40% of fishmeal protein in diets. However, 20% fishmeal protein replacement by dietary inclusion of cottonseed (9.4%) and soybean (8.7%) meal might be the optimum and safe level for the commercial use of CS in juvenile Japanese flounder.

Use of Cottonseed Meal in Aquatic Animal Diets: A Review

AbstractCottonseed meal is a plant protein source that is abundant in most parts of the world, relatively high in protein, and generally less expensive per unit of protein than soybean meal. It is highly palatable and readily digested by most aquatic animals, though generally not as digestible as soybean meal. Its use in aquaculture feeds may be limited because of the potential toxic effects of free gossypol and its relatively low available lysine and methionine content. However, depending on economics, the protein quality of cottonseed meal can be improved by supplementing it with lysine or both lysine and methionine. Also, the concentrations of free gossypol in diets containing significant levels of cottonseed meal are typically below the levels that are detrimental to many aquatic animals. However, even as a partial replacement of soybean meal, cottonseed meal has generally been used at relatively low levels in aquatic animal diets, partially because the safe levels of cottonseed meal appear to differ for various fish and crustaceans. Although some cultured aquatic species can tolerate relatively high dietary levels of cottonseed meal, its use will probably continue to be limited to about 10–15% of their diets. Although this is largely related to the higher nutritive value of soybean meal, it is, to a lesser degree, because of the variation of free gossypol levels in various sources of the meal and the potential toxic effects of gossypol on certain aquatic animals. However, when market conditions are favorable, the use of cottonseed meal will increase because some aquatic animals are largely unaffected by free gossypol, and for them cottonseed meal can lower rearing costs.

Effect of natural free gossypol and gossypol-acetic acid on growth performance and resistance of channel catfish (Ictalurus punctatus) to Edwardsiella ictaluri challenge

A study was conducted to evaluate the effect of free gossypol from glanded-cottonseed meal (G-CSM) (natural free gossypol) or gossypol-acetic acid on growth performance, body composition, haematology, immune response and resistance of channel catfish (Ictalurus punctatus) to Edwardsiella ictaluri challenge. Soya bean meal-based diets supplemented with 0, 100, 200, 400, and 800 mg kg−1 free gossypol from G-CSM or gossypol-acetic acid were fed to juvenile channel catfish in triplicate aquaria to apparent satiation twice daily for 12 weeks. Neither sources nor levels of dietary gossypol significantly influenced the final weight gain, feed intake, feed efficiency and survival of channel catfish. Similarly, whole-body proximate composition, haematological parameters (red blood cell, white blood cell counts, haemoglobin and haematocrit), serum protein concentration, macrophage chemotaxis ratio, phagocytic activity and antibody production against E. ictaluri 21-day postinfection were not significantly affected at either dietary sources or levels of gossypol. Gossypol concentrations of liver were linearly related to dietary level of gossypol but the retention rate varied dependent on sources of the dietary gossypol. At dietary gossypol levels of 400 or 800 mg kg−1, total gossypol concentrations in liver of fish fed dietary gossypol from G-CSM were significantly higher than those of fish fed the corresponding levels of gossypol from gossypol-acetic acid. The (+)-isomer of gossypol was predominantly retained in liver regardless of dietary sources of gossypol. The ratio of (+) to (−) gossypol isomers in liver decreased with increasing dietary concentrations of gossypol. Serum lysozyme activity of fish fed dietary gossypol levels of 200 mg kg−1 or higher, either from G-CSM or gossypol-acetic acid, was significantly higher than that of the control. At a level of 800 mg kg−1 diet, gossypol from G-CSM stimulated significantly higher lysozyme activity than gossypol from gossypol-acetic acid. Fish fed diets containing 400 mg kg−1 gossypol or higher from G-CSM or 800 mg kg−1 gossypol from gossypol-acetic acid had significantly increased superoxide anion (O) production. However, neither the sources nor the levels of dietary free gossypol influenced the resistance of juvenile channel catfish to E. ictaluri challenge.

