Milk Production Characteristics Research Articles

DRY BREWER GRAINS AS REPLACEMENT FOR ALFALFA IN DIETS FOR LACTATING EWES

The settlement of small and medium breweries in cities leads to the production of nutrient-rich organic residues, the quick decomposition of which causes unpleasant odours and attracts large amounts of flies. Under the hypothesis that replacing alfalfa (lucerne) with dry brewer grains (DBG) for lactating ewes would modify their milk production and physicochemical quality. The aim was to determine the effect of the DBG supplementation in the feed of ewes in milk production and quality, as well as in the physical condition of the animals. Fifteen 18-month-old ewes from a cross between Friesian × Rambouillet resulting from a first birth (30 days on milk) were distributed into 3 treatments with 0, 150 or 300 g of DBG. The experiment had a duration of 30 days, in which milk production, feed intake and physicochemical characteristics of the milk (fat, non-fatty solids, density, cryoscopic point, protein, lactose, and salts) were measured and each week the intake of feed in dry mass and the change in body weight were registered. Milk production displayed no differences between treatments and a decrease was observed in the production of milk for all treatments between weeks one (462 mL) and four (162 mL). Physicochemical variables of the milk displayed no differences between treatments, and quality was not affected. The change in body weight was the highest in the 300 g DBG treatment, with a modification of approximately 12.8 ± 0.45 kg (p ≤ 0.05) during the trial time, daily weight gain was 440 ± 0.08 g d-1 (p ≤ 0.05). The implementation of DBG in the feeds of ewes reduced the intake of dry matter, food conversion improved, and the cost of feed per ewe was reduced by up to 33.8 %.

Evaluation of the relationship between main type traits and longevity in Hungarian Simmental cows

The Hungarian Simmental cattle is a dual-purpose breed, having good milk and meat production characteristics. Simmental cows have some other important traits, for example, a longer productive life. The longevity or productive life is the time period between first calving and culling. The conformation contributes to productive life, reproduction, and milk production. The aims of this study were to analyze the longevity of Hungarian Simmental dual-purpose cows, to evaluate the effects of the size of the herd, age at first calving, main type traits (frame, musculature, feet and legs, mammary system), and combination of main type traits (frame and musculature, feet and legs and mammary system). Animal, age at first calving, herd*calving, musculature, the mammary system as well as the combination of mammary system and feet and legs were significant effects on longevity. The highest risk ratio was observed for cows first calved after 31 months. The risk of culling increased with increasing scores of musculature and decreasing scores of the mammary system. The highest risk ratio was estimated in category 11 (lower scores of mammary system with lower scores of feet and legs). In this case, the risk ratio was 36% higher than the reference group.

Effects of milk yield and quality at post-calving period on Algerian cows’ reproductive performances

This study was carried out to determine the association between milk production characteristics at the start of lactation (the first three month of lactation) and the performance of reproduction within dairy cows of Algeria. Data were collected from Holstein cows (n=920) that calved between October 2017 and October 2019. Reproductive parameters included in the study were: calving to first-service interval (CFSI, days), calving to conception interval (CCI, days), services per conception (SPC), and conception rate at first-service (CRFS %). Milk parameters such as peak milk yield, cumulative milk yield in the first 30 days (Milk30), 60 days (Milk60) and 100 days (Milk100) postpartum of the cows. The milk composition traits analyzed were milk fat concentration (MF %) and milk protein concentration (MP %). These variables were used to calculate fat to protein ratio (FPR) for each stage of lactation (stage 1: 15–30 days, stage 2: 45–60 days and stage 3: 75–90 days postpartum). Pearson’s correlation analysis was used to determine the correlation between reproductive parameters and milk production variables.The obtained results showed that peak milk yield, cumulative milk yield in the first 60 days (Milk60) and 100 days (Milk100) were significantly and positively (P<0.05) correlated with all the measured fertility parameters. Furthermore, fat to protein ratio (FPR) and milk fat content correlated significantly and negatively (P<0.05) with CFSI, CCI and SPC in the first two stages. The correlation between milk protein content with CFSI, CCI and SPC were negative and significant in the all three stages. Further research is required to identify the cause of this association.

