Effects of dietary cottonseed meal and iron-treated cottonseed meal in different laying hen genotypes

The effects of dietary screw-pressed cottonseed meal (CSM) and iron-treated CSM on laying performance and discolourations in eggs were examined in a range of hen genotypes. In experiment 1, six genotypes, obtained at point-of-lay from various sources, were fed on a non-CSM diet, a diet with 300 g CSM/kg, and a diet containing iron-treated CSM at 300 g/kg. In experiment 2, two of these genotypes were reared together from day-old and were fed from 10 to 18 weeks on a non-CSM diet or a diet containing iron-treated CSM at 250 g/kg. They were then fed on a non-CSM layer diet or a diet containing iron-treated CSM at 300 g/kg, in a 2 x 2 x 2 factorial design that also examined the effects of the rearing diet. 2. The effects on food intakes and egg production of including CSM and iron-treated CSM in layer diets depended on the genotype of the hens. The strongest interaction between breed and diet was on food intake, the breed Hubbard Golden Comet (HGC) being the least tolerant of CSM and iron-treated CSM. 3. Inclusion of iron-treated CSM in the rearer diet to supply approximately 70% of the dietary protein had no adverse effects on growth or age at first egg. Food intake and egg production between 18 and 26 weeks were affected by the iron-treated CSM layer diet, but there were no carry-over effects attributable to the rearing diets. 4. Genotype was not a factor in the development of the gossypol-related brown yolk discolouration in fresh or warm-stored eggs of hens fed on a CSM-based diet containing 197 mg free gossypol/kg and 52 mg cyclopropenoid fatty acids (CPFA)/kg (experiment 1). 5. In both experiments, the susceptibility of eggs to the CPFA-related cold storage effects depended on the genotype of the hen, eggs from hens of the HCG breed being more affected than those of ISA hens. 6. Treatment of CSM with crystalline ferrous sulphate heptahydrate, at a 4:1 weight ratio of iron to free gossypol, prevented brown yolk discolourations in all genotypes tested, as assessed by subjecting egg yolks to atmospheres of ammonia, and cold storage of eggs.     

Effects of dietary fat and sire breed on puberty, weight, and reproductive traits of F1 beef heifers

Prepubertal F1 heifers (n = 246; from crossbred dams bred to either Hereford [H], Limousin [L], or Piedmontese [P] sires) were fed 1.9% (LF) or 4.4% (HF) dietary fat from 254+/-4 d of age until they reached puberty or the breeding season started. Safflower seeds (37% oil with 79% linoleic acid) were the added fat source. Blood samples and backfat thickness measurements were obtained from 60 randomly selected heifers representing the sire breeds and diets studied. In addition, five H-sired heifers from both diets were serially bled at 28-d intervals. Total gain, ADG, body condition score, and backfat thickness were affected by sire breed (P < 0.001) but not diet. Backfat thickness was affected (P < 0.01) by the diet x time on feed interaction. Diet did not affect pubertal age (P > 0.10) but tended (P = 0.08) to affect the percentage of heifers pubertal by the beginning of breeding (June 4). Sire breed effects on puberty age at beginning of breeding, percentage pubertal at the beginning of breeding, and puberty age during the entire study were all highly significant. The effect of the diet x sire breed interaction on percentage of heifers pubertal at beginning of breeding (P < 0.05) was 74.4 vs 76.3% in H-sired, 69.8 vs 60.5% in L-sired, and 76.2 vs 97.6% in P-sired heifers (LF vs HF, respectively). Number of AI services per pregnancy and final pregnancy percentage were not affected by diet or the diet x sire breed interaction. Diet affected progesterone (P < 0.05) and cholesterol (P < 0.001) concentrations, and sire breed tended to affect (P = 0.06) cholesterol concentrations. The effect of the diet x time on feed interaction on cholesterol concentrations was highly significant. There were no effects of diet or sample period on insulin or growth hormone concentrations in serially collected blood samples. We conclude that effects of supplemental dietary fat may be breed-dependent and hypothesize that a feeding period of approximately 60 d duration may be more appropriate than the 162 d used in this study.     

