Effect of Bospro on High and Mid-to-Low Milk Yielding Chinese-Holstein Cow

A total of 90 cows from two farms (farm A 30 cows, farm B 60 cows) were used to study the effect of Bospro on milk production, milk quality and subclinical mastitis incidence. The cows in the test group were supplied with 20 g of Bospro per head per day and meanwhile, the percentage of milk fat, protein and lactose and moisture of the milk samples were analysed. The results showed that the milk yield of both high production and mid-to-low milk producting cows increased by 3.3% to 5.3% respectively compared with their control group of cows, but there was no changes on the milk content between the treated and the control cows. The treated cows also showed an increased body weight (P>0.05) and significantly reduced incidence of mastitis, as Compared with that of the control group.The experiment dcmonstrats that Bospro can increase milk yield, but not at the expense of milk quality and body weight.

Dietary supplementation with branchedchain amino acids enhances milk production by lactating sows and the growth of suckling piglets

Background:Under current dietary regimens,milk production by lactating sows is insufficient to sustain the maximal growth of their piglets.As precursors of glutamate and glutamine as well as substrates and activators of protein synthesis,branched-chain amino acids(BCAAs)have great potential for enhancing milk production by sows.Methods:Thirty multiparous sows were assigned randomly into one of three groups:control(a corn-and soybean meal-based diet),the basal diet+1.535%BCAAs;and the basal diet+3.07%BCAAs.The ratio(g/g)among the supplemental L-isoleucine,L-leucine and L-valine was 1.00:2.56:1.23.Diets were made isonitrogenous by the addition of appropriate amounts of L-alanine.Lactating sows had free access to drinking water and their respective diets.The number of live-born piglets was standardized to 9 per sow at d 0 of lactation(the day of parturition).On d 3,15 and 29 of lactation,body weights and milk consumption of piglets were measured,and blood samples were obtained from sows and piglets 2 h and 1 h after feeding and nursing,respectively.Results:Feed intake did not differ among the three groups of sows.Concentrations of asparagine,glutamate,glutamine,citrulline,arginine,proline,BCAAs,and many other amino acids were greater(P<0.05)in the plasma of BCAA-supplemented sows and their piglets than those in the control group.Compared with the control,dietary supplementation with 1.535%and 3.07%BCAAs increased(P<0.05)concentrations of free and protein-bound BCAAs,glutamate plus glutamine,aspartate plus asparagine,and many other amino acids in milk;milk production by 14%and 21%,respectively;daily weight gains of piglets by 19%and 28%,respectively,while reducing preweaning mortality rates by 50%and 70%,respectively.Conclusion:Dietary supplementation with up to 3.07%BCAAs enhanced milk production by lactating sows,and the growth and survival of their piglets.

Relationship of Somatic Cell Count with Milk Yield and Composition in Chinese Holstein Population

The objective of this study was to analyze the relationship of somatic cell count （SCC） with milk yield, fat and protein percentage, fat and protein yield using analysis of variance and correlation analysis in Chinese Holstein population. The 10 524 test-day records of 568 Chinese Holstein Cattle were obtained from 2 commercial herds in Xi＇an region of China during February 2002 to March 2009. Milk yield, fat percentage, fat and protein yield initially increased and then dropped down with parity, whereas protein percentage decreased and SCC increased. Analysis of variance showed highly significant effects of different subclasses SCC on milk yield and composition （P〈 0.01）. Compared with milk yield with SCC ≤ 200 000 cells mL-1, milk yield losses with SCC of 200 000-500 000 cells mL-1, 501000-1 000 000 cells mL-1, ≥ 1 000 000 cells mL-1 were 0.387, 0.961 and 2.351 kg, respectively. The highly significant negative correlation coefficient between somatic cell score （SCS） and milk and protein yield, milk yield and fat and protein percentage, protein percentage and fat yield were -0.084, -0.037, -0.061, -0.168, and -0.088, respectively （P〈 0.01）. The highly significant positive correlation coefficients between SCS and fat yield and fat and protein percentage, milk yield and fat and protein yield, fat percentage and protein percentage and fat yield, protein yield and protein percentage and fat yield were 0.041, 0.177, 0.105, 0.771, 0.865, 0.122, 0.568, 0.318, and 0.695, respectively （P〈 0.01）. There was no significant relationship between fat percentage and protein yield （P 〉 0.05）. The results of the present study first time provide the relevant base-line data for assessing milk production at Xi＇an region of China.