Comparison of phenotypic and heterotic effects affecting milk yield, composition and udder morphometry of Hair and F1, F2 and G1 generation cross-breeds of Alpine × Hair and Saanen × Hair dairy goats in a semi-intensive system.

This study was conducted to compare milk yield, milk components and udder traits of Hair goat, F1, F2 and G1 generation cross-breeds of Alpine × Hair and Saanen × Hair goats under a semi-intensive system. The effects of genotype, parity, flock and year on milk production, physical and chemical compositions were almost all significant (between p < 0.05 and p < 0.001). The F1, F2 and G1 generations produced 24 and 44% higher (p < 0.001) lactation milk yield (LMY), 12 and 35% (p < 0.001) fat yield and 19 and 35% (p < 0.001) protein yield than Hair goat. Positive heterosis was found in milk production and contents both Alpine × Hair F1 (AHF1) and Saanen × Hair F1 (SHF1) generations. The heterotic effect of the LMY was significant in the SHF1 generation (p < 0.05), but not in the AHF1 generation. The highest correlation was found between LMY and udder circumference and then udder volume (p < 0.001; r = from 0.34 to 0.75). The coefficient of determination of the obtained equation for the estimation of the LMY in the Hair and cross-bred goats ranged from 0.48 to 0.71. These results showed that as the level of cross-breeding increased in this semi-intensive system, better quality dairy products can be obtained from goats, and udder measurements can be a helpful tool in estimating milk yield, thus reducing the pressure on the ecosystem. Thus, it was concluded that with better modelling of environmental variations, milk production characteristics of local goats can be increased much faster by cross-breeding, especially at the F1 and G1 generation cross-breed levels.

Study of the allelic frequency of HSPA6 gene and its genotypes and their effect on some characteristics of milk production in Holstein cows

Study of the allelic frequency of HSPA6 gene and its genotypes and their effect on some characteristics of milk production in Holstein cows

Detection of the effect of PIT-1 gene genotypes on some productive traits in Holstein cattle

The research was conducted at the Taj Al-Nahrain cattle station in Al-Diwaniyah governorate in Iraq on a sample of 85 Holstein cows imported from Germany, which were selected during the third season of milk production, in order to determine the genotypes of the PIT-1 gene and its relationship to a number of production traits. The PCR product (451bp) of the PIT-1 gene was digested using the Hinf1 restriction enzyme, and the digestion results showed that the studied genetic segment of the POU1F1 gene appeared in three genotypes (AA, AB, and BB) with percentages of 55.3, 42.6, 2.1%, respectively, and there were highly significant differences (P≤0.01) between the distribution of these percentages, and the A allele (0.766) was superior to the B allele (0.234). The results of the analysis of variance showed that the effect of the genotype of the POU1F1 gene on the characteristics of milk production (daily milk production, total milk production, peak production) was not significant except in the characteristic of peak milk production in favor of the BB genotype at a rate of 538.50 kg on each of the genotypes AA and AB while the results did not show a significant effect between the genotypes (AA, AB, BB) in both the daily milk production rate and the total milk production. It was found that the effect of the POU1F1 gene on body dimension traits (body length, frontal body height, posterior body height) was significant (P≤0.05) in body length in favor of the BB genotype (164 cm) on each of the genotypes AA and AB, at 157,780. and 156,347 cm, respectively, while there were no significant differences between the genotypes in the anterior height and posterior height of the body.

