Effects of concentrate levels on fattening performance, carcass and meat quality attributes of Small East African × Norwegian crossbred goats fed low quality grass hay

To assess the effects of finishing Small East African × Norwegian crossbred goats with concentrate diets on the fattening performance, carcass and meat quality, 32 castrated crossbred goats (9.5 months old, 17.1 kg BWT) were equally allocated into four levels of concentrate supplementation. The concentrate levels were: Zero access to concentrate (T0), 33% access to ad libitum concentrate allowance (T33), 66% access to ad libitum concentrate allowance (T66) and 100% access to ad libitum concentrate allowance (T100). Each animal had access to ad libitum grass hay. Ad libitum concentrate intake for the goats was 663 g/d, which supported ME intake of 8.7 MJ/head/d. The attained maximum daily gain was 96 g/d. T100 and T66 goats were comparable in slaughter weight but the former had 2 kg heavier (P < 0.05) carcasses than the latter. T100 and T66 goats were similar in carcass fatness scores, though both were fattier (P < 0.05) than other diet groups. Dressing percentage (DP) was expressed in three different ways. In all but commercial DP, T100 were comparable to T66 goats, but all were higher than the other diet groups. For T0 goats, pH-values remained above 6 even after 24 h post-mortem. Cooking losses increased (P < 0.05) with increasing levels of concentrate supplementation. Moreover, among the muscles assessed, M. rectus abdominis had the least cooking loss. Warner–Bratzler shear force values of cooked muscles were highest (P < 0.05) in M. gluteobiceps, followed by M. vastus lateralis, while M. psoas major and longismus dorsi aged for 6 days had the least values. Finishing Small East African × Norwegian crossbred goats at 66% access to their ad libitum concentrate intake gives optimum carcass and meat quality, and that any increase above this level seems not to improve meat production.     

饲喂高精料日粮对泌乳期山羊泌乳性能及抗氧化能力的影响

为了研究长期饲喂高精料日粮对泌乳期山羊泌乳性能和乳腺组织抗氧化能力的影响,实验选用12只健康经产泌乳中期关中奶山羊,随机分为两组,分别饲喂精粗比为35∶65(低精料组, LC, n=6)和65∶35(高精料组, HC, n=6)的日粮。实验期共10周,实验期间采集羊奶与血液;实验结束后采用静脉注射的方法对山羊进行安乐死,随后采集乳腺组织并迅速置于液氮中速冻后保存于-70 ℃待测。结果显示,HC组山羊乳产量显著高于LC组(P<0.01),同时乳中乳糖,乳蛋白的比例随着泌乳时间的增加而显著升高。与LC组山羊比较,HC组山羊乳腺组织中SREBP1和GLUT1 mRNA表达显著下降(P<0.05);磷酸化AKT1蛋白表达呈下降趋势(P=0.08);除此之外,HC组山羊乳腺组织的总抗氧化能力T-AOC(P=0.06)和GSH酶活均呈下降趋势(P=0.08)。这些结果表明,长期饲喂高精料日粮可降低乳腺组织的抗氧化能力,同时可降低乳中乳脂率以及乳腺组织中SREBP-1和P-AKT的表达。     

Effects of dietary Cu, Mo and S on urinary Cu and Zn excretion in Simmental and Angus cattle

This study determined the effects of dietary copper (Cu), molybdenum (Mo) and sulphur (S) on urinary Cu and zinc (Zn) excretion in cattle. Four Simmental and four Angus heifers were fed low (L) or high (H) levels (mg/kg DM) of Cu (5, 40), Mo (1, 10) and S (0.2, 0.5%). Initially two of each breed was fed either LCu or HCu (2 mo). Then all eight animals were fed sequentially LCuHS (1.5 mo), HCuHS, HCuHMo and HCuHMoHS (2 mo each). Simmental had a higher urine flow, increased concentration and total excretion of urinary Cu and Zn compared to Angus, but only total Zn excretion was significantly higher. Urinary Cu excretion was greatest with the HCuHMoHS diet. Urinary Zn excretion significantly increased with HS but not HS in combination with HMo and/or HCu. This study, together with previously reported biliary excretion, allows a direct comparison of urinary and biliary Cu and Zn excretion responses to dietary Cu, Mo and S.     

