Lactation Season Research Articles

PREVALENCE OF BUFFALO MASTITIS IN Mastitis in Buffalo in DAKAHLIA Dakahyllia GOVERNORATEs

This study surveyed the mastitis prevalence and risk factors in buffalo’s population in Dakahlia Governorate. A total of 471 Water buffaloes (Bubalus bubalis) brought to the Veterinary Teaching Hospital, Mansoura, Dakahlia Governorates from 2009 to 2012 were analyzed to determine, the seasonal occurrence of mastitis, prevalence in relation to the lactation stage. Isolation and identification of causative agent using PCR and other serological technique were applied. The prevalence of buffalo's mastitis was 19.9% and 5.9% for clinical and subclinical mastitis respectively. A high incidence of clinical mastitis (51.6%) was observed in animal during their early lactation stage, while high incidences of subclinical mastitis recorded (12.9%) in late lactation stage. And the most isolated microorganism is E-coli spp. The Statistical analysis of our results revealed that a significant variance between the occurrence of mastitis and lactation season, P< 0.001.

Seasonal fluctuations in the steady-state mRNA levels of suppressor of cytokine signaling-3 (SOCS-3) in the mammary gland of lactating and non-lactating ewes

Prolactin (PRL) is a hormone that plays a crucial role during pregnancy and lactation. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, which is an important pathway in signal transduction from PRL to target cells, can be modulated by various factors, including suppressor of cytokine signaling-3 (SOCS-3). PRL may increase and decrease SOCS-3 expression, and its actions are mostly dependent on additional factors such as the photoperiod. There is also evidence for a relationship between suckling and SOCS-3 expression in the mammary gland. The aim of this study was to examine the influence of seasonality and physiological status on SOCS-3 expression levels in ovine mammary glands. Mammary gland fragments were obtained from 18 Polish Longwool ewes, and the fine-needle aspiration biopsy technique was used on 4 groups of animals under specific physiological and photoperiodic conditions: non-lactating ewes during long days (LD; n=6), ewes on day 30 (n=6) or day 56 of lactation (n=6) and non-lactating ewes during short days (SD; n=6). SOCS-3 mRNA levels were measured by real-time PCR. The results of this study confirmed that SOCS-3 mRNA expression in sheep is dependent on the season and stage of lactation. The highest expression of the examined factors was noted in the mammary glands of non-lactating sheep during SD, and the lowest levels were observed in ewes on day 30 of lactation. The transcript levels observed in the tissues collected from non-lactating sheep during SD and LD were higher (74% and 41%, respectively) compared with the expression observed on day 30 of lactation. On day 56 of lactation, the SOCS-3 mRNA level was similar to that observed in the udders of non-lactating sheep during LD. These results indicate that SOCS-3 could play an integrating role between hormones and other factors that are involved in the physiological functions of the mammary gland.

Vitamin B12 in meat and dairy products.

Vitamin B12 is synthesized exclusively by microorganisms; therefore, humans must absorb it from food. Excellent sources of B12 are foods of ruminant origin, so dairy and meat products play an important role in efforts to meet the official daily B12 intake recommendation of 3.0 μg. Concentrations of the vitamin vary within foods of ruminant origin, with the highest concentrations found in offal such as liver and kidney. In comparison, dairy products have much lower quantities of the vitamin. In bovine milk, the B12 concentration is stable with regard to breed, feed, season, and stage of lactation, but in ruminant meat, the amount of B12 can vary based on the feeding and husbandry of the animal as well as the cut of meat chosen and its preparation. Processing of ruminant food, including thermal treatment, usually diminishes the vitamin B12 concentration. This review summarizes the vitamin B12 content of foods and discusses the impact of food processing on vitamin content. The contribution of ruminant food sources to B12 intake is specifically evaluated, with its bioavailability taken into account.