Studying the effect of the genotypes of the prolactin gene (PRL) on the productive performance of Holstein cows

The study was conducted at Taj Al-Nahrain station in Al-Diwaniyah Governorate, which is 200 km from the center of Dhi Qar Governorate. For the period from 10/15/2021 to 4/15/2021, 85 Holstein cows imported from Germany were used in this experiment, and they were selected from among 700 cows in the station, all of which are in the third production cycle. As for the laboratory part of the study, it was conducted in the laboratories of the Department of Life Sciences at the College of Science / Dhi Qar University for the purpose of separating the genetic material (DNA), conducting polymerase chain reaction and electrophoresis, and identifying genetic mutations in the studied genetic segment on the prolactin gene, The animals in the station were fed according to the season and year in terms of the availability of feed and the percentage of costs involved in raising cows, as well as depending on the general state of cow productivity. But in general, it is provided with green fodder, which includes yoghurt, barley, corn stalks, and a percentage of both dry feed (hay and hay) and concentrated feed (barley, bran and cake) according to what is available from them, as well as limestone and table salt. The data on milk production were collected from the station records, where the milk production was recorded weekly for the morning circuit and the evening circuit by the station, and the milk components were analyzed in the Abu Ghraib Dairy Company / Research and Development Division by a Milk Analyzer, and 3 ml of blood was collected from a vein The udder of each cow was given by medical syringes with a capacity of 5 ml, suitable for the size of the animal’s vein, and placed in collection tubes containing an anticoagulant substance (K2 EDTA) and transferred in a cooler box for freezing at a temperature of -18°C until the time of extraction. From the results obtained from this study, it can be concluded that the mutation C83T changed the code of the amino acid histidine to the amino acid Tyrosine, which had a significant effect on the characteristics of daily and total milk production, while the mutation G168C changed the amino acid arginine to the amino acid Proline, which was significantly reflected on the traits of persistence. In milk production, the length of the milk season and the proportion of milk protein, most of the average traits for cows in the third season of production appeared higher than the general averages compared to other studies, and most of the simple correlation coefficients between the study traits were high and significant.

Spatiotemporal characteristics of smallholder milk production under changing climate: A case of Nandi County, Kenya

Milk production in Kenya is predominantly smallholder and dependent on rainfall. The study assesses spatiotemporal characteristics of smallholder milk production in Nandi County under changing climate. Climate (Rainfall and temperature), fodder availability (Normalized Difference Vegetation Index (NDVI) and soil moisture content) and milk production data were used. Methods included trend analysis, spatial plots, correlation and multi-regression analysis. Monthly NDVI and soil moisture content were high between April and November with seasonal analysis indicating highest/lowest June-August (JJA)/December-February (DJF) values. Percentage change (%Δ) for NDVI was 6.0% (DJF), 1.96% (March-May, MAM), 2.13% (JJA), 4.16% (September-November, SON) and (2.53% (Annual). Seasonal and annual %Δ for soil moisture content ranged 7.2-17.1% at 0-10cm level and 8.1-23.7% at 10-40 level. Trend analysis of milk production showed positive change from 2007 to 2016 and highest/lowest in December/April with seasonal %Δ of up to 186% (MAM), 183% (JJA), 202% (SON), 214% (DJF) and 204% (Annual). Majority of household (HH) owned between 1 and 20 acres of land with only 0.5 to 2 acres allocated to dairy farming while those allocating less than 1 acre practiced zero grazing. On average, HH had 2 lactating cows throughout the year with majority of dairy farmers (98.6%) owning improved cow breeds. Amount of milk per HH supplied to the farmer organization varied between 2.3 litres and 3.8 litres with computed daily average milk produced per HH being 18.8 litres. Active milk suppliers were highest/lowest in December/April whereas daily average milk production per HH between 2010 and 2016 was highest/lowest in January (23.7 litres)/August (15.6 litres). Lowest/highest correlation coefficients were found in precipitation/minimum temperature. Multi-regression analysis indicated that precipitation had significant contribution to dairy productivity. Given the sensitivity of milk production to climate and fodder availability, adequate adaptation and mitigation measures are necessary in order to sustainably enhance milk production.

