Lactation Yield Research Articles

Histomorphological Changes in the Mammary Gland of Local Indian Goat during Lactation Cycle

Background: In developing countries goat rearing is the sustainable source of income for marginal farmers. The goat milk contains lower fat per cent (3.5%) as compared to cow (4.1%) and buffalo milk (7.4%), with smaller and homogenous fat globules. It is suitable for the persons with poor digestibility of cow milk and infants having mother milk intolerance. To improve the milk production it is important to understand the mammary gland pattern during the different phases of lactation. The present study aimed at analyzing these changes by histological and histochemical observations. The mammary gland is composed of parenchyma containing acini and stroma including the ductual system. These components change during the lactation cycle. Methods: The present study was conducted on 24 goats, eighteen in lactating stage where as six from nonlactating stage. The mammary glands were collected from local abattoir with known history of stage of lactation and divided into three groups as early lactation (2-4 weeks), mid lactation (5-6 weeks) and late lactation ( greater than 6 weeks). The histological and histochemical studies were performed during the different stages of lactation and in non lactating stage to observe the morphological and morphometrical changes along with the presence and absence of different components. Result: The lobules of the mammary gland were polygonal, triangular, oval or elongated in shape during early lactation stage. Approximately all the alveoli observed in early lactation were filled with variable quantity of eosinophilic substance and appeared foamy, due to presence of variable size of fat vacuoles. In mid lactation the lobules became highly irregular. The long and short diameter of lobules was 1041.69 µm and 563.93 µm, respectively. The intralobular stroma was inconspicuous hence alveolar wall appeared to touch each other. In late lactation lobules became shorter in size. The large alveoli showed folded and collapsed appearance. In nonlactating stage well defined alveoli, clusters of desquamated cells were seen and degenerated alveoli were also observed. These histomorphological changes in the secretory unit of the mammary gland reflect the lactation yield and milk composition during different stages of lactation.

Catalytic Conversion of Glycerol to Methyl Lactate over Au-CuO/Sn-Beta: The Roles of Sn-Beta

The production of methyl lactate as a degradable polymer monomer from biomass was an important topic for a sustainable society. In this manuscript, glycerol was oxidated to methyl lactate catalyzed by the combination of Au-CuO and Sn-Beta. The influence of Sn content, Sn source, and the preparation conditions for Sn-β was studied. The Au content in Au/CuO was also investigated by varying the Au content in Au/CuO. The catalysts were characterized by XRD, FTIR spectroscopy of pyridine adsorption, and TEM to study the role of Sn and the influence of different parameters for catalyst preparation. After the optimization of reaction parameters, the yield of methyl lactate from glycerol reached 59% at 363 K after reacting in 1.6 MPa of O2 for 6 h.

Milk productivity of first-calf cows depending on the intensity of their breeding

The paper presents the results of studies of milk productivity of black-and-white cows depending on the age of the first insemination and live weight at the first calving in the conditions of the Irkutsk region. The dynamics of heifer rearing by year, milk productivity of cows in the 1st and 3rd lactations depending on the intensity of their development has been studied. The experiment was conducted on farm materials from the Irkutsk Region using generally accepted zootechnical, analytical, variation and statistical research methods from 2016 to 2020. Live weight of heifers at all ages met the requirements of the elite and elite-record classes. Analysis of the data showed that the growth rate of the animals increased during 5 years (6.0%, 6.8, 2.3 and 4.8% respectively with a significant difference p ≥ 0.90). With the increased intensity of heifer rearing, an increase in milk yield over 305 days of the first lactation was observed. The highest milk production was noted in the 1st (5309-5476 kg) and 3rd (5418-5817 kg) lactations in cows with the first fruitful insemination at 13-14 months. The lowest 1st and 3rd lactation yields are obtained from cows inseminated at 20 months of age or older. Higher milk production in the first and third lactations was obtained from cows with a live weight at first calving of 541-550 kg, 551 kg and higher (5197-5164, 5436-5545 kg respectively). Less milk production was obtained from cows with a live weight at first calving of up to 500 kg (4567-5122, 4943-5009 kg). The results obtained make it possible to reveal the influence of the intensity of rearing heifers on the productive qualities of cows.

