Antiradical function of sulfhydryl residues and oxidative stress markers in dairy cattle plasma

The antiradical function of sulfhydryl (SH) residue in dairy cattle plasma and the relationship of SH residue concentrations to other oxidative stress markers, ascorbic acid and thiobarbituric acid reactive substance (TBARS) in plasma were investigated. The concentration of reduced glutathione (GSH) in phosphate buffer solution (pH 7.6) and SH residues in dairy cattle plasma decreased significantly (P < 0.05) in vitro by the addition of peroxyradicals at 38°C, depending on incubation periods. The decrease of GSH concentration with the peroxyradical solution was partially protected by the addition of sodium ascorbate solution. A positive and significant correlation with SH residues and albumin concentration in the fresh plasma obtained from 15 dairy cattle was observed (P < 0.05). The SH residue concentration was not correlated with the TBARS concentration in plasma. The total ascorbic acid and SH residues concentration in the plasma correlated positively but not significantly (P < 0.10). These results suggested that SH residues in dairy cattle plasma play important part in the antiradical function.     

Effect of high environmental temperatures on ascorbic acid, sulfhydryl residue and oxidized lipid concentrations in plasma of dairy cows

Information on oxidative stress under hot conditions from the levels of cells to organs and the whole body has accumulated in the last decades. Although a hot climate decreased dairy performance, changes of oxidative stress markers under hot conditions have remained obscure. Therefore, the effect of high environmental temperature on ascorbic acid, sulfhydryl (SH) residue and oxidized lipids concentrations in plasma from a total of 128 dairy cows was investigated. The monthly average maximum day temperature varied from 9.2°C in January to 32°C in August of 2004 in this institute. High ambient temperatures increased the rectal temperature of dairy cows up to 39.3°C in August. One of the reducing equivalents in plasma, SH residue concentration, decreased in July compared with December (P < 0.05). Another antiradical molecule, ascorbic acid concentration in plasma, also decreased in July (P < 0.01). The oxidative stress index, thiobarbituric acid reactive substance (TBARS), which was produced from the oxidation of polyunsaturated fatty acids under oxidative conditions, increased in summer (P < 0.05). A significant positive relationship of SH residue and ascorbic acid concentrations in the hot season was observed (P < 0.01). A negative correlation between rectal temperatures and ascorbic acid concentrations in the hot season was obtained (P < 0.01). However, TBARS concentration varied independently of the SH residue and ascorbic acid concentration. These results suggest that the response of oxidative stress markers of SH residue, ascorbic acid and TBARS concentration to oxidative stress under hot conditions were not shown to be the same, and that oxidative stress in dairy cows in the hot season increased.     

Does the Microbial Flora in the Ejaculate Affect the Freezeability of Stallion Sperm?

In an attempt to evaluate the possible relationship between the microbial flora in the stallion ejaculate and its ability to freeze, three ejaculates from five stallions were frozen using a standard protocol. Before freezing, an aliquot was removed for bacteriological analysis. Bacterial growth was observed in all the ejaculates studied. The isolated microorganisms were: Staphylococcus spp. and Micrococcus spp. (in all the stallions), β-haemolytic Streptococcus (in stallions 3 and 4), Corynebacterium spp. (in stallions 1, 3–5), Rhodococcus spp. (in stallion number 2), Pseudomonas spp. (in stallion number 1) and Klebsiella spp. (in stallions 1, 3 and 5). The presence and richness of Klebsiella and β-haemolytic Streptococcus in the ejaculate were related to two sperm variables post-thaw, namely the proportion of dead spermatozoa (ethidium+ cells; r = 0.55, p < 0.05) and the amplitude of lateral displacement of the sperm head (ALH, μm; r = −0.56, p < 0.05), respectively. The degree of growth of Corynebacterium spp. in the ejaculate was positively correlated with the percentage of spermatozoa showing high caspase activity post-thaw (r = 0.62, p < 0.05). The presence and number of colonies of β-haemolytic Streptococcus were negatively correlated (r = −0.55, p < 0.05) with low sperm caspase activity. It is concluded that the microbial flora of the equine ejaculate may be responsible for some of the sublethal damage experimented by the spermatozoa during cryopreservation.     