Techno-Economics Assessment of Genetic Improvement via Artificial Insemination in Dairy Cattle in Dakahlia Governorate

In Egypt, the importance of increasing the domestic production of milk via genetic improvement stems from the lack of horizontal expansion in cattle population due to the limited feeds production because of water and agricultural land resources constraints. Dakahlia is the second highest governorate for rates of cattle milk productivity, estimated by 1.1, 2.8 and 5 t head–1 for Baladi, hybrid and foreign breed respectively in the average overall the period (2010-2014). Therefore, this research aims to study the merits and the feasibility of genetic Improvement via the Artificial Insemination (AI) in dairy cattle in Dakahlia governorate to extend the successful applying of genetic improvement program in this governorate and the other governorates; as a stress on the importance of increasing the domestic production and the income of dairy milk in Egypt through investments in AI. A statistical analysis and mathematical economic model were designed and implemented by using Excel and SPSS programs software to study some factors affecting milk production of dairy cattle herds; then, estimates the Extra Internal Rate of Return (EIRR) as a criterion of the feasible economic along the full productive life of the daughter of the cow served by AI of the concerned sire’s semen. The data of the cow milk productive and reproductive performance traits were collected from the questionnaire has designed and implemented through a stratified random sample survey of the commercial farms are specialized in the investment of hybrid dairy cattle in Dakahlia governorate in the year 2014. The results showed the effects of every order of the season of calving, the lactation season in the year and the age at the first calving are statistically significant at the confidence level less than 0.10. As, the economic criterions indicate the most probable Extra Internal Rate of Return (EIRR) is around 26, 31 and 33% for small, medium and large farm scale, respectively. The highest negative effect on EIRR for the three farm scales is the increase of feeding costs (It drops by about 7, 7 and 6%), followed by the negative effect of the increase of number of services for conception (EIRR decreases by around 6, 6 and 5%). Lastly, the negative effect of the decrease of dairy cow milk price (EIRR diminishes by about 4, 3 and 3%). Generally, the genetic improvement investment via AI in dairy cattle in Dakahlia governorate is high feasible.

THE INFLUENCE OF LACTATION NUMBER AND SEASON ON YIELD, CHEMICAL AND MICROBIOLOGICAL STATUS OF SHEEP MILK

In the investigation utilized 800 head of Pirot improved sheep during two lactation numbers (I and II) and two lactation seasons: I – winter, and II – summer. Investigated the influence of some factors on milk yield, fat content, protein content, pH value, SCC (somatic cell count) and CFU (total number of microorganismis). Control of milk yield was carried out by the AC method (ICAR, 2005). It was ascertained a significant impact (P 0.05). Total number of microorganisms (CFU) also did not depend on the number of lactation (P > 0.05). Sheep in the second season had a higher milk yield for 6.75 kg (P < 0.05) and higher total number of microorganisms (P < 0.01). Somatic cells in milk was also higher during the season II (P < 0.01).

Production of enterotoxins of Staphylococcus spp. isolated from samples of sheep milk

In our study was followed occurrence of mastitis in herd of 430 sheep of breed zoslachtena valaska with hand milking technology examined two times during one lactation season. Individual examination consisted from clinical examination of udder and microbiological examination of milk samples. By PCR was determined presence of genes coding production of enterotoxins, and by ELISA methods production individual types of enterotoxins. From individual forms of mastitis were frequently detected subacute (6.7%), subclinical (5.7%) and acute (2.9%). The coagulase-negative staphylococci (CNS) were identified in 102 (65.4%) from all 156 positive isolates. The CNS and S. aureus caused subacute (5.1%), subclinical (3.9%) and acute (2.4%) forms of mastitis. The most frequently isolated were S. epidermidis, followed by S. chromogenes and S. xylosus from ewes with subacute and subclinical mastitis. From acute and chronical forms of mastitis were predominantly isolated S. aureus, S. uberis and S. epidermidis. The production of staphylococcal enterotoxins (SE) - SEA, SEB, SEC, SED and the presence of genes sec (3), sea (2), seb (2) and sed (2) were determined in S. aureus, S. epidermidis, S. schleiferi and S. chromogenes, respectively. The results suggested on the high occurrence (12.4%) of subacute and subclinical forms. Confirmed production of enterotoxins and presence of genes coding their production present a risk for human health and decreased a quality of milk and products from sheep´s milk.