Genealogical structure and evaluation of Holstein breeding bulls

The Holstein bulls’ genealogical structure on the Russian Federation breeding enterprises (n= 3 75), as well as the selection types ratio of their breeding, genomic parameters’ assessments in the countries of exporting were studied. The evaluation of 21 breeding sires on their daughters quality and their mothers milk production comparison in the breeding plant’s herd was carried out. A narrow range of genealogical lines of imported Holsteins, that does not allow genetic variability’s effective use at domestic livestock populations improvement, has been identified. These bulls evaluation by the offspring quality revealed the distribution of daughters on milk yield terms and the mass fraction of protein (PC) at the herd improvement, but with the mass fat fraction (FC) decreasing relative to the groups of mothers. The determination of the daughter groups’ repeatability coefficients and ranking based on the milk production characteristics revealed significant differences with the genomic values estimated fortheir fathers: for milk yield rs = 0,395, for PC — rs =0,200, and for FC — rs = – 0,570. The author concludes that it is impossible to plan improvement ofthe main features of breeding in herd at breeding bulls selecting according to the genomic assessment indicators’ levels and givessuggestions for improvment of methodology of evaluating breeding sires by the quality of offspring in dairy cattle breeding of the Russian Federation.

Determination of factors affecting milk yield, composition and udder morphometry of Hair and cross-bred dairy goats in a semi-intensive system.

In this Research Communication we report milk yield, milk composition and udder morphometry of Hair, Alpine × Hair F1 (AHF1), and Saanen × Hair F1 (SHF1) cross-bred goat genotypes managed in a semi-intensive system. The SHF1 genotype had significantly higher lactation milk yield, fat yield, protein yield, and electrical conductivity than other genotypes, whilst AHF1 was intermediate. The milk fat, protein, lactose, solids-non-fat and total solids contents as well as pH and density of the Hair goat milk were significantly higher than the corresponding values of the cross-bred genotypes. The highest correlation amongst udder characteristics and production was between lactation milk yield and udder volume (P < 0.01; r = from 0.63 to 0.77). The results of this study suggest that crossbreeding can have a positive effect on the milk production characteristics of local goats, thereby reducing the pressure on the ecosystem, and suggest that udder measurements, especially volume, can be a helpful tool for estimating milk yield.

A comparative analysis of rumen pH, milk production characteristics, and blood metabolites of Holstein cattle fed different forage levels for the establishment of objective indicators of the animal welfare certification standard.

ObjectiveThis study was conducted to obtain an objective index that can be quantified and used for establishing an animal welfare certification standard in Korea. For this purpose rumen pH, ruminating time, milk yield, milk quality, and blood components of cows reared in farms feeding high forage level (90%) and farms feeding low forage level (40%) were compared.MethodsData on rumen pH, rumination time, milk yield, milk fat ratio, milk protein ratio, and blood metabolism were collected from 12 heads from a welfare farm (forage rate 88.5%) and 13 heads from a conventional farm (forage rate 34.5%) for three days in October 2019.ResultsThe rumination time was longer in cattle on the welfare farm than on the conventional farm (p<0.01), but ruminal pH fluctuation was greater in the cattle on conventional farm than the welfare farm (p<0.01). Conventional farms with a high ratio of concentrated feed were higher in average daily milk yield than welfare farms, but milk fat and milk production efficiency (milk fat and milk protein corrected milk/total digestible nutrients) was higher in cattle on welfare farms. Blood test results showed a normal range for both farm types, but concentrations of total cholesterol and non-esterified fatty acid were significantly higher in cows from conventional farms with a high milk yield (p<0.01).ConclusionThe results of this study confirmed that cows on the animal welfare farm with a high percentage of grass feed had higher milk production efficiency with healthier rumen pH and blood metabolism parameters compared to those on the conventional farm.