Netrin-1: Just an axon-guidance factor?

Glucose is the major precursor of lactose synthesis in the mammary gland. Lactose the major carbohydrate and osmolyte of milk, controls milk volume and its concentration. Glycosylated haemoglobin (HbG) is a retrospective measure of mean blood glucose level and it is largely unaffected by recent physiological conditions and environmental events. The purposes of this study were to determine the correlations between lactose traits and other milk production traits in dairy cattle and to investigate whether HbG level can be correlated with milk and lactose production traits. Here, HbG percentage, milk and lactose production traits including milk yield, lactose, protein, SNF, total solid and fat percentages and yields were measured in 485 second calved Iranian Holstein cattle. Statistically significant negative correlations were established between HbG and milk yield (r = −0.88), lactose yield (r = −0.83), SNF yield (r = −0.81), protein yield (r = −0.79) and total solid yield (r = −0.74). Positive correlations were established between lactose yield and milk (r = 0.96), protein (r = 0.81), SNF (r = 0.92) and total solid (r = 0.79) yields. The negative correlation between HbG and milk and total lactose production is probably related to the higher glucose demands in the lactating mammary gland of more productive cows. The positive correlation between lactose yield and milk, protein, SNF and total solid yield indicates that the level of lactose synthesis influences milk production traits in ways other than merely via its osmolytic action.     

Effect of propylene glycol and undegradable protein source on rumen fermentation, blood metabolism and milk production in lactating dairy cows

Eight lactating Holstein cows were divided into two groups ( n  = 4) and used in a double reversal trial with three periods of 14 days each, to evaluate diets containing propylene glycol (PG) and ruminally undegradable protein (RUP) blend on milk yield and composition, ruminal fermentation and blood metabolism. The control diet contained 20% chopped Sudangrass hay, 20% cubed alfalfa hay, 12% corn silage, and 48% of the respective concentrate mixtures (dry matter basis). The experimental diet (PG + RUP) partially replaced the concentrate mixture from the control diet with 1.4% PG and 2.1% RUP. Both diets contained about 16% crude protein and 71% total digestible nutrients. Dry matter intake was similar between the two diets. Daily production of milk, milk lactose and milk solids-not-fat increased by 9.0%, 11.3% and 9.3%, respectively ( P  < 0.1), for cows fed diets with PG + RUP; milk composition was unchanged. Although the concentration of ruminal total volatile fatty acids was unchanged, the proportion of propionic acid increased, and the proportion of acetic acid decreased with PG + RUP. The concentration of ruminal ammonia nitrogen and number of ciliate protozoa was not significantly affected by PG + RUP. The concentration of glucose in blood plasma increased, the concentration of urea nitrogen was unaffected, and the concentration of some essential free amino acids decreased with PG + RUP. It is suggested that these changes might be caused predominantly by PG, and the addition of PG may exert a favorable effect on milk production through increased metabolism.     