Factors affecting length of productive life of Brazilian Holstein cows assessed using survival analysis

Context Length of productive life is defined as the number of days from first calving to the last day of milking records, when the cow is no longer sufficiently productive. Although it has economic implications, length of productive life has not yet been included in Brazilian dairy cattle breeding programs because it depends on other traits such as age at first calving, milk production level and disease occurrence. In addition, its evaluation occurs later in life, and heritability coefficients are low. Aims The aim of this study was to identify the effects of both age at first calving and accumulated 305-day milk yield in the first lactation on length of productive life in Holstein cows. Methods Official dairy control data of 31 562 Holstein cows, calved from 2010 to 2014, in 321 herds from Paraná state, Brazil, were analysed by using the Kaplan–Meier estimator and Cox regression model. Key results First calving at <21 months was associated with shortest productive life (1197.01 ± 232.40 days), whereas first calving at 24 months was associated with the lowest hazard ratio (0.572), suggesting that this is the most suitable age of first calving for a longer productive life. Low-yielding cows (first lactation yield <6392 kg) had the second lowest survival probability (47.20%), the shortest productive life (1150.60 ± 234.51 days) and the highest voluntary hazard ratio (1.30) and were prematurely culled from the herds. High-yielding cows (first lactation yield >12 024 kg) had lower culling risk at the first lactation. Conclusions Cows that started their reproductive life ∼16 months of age (first calving at 24 months) had the longest productive life and an average first lactation milk yield ∼9000 kg. Implications Reproductive management practices could affect length of productive life through effects on age at first calving and first lactation milk yield. Most of the Holstein semen used in Brazil comes from countries where longevity has already been included in selection indexes; thus, early identification of cow longevity could be used for culling decisions.

Characteristics of lactation of bushuev breed cows

This article presents information on milk yield and characteristics of lactation of cows of the Bushuev, Holstein breeds, and cows of the first generation G’1 generation obtained from the mating of cattle of this breed.

AYRSHIRE BREED IN THE CONDITIONS OF UKRAINE

AYRSHIRE BREED IN THE CONDITIONS OF UKRAINE

Searching of Pregnancy Rate in Repeat Breeder Cows by Embryo Transfer Practices

The aim of this study is to compare the pregnancy rates by applying embryo transfer to the cows which are not pregnant and should be removed from herd as repeat breeder. In this study, 87 randomly selected Holstein cows utilized. The repeat breeder cows (n=45) were selected from at least one giving birth, having regular sexual cycle, missing clinical worsening into genital organ and not displaying an abnormal discharge. On the other hand, it was selected from nonpregnant cows which inseminated artificially at least 3 times or more. Besides, cows that used as the control group (n=42) were selected from the cows without any artificial insemination postnatally. The PGF2α application was performed to all recipient cows which are considered to benefit from as a recipient in control and testing groups just 24 days before the flushing day. After this application, the cows showing estrous symptoms were recorded and determined as candidate recipients. The pregnancy rates were 35.6% and 50% for testing and control groups, respectively and the difference between the groups was significant (P<0,05). As a result, even this difference between the groups it has been concluded that embryo transfer can be used to conceive especially for high-yielding cows as a treatment method for repeat breeder cows. Thereby, embryo transfer from the cows with high superior characteristics to the high milk yielding cows which have infertility problems can economically be beneficial by utilizing the high milk yield in the later lactation without any replacement cost.

Management-related factors in dry cows and their associations with colostrum quantity and quality on a large commercial dairy farm