The Effect of Using Sunflower Meal as A Protein Source Replacing Soybean Meal on Milk Production, Its Components and Some Blood Traits in Awassi Ewes: تأثير استخدام كسبة زهرة الشمس كمصدر بروتيني محل كسبة فول الصويا على إنتاج الحليب ومكوناته وبعض صفات الدم في النعاج العواسية

The research was conducted to study the effect of the use of sunflower meal (SFM) as a protein source in Awassi ewe feeding diets on milk production, milk components, and biochemical blood characteristics. In the study, 18 Awassi ewes were used, ranging in age from (3-4) years, with an average weight of (49) kg. The ewes were randomly divided into three equal groups in their weight and milk production rates. The first group ewes were fed on a standard diet consisting of soybean meal, yellow corn, barley, wheat bran, wheat flour, salt, and limestone. The sunflower fraction replaced the soybean meal in the diets of the second and third groups by 7 And 14 %, respectively. The feeding period lasted for (90) days. The results showed that the ewes of the second group were the highly significant difference at a level (p ≤ 0.05) in daily and total body weight and final weight. The daily milk production rate in the second treatment was significantly different at a level (p ≤ 0.05), as it reached 0.601 kg/day from the third treatment, which reached 0.513 kg/day and mathematically from the first treatment in which the daily milk production reached 0.541 kg/day, the same significant difference was found in the second group of treatment in total milk production rates compared to other treatments was (48.69, 54.09 and 46.17) kg/ewes for the three treatments, respectively. The study also showed that the differences between the first (standard) treatment and the treatments in which sunflower was used were not in the rates of ratios of (fat, protein, lactose and total solids) of milk, while a significant increase at a level (p≤0.05) was observed in the produced quantities of the protein (33.29 g / day) and the fat (43.09 g / day) of ewe milk of the second treatment compared to the quantities produced of the protein (27.44 g / day) and the fat (38.42 g / day) of the ewe milk that consumed the third diet. The analysis of biochemical blood samples did not differ significantly between the three treatments. The study recommends conducting research using a percentage higher than 14% for sunflower meal and knowing its effect on production, and conducting other studies to find out the effect of sunflower meal on the concentration and quality of fats in the tissues of carcasses and milk produced, in addition to conducting digestion experiments and knowing the rumen environment in Awassi sheep.

تأثير استخدام كسبة زهرة الشمس كمصدر بروتيني محل كسبة فول الصويا على إنتاج الحليب ومكوناته وبعض صفات الدم في النعاج العواسية

هدف البحث إلى دراسة تأثير استخدام كسبة زهرة الشمس كمصدر بروتيني في علائق تغذية النعاج العواسي على إنتاج الحليب ومكوناته وصفات الدم الكيموحيوية. استخدم في الدراسة (18) نعجة عواسية تراوحت أعمارها بين (3-4) سنوات وبمعدل وزن (49) كغم. قسمت النعاج عشوائيا إلى ثلاث مجاميع متساوية في معدلات أوزانها وإنتاج الحليب، غذيت نعاج المجموعة الأولى على عليقة قياسية تكونت من كسبة فول الصويا، الذرة الصفراء، الشعير، نخالة وطحين الحنطة، الملح وحجر الكلس، واستبدلت كسبة زهرة الشمس محل كسبة فول الصويا في علائق المجموعتين الثانية والثالثة وبنسبة 7 و14 % على التوالي. استمرت فترة التغذية لمدة (90) يوما. أوضحت النتائج تفوق نعاج المجموعة الثانية معنويا (أ≤0.05) في معدلات أوزان الجسم الحي اليومية والكلية والوزن النهائي. كما تميز معدل إنتاج الحليب اليومي في المعاملة الثانية معنويا (أ≤0.05) حيث بلغ 0.601 كغم/يوم عن المعاملة الثالثة اذ بلغ 0.513 كغم/يوم وحسابيا عن المعاملة الأولى والتي بلغ فيها إنتاج الحليب اليومي 0.541 كغم/يوم، التفوق المعنوي ذاته وجد لصالح المعاملة الثانية في معدلات إنتاج الحليب الكلي مقارنة مع المعاملات الاخرى حيث بلغت (48.69، 54.09 و46.17) كغم/نعجة للمعاملات الثلاث على التوالي. كما بينت الدراسة بعدم وجود فرق احصائي معنوي بمستوى أ≤0.05 ما بين المعاملة الأولى (القياسية) والمعاملات التي استخدم فيها كسبة زهرة الشمس في معدلات نسب كل من (دهن، بروتين، لاكتوز والمواد الصلبة الكلية) للحليب، في حين لوحظ وجود فرق احصائي معنوي بمستوى أ≤0.05 في الكميات المنتجة من البروتين (33.29 غم/يوم) والدهن (43.09 غم/يوم) من حليب نعاج المعاملة الثانية مقارنة بالكميات المنتجة من البروتين(27.44 غم/يوم) والدهن(38.42 غم/يوم) من حليب النعاج التي تناولت العليقة الثالثة. تحليل عينات الدم الكيموحيوية لم تختلف معنويا ما بين معاملات التجربة الثلاث. توصي الدراسة إلى اجراء بحوث باستخدام نسبة اعلى من 14% لكسبة زهرة الشمس ومعرفة تأثيرها على الإنتاج، واجراء دراسات اخرى لمعرفة تأثير كسبة زهرة الشمس على تركيز ونوعية الدهون في انسجة الذبائح والحليب المنتج، إضافة إلى اجراء تجارب الهضم ومعرفة بيئة الكرش في الأغنام العواسية.