Effect of Estradiol and Progesterone on Metabolic Biomarkers in Healthy Bitches

The aim of this study was to evaluate the possible association between hormonal changes that occur during oestrus and biomarkers related with glucose metabolism (glucose and insulin), lipid metabolism (lipidic profile and BChE) and adipokines (adiponectin and ghrelin) in healthy bitches. For this purpose, we measured these analytes in serum of bitches, at two times: before (T1) and after (T2) the LH peak that were established according to progesterone concentrations. Increased levels of total cholesterol (p < 0.01), high density lipoprotein cholesterol (HDL‐C) (p < 0.01), low density lipoprotein cholesterol (LDL‐C) (p < 0.01), adiponectin (p < 0.01) and ghrelin (p < 0.05) were observed at T2 in comparison with T1. No statistically significant changes were observed in serum glucose, insulin, homoeostasis model assessment for insulin sensitivity (HOMA), triglycerides and BChE. When all data of T1 and T2 were pooled, serum adiponectin showed positive correlation with progesterone (r = 0.353; p = 0.022) and HDL‐C (r = 0.307; p = 0.048), and negative with insulin (r = ?0.429; p = 0.005), HOMA (r = ?0.446; p = 0.003) and BChE (r = ?0.522; p < 0.001). Ghrelin showed negative correlation with estradiol (r = ?0.701; p = 0.004). BChE was negatively correlated with estradiol (r = ?0.441; p = 0.018) and glucose (r = ?0.343; p = 0.028), and positively with insulin (r = 0.460; p = 0.003) and HOMA (r = 0.505; p < 0.001). In conclusion, changes in metabolic biomarkers occur in bitches after LH peak, characterized by increased lipids (total cholesterol, HDL cholesterol and LDL cholesterol) without changes in BChE activity, and increased adiponectin and ghrelin concentrations, without significant changes in glucose and insulin.     

大豆皮替代产奶牛日粮精料中玉米与小麦麸对产奶性能的影响

本试验选用 4 2头荷斯坦产奶牛分为 3组 ,每组 1 4头。采用完全随机化区组设计进行试验。处理为 3种大豆皮替代水平 ,即 :大豆皮分别替代精料中 0 % (对照 )、2 5%和 50 %的玉米与小麦麸 ;区组 ( 4个 )为产奶牛的不同胎次和泌乳月。正式试验期 1 2周。结果表明 ,用大豆皮替代产奶牛精料中 0 %、2 5%和 50 %的玉米和小麦麸 ,日粮干物质、蛋白质进食量、日产奶量、4 %乳脂率校正奶产量、产奶的饲料转化效率、乳蛋白、乳糖、无脂固形物含量均没有明显变化 (P >0 .2 0 ) ,乳脂率随大豆皮替代水平的提高呈直线上升趋势 (P =0 .0 8)。以大豆皮替代精料中 2 5%和 50 %玉米与小麦麸饲粮喂奶牛 ,每千克产奶的饲料成本平均分别降低 0 .0 4 5和 0 .0 57元     

Effects of long-term exogenous bovine somatotropin on glucose metabolism and the utilization of glucose by the mammary gland in different stages of lactation of crossbred Holstein cattle

The effects of long-term administration of recombinant bovine somatotropin (rbST) on glucose turnover and the utilization of glucose in the mammary gland using a continuous infusion of [3-³H]glucose and [U-¹⁴C]glucose in lactating crossbred Holstein Friesian(HF) cattle were investigated. Glucose turnover of rbST-treated animals was significantly higher than those of control animals ( P  < 0.05) in mid lactation, while plasma glucose concentrations were not affected. The utilization of glucose of non-mammary tissues of rbST-treated animals significantly increased ( P  < 0.05) as lactation advanced. The glucose taken up by the mammary gland in early lactation increased flux through the lactose synthesis and the pentose cycle pathway with significant increases in NADPH formation for fatty acid synthesis during rbST administration. The utilization of glucose carbon incorporation into milk appeared to increase in milk citrate and milk triacylglycerol but not for milk lactose as lactation advances in rbST-treated animals. The stimulant effect for milk yield by rbST treatment was transiently and significantly increased in early lactation and was decreased in late lactation even though there was a high level of udder blood flow. These findings demonstrate that the regulation of biosynthetic capacity within the mammary gland would be influenced more by local than by systemic factors. The proportion of glucose would be metabolized less for lactose synthesis, but metabolized more via the Embden-Meyerhof pathway and the tricarboxylic acid cycle as lactation advances.     