Type of Cottonseed and Level of Gossypol in Diets of Lactating Dairy Cows: Plasma Gossypol, Health, and Reproductive Performance

Objectives were to determine effects of altering gossypol intake by feeding whole linted Upland (WUP) or a 1:2 blend of WUP and cracked Pima (BUPCP) cottonseed on plasma gossypol (PG) concentrations, reproduction, and health of Holstein cows. Cows, 813, on three dairy farms were assigned to one of two diets starting at 13±11 d in milk for a 170-d experiment. Diets contained 717 and 951mg of free gossypol/kg of dry matter from WUP and BUPCP, respectively. Concentrations of PG, as well as the proportion of total gossypol (TG) as the minus isomer were higher for cows fed BUPCP vs cows fed WUP. Conception rate at the first postpartum artificial insemination did not differ between treatments. However, cows consuming the higher gossypol diet had reduced subsequent conception rates and a lower pregnancy rate. Incidence of abortions increased in the higher gossypol diet, and cows that aborted or remained open had higher PG concentrations. Increasing PG concentrations resulted in reduced conception rates and extended days open. The probability of conception after the first artificial insemination declined at a decreasing rate as the plasma TG increased. Incidence of health disorders were unaffected by gossypol intake and PG concentrations. Similarly, gossypol intake and PG concentrations had no effect on culling or mortality. Six cows died in each diet, and none had postmortem signs compatible with gossypol toxicity. Consumption of a high gossypol diet for 170 d had no effect on health of lactating dairy cows, but it increased PG concentrations and impaired reproductive performance.

Growth performance and immune response of channel catfish (Ictalurus puctatus) fed diets containing graded levels of gossypol–acetic acid

This study was conducted to evaluate the effect of gossypol levels on growth performance, body composition, hematology, immune response and resistance of channel catfish to Edwadsiella ictaluri challenge. A purified basal diet supplemented with 0, 300, 600, 900, 1200 and 1500 mg of gossypol from gossypol–acetic acid was fed to juvenile channel catfish in quadruplicate aquaria to apparent satiation twice daily for 12 weeks. Final weight gain was inversely related to the concentration of dietary gossypol. Fish fed diets without and with 1500-mg gossypol/kg had significantly highest and lowest weight gain, respectively. Feed intake and feed efficiency were a reflection of weight gain. Survival was not affected by dietary levels of gossypol. Whole body moisture increased whereas lipid decreased with increasing dietary gossypol concentrations. Body protein significantly decreased in fish fed with 1500-mg gossypol diet, but did not differ among fish fed with other diets. Body ash did not differ in fish fed diets containing 0–900-mg gossypol/kg but was significantly higher in fish fed higher levels of dietary gossypol. Gossypol concentration in liver was linearly related (R 2 =0.991) to dietary levels of gossypol. Ratio of (+) to () gossypol isomers in liver of fish fed with different diets was relatively constant. Red blood cell (RBC) count of fish fed with the two highest levels of dietary gossypol (1200 and 1500 mg) was significantly lower than those of fish fed with control diet. Hemoglobin significantly decreased in fish fed with 900 mg or higher gossypol diets. Hematocrit was significantly affected at each incremental level of dietary gossypol of 600 mg/kg or higher. Serum protein did not differ for fish fed with the three lowest dietary levels of gossypol but was significantly reduced at 900 mg or higher gossypol. Macrophage chemotaxis ratio was similar for groups fed diets containing gossypol but was significantly higher than that of fish fed with the control diet. Serum lysozyme activity significantly increased at dietary gossypol levels of 900 mg or

A mixture of cottonseed meal, soybean meal and animal byproduct mixture as a fish meal substitute: growth and tissue gossypol enantiomer in juvenile rainbow trout (Oncorhynchus mykiss).