Productive diagnosis of Girolando cows on a farm in Alto Sertão Sergipano

Girolando breed has several blood grades, from 1/4 Dutch (Hol) x 3/4 Gir (G), to 7/8 Hol x 1/8 G. These animals have good milk production characteristics inherited from the Dutch breed and a good acquired rusticity of the Gir breed. In view of this, this work aimed to evaluate the productive performance of three different blood grades of the Girolando breed on a farm in the Alto Sertão Sergipano. For the research, the data used referred to the highest production in 305 days of distinct lactations, between the first and the fourth lactation. The blood grades evaluated were: 1/2 HG (G1); 3/4 HG (G2) and 7/8 HG (G3). For the diagnosis, the Individual Control Chart was used, which is one of the tools of the Statistical Process Control (SPC), with the purpose of evaluating and controlling, in a global way, all the production. The results obtained do not demonstrate superiority of production among the three genetic groups. However, the G1 group showed the highest regularity in milk production, with the highest average production and the lowest average range. However, in order to obtain a better diagnosis of milk production, more studies are needed addressing milk production in 305 days with different blood grades of the Girolando breed, in the Alto Sertão Sergipano region.

GENETIC PARAMETERS OF GIROLANDO CROSSBRED COWS IN DAIRY HERDS IN THE STATE OF ACRE, BRAZIL

This study aimed at estimating genetic parameters for milk production and conformation characteristics in Girolando crossbred dairy cows reared in the High and Low Acre region using the restricted maximum likelihood methodology, under an animal model. We estimated the variance components and genetic parameters using the REML/BLUP procedure (Restricted Maximum Likelihood Methodology/Best Linear Unbiased Prediction). The estimated average for milk production for 305 days of lactation (P305) was of 1523.25 ± 481.11 kg, with a heritability of 0.38 for this characteristic. The conformation characteristics showed no significant correlation with milk production. The phenotypical correlations between the linear characteristics of type were, in general, positive and moderate. The P305 obtained in this study can be considered low and indicates that there is a possibility of increasing milk production through selection in herds along with the use of tested and proven bulls. The heritability estimate found (0.38) indicates that there is genetic variability for milk production, demonstrating that selection for this characteristic would result in genetic progress.

Fertility and milk production on commercial dairy farms with customized lactation lengths