用大豆皮替代日粮中部分玉米对奶牛产奶量和乳成分的影响

选用36头产奶牛,按产奶量、泌乳月和胎次配对的原则随机均分为对照组和试验组。试验处理为大豆皮替代饲粮30％的玉米。正试期90天。结果表明,奶牛日产奶量、4％乳脂率校正奶(FCM)产量和乳脂率均较对照组有明显提高,处理组日产奶量提高1.5千克;由于乳脂率的差异,4％FCM产量提高2.7千克(P<0.08)。乳脂率提高0.32个百分点(P<0.05)。结论:在奶牛饲粮中用大豆皮替代30％玉米时,可以提高产奶量和乳脂率;大豆皮可作为奶牛较好的精料替代成分。     

Interrelationship between milk constituents,serum oestradiol and vaginal mucus indicators of oestrus in Egyptian buffaloes

The intensity of heat signs in buffaloes is generally low and the incidence of suboestrus varied from 15 to 73% (Buffalopedia). The objective of this study was to investigate the feasibility of monitoring the changes in some milk constituents, oestradiol levels and electrical conductivity of vaginal mucus during peri‐oestrous period in prediction of the timing of oestrus in buffaloes. Twenty‐one Egyptian buffaloes aged 3–9 year, 1st–6th lactations, were examined by oestrous detector and ultrasonographically for monitoring the ovarian and uterine activity for 7 days around the time of standing oestrus. Sodium, potassium, chloride and lactose were assayed in aqueous phase of milk; besides, oestradiol was estimated in serum. Current results declared highly significant acute changes in milk constituents at the time of oestrus characterized by peaking of chloride and sodium levels and lowering of potassium and lactose values. The alternation in milk composition when arranged in decreasing order of magnitude, sodium was the highest (77.78 ± 0.69%), followed by chloride (61.60 ± 1.52%) and potassium (?58.14 ± 10.89%). Concomitantly, milk lactose decreased by 26.07 ± 7.97% compared to baseline levels. Synchronously, vaginal electrical resistance (VER) showed a significant (p < 0.01) decrease, but serum oestradiol 17β levels surged (59.93 ± 7.29 pg/ml) on day of oestrus. Serum oestradiol level was negatively correlated with VER (r = ?0.577), potassium (r = ?0.661), positively correlated with chloride (r = 0.707) and sodium (r = 0.579) and not correlated with lactose levels. These results for the first time suggested that the changes in constituents of milk during peri‐oestrous period may be used as a practical non‐invasive indicator for oestrous detection and prediction of ovulation in Egyptian buffaloes.     

过瘤胃蛋白和丙二醇对乳牛瘤胃发酵、产乳量及乳成分的影响

用 8头荷斯坦黑白花奶牛 ,在饲粮中添加过瘤胃蛋白和丙二醇 ,研究其对乳牛瘤胃发酵、产乳量及乳成分的影响。结果表明 ,过瘤胃蛋白+丙二醇可显著提高丙酸浓度 (P <0 0 5) ,并且产乳量较对照组有增加的趋势。乳脂率、乳蛋白率、乳糖率及无脂固形物率 ,并未因添加过瘤胃蛋白和丙二醇而受到显著影响 (P >0 0 5)。乳蛋白质量、乳脂量及无脂固形物量 ,过瘤胃蛋白 +丙二醇组较对照组有增加的趋势 ,但差异均不显著 (P >0 0 5)。     