Reproductive effects on fecal nitrogen as an index of diet quality: an experimental assessment

Concentration of fecal nitrogen has been used widely as an indicator of dietary quality for free-ranging ruminants. Differences in digestive function between species of dimorphic ungulates render interspecific comparisons of fecal nitrogen unreliable; however, whether intraspecific sexual differences in digestive function also bias this nutritional index is unknown. Our objective was to compare sex-specific variation in concentration of fecal nitrogen using male, nonlactating female, and lactating female white-tailed deer (Odocoileus virginianus) on high- and low-quality diets. During weekly trials over spring and summer (2008–2009), we monitored intake rates, collected feces twice daily, and used micro-Kjeldahl procedures to determine percent fecal nitrogen. We also determined nitrogen content of feces following a neutral detergent fiber (NDF) rinse during pre-, peak, and postlactation. Fecal nitrogen reflected general differences in dietary quality between diets; however, fecal nitrogen of lactating females in both dietary groups was lower than for males or nonlactating females throughout lactation. Nitrogen concentration following an NDF rinse also was lower for lactating females during peak lactation. We hypothesize that the remodeling of the digestive tract and increased rumination by lactating females may enhance their ability to extract nitrogen from their forage. These adjustments may expand the foraging options of lactating females by increasing their ability to process low-quality foods, but also affects the interpretation of fecal nitrogen during the season of lactation.

SELCTION INDEX FOR SOME BODY MESUREMENTS TOWARDS IMPROVING MILK PRODUCTION IN DHOFARI GOAT

ABSTRACTThe present study investigate the possibilities of improving milk production in Dhofari goat raisedat Salalah of Sultanate of Oman through selection index containing body weight and dimensions atbirth. Records of 190 Dhofari does, daughters of 35 sires were available for this study. During twosuccessive years, data were collected on the same animal at birth (birth weight, BW; body length, BL;body height at withers, BH; heart girth, HG and rear girth, RG) and after the first lactation season(total milk yield, TMY). The present study estimated genetic and phenotypic parameters for thestudied traits and constructed 19 selection indices to predict TMY in Dhofari goat.The present study estimated averages of BW, BL, BH, HG, RG and TMY as 2.9 kg, 31.4 cm, 34.7cm, 33.6 cm, 37.0 cm and 50.0 kg, respectively. Among body dimensions, HG and RG were morevariable than BL and BH. Heritability estimates for all studied traits were little and ranged from 0.002to 0.1. The correlation coefficients among all studied traits were genetically high and phenotypicallylow. Genetic correlations between TMY and all live body measurements were close to one and muchhigher than the corresponding phenotypic ones. Genetically and phenotypically, TMY had positivecorrelations with BW, BL and BH and negative ones with HG and RG. The maximum accuracy of thefull index was 0.45. The greatest improvement in TMY was +0.25 kg. Selection on all indices reducedHG and RG. Selection on I13 while reducing HG (-0.31 cm) and RG (-0.42 cm), it increases the size ofanimal probably through BL (+0.11cm) and BH (+0.18 cm). The present study concluded that thesimplified selection index (I13) utilizing individual kid performance (HG and RG at birth) is the mostefficient (rTI =0.38), attain adequate improvement in TMY (+0.21 kg), less expensive and being about13% more efficient in the improvement than direct selection for milk yield alone compared with theother studied indices. Thus, I13 can be used as a selection criterion for the simultaneous improvementof milk and meat production in Dhofari goat.