Effects of dietary supplementation with vitamin E and organic selenium on the oxidative stability of beef.

The effects of supplementation of beef cattle diets with organic Se (0.3 mg/kg) and vitamin E (300 I.U. alpha-tocopheryl acetate/kg feed), for 55 d preceding slaughter, on the antioxidant status and oxidative stability of muscle was examined. Dietary vitamin E supplementation led to an increase (P < 0.05) in plasma, and longissimus muscle alpha-tocopherol levels. In minced longissimus muscle stored in 80% 02:20% CO2, lipid and oxymyoglobin oxidation were lower (P < 0.05) in muscle from vitamin E-supplemented animals compared with unsupplemented animals. Dietary Se supplementation did not significantly affect muscle Se levels, glutathione peroxidase activity, or susceptibility to lipid and oxymyoglobin oxidation in the presence or absence of vitamin E. Covariance analysis indicated that, in addition to muscle alpha-tocopherol, differences in muscle glutathione peroxidase activity, and pH could account for variation in the susceptibility of muscle to lipid and oxymyoglobin oxidation.     

Effects of feeding whole cottonseed and cottonseed products on performance and carcass characteristics of finishing beef cattle

Three experiments were conducted to determine the effects of whole cottonseed or cottonseed products on performance and carcass characteristics of beef cattle. In Exp. 1, 120 beef steers (initial BW = 381 +/- 31.7 kg) were fed steam-flaked corn-based finishing diets with 10% (DM basis) basal roughage, and whole cottonseed or individual cottonseed components (cottonseed hulls, meal, and oil). Over the entire feeding period, ADG did not differ (P = 0.95), but DMI increased (P = 0.07) and G:F decreased (P = 0.06) for steers fed the cottonseed diets compared with the control diet. Dressing percent (P = 0.02) and marbling scores (P = 0.02) of carcasses from steers fed the cottonseed diets were less than for steers fed the control diet. In Exp. 2, 150 beef steers (initial BW = 364 +/- 9.9 kg) were used to determine the effects of whole cottonseed or pelleted cottonseed (PCS) on performance and carcass characteristics. Cattle were fed steam-flaked corn-based finishing diets in which whole cottonseed or PCS replaced all of the dietary roughage, supplemental fat, and supplemental natural protein of the control diet. Over the entire feeding period, steers fed the cottonseed diets had lower (P = 0.04) DMI and greater (P < 0.01) G:F than steers fed the control diet. Carcass characteristics did not differ (P = 0.16 to 0.96) among dietary treatments. In Exp. 3, 150 beef heifers (initial BW = 331 +/- 17.1 kg) were used to determine the effects of PCS or delinted, whole cottonseed (DLCS) on performance and carcass characteristics. Heifers were fed rolled corn-based finishing diets in which cottonseed replaced the dietary roughage, supplemental fat, and all or part of the supplemental natural protein of the control diet. Over the entire feeding period, ADG, DMI, and G:F of heifers fed the control diet did not differ (P = 0.19 to 0.80) from those of the cottonseed diets; however, heifers fed the diets containing PCS had greater ADG (P = 0.03) and G:F (P = 0.09) than heifers fed diets containing DLCS. Carcass characteristics of heifers fed the control diet did not differ (P > or = 0.28) from those fed the cottonseed diets. Heifers fed the diets containing PCS had greater (P < or = 0.03) HCW, dressing percent, and LM area than those fed DLCS. Based on our results, whole cottonseed, or products derived from processing whole cottonseed, can replace feedstuffs commonly used in beef cattle finishing diets with no adverse effects on animal performance or carcass characteristics.     