The Effects of Graded Abomasal Glucose Infusion on Milk Yield and Composition in Lactating Goats

Four non-pregnant multiparous lactating goats were used in a 4 × 4 latin square experiment in the present study. The four treatments were abomasal infusion of 0, 50, 100, and 150 g d^-1 glucose. The results showed that graded glucose infusion increased milk yield （P 〈 0.01）. The highest milk yield was observed when 50 g d^-1 glucose was infused. An infusion of glucose at 100 or 150 g d^-1 failed to increase milk yield further and milk yield of the 100 g d ^-1 glucose infusion treatment was even significantly lower than that of the 50 g d^-1 treatment （P 〈 0.01）. Though milk fat content was gradually decreased by graded glucose infusions and milk fat yield of the 100 and 150 g d 1 treatments were lower than that of the control （P 〈 0.01）; milk fat yield of the 50 g d i treatment was not depressed and was higher than that of the control （P 〈 0.01）. Graded glucose infusion did not change the contents of milk protein and non-fatty solids. Yields of milk protein （P 〈 0.05）, lactose （P 〈 0.01）, non-fat solids （P 〈 0.01）, and lactose content （P 〈 0.01） of the 50 g d^-1 treatment were higher than those of the control but had no difference among the other three treatments. Contents of those de novo synthesized fatty acids in milk fat remained unchanged or increased and those preformed fatty acids remained unchanged or decreased by graded glucose infusion. Glucose infusion decreased the total yields of C16 ＋ C16：1 and 〉 C16 fatty acids and had no influence on the yield of C4-C14：1 fatty acids （P 〈 0.05）. Results of the present study implied that increased glucose supply had positive effects on the production of milk, milk protein, milk fat, and lactose only when glucose was a limiting factor for milk synthesis. Excessive glucose supply had no further beneficial effects and might depress milk fat synthesis.

Milk Yield of Holstein Cows Induced into Lactation Twice Consecutively and Lactation Curve Models Fitted to Artificial Lactations

Nineteen multiparous barren Holstein cows were subjected to an induction of lactation protocol for 21 d administering estradiol cypionate （2 mg kg-1 of body weight （BW） d-1, on day 1 to 14）, progesterone （0.10 mg kg-1 of BW, on day 1 to 7）, lfumethasone （0.03 mg kg-1 of BW, on day 18 to 20） and recombinant bovine somatotropin （rbST;500 mg per cow, on day 1, 6, 16 and 21）. At the end of lactation and with a minimum of a 2-mon dry period, the same cows were again hormonally induced into lactation. Cows in both lactations were not artiifcially inseminated, they were milked 3 times daily and received rbST throughout lactation. Mean accumulated milk yield at 305 d in milk （DIM） did not differ between the ifrst and second induced lactations （（9 710 ＆#177;1 728） vs. （9 309＆#177;2 150） kg;mean＆#177;SD）. Total milk yield （（12 707＆#177;3 406） vs. （12 306＆#177;4 218） kg;mean＆#177;SD） and lactation length （（405＆#177;100） vs. （410＆#177;91） d;mean＆#177;SD） were not different between the ifrst and second induced lactations. In a second study, 15 empirical models including exponential, power law, yield-density, sigmoidal and miscellaneous models were compared for their suitability by modeling 12-mon （n=334）, 18-mon （n=164） and 29-mon （n=22） lactation cycles of Holsteins cows induced into lactation and treated with rbST throughout the lactation. Hoerl （Y=ab1/xxc）, Wood （Y=axb exp（cx）） and Dhanoa （Y=ax（bc）exp（cx）） models were equally suitable to describe 12-mon lactations. An exponential model with ifve parameters （Y=exp（a＋bx＋cd2＋e/x）） showed the best ift for milk yield for 18-mon lactations. The rational model （Y=a＋bx/1＋cx＋dx2） was found to produce the closest ift for 29-mon lactations. It was concluded that, with the protocol used in the present study, multiparous cows respond favorably to a second cycle of induced lactation, with milk yield similar to that experienced during the ifrst cycle. Thus, dairy producers might be able to lengthen the productive life of infertile high producing cows with a renewal of artiifcial lactation, which would imply an overall reduction in voluntary culling of cows. Also, various equations used to describe the lactation curves demonstrated the potential for iftting monthly milk records of Holstein cows with prolonged lactations and induced hormonally into lactation.