Effects of gestation and lactation on vitamin D receptor amounts in goats and sheep

During gestation and lactation, an increased demand for calcium (Ca) due to the development of fetal skeleton and excretion via milk is observed. The higher need for Ca is met by an augmented mobilisation of Ca from bones and by an increased absorption from the intestines. The main influence on this physiological process of active absorption has Vitamin D, acting through Vitamin D receptors (VDR) located in the mucosal wall of the intestines, thus increasing Ca absorption. As a consequence of inadequate Ca absorption, metabolic diseases like milk fever can develop. In this study immunohistochemical procedures were applied to colon mucosa biopsies of pregnant and lactating goats and sheep, to study the effect of late gestation, parturition and lactation on VDR amount. Colon mucosa biopsies were collected 2 weeks before parturition, 1 and 4 weeks post partum (pp), 2, 3, 4, and 5 months pp from 11 dairy goats and 11 sheep. Immunohistochemistry was performed employing a biotinylated monoclonal rat anti-VDR antibody and streptavidin peroxidase techniques. Nuclei and cytoplasm of enterocytes stained positively for VDRs. Strongest immunoreactions were observed in intermediate and superficial glandular cells. The biopsy samples taken during early lactation revealed a lower immunoreaction for VDR compared with samples taken during later stages of lactation. In conclusion, immunochemistry and biopsy technology are useful tools to assess changes in VDR expression in relation to varying demands for Ca in the process of a reproductive cycle. These results show that in dairy goats and sheep, an influence of gestation and lactation on VDR is obvious.     

Utilization of citrus pulp based diets and Enterolobium cyclocarpum (JACQ. GRISEB) foliage by West African dwarf goats

Sixteen West African dwarf goats weighing 5.0–5.6 kg were used in an experiment that lasted 112 days to investigate the utilization of citrus pulp based diets and E. cyclocarpum. A control diet which contained 88.5% dried brewers' grains (DBG) and other three experimental diets in which DBG was replaced with dried citrus pulp (DCP) at 25, 50 and 75% levels, respectively constituted the four treatments. The goats were divided into four groups of four animals each to balance for variation in live weight before they were assigned to the four different experimental diets. Significant differences (P < 0.05) were obtained in growth rate with (22.14–34.02 g/d) the highest and lowest value from 50 and 75% DCP inclusion respectively. The digestibility coefficients of DM, Ash, NFE, NDF, ADL, cellulose and hemicellulose increased with increasing levels of dried citrus pulp in the diets and were highest at 75% level of replacement. However, the CP digestibility of 83.85% was highest in the control diet and was significantly (P < 0.05) different from other diets containing citrus pulp. Nitrogen intake (g/d) decreased significantly (P < 0.05) with increasing levels of dried citrus pulp in the diets from 45.57–33.28 and was lowest in the control diet. Nitrogen balance also followed the same trend, being highest (42.07 g/d) at 25% DCP and lowest at 75% DCP. The Packed cell volume (PCV), haemoglobin concentration (Hb), red blood cells (RBC), white blood cells (WBC) and total blood protein (TBP) were significantly (P < 0.05) different across the dietary treatments at the start and end of the trial. The values for PCV, RBC, MCH, glucose and total protein decreased slightly in the control diet. Serum glutamate pyruvate transaminase (SGPT) values also increased significantly (P < 0.05) with increasing levels of dried citrus pulp in the diets at the end of the experiment and were highest (6.50 IU/L) at 75% level of citrus pulp. Therefore, the efficient utilization of citrus pulp and E. cyclocarpum by WAD goats was attained at the 50% level of inclusion in the diets.     