EFFECT OF PUERPERAL METRITIS ON HOLSTEIN COWS PRODUCTIVE, REPRODUCTIVE VARIABLES AND CULLING RATES

The objective of the study was to determine the eff ect of puerperal metritis prevalence in high yieldi ng Holstein cows on productive (305 days, actual milk yields), reproductive (days to first estrus, days o pen and services per conception) variables and culling rate s. Throughout the study, 2885 dairy records were collected from high yielding private Holstein dairy farm (average milk yield was up to 9000 kg) for 3 successive lactation seasons. Dairy cows were class ified according to their uterine affection into two groups, healthy and those with puerperal metritis. Dairy cows which affected with puerperal metritis w ere diagnosed during the first 3 weeks of lactation. Me tritic cows were diagnosed and treated at the discr etion of the herd veterinarian. Affected dairy cows were grouped into four groups according to time of the puerperal metritis attack during the first 21 Days In Milk (DIM) as ( 15 DIM, respectively). Moreover, the dairy females were gro uped into 3 groups according to frequency of puerpe ral metritis of once, twice and triple, respectively. D airy cows were also grouped according to their calv ing season (winter, spring, summer and fall calving sea sons). Productive, reproductive variables and culli ng due to puerperal metritis were detected from the on-far m record system (DairyComp305). Results of this study revealed that, puerperal metritis had bad effects o n high yielding cows productive and reproductive variables, that decreased the 305 milk yield, incre ased days to first estrus, days open and number of services per conception. Moreover, the occurrence of puerper al metritis increased during the warm months of spr ing and summer seasons. Also, the occurrence of such di sease was increased during the first 10 days of postpartum as (89.98%) of the affected cases occurr ed within this period. Care must be directed to dai ry cows which had a history of puerperal metritis as t hese cases had a greater tendency for recurrence. A lso, the re- attacked cows with puerperal metritis had a great chance to be culled from the dairy herds, as they reached to (53.33% and 100%) for the second and third attack, respectively.

Prevalence of Staphylococcus aureus subclinical mastitis in dairy buffaloes farms at different lactation seasons at Assiut Governorate, Egypt

Two hundred and thirty nine buffaloes of different lactation seasons from two milk-producing farms at Assiut Governorate, Upper Egypt, were monthly tested by California mastitis test during one lactation season for the presence of subclinical mastitis. The prevalence of subclinical mastitis ranged from 11.11 % to 37.21 % based on the number of lactation seasons. The linear relationship between number of lactations and prevalence of subclinical mastitis was studied and revealed that there is strong negative correlation (P < 0.01, r = -0.91). The prevalence of subclinical mastitis of the investigated farms was dramatically increased (P < 0.05) during the first three lactation seasons and thereafter was gradually decreased by increasing the number of lactations (P < 0.01). Milk samples of the subclinical mastitis buffaloes examined bacteriologically, 77.27% of them were culturally positive, and the remainders were negative. Staphylococcus aureus was the predominant mastitis pathogens followed by Streptococcus agalactiae and Escherichia coli. The culturally negative samples examined by PCR technique using species-specific primer, which indicated that 80% of them were positive to Staphylococcus aureus referring to the false positive results on the conventional culturing procedures with that microorganism. This may act as a deceptive result in case of control measures of mastitis associated with Staphylococcus aureus on farms, and one-time culturing procedures appears to be insufficient for decision. However, PCR as a rapid diagnostic tool for direct detection of Staphylococcus aureus in milk is still precious in comparison with conventional culturing procedures.

Cross validation of cut-off limit estimations for milk indicators of subclinical ketosis

Real time analyses of main milk components are attended in milking parlours today. Breeders can know milk composition regularly. Energy (ketosis) milk quotients such as fat/crude protein (F/CP) and fat/lactose (F/L) could be essential for ketosis prevention and losses which can be linked with it. Aim was to do a reciprocal validation of reliability of milk indicators for subclinical ketosis (SK) identification. There were: dairy cows on 1st and other lactations free of clinical and superior subclinical mastitis; 3 herds of Czech Fleckvieh (CF) breed, 3 herds of Holstein (H) breed and 1 herd with CF and H; 329 individual milk samples from summer and winter season and 1st third of lactation. Average milk yield varied from 5,500 to 10,000 kg per lactation. Thresholds of F/CP and F/L were estimated (P &lt; 0.05) according to SK milk acetone cut–off limit (≥10 mg.l−1). These were: for first lactation 1.27 (CF) and 1.32 (H), for other lactations 1.52 (CF) and 1.42 (H) in F/CP; for first lactation 0.84 (CF) and 0.84 (H), for other lactations 0.87 (CF) and 0.85 (H) in F/L. They were used for cross validation (P &lt; 0.001) in the same order: 1.251, 1.31, 1.31 and 1.383 in F/CP; 0.831, 0.821, 0.989 and 0.852 in F/L. Validated cut–off limits are quite similar to their original values. It confirmes good reliability of original limits. The validated cut–off limits of milk indicators (F/CP and F/L) for SK in early lactation can be used at technological innovation in animal husbandry. Use of both quotients could improve the regular investigation of SK in practice.