Effects of Rumen Protected Methionine on Milk Yield and Milk Composition in Earlier Lactating Cow

A total of 12 mature healthy Holstein dairy cows of the nearly body weight （580±30） kg, milk yield （22.5±2.8） kg in the early stages of lactation were selected in this experiment. The cows were randomly divided into 2 groups, every group had 6 cows, every group had 6 repeats, and every repeat had 1 cow. Added 20 g protected methionine in earlier lactating cow food every day. The results showed that protected methionine increased milk yield by 10.83%, testing group milk yield was significantly different than that of control （P〈0.05）; protected methionine increased milk fat by 5.98%, testing group milk fat was significantly different than that of control （P〈0.05）; Milk protein increased by 2.15%, but bad insignificantly different （P〉0.05）; dry matter of milk had the tendency of decrease, but had insignificant difference （P〉0.05）.

Bacillus subtilis Co-transfected with a Lysine-rich and a Methionine-rich Protein Gene and Its Effect on Cow Milk Production

The probiotic Bacillus subtilis （B. subtilis） was widely applied in animal production as feed additive. Lysine （Lys） and methionine （Met） were the two most important limiting amino acids in livestock animal feed. Raising Lys and Met contents in B. subtilis would provide better effects for animal production and save Lys and Met supplements. We still didn＇t know whether Lys- rich and Met-rich protein genes from plants could be transfected into B. subtilis and expressed at a high level so as to improve animal production, such as milk production as an additional diet. The Lys-rich protein gene （Cflr） and Met-rich 10 ku-δ Zein were cloned from pepper anther and maize endosperm, respectively. Then they were constructed into plasmids individually and successfully cotransfected into B. subtilis. Upon IPTG induction, mRNAs and protein expressions could be observed. Lys and Met contents in the fermentation broth were raised by 65.92% and 46.39%, respectively. After feeding 200 g and 400 g· cow^-1· d^-1, transgenic B. subtilis fermentation broth, the milk yield, milk protein and milk fat contents all significantly increased. The Lys-rich protein gene （Cflr） and Met-rich 10 ku-δ Zein were successfully transfected into B. subtilis. Contents of Lys and Met in the transgenic B. subalis obviously raised and the fermentation broth of the transgenic bacteria could effectively improve milk yield and quality.

Study on the Milk Yield Pattern of Maiwa Yak

The change in lactation of Maiwa yak was studied based on the data of locating Maiwa yak in warm seasons during 2003- 2009. The results showed that the milk yield was increasing gradually during days 30- 70 after calving,reached the peak at days 70- 110,and decreased gradually to no milking whenafter. The milk yield of Maiwa yak was greatly influenced by lactation age rather than the yearly effect.

Effects of Chinese Herb Additive on Milk Yield and Anti-heat Stress Ability of Holstein Cows

[Objective] To explore the effects of Chinese herb additive on milk yield and anti-heat stress ability of Holstein diary cow. [Method] A total of 36 Holstein cows at same parity and with similar milk yield were randomly divided into three groups, namely, control group, Chinese medi- cine group I and Chinese medicine group I1. The cows in the Chinese medicine group I were fed basal diet containing 4% compound Chinese herb additive; those in the Chinese medicine group II were fed basal diet containing 3% compound Chinese herb additive; and those in the control group were fed common basal diet. All cows in the three groups were analyzed comparatively. [Result] Supplementing some compound Chinese herb ad- ditive into basal diet increased milk yield and anti-heat stress ability of Holstein cows, besides, it also decreased cow diseases like cow mastitis. The Chinese medicine group I generated the highest economic benefit of practical production. [ Conclusion] Supplementing Chinese herb additive in- to basal diet is an effective way to relieve heat stress and increase milk yield.