Effects of Teladorsagia (Ostertagia) circumcincta infection on lambs selected for high fleece weight

The physiological processes leading to the expression of the resilient phenotype, which allow animals to maintain a relatively higher production level during infection, have been investigated in lambs from a closed flock selected for 40 generations for high fleece weight (HFW), but with higher FEC and worm burdens than their unselected control (C) flock run in parallel. After recovery from surgery to implant abomasal cannulae, eight parasite-naïve lambs from each flock were infected intraruminally at 4.5 months-of-age with 50,000 Teladorsagia circumcincta L3. Blood, abomasal fluid and faecal samples were collected daily for measurement of serum gastrin and pepsinogen concentrations, blood eosinophils, abomasal pH and FEC. Four lambs from each flock were euthanased on Day 8 post-infection and the other four on Day 28 post-infection. At necropsy, abomasal contents and tissues were collected for worm counts, abomasal lymph nodes and fundic tissue for cytokine gene expression and fundic tissue for histopathology. Expression of resilience appeared to be age-dependent as there were no significant differences in either FEC or worm burden between lambs from the two flocks, unlike older HFW lambs in a previous study. Abomasal secretion did not differ between flocks. Histopathological changes were typical of parasitism: inflammatory cells, mainly eosinophils and lymphocytes, were numerous in nodular areas and there were fewer TGF-α positive parietal cells, many of which were vacuolated. By Day 28 p.i., globule leucocytes were present. Mucosal thickness was significantly greater on Day 8 than Day 28 p.i. (p = 0.000) and in C than HFW lambs. There were fewer parietal cells on Day 28 than on Day 8 p.i. (p = 0.003) for pooled data. Circulating eosinophil counts increased moderately in both groups, significantly less in the HFW lambs. Fewer tissue and blood eosinophils in the HFW than C group on Day 8 p.i. were consistent with cytokine gene expression patterns, particularly lower IL-5 levels. Worm count decreased by 90% by Day 28 p.i., along with declining tissue eosinophil counts and IL-13 gene expression and increasing IL-10 and IL-4 gene expression. Food intake was depressed less in the HFW lambs, suggesting that maintenance of appetite could be an important aspect of the physiological basis for resilience. Although the resilient phenotype was not apparent at the younger age, lesser effects on food intake, differences in ALN cytokine profiles and lower blood and tissue eosinophil numbers in the HFW lambs may lead to the expression of resilience when older.     

高精料对泌乳奶山羊瘤胃上皮氧化应激和胆固醇代谢的影响

为了研究长期或短期饲喂高精料日粮对泌乳期奶山羊瘤胃上皮组织氧化应激和胆固醇代谢的影响,实验选用17只健康的经产泌乳中期关中奶山羊,随机分为3组:饲喂低精料组(对照组,LC,n=5);长期饲喂高精料组(HL, n=7),19周饲喂期;短期饲喂高精料组(HS,n=5),4周饲喂期。实验结束后采集瘤胃组织,用PBS反复清洗,于液氮中速冻后置于-80 ℃冰箱保存。结果显示,与对照组相比,HL和HS组山羊瘤胃上皮组织中细胞周期相关基因CDK2和CDK4 mRNA表达水平显著升高(P<0.05),且HS组p-ERK1/2蛋白表达显著升高(P<0.05),但GPR41和GPR43蛋白表达无显著变化(P>0.05);HL和HS组山羊瘤胃上皮组织促细胞凋亡基因Casepase9 mRNA表达显著升高(P<0.05),HS组抗凋亡Bcl-2/Bax mRNA表达比例呈下降趋势(0.050.05);HS组瘤胃上皮组织中胆固醇含量下降达显著水平(P<0.05),且HL组呈下降趋势(0.05+ ATPase mRNA表达显著升高(P<0.05),NHE2蛋白表达升高但未达显著差异水平(P>0.05)。与HL组相比,HS组山羊瘤胃上皮组织中总抗氧化能力T-AOC显著升高(P<0.05);且胆固醇含量显著下降(P<0.05)。以上结果说明,短期饲喂高精料日粮可加快泌乳期奶山羊瘤胃上皮组织的更新,提高组织总抗氧化能力;而长期饲喂高精料日粮未引起细胞增殖相关蛋白和总抗氧化能力的显著变化;饲喂高精料日粮可以加快瘤胃上皮组织对VFA的转运。此外,饲喂高精料日粮引起瘤胃上皮组织内胆固醇含量降低,胆固醇酰基转移酶基因表达的显著上调,提示其对瘤胃上皮组织更新的潜在影响。     

Differential Effects of Continuous Exposure to the Investigational Metastin/Kisspeptin Analog TAK-683 on Pulsatile and Surge Mode Secretion of Luteinizing Hormone in Ovariectomized Goats