Effect Of Drying- Off Period And Teat Dipping On Productivity Of Dairy Cows

This study was conducted to investigate effect of period of drying off and teat dipping on dairy cow production. This study was carried out at Sami Asaad Dairy Farm at Abo-Hamad city in SharkiaProvince in the period from first of December, 2010 till end of November, 2011. The data were obtained from farm book record and were collected from one hundred dairy cows (Holstein Friesian) to assess the effect of length of dry off period, age and lactation season on dairy cow production. The obtained results showed that the cows with a dry period of 45, 46 and 59 days, had the highest milk yield at 305-day. So, increasing the dry period lead to an increase in milk yield of subsequent lactation. Furthermore, the total milk production was increased gradually from 3 to 7 years, after that it decreased. Also to evaluate the effect of teat dipping on dairy cow’s milk production in the period from first of July till end of September, 2011; the data obtained from sixteen dairy cows (Holstein Frisian), divided into 2 groups, group A (n= 8) wherethe udder washed, dried with a clean toilet tissues and the teats dipped in 70% ethyl alcohol solution, while group B (n=8) without teat dipping. The results revealed that the teat dipping after milking decrease the incidence of mastitis and increase milk yield. In conclusion, length of dry off period, age, lactation season and teat dipping have significantly effect on milk yield in dairy cows.

Associations of acetyl-coenzyme A carboxylase α, stearoyl-coenzyme A desaturase, and lipoprotein lipase genes with dairy traits in Alpine goats

Milk yield and composition are of great economic importance for the dairy goat industry. The identification of genes associated with phenotypic differences for these traits could allow for the implementation of gene-assisted selection programs in goats. Associations between polymorphisms at 3 candidate genes and milk production traits in Alpine goats farmed in Italy were investigated in the present research. Considered genes were acetyl-coenzyme A carboxylase α (ACACA), the major regulatory enzyme of fatty acid biosynthesis; stearoyl-coenzyme A desaturase (SCD), involved in the biosynthesis of monounsaturated fatty acids in the mammary gland; and lipoprotein lipase (LPL), which plays a central role in plasma triglyceride metabolism. An approach somewhat similar to the granddaughter design for detecting quantitative trait loci in dairy cattle was followed. Effects of genotypes of a sample of 59 Alpine bucks on phenotypes of their 946 daughters raised in 75 flocks were investigated. Data comprised 13,331 daily records for milk yields (L/d), fat and protein yields (kg/d), and fat and protein contents (%) of 2,200 lactations. Population genetics parameters were calculated and associations between milk production traits and 10 single nucleotide polymorphisms (SNP) at the 3 genes were tested. Two markers at the ACACA, 1 for the SCD and 1 at the LPL locus, deviated significantly from the Hardy-Weinberg equilibrium, with an observed heterozygosity lower than expected. Flock, age of the goat, kidding season, and stage of lactation affected all traits considered, except fat percentage. Three SNP were found to be significantly associated with milk production traits. The SNP located on the ACACA gene showed an effect on milk yield, with daughters of TT bucks having an average test-day milk yield of about 0.3 to 0.25 L/d lower than the other 2 genotypes. The marker on the LPL locus was highly associated with milk yield, with the largest values for CC daughters (about 0.50L more than GG). The TGT deletion located on the untranslated region of the SCD gene showed significant effects on average milk and protein yields. The homozygote-deleted genotype had values about 0.5 L/d and 16 g/d lower for milk and protein daily yield, respectively, compared with the TGT/TGT genotype. Differences between genotypes were quite constant across most of the lactation. Associations found in the present study, which should be tested in a larger sample, especially for those markers that show rare genotypes, may offer useful indications for the genetic improvement of dairy traits in goats.