The objective of this observational study was to evaluate the association of management-related factors in dry cows and colostrum quantity and quality in Holstein cows on a large commercial dairy farm. This study was conducted from January 2018 to December 2020 on a commercial dairy farm in Germany, milking approximately 2,500 Holstein cows. Dairy personnel recorded colostrum quantity (n = 7,567) and evaluated colostrum quality in a subsample of animals (n = 2,600) using a digital Brix refractometer. Generalized linear mixed models were constructed to evaluate the association of management-related factors and colostrum quantity and quality. Models were run separately for primiparous or multiparous cows. The outcome variable was either colostrum quantity (kg) or quality (%Brix). Average colostrum quantity was 4.0 ± 2.5 kg, 5.1 ± 3.4 kg, and 5.5 ± 3.5 kg for cows in lactation 1, 2, and ≥3, respectively. In primiparous cows (n = 2,351), colostrum quantity was affected by month of calving (greatest in April = 4.1 kg, and lowest in November = 3.2 kg), sex of the calf (female singleton = 3.50 ± 0.26 kg; male singleton = 3.76 ± 0.27 kg; twins = 2.97 ± 0.66 kg), stillbirth (stillbirth = 3.14 ± 0.39 kg; no stillbirth = 3.68 ± 0.31 kg). In multiparous cows (n = 5,216), colostrum quantity was affected by month of calving (greatest in May = 5.5 kg, and lowest in October = 3.8 kg), calving ease (calving ease 0 = 4.23 ± 0.26 kg; score 1 = 4.77 ± 0.21 kg; score 2 = 4.98 ± 0.22 kg; score 3 = 5.30 ± 0.22 kg), sex of the calf (female singleton = 4.42 ± 0.21 kg; male singleton = 5.00 ± 0.21 kg; twins = 5.03 ± 0.30 kg), stillbirth (stillbirth = 4.24 ± 0.38 kg; no stillbirth = 5.39 ± 0.11 kg), milk yield in previous lactation (+0.1 kg increase for 1,000 kg more milk yield in previous lactation), days spent in the far-off group (0.05 ± 0.003 kg for every day), and days in the close-up pen (0.06 ± 0.010 kg for every day). Average colostrum quality was 25.1 ± 3.4% Brix, 24.7 ± 3.3% Brix, and 27.6 ± 4.4% Brix for cows in lactation 1, 2, and ≥3, respectively. In primiparous cows (n = 817), colostrum quality was affected only by month of calving. Colostrum quality in primiparous cows was greatest in December (26.8%Brix) and lowest in August (23.9% Brix). In multiparous cows (n = 1,783), colostrum quality was affected by parity (lactation 2 = 25.2 ± 2.7% Brix; lactation 3+ = 27.9 ± 2.7%Brix), month of calving (greatest in February = 27.5% Brix, and lowest in August = 25.7% Brix), milk yield in previous lactation, and colostrum quantity. We observed a seasonal pattern for colostrum quantity and quality. Future intervention studies using multiple farms need to elucidate whether management of the photoperiod or length of exposure to close-up diets, or both, can help to optimize colostrum production.

Генетическая изменчивость показателей продуктивности и оценки экстерьера голштинских коров в зависимости от типа телосложения

Abstract. The aim of the research is to study the selection and genetic parameters of the characteristics of productivity and the exterior of Holstein first-calf cows, depending on their body type. Research methods. Based on the data from the SELEX database, we researched the performance indicators and measurements of the trunk of first calving cows in the amount of 4049 heads. Based on the RENUMF90 software shell of the BLUPF90 program, we obtained digital values of the genetic variability of productivity indicators and the external structure of animals in accordance with the equation of the mixed model. Results. The most broad-bodied animals classified as airysomal type had the highest milk yield in the first lactation, and exceeded animals of the leptosomal type by 563.3 kg (p ≤ 0.001). According to the "B" system, broad-bodied cows are superior to narrow-bodied animals: stature – by 1 point (p ≤ 0.001); body depth – by 0.8 points (p ≤ 0.01); rump width – by 1.9 points (p ≤ 0.001); rump angle – by 0.9 points (p ≤ 0.01); fore udder attachment – by 1 point (p ≤ 0.01). Animals of the narrow-bodied type reliably (p ≤ 0.001) had a high genetic relationship between milk yield in 305 days of first lactation and the mass fraction of protein in milk (0.59 ± 0.005). At the same time, the leptosomal type of cows also had the greatest correlation between milk yield and mass fraction of fat (0.51 ± 0.005) (p ≤ 0.001). According to body measurements, the highest correlation coefficients were found in animals of the airysomal type – 0.24 ... 0.50. All Holstein heifers of different body types have high heritability coefficients in terms of fat mass fraction (h2 = 0.37 ... 0.49) and protein mass fraction (h2 = 0.42 ... 0.51). Scientific novelty. For the first time, studies of the genetic variability of productivity indicators and the exterior of Holstein cows, depending on their body type, were conducted.

Non Genetic Factors Affecting Production and Reproduction Traits of Graded Murrah Buffaloes

Background: Environmental factors play a major role and influence the economically important traits in dairy animals. The present investigation was undertaken to study the influence of season on production and reproduction traits of graded Murrah buffaloes reared under farm conditions. Methods: The data pertaining to 164 graded Murrah buffaloes was utilized to study influence of seasons on various climatic factors like maximum, minimum and mean temperature, relative humidity (morning and evening), rainfall, sunshine, wind speed, evaporation and production and reproduction traits like lactation length, lactation yield, days to attain peak yield, persistency, calving interval, birth weight and number of lactations. Result: The present investigation revealed significant effect of season on all the meteorological parameters, production and reproduction parameters studied. The correlations among meteorological parameters and production and reproduction traits were also significant.