饲粮钙磷水平对伊犁马初乳成分、乳脂脂肪酸组成、产后血液钙磷及激素的影响

旨在研究妊娠后期饲喂不同钙磷水平饲粮对产后伊犁马初乳成分、乳脂脂肪酸组成、血液钙磷及钙磷代谢激素、繁殖及生长代谢激素等生理生化指标的影响，为明确伊犁马在妊娠后期对钙磷的适宜需要量提供参考。本试验选取健康、无亲缘关系、12~13周岁、体重为（380±32）kg、胎次为4~5胎、处于第10妊娠月左右的伊犁马25匹，随机分为5组，每组5个重复。各组饲粮钙饲喂水平分别为36.00、39.00、42.00、45.00和48.00 g·d^-1，磷饲喂水平分别为26.30、28.30、30.30、32.30和34.30 g·d^-1。试验预试期10 d，正试期从第11天至母马分娩后第2天结束。母马分娩后12 h内采集初乳用于测定乳成分和乳脂脂肪酸含量，空腹血液用于测定Ca、P、甲状旁腺素（PTH）、降钙素（CT）、骨钙素（OC）、胎盘催乳素（PL）、垂体催乳素（PRL）、雌酮（E₁）、雌二醇（E₂）、血清孕酮（PROG）、甲状腺素（T₄）、三碘甲状腺原氨酸（T₃）、生长激素（GH）、胰岛素样生长因子-Ⅰ（IGF-1）等激素浓度。结果表明：1）饲粮钙磷水平对初乳中钙、磷、乳脂率、乳糖率均无显著影响，组间乳蛋白率、总固形物、体细胞数、乳脂中饱和脂肪酸（SFA）和不饱和脂肪酸（UFA）比例存在显著差异（P<0.05）。随着饲粮钙、磷水平的增加，乳磷浓度、乳蛋白率和UFA比例呈显著线性增加（P<0.05），总固形物呈显著二次增加（P<0.05），而乳糖率、SFA及肉豆蔻酸比例呈显著线性降低（P<0.05）。2）饲粮钙磷水平显著影响血液中OC和PROG浓度（P<0.05），随着饲粮钙磷水平的增加，血液中离子钙、CT和OC浓度呈显著的线性降低（P<0.05），而PTH和PROG水平呈显著的线性升高（P<0.05）。饲粮钙、磷水平对PL、PRL、E₁、E₂等生殖激素以及T₃、T₄、GH和IGF-1等生长代谢激素浓度均无显著影响。由此可见，在本试验条件下，饲粮钙磷通过提高初乳中乳蛋白率和总固形物来改变乳脂中饱和脂肪酸含量和不饱和脂肪酸比例影响初乳成分；通过降低血液中OC浓度影响钙磷代谢；通过提高血液中PROG浓度影响繁殖状况。     

Milk protein responses to balanced amino acid and removal of Leucine and Arginine supplied from jugular‐infused amino acid mixture in lactating dairy cows

This study was undertaken to evaluate the milk protein response when cows were supplied a balanced AA profile and to determine whether a deficiency of Leucine (Leu) or Arginine (Arg) had a negative effect on milk protein. Eight mid‐lactation Holstein cows were randomly assigned to 5‐day continuous jugular infusions of saline (CTL), EAA mixture prepared on the profile of casein and supplied (in % of lysine (Lys)) 100% of Lys, 33.3% of methionine (Met), 110.2% of Leu, 43.6% of Arg, 50.8% of threonine (Thr), 81.6% of valine (Val), 69.7% of isoleucine (Ile), 61.4% of phenylalanine (Phe) and 34.2% of histidine (His) (Casein, 160 g/d), EAA mixture excluding Leu (?Leu, 163 g/d) or EAA mixture excluding Arg (?Arg, 158 g/d) in a duplicated 4 × 4 Latin square design with four infusion periods separated by 7‐day interval period. The basal diet supplied 1.6 Mcal NE_L and 94.4 g MP per 1 kg DM to meet requirements for lactation. The Casein treatment provided a balanced supply (in % of MP) of 10.3% Leu and 5.3% Arg, whereas in the two subsequent ?Leu and ?Arg treatments, the concentration of Leu and Arg was reduced to 8.4 and 4.6% respectively. Dry matter intake (15.4 kg/day) was not affected by treatments. The Casein treatment increased milk yield (14.9%, p < 0.001), milk protein yield (120 g, p < 0.001) and milk protein efficiency (0.03, p = 0.099) than CTL treatment. However, the ?Leu treatment decreased the responses of above‐measured parameters by 6.25%, 70 g, 0.05 (p < 0.06) (compared with Casein). These effects of Leu were related to decreased Leu concentration and improved concentration of Ile and Val in plasma. The ?Arg treatment decreased the plasma Arg concentration than the Casein treatment, whereby resulted in the decrease of milk yield (5.7%, p = 0.073), milk protein yield (60 g, p = 0.011) and milk protein efficiency (0.04, p = 0.037). In conclusion, supply of EAA profile of casein can increase the lactation production in dairy cows, and 8.6% of Leu in MP partly limits the milk protein response when the requirements of Lys, Met and His were met. The level of Arg at 4.6% MP is not deemed to an ideal profile, as evidenced by decreased milk protein efficiency.     