Ocorrência da mastite clínica e fatores ambientais que favorecem sua incidência

O objetivo deste estudo foi verificar as frequências de mastite clínica (MC) em vacas Holandesas de alta produção de leite, bem como os fatores ambientais que influenciam sua incidência. A média da produção de leite aos 305 dias de acordo com a classe de mastite foi estimada pelo método de quadrados mínimos. As frequências de MC foram analisadas de acordo com as ordens do parto (1 a 6), ano do parto, estação do ano, fase da lactação, e quarto infectado (anterior direito, anterior esquerdo, posterior direito, posterior esquerdo). A frequência da MC por ordem de parto variou de 11,39% no primeiro parto a 21,18% no terceiro parto. 58,56 % dos casos de mastite ocorreram no período das águas e 41,44% no período da seca. O terço final da lactação foi o período com maior ocorrência de casos de MC (45,33%). Os quartos posteriores apresentaram maior frequência de MC (54,25%). Os animais com maiores níveis de produção de leite aos 305 dias (9.466,42 Kg) foram os que apresentaram maior incidência de mastite clínica. Deve-se encontrar um ponto de equilíbrio entre a produção de leite e a mastite a fim de aumentar a rentabilidade da produção. O estudo dos períodos de maior frequência de ocorrência de mastite clínica é fundamental para a pecuária leiteira, para o direcionamento de um programa de controle dessa doença.

Preliminary results of bivariate analysis in joint Slovenian and Croatian evaluation for milk traits in Holstein breed

The objective of this study was to estimate genetic parameters for milk traits (daily milk, fat, and protein yield) for a joint genetic evaluation in Holstein breed in Croatia and Slovenia and to compare results from the joint and national evaluation systems. Test-day records from Croatian (CRO) and Slovenian (SVN) routine genetic evaluation in May 2012 were used. A joint data set included 1,840,816 CRO and 2,680,001 SVN test-day records of 111,218 CRO and 127,774 SVN cows. The total number of animals included in the joint pedigree was 382,991. Genetic parameters for milk traits were estimated using bivariate model. SVN data were evaluated with a model which included fixed effects of calving season and stage of lactation fitted by the Ali-Schaeffer’s lactation curve nested within parity. Random part of the model consisted of a common herd environment, direct additive genetic, and permanent environment effect within lactation. In addition to these, fixed class effect of region and covariate age at the first calving were included in the model for CRO data. In the random part, the contemporary group was defined as an interaction between the herd and year of testing for CRO data and as herd effect in SVN data. The estimated heritabilities of daily milk, fat, and protein yield were 0.19, 0.15, and 0.17 for CRO and 0.23, 0.19, and 0.21 for SVN data. Genetic correlation between countries was medium to high (0.78, 0.64, and 0.63) indicating some differences between countries. Correlations between inferred breeding values from the joint and national evaluations were high (0.997 for CRO and 0.999 for SVN evaluation). On SVN scale, genetic trend obtained from the joint evaluation was higher compared to the national evaluation. On CRO scale, the national genetic trend for daily protein yield was similar to the trend from joint model.