The aim of the present study was to determine if the estradiol-induced luteinizing hormone (LH) surge is influenced by the constant exposure to TAK-683, an investigational metastin/kisspeptin analog, that had been established to depress the pulsatile gonadotropin-releasing hormone (GnRH) and LH secretion in goats. Ovariectomized goats subcutaneously received TAK-683 (TAK-683 group, n=6) or vehicle (control group, n=6) constantly via subcutaneous implantation of an osmotic pump. Five days after the start of the treatment, estradiol was infused intravenously in both groups to evaluate the effects on the LH surge. Blood samples were collected at 6-min intervals for 4 h prior to the initiation of either the TAK-683 treatment or the estradiol infusion, to determine the profiles of pulsatile LH secretion. They were also collected at 2-h intervals from –4 h to 32 h after the start of estradiol infusion for analysis of LH surges. The frequency and mean concentrations of LH pulses in the TAK-683 group were remarkably suppressed 5 days after the start of TAK-683 treatment compared with those of the control group (P<0.05). On the other hand, a clear LH surge was observed in all animals of both groups. There were no significant differences in the LH concentrations for surge peak and the peak time of the LH surge between the TAK-683 and control groups. These findings suggest that the effects of continuous exposure to kisspeptin or its analog on the mechanism(s) that regulates the pulsatile and surge mode secretion of GnRH/LH are different in goats.     

Effect of feeding sweet‐potato condensed distillers solubles on intake and urinary excretion of minerals in Japanese Black steers

Four Japanese Black steers (16 months of age) were assigned to a 4 × 4 Latin square design to investigate the effect of graded levels of sweet‐potato condensed distillers solubles (SCDS) in their diets on intake and urinary excretion of minerals. The four diets consisted of 0%, 10%, 20% and 30% (dry matter (DM) basis) SCDS, with SCDS replacing commercial concentrate (CC). Intake of K, Cl, S, P and Mg increased linearly with increasing SCDS content. Urinary pH increased linearly with increasing dietary SCDS content. SCDS feeding increased urinary K concentrations (linear and quadratic effects). Urinary concentrations of Cl increased linearly with increasing SCDS content. In contrast, urinary concentrations of Mg decreased with increasing SCDS content. Feeding of SCDS did not apparently affect urinary NH₃,P, Na or Ca concentrations. These results suggest that high SCDS feeding is not a risk for crystallization of minerals leading to the formation of magnesium‐phosphate type calculi: although SCDS contains large amounts of P and Mg, high SCDS feeding decreased the Mg concentration and did not affect the P concentration in urine. Additionally, high SCDS feeding had no apparent effects on plasma concentrations of Na, K, Cl, Ca or inorganic P.     

The effect of sulfaphenazole and sulfadoxine on tolbutamide disposition in dwarf goats (Caprus hircus aegagrus)

The aim of the present study was to investigate the effects of intravenously administered sulfadoxine (5 mg kg ⁻¹ bodyweight) or sulfaphenazole (5 mg kg⁻¹ bodyweight) on the in vivo elimination of i.v. tolbutamide (5 mg kg⁻¹ bodyweight), as both compounds were shown to inhibit tolbutamide hydroxylation in vitro. It was shown that relative large differences in tolbutamide clearance exist among goats (n = 6). A high correlation was seen between tolbutamide and sulfadoxine clearances. Tolbutamide clearance was significantly reduced by concommitant administration of sulfaphenazole. Sulfadoxine ( ) had a less consistent effect. Mean tolbutamide plasma clearance was not significantly affected due to the fact that three animals showed an inhibition, whereas three others apparently did not respond. A negative correlation was found between the amount of N4-acetyl in urine and the clearance. Approximately 93 per cent of tolbutamide was bound to plasma proteins. However, there was no evidence for displacement of tolbutamide from its protein binding sites by sulfaphenazole or sulfadoxine. The results described in the present study confirm previous in vitro data obtained with goat hepatocytes. Although quantitative differences in inhibition exist between in vivo and in vitro results, hepatocytes are a good model to study potential drug-drug interactions at the level of biotransformation processes.     