Drying-off, calving, and start of lactation are critical transition events for a dairy cow. As a consequence, most animal health issues occur during these periods. By extending the voluntary waiting period for first insemination after calving, calving interval (CInt) can be extended, with possible positive effects for fertility and health. Some cows might be better suited for an extended CInt than others, due to differences in milk yield level, lactation persistency, or health status, which would justify a customized CInt based on individual cow characteristics. This study aims to investigate 13 farms with customized CInt, with respect to calving to first service interval (CFSI), accomplished CInt, services per conception (SC), conception rate at first artificial insemination (CR1AI), peak yield, lactation persistency, 305-d yield, and effective lactation yield. In total, 4,858 complete lactations of Holstein Friesian cows between 2014 and 2019 from the 13 farms were grouped by parity (1 or 2+) and CFSI (CFSI class; CFSI-1 < 84; 84 ≤ CFSI-2 < 140; 140 ≤ CFSI-3 < 196; 196 ≤ CFSI-4 < 252, CFSI-5 ≥ 252 d) or CInt (CInt class; CInt-1 < 364; 364 ≤ CInt-2 < 420; 420 ≤ CInt-3 < 476; 476 ≤ CInt-4 < 532, CInt-5 ≥ 532 d). Cow inseminations, available for 11 out of 13 farms (3,597 complete lactations), were grouped by parity (1 and 2+) and CFSI class or CInt class. The fertility and milk production characteristics were analyzed with generalized and general linear mixed models. The CFSI class was not associated with SC, but extended CInt class was associated with increased SC (CInt-1-5; 1.11-3.70 SC). More than 50% of cows in the CFSI class <84 d ended up in longer than expected CInt (>364 d), showing that these cows were not able to conceive for the desired CInt. More than 50% of cows in CInt classes 3 and higher (CInt ≥ 420 d) had an earlier first insemination before successful insemination (CFSI class 1; <196 d), showing that these extended CInt classes consisted of both cows with an extended waiting period for first insemination and cows that failed to conceive at earlier insemination(s). On most farms, lactation persistency was greatest in CInt class 1 (<364 d), probably related to the low peak yield in this class. When this shortest CInt class was excluded, persistency increased with extended CInt classes on most farms. Although at the majority of farms 305-d yield was greater in CInt ≥ 532 d, effective lactation yield at most farms was greatest in CInt from 364 to 531 d, especially for multiparous cows. Based on the results of this study, a CInt between 364 and 531 days seems most optimal for milk production, when high-yielding cows were selected.

Microbial Safety of Milk Production and Fermented Dairy Products in Africa

In Africa, milk production, processing and consumption are integral part of traditional food supply, with dairy products being a staple component of recommended healthy diets. This review provides an overview of the microbial safety characteristics of milk production and fermented dairy products in Africa. The object is to highlight the main microbial food safety hazards in the dairy chain and to propose appropriate preventive and control measures. Pathogens of public health concern including Mycobacterium bovis, Brucella abortus and Coxiella burnettii, which have largely been eradicated in many developed nations, still persist in the dairy chain in Africa. Factors such as the natural antimicrobial systems in milk and traditional processing technologies, including fermentation, heating and use of antimicrobial additives, that can potentially contribute to microbial safety of milk and dairy products in Africa will be discussed. Practical approaches to controlling safety hazards in the dairy chain in Africa have been proposed. Governmental regulatory bodies need to set the necessary national and regional safety standards, perform inspections and put measures in place to ensure that the standards are met, including strong enforcement programs within smallholder dairy chains. Dairy chain actors would require upgraded knowledge and training in preventive approaches such as good agricultural practices (GAP), hazard analysis and critical control points (HACCP) design and implementation and good hygienic practices (GHPs). Food safety education programs should be incorporated into school curricula, beginning at the basic school levels, to improve food safety cognition among students and promote life-long safe food handling behaviour.

Transition Period of the Dairy Cow Revisited: I. Homeorhesis and Its Changes by Selection and Management