发酵棉粕对安格斯肉牛生长性能和血清生化指标的影响

试验旨在研究饲喂发酵棉粕对安格斯肉牛生长性能和血清生化指标的影响。试验选用10月龄健康初始体重[(259.11±22.62)kg]无明显差异的黑安格斯肉牛(公牛)18头,随机分成两组(每组9头),即试验组和对照组。试验组添加6%的发酵棉粕,对照组添加6%的未发酵棉粕。试验期共42 d,预饲期10 d,正饲期32 d。试验结果表明:(1)试验组平均日增重和平均日采食量与对照组相比较有明显的差异(P<0.05),相较于对照组,试验组平均日采食量提高了31.51%(P<0.05),平均日采食量提高了9.1%(P<0.05);对照组与试验组的料重比相比有极显著差异,和对照组相比料重比下降了16.58%(P<0.01)。(2)对照组和试验组血清中总蛋白、尿素氮、钙、磷、铁、免疫球蛋白A等含量均差异不显著(P>0.05)。血清中总蛋白、葡萄糖及免疫球蛋白G含量,试验组相较于对照组有显著差异,分别提高36.64%(P<0.01)、37.5%(P<0.01)和36.99%(P<0.05)。因此,饲喂发酵棉粕可改善安格斯肉牛的生长性能。     

饲粮维生素E水平对公猪繁殖及精浆营养生化参数的影响

选择年龄、体重、精液质量较一致、正在使用的健康壮年杜洛克公猪5头,采用5×5正交拉丁方试验设计,在不同阶段分别饲喂含维生素E10.0mg/kg(处理1)、22.5mg/kg(处理2)、35.0mg/kg(处理3)、47.5mg/kg(处理4)、60.0mg/kg(处理5)的饲粮,研究饲粮中维生素E对公猪繁殖参数、精浆生殖激素、精浆营养生化参数的影响。结果表明,⑴处理3、4、5公猪精子活率显著高于处理1(P<0.05);处理1公猪精子畸形率显著高于处理3、4、5(P<0.05);精子活率、精子畸形率随饲粮维生素E含量(10.0mg/kg～60.0mg/kg)的增加而分别增加或降低。⑵采精量、精子密度、精浆FSH、精浆LH、精浆T、精液pH、精浆尿素含量、精浆总蛋白质含量,各处理间没有显著的差异(P>0.05)。⑶精浆的GSH-Px活力随饲粮维生素E含量的增加而升高。⑷结论,杜洛克公猪饲粮中维生素E的含量以35.0mg/kg较为适当。     

Effects of dietary cottonseed meal, with and without iron treatment, on laying hens

1. The effects of feeding a screw-press expelled cottonseed meal (CSM) to laying hens at dietary concentrations of up to 300 g/kg, were studied over a 10 week period. 2. The overall performance of hens fed on a 75g CSM/kg diet was not significantly different from controls but a 300g CSM/kg diet, containing 255 mg free gossypol/kg and 87 mg cyclopropenoid fatty acids (CPFA)/kg and giving daily intakes per hen of 26.2 mg free gossypol and 9.0 mg CPFA, significantly reduced food intake (P less than 0.01) and egg production (P less than 0.01). The 150g CSM/kg diet (daily intakes of 14.6 mg free gossypol and 4.8 mg CPFA per hen) did not produce adverse effects initially but egg production was slightly depressed towards the end of the experimental period. 3. Treatment of the CSM with a solution of ferrous sulphate hepta-hydrate for inclusion in a 300g CSM/kg diet (100 mg/kg supplemental dietary iron) further reduced food intake (P less than 0.05) and egg production (P less than 0.05). 4. Storage of eggs at warm temperatures for up to 1 month did not lead to discolourations of any kind in the CSM diet groups, but resulted in yolk mottling, a condition reduced by treatment of the CSM with iron. 5. Storage of eggs at cold temperatures for 3 months resulted in brown yolk discolouration and the initial stages of pink albumen discolouration in the 300g CSM/kg diet group; the brown yolk discolouration was reduced by treatment of the CSM with iron.     