Effects of hypothalamic dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) secretion in male goats

The aim of the present study was to clarify the effects of hypothalamic dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) release in goats. The PRL‐releasing response to an intravenous (i.v.) injection of SAL was examined after treatment with augmentation of central DA using carbidopa (carbi) and L‐dopa in male goats under 8‐h (8 h light, 16 h dark) or 16‐h (16 h light, 8 h dark) photoperiod conditions. The carbi and L‐dopa treatments reduced basal PRL concentrations in the 16‐h photoperiod group (P < 0.05), while a reduction was not observed in the 8‐h photoperiod group. The mean basal plasma PRL concentration in the control group for the 8‐h photoperiod was lower than that for the 16‐h photoperiod (P < 0.05). SAL significantly stimulated the release of PRL promptly after the injection in both the 8‐ and 16‐h photoperiod groups (P < 0.05). PRL‐releasing responses for the 16‐h photoperiod were greater than those for the 8‐h photoperiod (P < 0.05). The carbi and L‐dopa treatments blunted SAL‐induced PRL release in both the 8‐ and 16‐h photoperiods (P < 0.05). These results indicate that hypothalamic DA blunts the SAL‐induced release of PRL in male goats, regardless of the photoperiod, which suggests that both SAL and DA are involved in regulating the secretion of PRL in goats.     

Effects of 5'-uridylic acid feeding on postprandial plasma concentrations of metabolites and metabolic hormones in pre-weaning goats

5'-Uridylic acid (UMP), which is present at high concentrations in cow's colostrum, has been shown to cause a reduction in increased plasma levels of insulin and glucose after ingestion of milk replacer in pre-weaning calves. However, the precise mechanisms of UMP action have not been investigated, and its action has not been investigated in other pre-weaning ruminants. In order to demonstrate whether UMP causes changes in postprandial metabolic and hormonal parameters in pre-weaning goats, 11 Saanen kids were given milk replacer (twice a day) without ( n  = 5) or with ( n  = 6) UMP (1 g for each meal, 2 g/day for each head) for 14 days. Analysis of blood samples taken in the morning of day 14 demonstrated that the feeding of milk replacer with UMP abolished the significant changes in postprandial plasma glucose, NEFA, GH and insulin concentrations induced by feeding of milk replacer alone, and demonstrated a tendency to increase IGF-I levels. However, there was no significant difference between the two groups at any sampling time. We conclude that UMP feeding with milk replacer showed a tendency to blunt the postprandial changes in levels of some plasma metabolites and hormones that are induced by replacer alone in pre-weaning goats.     

The effect of long-term feeding of fresh and ensiled cassava (Manihot esculenta) foliage on gastrointestinal nematode infections in goats

The benefit of long-term feeding of fresh or ensiled cassava foliage on gastrointestinal parasite in goats was evaluated. Eighteen male goats (15.15 ± 2.83kg and between 4–6months) were randomly allocated into three treatments supplemented with 200g of wheat bran head⁻¹ day⁻¹. All groups were fed ad-libitum on either grass (CO), fresh cassava (CaF) or ensiled cassava foliage (CaS). At the beginning of the trial, each goat was inoculated with 3000 L3 containing ≈50% Haemonchus contortus. Individual LWt, FEC and PCV were measured at weekly intervals for 10weeks. At the termination of the experiment all goats were slaughtered for worm recovery and enumeration. The goats in CaF and CaS had similar weight gains while those in CO lost weight (p < 0.05) through the trial. FEC in CaF and CaS were lower (p < 0.05) than CO during the patency of parasite infections, but there was no difference between CaF and CaS goats. PCV of all groups decreased from above 30% to around 25% at the end of the trial. The compositions of established worm burdens were mainly H. contortus (19–40%) and Trichostrongylus colubriformis (55–76%). TWB did not differ among the groups, however, CaS significantly reduced H. contortus burdens, as compared to CaF and CO (p ≤ 0.005). Thus, ensiled cassava foliage reduced the H. contortus population while the fresh foliage only reduced worm fecundity.     