Relation between Climate and Milk Yield of Holstein in Nanshan

Nanshan, an unique natural meadow, has cool climate. In Nanshan, annu- al average temperature was 11.2 ℃; average temperature in the hottest month July was 18.4 ℃, and extremely maximum temperature was 26.8 0℃; average tempera- ture in the coldest month January was 2.2 ℃, and extremely minimum temperature in February was -16.0 ℃. Holstein is resistant to low temperature but not resistant to high temperature. The suitable temperature for Holstein ranges from 11 to 16 ℃, so the climatic environment in Nanshan is suitable for the breeding of Holstein. An- nual average milk yield of each Holstein was up to 6 900 kg, reaching the ad- vanced level of annual average milk yield of each Holstein in China. The milk yield of cows was the highest in June and the lowest in October.

Effect of Palm Oil By-pass Fat on Milk Composition of Early Lactation Holstein Cows Fed Whole Plant Corn Silage during Dry Season

The objective of this study was to investigate the effect of Palm Oil By-pass Fat （POBF） on milk composition of early lactation Holstein during dry season, 24 postpartum Holstein （1 d-14 d） were selected and align to two groups according to CRD experimental design; each group included 12 Holstein cows. The control received by-pass fat 0 g/h.d, the experimental group received by-pass fat 300 g/h.d. The results shown, DMI and yield of milk did not be affected with supplementation of by-pass fat, however, milk protein increased by 6.71%, milk fat increased by 8.16%, lactose increased by 0.22%, SNF increased by 1.98%, TS increased 4.08%; digestibility of diet protein decreased by 6.62%, digestibility of EE decreased by 7.96%, digestibility of NDF and ADL decreased by 1.36%, 8.97% respectively, digestibility of DM and OM decreased by 4.42, 3.07 percentage units; amount of C4-C17 milk fatty acids showed a decreased tendency, that of CIs-C22 showed an increased tendency, the milk CLA increased significantly （P 〈 0.01）. To sum up, supplementation of by-pass fat for early lactation Holstein is an important measure to balance energy and sustain milk yield and quality.

Practical Application of Diets Rich in Ground Linseed to Enhance Omega-3 Milk Production in Holstein Dairy Farms Located in Northeast Iran

In an attempt to enhance organic omega-3 milk production, a practical study was performing in 7 Holstein dairy farms in Northeast Iran. The experiment was conducted at the ＂ShafashirToos industrial dairy farmers production and distribution cooperative＂ located in Northeast Iran, between June 2010 and December 2010. In Golshid-Mashhad Co., cows were fed with no linseed containing diets （NO-Lin）, while in the other farms （Hanaei Co., Ghasemi Co., Taheri Co., Teliseh Co., Arasp Co. and Navingholshid-Khorasan Co.）, cows were fed diets containing 9% ground linseed （Lin）. Cows were used in a randomized complete block experimental design. Diets were provided as TMR. Concentration of fat, protein and lactose in milk was measured. Milk fat extraction and fatty acid separation were determined. There were no differences in the most of the milk fatty acid profiles of cows in farms that received ground linseed but feeding Lin diets compared with NO-Lin, significantly decreased （P 〈 0.05） C8：0-C16：0 concentration and it increased those of C 18：1 n9trans, C 18：1 n9cis, C 18：2 trans and C 18：3 n3. As a result, farms with Lin diets had better milk fatty acid profiles with doubled in a-Linolenic acid concentration and increased in mono and polyunsaturated fatty acids and decrease in medium chain and saturated fatty acids compared with those of the NO-Lin diet. These results clearly demonstrate the possibility for sustainable production of organic omega-3 milk with levels ofC18：3 FA up to 2.4 times higher than typical levels in dairy fat. The manufacture of omega-3 enriched milk and milk products could supply dietary fatty acids at levels that may henefit health, without the need for unrealistic changes to eating habits.

Effect of Pennisetum purpureum Schum cv. Guiminyin on Milk Yield and Quality of Jersey Cattle at Lactation Stage

The study aimed to research the forage value of Pennisetum purpureum Schum cv.Guiminyin in dairy industry and then provide scientific support for feeding jersey cattle with P.purpureum Schum cv.Guiminyin.Totally 20 jersey cattle at lactation stage were selected and divided into two groups randomly,10 cattle each group.The cattle were fed with P.purpureum Schum cv.Guiminyin and P.purpureum cv.Mott×（P.americanum×P.purureum）cv.Guimu No.1,respectively.The results showed that P.purpureum Schum cv.Guiminyin performed well in both nutritional value and palatability,and received remarkable effects on jersey cattle.The milk yield was 5.4%higher than that of before test,and the average daily milk yield was（11.65±0.07）kg/cattle.Compared with control group,milk fat percentage,lactoprotein content and overall milk-solid content were improved somewhat.Feeding jersey cattle with P.purpureum Schum cv.Guiminyin at lactation stage could increase their milk yield and milk quality.