Genetic and Non Genetic Sources of Variation for Linear Body Conformation Traits in Bunaji and Friesian X Bunaji cows

The effects of Age of dam at calving, Sex of calf, Breed, Sire, month of calving and season of lactation on linear body conformation traits was investigated in the dairy herd of the National Animal Production Research Institute, Shika Zaria, Nigeria. Seven linear body conformation traits of 25 Bunaji and 25 crossbred (Friesian x Bunaji) cows were measured. The measurements were taken monthly by 3 evaluators for the complete lactation length of the cows, this resulted in 1275 cumulative records, (with 750 records from Friesian x Bunaji and 525 records from Bunaji). The 7 body conformation traits (stature, chest width, wither height, heart girth, body length, body depth and rump width) were measured in centimeter using flexible tape. The results showed that all the genetic and non genetic factors considered had significant effect (P 0.05) variation amongst the evaluators in their measurements, except RW. The body size characteristics increased with age. The male bearing cows were relatively broader (CW, HG) and longer (BL) than the female bearing cows, though there was no significant difference (P>0.05) in their statures (ST) and the body depth (BD). The crossbred cows were taller (ST, HW) longer (BL), broader (CW, HG), but less deep (BD) than the pure Bunaji. The animals of season 1 were taller (ST, WH), deeper (BD) and longer (BL) than the others. However, animals of season 2 and 3 had similar body sizes (ST, CW, BD, WH, HG, BL and RW). It is therefore suggested that in selecting for body conformation these genetic and non genetic factors should be taken into consideration. Key words: Friesian x Bunaji, linear body conformation, evaluators, breed, sire

Milk production performance of a flock of Sudan Nilotic does fed pelleted molasses- and mash sorghum-based diets

The main objectives of the study are to evaluate the milk production potentials of a flock of Sudan Nilotic goats and the efficiency of the formulated complete pelleted molasses-based diet (PMD) and mash sorghum-based diet (MSD) for milk yield. The experiment commenced by 27 Nilotic does in their first season of lactation. The experimental animals were divided according to live weight into 12 subgroups (2–3 does each) of which six subgroups were allotted randomly to each diet treatment, housed and fed in separate pens. Fourteen heads were fed on MSD whereas the remaining 13 does were offered PMD. The experiment continued to the end of lactation and the data were subjected to analysis of covariance (number of days before delivery was taken as a covariate). Regression of weekly milk yield on week of lactation was calculated according to the formula (yn=anbexp−cn) to estimate lactation curve components. The overall kidding weight, end of lactation weight, total milk yield, lactation period, and milk yield persistency were 19.5±4.49kg, 21.1±3.52kg, 60.8±45.18kg, 143.1±39.68 days and 58.0±19.34%, respectively. No significant differences (P>0.05) were observed between the two diet groups in most of the examined parameters except daily live weight gain and crude protein intake where PMD group excelled (P<0.05) the MSD group. All experimental does started milk yield at 3.4±1.85kg/week and continued increasing milk yield at a rate of 0.4±0.26kg/week to reach a peak of 4.9±2.69kg/week after 5.2±2.5 weeks and persisted at this peak for 3.5±0.79 weeks before starting gradual decline at a rate of 0.1±0.06kg/week to the end of lactation. It has been concluded that Nilotic does have poor feed utilization efficiency for milk production and poor sustainability of milk yield during lactation. The results also confirmed that the pelleted molasses diet is a good substitute for the sorghum mash diet for lactating does releasing more cereal grains for human consumption.

Response of common seals (Phoca vitulina) to human disturbances in the Dollard estuary of the Wadden Sea