Diets incorporating three different sources of extracted cottonseed meal (CM), soybean meal and an animal protein mixture were evaluated for juvenile rainbow trout. Fish averaging 0.96 g were divided into groups of 30; 3 groups per treatment, and each group was fed one of four diets for a 16-week period. Fish meal (FM) was replaced on a 25% protein basis by each of three different sources of CM from California (CA), Tennessee (TN), and Arkansas (AR), U.S.A. In the three CM-containing diets another 25% soybean meal protein and 50% animal protein mixture were also incorporated to completely replace FM protein. The results of growth rate and feed utilization showed that FM could be entirely replaced by a mixture of plant proteins (CM and soybean meal) and animal by-product proteins. Hematocrit levels were significantly lower in the group fed CM-containing diets than in the control. The findings suggest that CM can be used as a good protein source by the incorporation of at least 15% in diets (25% of fish meal protein replacement), and that the nutritive values of CM in juvenile trout can be different due to their different origin. Significantly higher concentrations of total gossypol were found in faeces of CM-TN (5.8 +/- 0.4 micromol/g) and CM-AR (5.6 +/- 0.6) groups than in that of CM-CA (3.7 +/- 0.4) group. It was documented that gossypol enantiomers, present in an equal proportion in diets, selectively accumulated in liver and bile, whereas equal proportions of (+)- and (-)-enantiomers were found in whole-body and faeces. Depending on CM source, fish can absorb approximately 35-50% of dietary gossypol, and the majority of the absorbed gossypol seemed to be excreted.

Type of Cottonseed and Level of Gossypol in Diets of Lactating Dairy Cows: Effects on Lactation Performance and Plasma Gossypol

Objectives were to determine the effects of feeding whole linted Upland (WUP) and cracked Pima cottonseed (BUPCP) to lactating cows on plasma gossypol concentrations and lactation performance. Holstein cows (n=813) from three commercial dairies were assigned to one of two diets starting at 13±11 d in milk (DIM) for a 170-d experimental period. Cottonseed was included at 10% of the diet dry matter, and treatments consisted of replacing WUP with a 1:2 blend of BUPCP. Blood was collected from all cows at 61 and 91 DIM and from a subset of 56 cows on one dairy at 10, 33, 61, 91, 120, and 152 DIM. Intakes of free gossypol increased 32% in cows receiving the BUPCP diet, and concentrations of total gossypol (TG), as well as the proportion of TG as minus (–) isomer in plasma, were higher for cows fed BUPCP than WUP. Plasma TG increased linearly with increasing DIM, but cows fed the BUPCP, especially multiparous cows, had a higher increase in plasma TG over time. Yields of milk and milk components did not differ between the two treatments, although, yields of milk and milk components were greater in cows with higher plasma TG. Replacement of WUP cottonseed with BUPCP cottonseed increased plasma gossypol, but dry matter intake and yields of milk and milk components were not affected.

Growth, feed utilization and body composition of tilapia (Oreochromis sp.) fed with cottonseed meal-based diets in a recirculating system

The suitability of cottonseed meal (CSM) as a major source of plant protein in feeds for tilapia (Oreochromis sp.) was tested by examining growth and feed intake, feed digestibility, liver gossypol concentrations, feed utilization, and body mineral composition. Juvenile tilapia at an initial average size of 11.8 +/- 1.6 g were divided into triplicate groups per dietary treatment and offered five different formulated diets. In these feeds fish meal (FM) protein was gradually replaced by protein from CSM (0, 25, 50, 75, and 100%; diets 1, 2, 3, 4 and 5, respectively). The experiments were conducted in a recirculation system at a water temperature of 27 +/- 1 degrees C in glass aquaria for 16 weeks. Tilapia growth did not differ significantly (P > 0.05) with up to 50% substitution of FM with CSM. Fish meal replacement above 50% resulted in significant growth decline with time. Fish fed with 100% FM and diets including 50% CSM had significantly better daily weight gain, daily feed intake and feed efficiency ratio than those fed with 100% CSM. Fish fed with 75% CSM and above had lower concentrations of body iron, calcium and phosphorus than controls (100% FM). Concentrations of total gossypol in diets (ranging from 0.11 to 0.44% in diets 2-5) resulted in proportional increase of total gossypol in fish liver (32.3, 72.3, 99.4 and 132.1 microgram g(-1) wet weight) in groups fed with diet 2, 3, 4, and 5, respectively. We concluded that CSM can partially replace FM as a main source of protein in feed for tilapia at not more than 50%. The presence of gossypol in CSM was identified as the major limiting factor for acceptance and utilization of CSM-based diets in tilapia farming.