Fermentative lactic acid production from seaweed hydrolysate using Lactobacillus sp. And Weissella sp

Lactic acid (LA) is an essential commodity chemical, with bio-based LA ruling the market share. Macroalgae are a desirable feedstock for LA fermentation due to their high carbohydrate and low lignin content. Ulva sp., Gracilaria sp., and Sargassum cristaefolium were evaluated as a feedstock for LA fermentation. Mild acid-thermal hydrolysis (sulfuric acid concentrations < 5%) resulted in superior reducing sugar recovery. Gracilaria sp. attained maximum reducing sugar recovery (0.39 g/g biomass) and lactate yield (0.94 g/g). LA fermentation of fucose-rich hydrolysate of Sargassum cristaefolium is demonstrated for the first time, with 0.81 g/g LA yield and 0.36 g/g reducing sugars. Ulva sp. attained 0.21 g/g reducing sugars and 0.85 g/g LA yield. The efficiency of macroalgae for lactate bioconversion was in the order: red macroalgae > green macroalgae > brown macroalgae. L. rhamnosus and L. plantarum could efficaciously utilize seaweed sugars for LA production. Macroalgae can potentially replace lignocellulosic biomass as a feedstock in LA fermentation.

525 Late-Breaking: Late Gestational Nutrient Restriction of Primiparous Beef Heifers Decreases Milk Yield and Pre-weaning Calf Growth

Abstract Fall-calving Hereford-SimAngus heifers (single-sired; BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) bred to a single sire were individually-fed 100% (control; CON; n = 12) or 70% (nutrient restricted; NR; n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to calving. Post-calving, all females were limit-fed chopped tall-fescue hay supplemented to meet lactational nutrient requirements in Calan gates to constrain calves’ diets to milk only until d 147. Four-hour milk yields were measured 5 times; calf size was determined every 21 d. Data were analyzed with treatment, calving date, and calf sex (when P &amp;lt; 0.25) as fixed effects; day and day x treatment were included for milk yield. From calving to d 147, CON cows had greater (P ≤ 0.003) BW, BCS, and backfat, but NR cows gained more (P ≤ 0.004) BW, BCS, and backfat. Milk weight and volume was 15% less (main effect; P &amp;lt; 0.04) for NR cows. Calf size did not differ at birth (P ≥ 0.27). From d 42 to 147, calves born to NR dams had lower (P ≤ 0.02) BW. Heart, abdominal, and flank girths were less (P ≤ 0.07) for NR calves through d 147. Calf ribeye area tended to be less (P ≤ 0.11) in NR calves at d 42, 84, and 126. Nutrient restricted calves had less shoulder to rump length (d 63 to 147; P ≤ 0.08), shoulder height (d 63 to 126; P ≤ 0.02), cannon length (d 42 to 105 and 147; P ≤ 0.09), and cannon circumference (d 63 and 105 to 147; P ≤ 0.06). These data indicate that even when dams are fed to meet lactational requirements, milk yield and calf growth are reduced by late gestational nutrient restriction.

PSXII-18 Immunoglobulin G content and composition of colostrum in different cattle breeds

Abstract Immunoglobulins (Ig) are essential bioactive components in colostrum that enable passive immunization of newborn calves. Compared to mature milk, concentrations of fat and protein are greater in colostrum, and represent a vital source of energy and nutrients. Colostral IgG was shown to vary between individual dairy cows, but comparative data on different breeds and performance levels are scarce. The objective of the present field study was to investigate the contents of total IgG, fat, protein, and lactose in colostrum in different Swiss and German dairy and dual-purpose breeds. We collected colostrum samples of 458 cows of 13 different breeds (dairy breeds: Brown Swiss, Swiss and German Holstein Friesian, and New Zealand Holstein; dual-purpose breeds: German Fleckvieh, Holstein Friesian × Montbéliarde, Montbéliarde, Murnau-Werdenfels, Original Braunvieh, Pinzgauer, Rhetic Gray, and Simmental; beef type crossbred Charolais × Holstein Friesian). Colostrum samples were obtained between 5 and 900 min after calving and analyzed for total IgG, fat protein, and lactose contents. Statistical analysis was carried out using a GLM model with breed, parity number, and time of colostrum collection as fixed effects. Immunoglobulin G concentrations varied between 12.7 and 204.0 mg/mL. No effect of breeding purpose (i.e., dairy or dual-purpose), nor of previous lactation yield on IgG content was observed. However, milking of cows for the first time later than 12 h after parturition resulted in lower colostrum IgG concentrations compared to colostrum harvest within 9 h after calving (P &amp;lt; 0.05). Multiparous cows had a higher colostral IgG concentration than primiparous cows (P &amp;lt; 0.0001). Overall, concentrations of IgG and other constituents in colostrum varied widely in the different cattle breeds. High-yielding dairy cows did not have poorer colostrum quality compared to lower yielding animals or beef and dual-purpose breeds, which suggests an individually different transfer of circulating IgG into colostrum.