Use of 25-hydroxyvitamin D3 and vitamin E to improve tenderness of beef from the longissimus dorsi of heifers

The objective of this trial was to determine whether a single bolus of 25-hydroxyvitamin D(3) (25-OH D(3)), vitamin E, or a combination of the 2 would improve the tenderness of steaks from the LM of beef heifers. Forty-eight Angus crossbred heifers were allotted randomly to 8 pens. Six heifers were in each pen, and there were 2 pens per treatment. The 4 treatments included control (no 25-OH D(3) or vitamin E); 25-OH D(3) (500 mg of 25-OH D(3) administered as a one-time oral bolus 7 d before slaughter); vitamin E (1,000 IU of vitamin E administered daily as a top-dress for 104 d before slaughter); or combination (500 mg of 25-OH D(3) administered as a one-time oral bolus 7 d before slaughter and 1,000 IU of vitamin E administered daily as a top-dress for 104 d before slaughter). Blood samples were obtained on the day that heifers were allotted to treatments, on the day 25-OH D(3) was administered, and on the day before slaughter. Plasma calcium concentration was increased when 25-OH D(3) was administered with or without vitamin E (P < 0.007). In LM, calcium concentration tended to increase (P = 0.10) when 25-OH D(3) was administered alone but not when 25-OH D(3) was administered with vitamin E. Concentrations of 25-OH D(3) and 1,25-dihydroxyvitamin D(3) in plasma were increased when 25-OH D(3) was administered with or without vitamin E (P < 0.001). Steaks from heifers treated with 25-OH D(3) or vitamin E, but not both, tended to have lower Warner-Bratzler shear force than steaks in the control group at 14 d postmortem (P = 0.08). Postmortem protein degradation as measured by Western blot of the 30-kDa degradation product of troponin-T was increased with all treatments after 3 d postmortem (P 相似文献   

Effects of gossypol and cottonseed products on reproduction of mammals.

Gossypol is a toxic factor indigenous to the cotton plant genus Gossypium. Concentrations of free gossypol contained in feedstuffs such as whole cottonseed and cottonseed meals vary considerably. Nonruminant animals are particularly sensitive to the toxic effects of gossypol, whereas ruminants are somewhat more resistant. Signs of gossypol toxicosis in nonruminants, preruminants, and ruminants are similar and include labored breathing, dyspnea, decreased growth rate, and anorexia but are not pathognomonic. Postmortem findings include generalized edema and congestion of lungs and liver, fluid-filled thoracic and peritoneal cavities, and degeneration of heart fibers. The antifertility effect observed in many nonruminant species is overshadowed by toxic effects, particularly in females. Gossypol seems to disrupt estrous cycles, pregnancy, and early embryo development in females of all nonruminant species studied. Probable mechanisms include an endocrine effect on the ovary as well as a cytotoxic effect on the uterus or embryo. The female ruminant seems to be relatively insensitive to the antifertility effect of gossypol; however, in vitro data indicate some inhibition of embryonic development and ovarian steroidogenesis. The antifertility effect of gossypol has been studied most in males of nonruminant species. The effects of gossypol in the male are both dose- and time-dependent. At effective doses, gossypol causes males to be infertile because of sperm immotility and depressed sperm counts. Specific mitochondrial damage in the tails of spermatozoa seems to render them immotile, and extensive damage to germinal epithelium may be responsible for depressions in spermatogenesis. In ruminant males fed diets containing gossypol, ejaculated sperm appears normal under light microscopy. The integrity of the membrane of sperm cells may be damaged. Extensive damage to the germinal epithelium has been shown in both rams and bulls fed diets containing gossypol and is of major concern.     