A Study on the Correlation of Milk Yield of Cows with Seismicity and ULF Magnetic Field Variations

A statistical study on the basis of one-year data of 2014 has been performed in order to find whether abnormal animal behavior is related with seismic activity and also whether the ULF (Ultra Low Frequency) electromagnetic radiation might be a possible sensory mechanism of abnormal animal behavior. Abnormal animal behavior has been studied with the use of digitally recorded milk yield of cows at Ibaraki Prefecture Livestock Station, and the ULF magnetic field changes have been studied with the data at a magnetic observatory of Kakioka. As the result of correlation analyses, clear responses are observed for both the milk yield of cows and ULF magnetic field changes (both ULF radiation (ULF emissions from the lithosphere) and ULF depression (as an indicator of lower ionospheric perturbations)) for most powerful and not distant earthquakes (EQs) with magnitude > 6, that is, the milk yield of cows is found to exhibit a conspicuous depletion about 17 - 18 days before an EQ, though the correlation coefficient is not so big. Another important objective in this paper is to identify that ULF radiation is the main agent of abnormal behavior so that we have compared the temporal evolutions of milk yield of cows, ULF radiation and ULF depression for three major EQs. As a result, it is found that ULF radiation happens, at least, during the periods of abnormal depletion of milk yield of cows.

Effect of Zinc Methionine Supplementation on Productive Performance of Lactating Friesian Cows

Twelve lactating Friesian Cows with body weight of 450 to 550 kg and in the second to fifth lactating season were used after 8 weeks of cal- ving in a complete switch-back design. The cows were fed a basal ration of 35% concentrate feed mix-ture with 40% berseem and 25% rice straw （ on a dry matter （DM） basis） without supplementation （ G1 ） or supplemented with 5 and 10 g zinc methionine per head per day （G2 and G3, respectively）. Nutrient digestibility coefficients and nutritive values were significantly increased （P 〈0.05） by zinc methionine supplementation. Cows in G2 had the highest feed intake of total digestible nutrients （TDN） and digestible crude protein （DCP）, followed by Ga and G1, respectively （ P 〈 0.05 ）. The ruminal total volatile fatty acid concentration increased and ammonia nitrogen decreased significantly （ P 〈 0.05 ） by zinc methio-nine supplementation. Cows in G3 showed the highest plasma total protein, albumin, and globulin concen- trations （ P 〈 0.05 ）. Zinc methionine supplementa- tion led to significant decreases （ P 〈 0.05 ） in the activities of aspartate aminotransferase and alanine aminotransferase. A significant increase （ P 〈 0.05 ） was observed in the milk yield for G2 （2.54 kg/d or 18. 1% ） and G3 （ 1.95 kg/d or 14.2% ） compared with the control group. The corresponding increase in 4% fat-corrected milk （FCM） was 2.85 and 2.03 kg/d （21.63% and 15.74% ） for G2 and G3, respectively. Cows in G2 had the highest fat, total protein, and total solids contents, and the yield of all milk constitu- ents and animals in G3 showed the highest lactose, solids-not-fat, and ash contents. Zinc methionine sup- plementation improved feed conversion, reducing the quantities of DM, TDN, and DCP required to pro- duce 1 kg of 4% FCM （P〈0.05）. The average dai- ly feed cost per kilogram of 4% FCM decreased and the average income from milk production increased with zinc methionine supplementation （ P 〈 0.05 ）. Quadratic analysis showed that the optimal level of zinc methionine supplementation is 6 g per head per day in terms of milk yield and net revenue.