Composition and milk cell characteristics in quarter milk fractions of dairy cows with low cell count

Variation in milk composition and milk polymorphonuclear neutrophil leukocyte (PMN) characteristics and functions among quarter milk fractions were investigated in order to evaluate the optimal fraction for the determination of local immune response. Five fractions were classified during milking: foremilk (I), cisternal milk (II), main milk (III), strippings (IV) and residual milk (V). Somatic cell count (SCC), fat, protein, lactose, sodium, potassium, chloride, polymorphonuclear leukocyte necrosis, apoptosis and oxidative burst were analysed in each fraction. The logSCC and fat concentration were highest in residual milk (P < 0.05), whereas protein and lactose concentration were highest in the earliest fractions (I, II, III) (P < 0.05). Polymorphonuclear neutrophil leukocyte necrosis was lowest in strippings and residual milk (P < 0.05), and PMN apoptosis was lowest in residual milk (P < 0.001). The highest percentage of PMN with oxidative burst was found in residual milk (P < 0.05), and was associated with the highest mean fluorescence intensity (MFI) (P < 0.05). In conclusion, late fractions have more PMN and more active PMN. Nevertheless, it is suggested that each fraction is appropriate in the study of local immune response of the mammary gland, however the fraction used in the study has to be specified.     

Effects of Supplemental Carbohydrate Sources on Lactation Performance, Nitrogen Balance, and Ruminal Fermentation in Dairy Cows Fed Energy-Deficient Total Mixed Rations

The effects of supplemental carbohydrate (CHO) sources on milk yield and composition,nitrogen (N) balance,and ruminal fermentation were evaluated in lactating dairy cows fed energy-deficient total mixed rations (TMR).Fifty-six lactating Holstein cows (36.8 ±3.4 kg/d of milk yield; 152 ±26days in milk [ DIM ] ) were randomly assigned to one of four diets:( 1 ) basal TMR ( control ) ; ( 2 ) basal TMR + 1.25 kg/d sucrose (SUC) ; ( 3 ) basal TMR + 2.12 kg/d steam-flaked corn ( SFC ) ; ( 4 ) basal TMR + 2.23 kg/d wheat (WHE).The trial lasted 70 days,including the first 10 days of adaptation.Simultaneously,a 4 × 4 Latin square trial was conducted with four ruminally cannulated cows of similar DMI (Dry Matter Intake) fed on the above four diets.Each testing period lasted 18 days:15 days for adaptation and 3 days for sampling.Cows fed SUC-,SFC-,and WHE-supplemented diets produced 1.6,2.9,and 0.8 kg/d,respectively,more milk than those on the basal TMR control diet,but the difference was not significant (P =0.160).However,the production of energy-corrected milk of cows fed CHO-supplemented diets improved significantly (P =0.020),and the yield of 4％ fat-corrected milk tended to be higher (P =0.063 ) than in control animals.Percentages of milk protein,lactose and solidsnot-fat (SNF) increased significantly in cows fed CHO-supplemented diets ( P ＜ 0.05 ),and yields of milk protein and SNF were significantly higher (P＜0.05); yields of milk fat and lactose were somewhat higher ( P ＜ 0.10 ).Cows receiving supplementary CHO diets consumed more DM (Dry Matter) ( P =0.023 ) ; however,there was no significant difference in N retention,digestibility,or utilization efficiency among the treatments (P ＞ 0.10 ).The average ruminal pH was lowest in cows supplemented with SUC,while that in cows supplemented with SFC and WHE was only slightly reduced (P =0.025 ).Ruminal NH3-N concentration was highest with no supplementary CHO ( P =0.017 ),and changes in postfeeding time were similar across the diets.Total volatile fatty acid concentration was significantly lower in control animals than in those on SUC- and WHE-supplemented diets ( P =0.001 ) ; significant dietary responses were observed in the concentrations of acetate,butyrate,and branched-chain fatty acids and in the acetate-to-propionate ratio ( P ＜ 0.001 ).These results indicate that supplementation with different CHO sources in energy-deficient diets substantially improved the balance of energy and N in the rumen,altered ruminal fermentation,and improved lactation performance in dairy cows.     