棉酚降解酶及热带假丝酵母ZD-3对棉籽粕脱毒的对比研究

试验旨在研究对比棉酚降解酶及热带假丝酵母ZD-3对棉籽粕中游离棉酚与营养物质的影响,从而评定棉酚降解酶对棉籽粕脱毒的效果。利用棉酚降解酶及热带假丝酵母ZD-3对棉籽粕分别进行酶解与固态发酵。检测原棉籽粕及处理后棉籽粕中游离棉酚与营养物质的含量及蛋白质分子质量分布。棉籽粕经棉酚降解酶酶解后,游离棉酚的含量与原棉籽粕相比极显著降低,棉籽粕的脱毒率为92.67%,较热带假丝酵母ZD-3发酵后的脱毒率上升了4.46%,经棉酚降解酶酶解后及热带假丝酵母ZD-3发酵后的棉籽粕,两者的营养物质含量差异不显著,均未检测到棉籽粕中大分子蛋白质降解成小分子蛋白质的现象。棉酚降解酶可以很好的代替热带假丝酵母ZD-3应用于棉籽粕的脱毒,同时棉酚降解酶酶解脱毒较热带假丝酵母ZD-3固态发酵能够极大地缩短时间。     

Effect of feeding of calcium hydroxide-treated or vitamin E-supplemented cottonseed meal on plasma gossypol levels, blood parameters, and performance of Bikaneri lambs

To study the effect of feeding calcium hydroxide-treated or vitamin E-supplemented cottonseed meal (CSM) incorporated diets on plasma gossypol, blood parameters and animal performance, 24 male Bikaneri lambs of 6–7 months of age and of uniform body weight were divided into four groups of six animals each in a completely randomized design and respectively fed isonitrogenous and isocaloric concentrate mixtures containing 20 % soybean meal (CON) or 40 % raw CSM (RCSM), 40 % raw CSM supplemented with 500 IU of vitamin E per head per day (ERCSM), and 40 %, 1.5 % calcium hydroxide-treated CSM (CaCSM) along with ad libitum wheat straw throughout 510 days of experimental feeding. The lambs on all the diets grew linearly throughout the experimental period. The total weight gain, in turn the average daily gain (ADG), was not affected by dietary variations. The daily intake of dry matter, crude protein (CP), digestible crude protein (DCP) and total digestible nutrients (TDN) were found comparable among lambs of all the groups. Though total gossypol intake was similar in RCSM, ECSM and CaCSM groups, however, free gossypol intake was significantly higher (P?<?0.01) in RCSM, ECSM groups as compared to CaCSM group. Serum iron and blood hemoglobin levels were significantly (P?<?0.05) lower in RCSM group as compared to CaCSM and CON groups, and ALT activity was significantly (P?<?0.05) higher on RCSM group as compared to other groups. Plasma gossypol and osmotic fragility of erythrocytes were significantly (P?<?0.05) increased in RCSM group as compared to CaCSM and ERCSM groups. However, there was no significant difference in the concentration of other blood/serum biochemical constituents among the lambs on different groups. Based on the results, it may be concluded that feeding of 40 % CSM in the concentrate mixture of the diet in Bikaneri lambs did not have any major adverse effect in blood parameters and animal performance. Either calcium hydroxide treatment or vitamin E supplementation did not produce any major additional benefits.     