Feeding Effect of Triticale Fodder as Replacement of Straw on Production Performance of Dairy Cows

Twenty lactating cows of two to five parity having an average live weight of 290.00 to 330.00 kg and an average milk production of 4.54 kg/head/day to 4.66 kg/head/day were selected from the Central Cattle breeding Station and Dairy Farm. The four dietary treatment were： SlooTo （Straw 100： Triticale 0 as control）; $5oT5o （Straw 50： Triticale 50）; $25T75 （Straw 25： Triticale 75） and SoTloo （Straw 0： Triticale 100）. It was observed that the roughage dry matter intake （DMI） （2.61 ~ 0.07 kg） in percent live weight was significantly （P 〈 0.05） higher in $25T75 and the lowest （1.76 ~ 0.018 kg） in the control group （SlooTo） and the differences were significant among the dietary treatments except $5oT5o and SoTloo. The total DMI was significantly （P 〈 0.05） higher in SoT^oo （13.36 i 0.13 kg） followed by $25T75, $5oT5o and SlooTo, respectively. The digestibility of crude protein （CP） was slightly higher in $25T75 （75.48 ~ 0.96） compared to SoTtoo （75.31 ~ 1.45） and the difference was non-significant （P 〉 0.05）. Milk production was significantly （P 〈 0.05） the highest in $5oT5o and the lowest in SlooTo followed by SoTloo, $25T75, respectively. The percent increased in milk yield was also the highest in $5oT5o （67.68%） and the lowest in SlooTo （28.85%）. The 4% fat corrected milk was also significantly （P 〈 0.05） higher in $5oT5o followed by SoTloo, $25T75 and SlooTo, respectively. Therefore, it can be concluded that triticale and straw at a ratio of 50：50 may be fed for better production performance of dairy cows.

Genomic patterns of homozygosity and inbreeding depression in MurcianoGranadina goats

Background:Inbreeding depression can adversely affect traits related to fitness,reproduction and productive performance.Although current research suggests that inbreeding levels are generally low in most goat breeds,the impact of inbreeding depression on phenotypes of economic interest has only been investigated in a few studies based on genealogical data.Results:We genotyped 1040 goats with the Goat SNP50 BeadChip.This information was used to estimate different molecular inbreeding coefficients and characterise runs of homozygosity and homozygosity patterns.We detected38 genomic regions with increased homozygosity as well as 8 ROH hotspots mapping to chromosomes 1,2,4,6,14,16 and 17.Eight hundred seventeen goats with available records for dairy traits were analysed to evaluate the potential consequences of inbreeding depression on milk phenotypes.Four regions on chromosomes 8 and 25were significantly associated with inbreeding depression for the natural logarithm of the somatic cell count.Notably,these regions contain several genes related with immunity,such as SYK,IL27,CCL19 and CCL21.Moreover,one region on chromosome 2 was significantly associated with inbreeding depression for milk yield.Conclusions:Although genomic inbreeding levels are low in Murciano-Granadina goats,significant evidence of inbreeding depression for the logarithm of the somatic cell count,a phenotype closely associated with udder health and milk yield,have been detected in this population.Minimising inbreeding would be expected to augment economic gain by increasing milk yield and reducing the incidence of mastitis,which is one of the main causes of dairy goat culling.

Impact of Quebracho Tannins Supplementation on Productive and Reproductive Efficiency of Dairy Cows

This study was conducted to investigate effects of supplementing two doses of quebracho tannins (QT;100 or 200 g/cow/d;QT100 or QT200) pre and post parturition to thirty Holstein dairy cows on Dry Matter Intake (DMI), milk yield and composition, blood metabolites and reproductive performance for 12 weeks. There were no significant changes in DMI due to QT at transition period of dairy cows. QT supplementation at either level decreased (P 0.05) the total number of ovarian follicles, number of large follicles, diameter of largest follicle, number of small follicles, number and diameter of corpus luteum, and progesterone concentration. The inclusion of QT increased days open and number of services per conception, which consequently decreased conception rate, compared to the control cows. QT100 decreased (P

A case study investigating the efects of emergency vaccination with Brucella abortus A19 vaccine on a dairy farm undergoing an abortion outbreak in China