Influence of high phosphorus intake on salivary and plasma concentrations,and urinary phosphorus excretion in mature ponies

This study addressed the question whether the concentration of phosphorus (P) in saliva of ponies is influenced by P intake. Six ponies were fed a diet high in P (HP treatment), providing 21 g P/day, and a diet low in P (LP treatment), supplying 7 g P/day. The two diets provided approximately 21 g calcium (Ca) and 6 g magnesium (Mg)/day. The experiment had an A‐B‐A design with treatment periods of 30 days. The ponies first received the HP diet (HP1), followed by the LP treatment and were then fed again the HP diet (HP2). Urinary P excretion was increased in both HP feeding periods and equalled approximately 7% of P intake vs. 0.5% on the LP diet. Plasma P concentration was higher for the HP treatment. The salivary P concentration ranged from 0 to 1.01 mmol P/l between ponies and there was no effect of P intake. It is suggested that saliva is not an important excretion route of P. The percentage of Ca and Mg in urine (% of intake) was higher for the LP treatment than for the HP treatments. The results of this study suggest that salivary Mg may contribute to Mg homeostasis.     

Effect of feeding tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on nutrient utilization,urinary purine derivatives and growth performance of goats fed on Quercus semicarpifolia leaves

To study the effect of supplementation of tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on growth performance, nutrient utilization and urinary purine derivatives of goats fed on oak (Quercus semicarpifolia) leaves. For growth study, eighteen billy goats (4 month old, average body weight 9.50 ± 1.50 kg) were distributed into three groups of six animals each. The animals of group 1 served as control while animals of groups 2 (T1) and 3 (T2) were given (@ 5 ml/kg live weight) autoclaved and live culture of isolate TDGB 406 (10⁶ cells/ml) respectively. The animals were fed measured quantity of dry oak leaves as the main roughage source and ad libitum maize hay along with fixed quantity of concentrate mixture. The feeding of live culture of isolate TDGB 406 (probiotic) did not affect dry matter intake and digestibility of nutrients except that of dry matter and crude protein, which was higher in T2 group as compared to control. All the animals were in positive nitrogen balance. There was no significant effect of feeding isolate TDGB 406 on urinary purine derivatives (microbial protein production) in goats. The body weight gain and average live weight gain was significantly higher (p = 0.071) in T2 group as compared to control. Feed conversion efficiency was also better in the goats fed on live culture of TDGB 406 (T2). The feeding of tannin degrading bacterial isolate TDGB 406 as probiotic resulted in improved growth performance and feed conversion ratio in goats fed on oak leaves as one of the main roughage source.     

Effects of extracerebral dopamine on salsolinol‐ or thyrotropin‐releasing hormone‐induced prolactin (PRL) secretion in goats

The aim of the present study was to clarify the effect of extracerebral dopamine (DA) on salsolinol (SAL)‐induced prolactin (PRL) secretion in goats. An intravenous injection of SAL or thyrotropin‐releasing hormone (TRH) was given to female goats before and after treatment with an extracerebral DA receptor antagonist, domperidone (DOM), and the PRL‐releasing response to SAL was compared with that to TRH. DOM alone increased plasma PRL concentrations and the PRL‐releasing response to DOM alone was greater than that to either SAL alone or TRH alone. The PRL‐releasing response to DOM plus SAL was similar to that to DOM alone, and no additive effect of DOM and SAL on the secretion of PRL was observed. In contrast, the PRL‐releasing response to DOM plus TRH was greater than that to either TRH alone or DOM alone and DOM synergistically increased TRH‐induced PRL secretion. The present results demonstrate that the mechanism involved in PRL secretion by SAL differs from that by TRH, and suggest that the extracerebral DA might be associated in part with the modulation of SAL‐induced PRL secretion in goats.     