The transition period of the dairy cow involves the end of pregnancy, parturition, and the onset of lactation. Multifaceted and rapid changes occur during this time, and in particular, the increase of milk secretion requires the large-scale reorientation of metabolism. The underlying mechanisms of this metabolic regulation are collectively named homeorhesis, a process that governs milk production during this phase and that exhibits (A) a chronic nature, (B) the simultaneous inclusion of multiple tissues, and (C) altered responses to homeostatic signals, but (D) no direct feedback mechanisms for possible control or limitation. Priority of milk production is one important consequence of this homeorhetic regulation with possible constraints on other physiological functions. These general properties of the homeorhetic regulation of milk secretion are specifically characterized by a) milk production according milking (suckling) frequency, b) a natural but inadequate dry matter intake, c) the mobilization of fat acids + glycerol from adipose tissue and of amino acids from protein, d) the partitioning of metabolites, IgG, and dietary nutrients to the mammary gland, e) the stimulation of milk production by high protein intake, and f) a negligible negative energy balance (NEB) at low milk production. Such a combination assures the optimal milk yield for the nutrition of the calf and for its successful survival but without a metabolic challenge or health risk for the cow. However, selection for higher milk production (uncoupled from calf nutrition) and management have changed the above-listed properties, and the regulation of homeorhetic milk production of the modern high-producing dairy cow is nowadays mostly characterized by a) increasing and maximal milk production at increased milking frequency and, under certain circumstances, the uncoupling of the GH-IGF-1 axis, b) enduring insufficient dry matter intake in relation to requirement, c) the mobilization of energy (lipolysis) and release of non-esterified fatty acids (NEFA) above the acute requirement, d) the mobilization of amino acids, e) the partitioning of metabolites, IgG, and dietary nutrient to the mammary gland, f) the potential enhanced partitioning of energy to the mammary gland at high CP intake, g) a sudden and long-lasting NEB, and h) possibly lower weight gain or even net loss of energy during the entire lactation period. These altered and often unfavorable characteristics of high milk production are, furthermore, still regulated by homeorhesis and are thus also given top priority, lack feedback control, and possibly ensue at the expense of other functions without regard for health risks. Hence, the promotion of milk yield by breeding or management might cause metabolic overload, imbalances, or even antagonisms and makes possible health hazards evident. The high incidence of various diseases, the untimely culling rates, and the increasing number of dead cows during early lactation support the assumption of general health threats at high milk production. For this reason, more attention should be paid to the physiological mechanisms of homeorhetic-regulated milk production, its indisputable alterations by breeding and management, and the resulting health risks.

Whey protein polymorphisms in Sudanese goat breeds.

The aim of the present study was to assess genetic variation that is characteristic for Sudanese goat breeds in the milk whey protein genes (LALBA and BLG). Four Sudanese goat breeds were screened for variability in LALBA and BLG genes at the DNA level by comparative sequencing of five animals per breed. Sixteen SNPs were identified in LALBA: seven in the upstream region, six synonymous, and three in the 3´-UTR. Three novel synonymous SNPs in exon 2 (ss5197800003, ss5197800012, and ss5197800004) were found in Nubian, Desert, and Nilotic, but not in Taggar goats. One SNP in the promoter of LALBA (rs642745519) modifies a predicted transcription factor binding site for Tcfe2a. The SNPs in the 3'-UTR (rs657915405, rs641559728, and rs664225585) affect predicted miRNA target sites. With respect to haplotypes in the exonic region, haplotype LALBA-A is most frequent in Nubian, Desert, and Nilotic goats, while haplotype LALBA-D is prevalent in Taggar goats. In BLG, 30 SNPs were detected: eight in the upstream gene region, two synonymous, 17 intronic, and three in the 3'-UTR. Among the 30 identified SNPs, 15 were novel. Four of these novel SNPs were located in the upstream gene region, one was synonymous, and ten were intronic. The novel synonymous SNP (ss5197800017), located in exon 2, was only found in Nubian and Nilotic goats. The SNPs ss5197800010 and rs635615192 in the promoter are located in predicted binding sites of transcription factors (M6097, Elk3, Elf5, and GABPA). Among seven haplotypes detected in the coding region, haplotype BLG-A is most frequent in Nubian and Nilotic goats while haplotype BLG-B is most frequent in Desert and Taggar goats. The high variability in regulatory gene regions among Sudanese goats could potentially affect the quality and yield of whey proteins in goat milk and provide a wide resource for genetic improvement of milk production and milk technology characteristics.

Effect of habituation to milking and natural suckling on milking behaviour and milk production characteristics in primiparous Sahiwal cows

Effect of habituation to milking and natural suckling on milking behaviour and milk production characteristics in primiparous Sahiwal cows