Brucellosis is an important zoonosis that results in substantial economic losses to the livestock industry through abortions and reduced milk yield.This study investigated an abortion outbreak in a dairy herd and then explored the efects of emergency vaccination with Brucella abortus A19 vaccine on the incidence of abortion and milk yield.A full dose of vaccine(6×10^(10)—12×10^(10)colony forming units,CFU)was administered subcutaneously to calves and non-pregnant heifers,and a reduced dose(6×10^(8)—12×10^(8)CFU)to adult cows and pregnant replacement heifers.Rose Bengal Test was used to screen Brucella infection status and then positive samples were tested with a C-ELISA.Animals that tested positive for both tests were considered positive to Brucella spp.The animal-level seroprevalence of brucellosis was 23.1%(95%CI:17.0,30.2),and the attributable fraction of abortions in seropositive animals was 89.1%(95%CI:64.3,96.7).The odds of seropositivity were signifcantly higher in cows that aborted compared to cows that calved normally(OR=21.4,95%CI:4.4,168.4).Cows in sheds A2 and C1 were 10.2(95%CI:1.4,128.0)and 17.0(95%CI:2.8,190.3)times more likely to be seropositive than cows in shed B1.Antibodies were not detectable in most heifers 12 months post-vaccination.The efectiveness of the vaccine in preventing abortions was estimated to be 56.8%(95%CI:15.8,77.8)for the entire herd,but increased to 86.7%(95%CI:4.4,98.1)when only primiparous heifers were considered.Furthermore,a signifcant increase in the average herd 305-day milk yield one-year after vaccination was also observed relative to that in the previous three years.It is concluded that emergency vaccination of a dairy herd undergoing an abortion outbreak with the A19 vaccine efectively reduced the incidence of abortion and indirectly increased milk yield one-year after vaccination.

Study on Feeding Effect of Different Levels of Protein and Energy on Production Performance of Pregnant Mother and Neo-Natal Calves

The present study was undertaken to assess feeding effect on productive and reproductive performances of pre-natal and post-natal Red Chittagong Cattle （RCC） cows under on-station condition. A total of 16 pregnant RCC cows having pregnancy 6-7 months and between 1-3 parities was selected for the study and was allocated randomly into four dietary treatment groups. There are four type diets, i.e., To （standard diet according to National Research Council （NRC）, 1995）, T1 （5% below standard diet）, T2 （5% above standard diet）, T3 （10% above standard diet） and a control treatment T4 （maintained as farm practice）. The energy and protein requirements of experimental cows were determined as per standard developed by NRC. The results revealed that crude protein （CP） and metabolizable energy （ME, MJ/day） requirements among cows of different dietary groups were not significantly different, although CP requirements between T1 and T3 differed significantly. Total dry mater （DM） and ME intake differed significantly （P 〈 0.001） among cows of different dietary groups, but DM intake was significantly lower for cows in farm practice group Z4 compared to the cows of other dietary groups. The total CP intake had no significant variation （P 〉 0.05） among cows of all dietary groups, but CP intake from roughage varied significantly （P 〈 0.001）. Final live weight and total live weight gain had no significant variation for cows of all groups, but there were significant （P 〈 0.05） variation for daily weight gain. Daily weight gain of cows for first four dietary groups were significantly （P 〈 0.05） higher than cows of farm practice groups T4. Weight of calf from birth to 90 days and daily weight gain calves under different dietary groups showed that there were no significant （P 〉 0.05） variation of calf birth weights for all dietary groups, although lower birth weight was found in farm practice groups T4. Gestation length and postpartum heat period of cows of different dietary treatment groups revealed that there was no significant （P 〉 0.05） variation for those traits among cows of different dietary treatment groups, although there seems to be shorter postpartum heat for cows in dietary group T2 and longer period in farm practice group T4. Total and daily milk yield up to 30 days and 90 days of cows had no significant （P 〉 0.05） effect for different dietary treatment groups, although there seems to be slightly better milk production performance for dietary T2 and To, respectively for 30 days and 90 days total and daily milk yield. There were no significant （P 〉 0.05） changes of total and daily weight gain of cows for all dietary groups, however cows of standard dietary group To performed slightly better than those of cows of other dietary groups. Milk composition of cows of different dietary treatment groups showed that there was no significant （P 〉 0.05） variation on milk composition for cows of different dietary groups. Post-natal body condition score （BCS） for the 1st, 3rd and 4th months differed significantly （P 〈 0.05） among different dietary groups, while not found significant difference on the 2nd month. Therefore, it may be concluded that pre-natal feeding has significant effect on body weight gain, birth weight of calves and milk production of dairy cows. Hence, it is suggested that better nutrition may be provided during pre-natal period to harvest good quality of calves and higher milk yield from post-natal period.