Effects of dietary vitamin E and fat supplementation on pork quality

The effects of dietary vitamin E (VE, alpha-tocopherol acetate) and fat supplementation on growth and carcass quality characteristics, oxidative stability of fresh and cooked pork patty in storage, fatty acid profiles of muscle and adipose tissue, and VE concentrations of plasma, muscle, and adipose tissue were studied. Six hundred pigs were allocated to 1 of 6 diets and fed for 63 d in a 3 x 2 factorial design. The dietary treatments included 3 fat levels (normal corn, high oil corn, high oil corn plus added beef tallow) and 2 levels of VE supplementation (40 IU/kg, normal VE supplementation; and 200 IU/kg, high VE supplementation). At 113 kg of BW, 54 pigs were slaughtered as a subsample to evaluate dietary effects on pork quality. Growth performance and meat quality characteristics did not differ (P > 0.05) among treatment groups. The high level of VE supplementation had a beneficial effect on the oxidative stability of pork as indicated by thiobarbituric acid reactive substance (TBARS) values. Lean tissue had lower (P < 0.05) TBARS in the group fed the high VE than in those fed the normal VE level. The TBARS values differed among storage periods (0 to 6 d) and also between fresh and cooked ground ham. Fat type did not significantly affect total saturated and unsaturated fatty acids proportions in the neutral and polar fraction of muscle. Adding VE acetate led to greater (P < 0.05) monounsaturated and total unsaturated fatty acid proportions in neutral lipids of muscle and adipose tissues. Increasing dietary levels of VE acetate increased the concentration of VE in plasma and muscle. These results indicate that dietary VE acetate supplementation increased (P < 0.05) lipid stability and the VE concentration of muscle.     

Effects of dietary vitamin and fatty acid content in E on muscle vitamin E Aohan fine-wool sheep

Background： Increasing the polyunsaturated fatty acid （PUFA） content and decreasing the saturated fatty acid （SFA） content of mutton can help to improve its nutritional value for consumers. Several laboratories have evaluated the effects of vitamin E on the fatty acid （FA） composition of muscle in sheep. However, little information is available on wool sheep, even though wool sheep breeds are an important source of mutton, especially in northern China where sheep are extensively farmed. The present study was designed to address the effects of vitamin E on muscle FA composition in male Aohan fine-wool sheep. Methods： Forty-two male Aohan fine-wool lambs （5 mo old） with similar initial body weight were randomly divided into seven groups and fed diets supplemented with 0 （control group）, 20, 100, 200, 1,000, 2,000, or 2,400 IU/sheep/d vitamin E for 12 mo. Three lambs from each group were slaughtered to measure vitamin E and FA content in the Iongissimus lumborum （LL） and gluteus medius （GM） muscles. Results： Vitamin E concentrations in the LL and GM increased significantly after 12 mo of vitamin E supplementation （P 〈 0.05）. However, this increase did not occur in a dose-dependent manner because the muscle vitamin E concentration was highest in the 200 IU/sheep/d group. Dietary vitamin E supplementation also caused a significant reduction in SFA content and an increase in monounsaturated FA （MUFA） content in the LL and GM （P 〈 0.05）. All six doses of vitamin E significantly increased cis9 tronsl -conjugated linoleic acid （cgtl -CLA） content in the LL compared with the control group （P 〈 0.05）. Conclusions： Dietary supplementation with vitamin E increased muscle vitamin E content and improved the nutritional value of mutton by decreasing SFA content and increasing MUFA and c9tl 1-CLA contents in Aohan fine-wool sheep. These effects were greatest in sheep fed a diet containing 200 IU/sheep/d vitamin E.     

Effects of dietary vitamin E on muscle vitamin E and fatty acid content in Aohan fine-wool sheep

Background

Increasing the polyunsaturated fatty acid (PUFA) content and decreasing the saturated fatty acid (SFA) content of mutton can help to improve its nutritional value for consumers. Several laboratories have evaluated the effects of vitamin E on the fatty acid (FA) composition of muscle in sheep. However, little information is available on wool sheep, even though wool sheep breeds are an important source of mutton, especially in northern China where sheep are extensively farmed. The present study was designed to address the effects of vitamin E on muscle FA composition in male Aohan fine-wool sheep.

Methods

Forty-two male Aohan fine-wool lambs (5 mo old) with similar initial body weight were randomly divided into seven groups and fed diets supplemented with 0 (control group), 20, 100, 200, 1,000, 2,000, or 2,400 IU/sheep/d vitamin E for 12 mo. Three lambs from each group were slaughtered to measure vitamin E and FA content in the longissimus lumborum (LL) and gluteus medius (GM) muscles.