The Dollard area is a core breeding area of common seals, Phoca vitulina, in the Dutch Wadden Sea. Seals mainly use this area in the birth season, and it is at this time that mother and pup pairs are prone to disturbance. Seals in the Dollard lie on sandbanks close to the dyke area which exposes them to various human activities on land and in the coastal waters.The colony of common seals on the sandbanks of the Dollard has increased from 77 individuals in 1993 to 332 in 2010. Observations were made during the pupping and lactation seasons in 2007, 2008, 2009 and 2010. In total, 692h of observations were made over the last 4 years, and a total of 1329 potential disturbances were recorded. Human activities were more frequent on land than on water or in the air. In total, most disturbances were also recorded as arising from land. Actual disturbances of seals were recorded 344 times; seals were alerted 249 times and seals escaped into the water 95 times. An escape response was observed for 81 of the 1037 (7.8%) recorded land activities, 6 of the 92 (6.5%) recorded water activities, and 8 of the 200 (4%) air activities. These percentages of escape responses did not differ significantly between the land, water and air activities.The construction of a culvert in the dyke in 2001, and the building up of sand ridges along the water flow towards the culvert, provided the seals with an extra place to haul out. Land activities only affected seals resting on these sand ridges which are at a distance of 50–200m of the dyke. Boats have the potential to disturb seals on all sandbanks of the study area. They affected the highest number of seals per disturbance, with up to 117 animals fleeing into the water. Flying at lower altitudes appeared to cause more disturbances of seals. Therefore, the effect of flying at low altitudes (150–300m) warrants further investigation.Disturbances which lead to fleeing into the water create the potential risk of separating pups from their mothers. This may contribute to the high incidence of orphaned pups found in the Dollard region. Yearly numbers fluctuated between 13 and 24 orphans representing a substantial proportion of the seals born in this area (with highest pup counts of ca. 100). In addition to separation, disturbances may also impact the condition of pups if they occur repeatedly during suckling.The results of this study demonstrate that disturbance is caused by various human activities to a colony of seals using sandbanks close to the mainland. As these disturbances pose a risk that pups become orphaned or are impacted in terms of their body condition, efforts should be made to minimise the effects of human presence.

Transfer of PBDEs and chlorinated POPs from mother to pup during lactation in harp seals Phoca groenlandica

Seven mother–pup pairs of harp seal (Phoca groenlandica) were sampled during the lactation season near Magdalen Islands, QC, Canada. The blubber and serum of pups and mothers as well as the milk of mothers were analyzed for polybrominated diphenyl ethers and several chlorinated persistent organic pollutants (POPs) to evaluate their transfer prior to weaning. Principal component analysis demonstrated significant variations in contaminant distribution patterns between seal tissues of mothers and pups. The selectivity in the transfer of POPs between mothers and pups appeared mainly driven by their log Kow (octanol/water partition coefficient). The most selective transfer step for the POPs examined occurred between the blubber and the serum of the mother. A novel approach to examine temporal changes of POP concentrations in tissues of seals which take into account the contamination of mothers was developed. A general decrease of POP concentrations in pup tissues throughout lactation may suggest a growth dilution. A concomitant rise of POP concentrations was observed in maternal blubber and serum and in milk as lactation progresses. The intensive offloading of contaminants via lactation constitutes a major but selective excretory route for reproductive female seals and also a significant route of exposure for suckling pup seals.

Some factors affecting dairy she-camel performance

In order to determine the effect of some factors, as different levels of energy and protein, interval, lactation stage, and lactation rank on she-camel performance after weaning of camel-calves, 20 lactating shecamels were divided into four groups, 5 animals each, according to age and weight at last parturition. Groups had randomly allocated to one of four treatments diets. Group A received diet with 13% Crude Protein (CP) and 2.4 MCal Metabolisable Energy (ME). Group B received diet with 13% CP and 3.0 MCal ME. Group C and D received diet with 15% CP and 2.4, 3.0 MCal ME respectively. Diets contain 35/65 (roughage/concentrate, respectively). After 14 days of adaptation period, individual feed offered and orts had been recorded, daily and continued up to entire experimental period of 10 months. Milk yield was recorded two time from three consecutive days. The results show that diet (B) gave higher milk yield (MY), Fat Corrected Milk (FCM), Energy Corrected Milk (ECM) and Feed Conversion Ratio (FCR) 8.32, 11.77, 7.47, and 1.38 respectively. Diet (A) has higher fat % content when comparing with the other diets. Treatment did not affect milk composition except on fat and ash percentage. Milk secretion rate for 10 hours interval evening milking was higher comparing with 14 hours interval morning milking 397, 353 g/h respectively. Maximum MY, FCM and ECM were at mid lactation. In late lactation MY, FCM, ECM decreased. Higher milk productivity was at 3rd and 6th season of lactation. (Resume d'auteur)