Effect of dietary fish oil on milk yield, fatty acids content and serum metabolic profile in dairy cows

The aim of the study was to evaluate the effects of dietary unprotected fish oil on milk yield, fatty acids content and serum metabolic profile in dairy cows. Forty lactating Polish Holstein-Friesian cows were assigned to two groups. The cows were fed a control basal diet (C group), or a basal diet containing 2% addition of fish oil on mineral carrier (FOM group) during a 8-week period. Supplementing FOM diet of dairy cows had no significant effect on milk fat, milk protein, milk lactose concentration and somatic cells count, but increased the milk yield (36.5 kg/d), (p < 0.05) compared with the control cows (34.28 kg/d). We observed an increase (p < 0.05) in body condition scoring between C and FOM groups. Additionally, higher levels of non-esterified fatty acids and β-hydroxybutyrate acid were noticed in FOM group after 8 weeks of the experiment; however, these serum parameters still were in the reference range. Concentration of insulin was higher (30.40 μU/ml; p < 0.01) in the FOM group compared with the control group (14.03 μU/ml). In the FOM group, significant increase (p < 0.01) in long-chain fatty acids, mainly cis-9, trans-11 CLA and n-3 fatty acids (eicosapentaenoic and docosahexaenoic acids) was observed. The obtained results demonstrated that addition of fish oil to cows' diet could profitably modify the fatty acids in cow's milk.     

Effects of feeding fermented fish on egg cholesterol content in hens

This study was conducted to investigate the effects of feeding fermented fish (FF) to layers on laying performance, and polyunsaturated fatty acid and cholesterol levels in eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this study. They were randomly assigned to four numerically equal groups with eight replicates per treatment, three birds per replicate. All the birds were housed in individual cages. The dietary treatments were: Control diet, without FF; FF3 diet containing 3% (w/w) FF, FF6 diet containing 6% (w/w) FF and FF9 diet containing 9% (w/w) FF. The study was carried out for 16 weeks inclusive of two weeks of adjustment. Weekly feed intake and egg production were recorded. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the experiment. FF did not enhance ( P  > 0.05) egg mass but ( P  < 0.05) decreased egg weight slightly. However, egg yolk cholesterol and plasma cholesterol concentrations were reduced ( P  < 0.05) by FF. The n-6:n-3 fatty acids ratio in the egg yolk (Control = 7.9, FF9 = 6.2) and plasma (Control = 10.6, FF9 = 6.2) were decreased by feeding FF. Moreover, FF was able to increase ( P  < 0.05) the docosahexaenoic acid (DHA) concentrations in egg yolk and plasma. In conclusion, this study demonstrated that FF increased DHA and reduced egg yolk cholesterol in poultry eggs.     