Pathology and Histopathology of Gossypol Toxicity in Broiler Chicks

Two experiments were conducted to determine the toxicity, pathology, and histopathology of purified gossypol in broiler chicks. Gossypol was added to broiler feed at 0, 100, 200, and 400 mg/kg of feed in Experiment 1 and at 0, 800, and 1600 mg/kg of feed in Experiment 2. Day-old broiler chicks were fed these diets from 1 to 21 days in Experiment 1 and from 1 to 23 days in Experiment 2. In Experiment 1, body weight and feed intake at 21 days were not significantly affected by dietary gossypol. However, chicks fed gossypol at 400 mg/kg of feed had poor feed conversion ratio compared with the other treatment. Feed conversion ratios were 1.493, 1.564, 1.471, and 1.60 for chicks fed gossypol at 0, 100, 200, and 400 mg/kg of feed, respectively (Experiment 1). Chicks fed 400 mg/kg gossypol also had mild perivascular lymphoid aggregate formations and bilary hyperplasia in the liver. In Experiment 2, gossypol at 1600 mg/kg resulted in 28.1% mortality. Gossypol at 800 and 1600 mg/kg feed resulted in significant decreases in body weight and feed intake of chicks. The average body weights of 23-day-old chicks in Experiment 2 were 676, 224, and 111 g for 0, 800, and 1600 mg/kg gossypol, respectively. Feed conversion ratios of chicks fed 800 and 1600 mg/kg gossypol were significantly higher than those of chicks fed control diets (1.383 vs. 1.564 vs. 1.745 for 0, 800, and 1600 mg/kg gossypol, respectively). Plasma iron and hematocrit values were significantly reduced by gossypol at 800 and 1600 mg/kg of feed. Enlarged gallbladder was the only gross pathology symptom associated with gossypol levels. Severe cases of perivascular lymphoid aggregate formation, biliary hyperplasia, and hepatic cholestasis were observed in chicks fed 800 and 1600 mg/kg of gossypol in feed. No gossypol-related changes were observed in kidney tissues of chicks. These results show that gossypol is toxic to broiler chicks at high levels. This study also shows that histopathologic changes in liver due to gossypol also occur at levels lower than the levels that affect body weight.

Gossypol isomers bind specifically to blood plasma proteins and spermatozoa of rainbow trout fed diets containing cottonseed meal

We investigated the role of gossypol isomers binding to blood plasma, seminal plasma and spermatozoa to elucidate gossypol anti-fertility action in the teleost fish, rainbow trout ( Oncorhynchus mykiss). Growth and hematological indicators of males were depressed when fish meal protein in diets was completely replaced with cottonseed meal. The cottonseed meal contained equal proportions of (−) (47.8±1.6%) and (+) gossypol isomers. Concentrations of spermatozoa were decreased with increasing proportions of gossypol in diets (from 0.22% to 0.95%); however, sperm motility and fertilizing ability were not affected. In contrast to mammals, steroid hormone concentrations were not suppressed in fish given diets with gradual increase of gossypol level. Gossypol concentrations were 100-fold higher in blood plasma than in seminal plasma, confirming a barrier in gossypol transfer between the general circulation and the testis. Spermatozoa accumulated predominantly (+) enantiomer (65–75%) with decreasing proportions as dietary gossypol concentrations increased. Spermatozoa bound most of the gossypol contained in the semen; however, this did not result in impairment of the sperm motility apparatus. Teleost fish sperm rely on ATP stores that accumulate during maturation as a source of energy during activation. In addition, the duration of sperm movement is short in these fish. As such, we hypothesize that the major action of gossypol on mammalian sperm, which is uncoupling of oxidative phosphorylation, does not impair the energy supply required for flagellar beating in fish spermatozoa.