Ruminal degradation kinetics of diets with different lipid sources and its influence on intake and milk yield of early lactation crossbred Holstein × Gir cows

The hypothesized that the dietary inclusion of different lipid sources does not alter diet quality, feed intake, and, consequently, milk yield of cows. Thus, this study aimed to evaluate the effects of supplemental lipid sources for early lactation crossbred cows on milk yield, intake, and diet quality through in vitro digestibility and fermentation kinetics, and to demonstrate which variables have the most impact on each diet using principal component analysis (PCA). Five early lactating crossbred ¾ Holstein × ¼ Gir cows (35 ± 8days in milk), with a mean body weight of 410 ± 7.15kg of body weight, were randomly allotted to a 5 × 5 Latin square. The treatments consisted of five experimental diets: a control diet with no additional lipid source and four diets with different lipid sources: cottonseed (242.6g/kg of dry matter (DM)), sunflower seed (243.0g/kg of DM), whole soybeans (234.0g/kg of DM), and soybean oil (42.0g/kg of DM), which were included at a rate to provide 70g/kg of lipid. Diets with no additional lipid source and containing whole soybeans had higher DM, OM, and CP digestibility than other treatments. The diet containing soybean oil had the highest EE digestibility. Gas production was highest in the diet containing soybean oil. The dietary treatments did not affect DM intake. Milk yield was lower in cows receiving diets containing cottonseed. Whole soybeans can be included in diets for lactating cows to increase the energy intake without impairing the feed intake and milk yield.

Bias of Calf Sex on Milk Yield and Fat Yield in Holstein Crossbreed Cows.

Simple SummaryCattle comprise a species of a domestic animal that is primarily bred for milk production. The birth of a calf is the initiator for the lactation period and the sex of the calf can affect milk yield. Additionally, a calf from a new pregnancy can affect the lactation from the previous calving, since the mother gets pregnant and remains pregnant during most of the lactation, usually at lactation peak. Therefore, the aim of this paper was to further investigate the possibilities of sexually biased milk production of Holstein and Holstein crossbreed cows using data from the Republic of Serbia. We also wanted to test the Trivers–Willard (TW) hypothesis that natural selection favors unequal parental investment between daughters and sons under certain maternal conditions. At the same time, this hypothesis assumes that mothers in good health and condition invest more in sons, while mothers in a poor condition invest more in daughters. The obtained results deviate from the view of the TW hypothesis because it was found that milk and fat yields in the first two lactations were the highest in cows that had a female calf and were then pregnant with a second female calf while the lactation from the previous calving was still in progress. We were the first in the world to investigate the effect of the sex of calves at first and second calving on milk yield and fat yield in the first and second standard lactation, depending on milk production levels on farms.In order to examine the biased milk production depending on the sex of calves, data on calving and milk yield characteristics of 15,181 Holstein type cows in PK Belgrade, Serbia were analyzed. A total of 30,362 lactations that were realized in the period from 1985 to 2017 were analyzed. Data were prepared and analyzed using the SAS software package (SAS Institute Inc. Software License 9.3, 2012). The expression and variability of investigated traits were determined using the PROC MEANS procedure, while the effect of individual factors on milk yield traits was analyzed using the PROC GLM procedure. Obtained results deviate from the views of the Trivers–Willard (TW) hypothesis. The results indicate that mothers invest more in female offspring by producing a higher milk and fat yield in the first and second lactation compared to male offspring. This is especially emphasized under better environmental conditions. The highest milk yield (7788 kg) and fat yield (271 kg) in the second lactation were achieved in the combination with two consecutive female calves in the group of higher-than-average milk production farms, and lowest in the combination of two consecutive male calves (6783 kg for the MY and 243 kg for the FY), respectively.