Factors affecting agonistic interactions of pigs after regrouping in pens with a box

To determine the factors affecting agonistic interactions after regrouping, 24 pigs were allocated to six pens that each had a box. Half of the pigs were experienced in using the box. One castrated male and one female pig were transferred from each pen to another pen at random. The number of pigs attacked was particularly large for the pigs that had no experience in using the box and were transferred on the first day ( P <  0.05). The duration of access to the box was markedly longer for the pigs that had experience in using the box and were not transferred on the first day ( P <  0.05). The number and duration of attacks were significantly larger and longer toward unfamiliar individuals than toward familiar ones (both P < 0.01). The number of attacks toward the same sex was significantly larger than toward the opposite sex ( P <  0.01). A negative correlation was found between the number of agonistic interactions on the first day and the range of body weights in the pen mates ( r =  −0.78, P  = 0.07). In conclusion, regrouping with unfamiliar individuals should be avoided, but when unavoidable, the following methods are recommended to reduce agonistic interactions: (1) ensure the intruders are experienced in using a box, (2) move experienced intruders in with residents that have no experience in using a box, (3) mix different sexes, and (4) have wide variations in body weights in a pen.     

Effect of citrus pulp silage feeding on concentration of beta‐cryptoxanthin in plasma and milk of dairy cows

Citrus pulp is known to contain a functional molecule of beta‐cryptoxanthin which is one of the carotenoids showing anti‐oxidative capacity. Influences of citrus pulp silage feeding to dairy cows on beta‐cryptoxanthin concentration in plasma, other blood properties and milking performances were investigated. Four Holstein cows were fed total mixed ration (TMR) containing citrus pulp silage 20% dry matter (DM) for 2 weeks with free access to the TMR. Dry mater intake, milk production and milk components 2 weeks later were not altered compared with those of the control group without citrus pulp silage. Activities of aspartate aminotransferase, alanin aminotransferase and gamma‐glutamyltranspeptidase in plasma were not affected by feeding of citrus pulp silage. Concentrations of protein, albumin, sulfhydryl residue, ascorbic acid, thio‐barbituric acid reactive substance and urea nitrogen in plasma were also not altered by citrus pulp silage feeding. Concentration of beta‐cryptoxanthin in plasma was increased approximately 20‐fold compared with the control group (P < 0.05). Content of beta‐cryptxanthin in pooled milk fat fraction was also increased approximately three times compared with that of the control group. Feeding of TMR containing citrus pulp silage 15% DM for 30 days to eight dairy cows also increased plasma beta‐cryptoxanthin concentration 30‐fold compared with that before feeding.     

饲粮全棉籽比例对奶牛泌乳性能及乳脂脂肪酸组成的影响

本试验旨在研究饲粮全棉籽比例对奶牛泌乳性能和乳脂脂肪酸组成的影响.试验采用4×4拉丁方试验设计,选择8头泌乳早期的经产中国荷斯坦奶牛(产奶量、胎次、产犊日期接近,健康无疾病),分为4组,每组2个重复,每个重复1头牛.A组饲喂基础饲粮,B、C和D组分别饲喂含5％、10％、15％全棉籽的试验饲粮.每期试验28 d,其中预试期为7d,正试期为21 d.结果表明:随着饲粮全棉籽比例的增加,奶牛产奶量有提高趋势(P＞0.05),校正乳产量极显著提高(P＜0.01).全棉籽极显著地提高了奶牛的乳脂率(P＜0.01),对乳蛋白率、乳糖率和乳非脂固形物率无显著影响(P＞0.05).全棉籽极显著降低了饱和脂肪酸( SFA)的含量(P＜0.01),不同程度地提高了乳中多不饱和脂肪酸( PUFA)和单不饱和脂肪酸(MUFA)的含量(P＜0.05或P＜0.01);短链脂肪酸和中链脂肪酸含量都显著降低(P＜0.05),长链脂肪酸含量有不同程度的提高(P＜0.05或P＜0.01).结果提示,饲粮中添加全棉籽可以提高奶牛产奶量,优化乳脂脂肪酸组成,改善乳脂品质,并以10％为泌乳早期奶牛最佳饲粮全棉籽比例.