Results

Vitamin E concentrations in the LL and GM increased significantly after 12 mo of vitamin E supplementation (P < 0.05). However, this increase did not occur in a dose-dependent manner because the muscle vitamin E concentration was highest in the 200 IU/sheep/d group. Dietary vitamin E supplementation also caused a significant reduction in SFA content and an increase in monounsaturated FA (MUFA) content in the LL and GM (P < 0.05). All six doses of vitamin E significantly increased cis9 trans11-conjugated linoleic acid (c9t11-CLA) content in the LL compared with the control group (P < 0.05).

Conclusions

Dietary supplementation with vitamin E increased muscle vitamin E content and improved the nutritional value of mutton by decreasing SFA content and increasing MUFA and c9t11-CLA contents in Aohan fine-wool sheep. These effects were greatest in sheep fed a diet containing 200 IU/sheep/d vitamin E.     

Effects of dietary garlic scape meal on the growth and meat characteristics of geese

1. This study evaluated the growth performance and meat characteristics of grower geese whose diets included garlic scape meal (GSM), a by-product of garlic production. Scape is the leaf-less flower stem of garlic.

2. Garlic scape (GS) extracts contained 84.7 ± 3.8 μg/g dry weight (DW), 81.4 ± 8.2 μg/g DW, 0.78 ± 0.05 mg gallic acid equivalent/g DW and 31.67 ± 2.25 μg/g DW of allicin, alliin, total phenolics and flavonoid contents, respectively.

3. In total, 120 White Roman geese aged 5 weeks were randomly distributed among 12 pens and fed on a grower diet ad libitum during the growth period. Employing a completely random design, 5 males and 5 females were placed in each pen.

4. Each treatment was applied to three pens (in total 30 birds) and the treatments comprised the following: 1) control (maize–soybean meal), 2) 5% of maize replaced with 5% of GSM (5% GSM), 3) 10% of maize replaced with 10% of GSM (10% GSM) and 4) 15% of maize replaced with 15% of GSM (15% GSM). Each group of 30 birds was treated for 8 weeks.

5. The results revealed that the 15% GSM group was characterised by a lower feed conversion ratio than the control group; however, these groups did not differ significantly in their body weights (BWs). In addition, the 10% GSM group did not differ in both the feed conversion ratio and consumption.

6. The flavour intensity score of meats in the 10% GSM group was significantly lower than those of meats in the 5% GSM and control groups. The general acceptability scores of meats in the 5% GSM and control groups were higher than those of meat in the 10% GSM group.

7. The study concluded that 5% dietary GSM in the feed did not adversely affect the growth performance, meat characteristics or sensory evaluation of grower geese. Hence, the environment can be protected by including agricultural waste in goose diets.

     

Effects on dietary phosphorus of treating cottonseed meal with crystalline ferrous sulphate for the prevention of brown yolk discolouration

1. Two experiments were carried out to examine whether the adverse effects on laying hen performance of treating cottonseed meal (GSM) with crystalline ferrous sulphate heptahydrate (FSH) to prevent brown yolk discolouration, was a consequence of iron reducing the availability of dietary phosphorus. Two batches of CSM, with different free gossypol and cyclopropenoid fatty acid contents, were treated with FSH at a 4:1 weight ratio of iron to free gossypol, and incorporated into diets at 300 g/kg with or without supplementation with sodium dihydrogen phosphate (SHP), and fed to hens.

2. FSH treatment of CSM reduced food intake and egg production. Although performance was improved by supplementing the FSH‐treated CSM diets with SHP, it was still poorer than that achieved by hens fed a non‐CSM control diet.

3. Brown yolk discolouration was prevented by treatment of CSM with FSH. Additional phosphorus did not produce any significant effects on brown colour development in yolks, indicating that the bioavailable gossypol content of the diets had not been altered; however, chemical analyses showed an apparent increase in the free gossypol content of the diets with the inclusion of SHP, suggesting that the assay gives misleading results.