Effects of a second mutant allele (V199I) at the PRKAG3 (RN) locus on carcass composition in pigs

The effect of a second mutant allele (V199I, here denoted rn*) at the PRKAG3 (RN) locus on carcass composition was determined in 334 pigs, entire males and females, from crosses between Swedish Hampshire (H) and Finnish Landrace (L) (H × LH; LH × H; LH × LH). Pigs were classified according to DNA test into the following PRKAG3 genotypes: RN⁻/RN⁻ (23%), RN⁻/rn⁺ (24%), RN⁻/rn* (33%), rn⁺/rn⁺ (8%), rn⁺/rn* (9%) and rn*/rn* (2%). The pigs were slaughtered at a commercial slaughterhouse and assessed 24 h postmortem. Right sides were fabricated into primary wholesale cuts, then further processed into defatted hams and loins, and a subset of hams (n = 122) was dissected into the five major individual muscles. The genotype frequencies for the subsample were RN⁻/RN⁻ (27%), RN⁻/rn⁺ (20%), RN⁻/rn* (35%), rn⁺/rn⁺ (9%), rn⁺/rn* (8%) and rn*/rn* (1%). Weights were recorded for meat and bone in ham and loin, fat in ham, back and shoulder and the individual dissected muscles. The genotype effect was significant (P < 0.05) for estimated lean meat content and the proportions of meat and bone and fat in ham and loin (of carcass weight). Also, the content of meat and bone in ham and loin, in proportion of whole ham and loin, respectively, differed significantly (P < 0.01) between genotypes. Estimated lean meat content was highest for RN⁻/RN⁻ (63.0%) and RN⁻/rn⁺ (63.1%) and lowest in the combined group rn*/⁻ (rn⁺/rn* and rn*/rn*, 61.7%); RN⁻/rn* (62.5%) and rn⁺/rn⁺(62.1%) were intermediate. The same results were found for meat and bone in ham and loin, as a proportion of whole ham and loin, respectively. RN⁻/RN⁻ and RN⁻/rn⁺ did not differ in any trait; however, they produced carcasses with the lowest proportions of fat within loin and the major wholesale cuts (ham, loin and shoulder). The carcass percentage of meat and bone in ham was higher in the three RN⁻/ genotypes (RN⁻/RN⁻, RN⁻/rn⁺ and RN⁻/rn*, P < 0.05) than in the rn*/⁻ group, whereas rn⁺/rn⁺ did not (P > 0.05) differ from any of the other genotypes. RN⁻/rn⁺ and RN⁻/rn* had higher (P < 0.05) proportion of meat and bone in loin compared to the rn*/⁻ group. We conclude that the second mutant allele found at the PRKAG3 (RN) locus, rn*, decreased the lean meat content compared with the two other alleles (RN⁻, rn⁺). The RN⁻/RN⁻ and RN⁻/rn⁺ genotypes were leanest, followed by RN⁻/rn* and rn⁺/rn⁺, and rn⁺/rn* and rn*/rn* were the fattest.     

全株水稻与平菇菌糠共发酵料对浏阳黑山羊屠宰性能、肉品质和器官指数的影响

本试验旨在研究全株水稻与平菇菌糠共发酵料对浏阳黑山羊屠宰性能、肉品质和器官指数的影响.试验依据日粮不同分为两个组,试验组为65％精补料+35％全株水稻与平菇菌糠共发酵料,对照组为65％精补料+35％全株玉米青贮料.采用随机区组设计,选取18只体重为(15.53±2.22)kg的浏阳黑山羊,根据性别相同及体重相近原则首先...     

The binding of soybean agglutinin (SBA) to the intestinal epithelium of Atlantic salmon, Salmo salar and Rainbow trout, Oncorhynchus mykiss, fed high levels of soybean meal

A lectin present in soya, soybean agglutinin (SBA), was identified in electrophoretic profiles and immunoblots of dehulled solvent-extracted soybean meal (DSSM), full-fat soybean meal (FFSM) and of aqueous extracts of feeds incorporating them in their formulation. A quantitative estimation was made of the proportion of SBA comprising the total protein in FFSM and a trial diet was prepared containing an amount of pure SBA similar to that in diets incorporating high levels of the whole soya product. Fish fed with this diet exhibited similar pathological disruption of the intestinal tract to that observed in fish given a diet with a high level of DSSM (60% of the diet). Furthermore, immuno-histochemistry revealed the binding of the SBA to the enterocytes lining the intestinal villi both of fish fed a diet incorporating pure SBA and those fed a diet containing a high-level of soya (60%). Our results suggest that SBA binds in vivo to the intestinal epithelium of fish and has a contributory role in pathological changes associated with fish feeds containing high levels of soybean proteins.