Prolactin and the swine mammary gland

Prolactin is a hormone that is most important for mammary development in swine. It is also essential for both the onset and the maintenance of lactation. In early studies, exogenous recombinant porcine prolactin was used to detect its biological effects on mammary tissue. In these studies, a stimulatory role of prolactin for mammary development of prepubertal gilts was demonstrated. However, when injected throughout lactation, prolactin did not increase sow milk yield likely because mammary receptors were saturated. The secretion of prolactin is largely under negative regulation via dopamine. Inhibition studies using the dopamine agonist bromocriptine showed that prolactin is required in the last third of gestation to sustain mammary development in gilts. When creating a hyperprolactinemic state during that same period, with the dopamine antagonist domperidone, differentiation of mammary epithelial cells was stimulated and milk yield in the subsequent lactation was increased. Domperidone given throughout lactation also led to greater milk yield. A study using domperidone in prepubertal gilts, however, did not reproduce the stimulatory effect of exogenous prolactin on mammary development and demonstrated that timing of the prolactin increase in relation to age of the animals is most important to elicit a response on mammary tissue. Attempts were made to use feed ingredients such as the plant extract from milk thistle, sylimarin, to stimulate prolactin secretion in sows. However, even though prolactin concentrations were increased, this augmentation was not important enough to have an impact on mammary development in late gestation or to increase milk yield. The current knowledge that hyperprolactinemia has beneficial effects for mammary development at various physiological stages and can enhance milk yield in swine leads to new avenues in elaborating strategies that could be used at the farm level to improve sow lactation performance.

Comparative evaluation of in vitro techniques for predicting metabolizable energy content of total mixed ration for Murrah buffaloes

The present study was conducted to ascertain the sensitivity of in vitro techniques namely, in vitro gas production (IVGPT) and Cornell Net Carbohydrate and Protein System (CNCPS) fraction for predicting the metabolizable energy (ME) content of total mixed ration for Murrah buffaloes. The total mixed ration forming dietary treatment were TMR1, TMR2 and TMR3 having mixture of maize silage and concentrate in ratio of 30:70, 40:60 and 50:50, respectively. The diets formulated were isocaloric and isonitrogenous. The in vitro gas production was studied by incubation of diet with rumen liquor as inoculum to predict the metabolizable energy content of ruminant feeds. The CNCPS fraction analysing ME content of feed samples was carried out in laboratory. Lactating Murrah buffaloes (n = 18) having similar lactation yield (MY 9 kg±2.5) were allotted to three groups in a completely randomised design and fed TMR as per the dietary treatments. The feeding trial was carried out for 3 months and nutrient utilization was analysed. The efficiency of ME utilization in vivo were compared to in vitro gas production and CNCPS fraction. Correlation coefficient (r) between in vitro techniques and in vivo trial in evaluating ME content demonstrated a significantly (P&lt;0.01) high correlation of 0.734 with IVGPT and 0.752 with CNCPS fraction indicating that both in vitro techniques were reliable in predicting metabolizable energy content of feedstuffs for ruminant feeding.

Improvement of Biohydrogen and Usable Chemical Products from Glycerol by Co-Culture of Enterobacter spH1 and Citrobacter freundii H3 Using Different Supports as Surface Immobilization

Glycerol is a by-product of biodiesel production in a yield of about 10% (w/w). The present study aims to improve the dark fermentation of glycerol by surface immobilization of microorganisms on supports. Four different supports were used—maghemite (Fe2O3), activated carbon (AC), silica gel (SiO2), and alumina (γ-Al2O3)—on which a newly isolated co-culture of Enterobacter spH1 and Citrobacter freundii, H3, was immobilized. The effect of iron species on dark fermentation was also studied by impregnation on AC and SiO2. The fermentative metabolites were mainly ethanol, 1,3-propanediol, lactate, H2 and CO2. The production rate (Rmax,i) and product yield (Yi) were elucidated by modeling using the Gompertz equation for the batch dark fermentation kinetics (maximum product formation (Pmax,i): (i) For each of the supports, H2 production (mmol/L) and yield (mol H2/mol glycerol consumed) increased in the following order: FC &lt; γ-Al2O3 &lt; Fe2O3 &lt; SiO2 &lt; Fe/SiO2 &lt; AC &lt; Fe/AC. (ii) Ethanol production (mmol/L) increased in the following order: FC &lt; Fe2O3 &lt; γ-Al2O3 &lt; SiO2 &lt; Fe/SiO2 &lt; Fe/AC &lt; AC, and yield (mol EtOH/mol glycerol consumed) increased in the following order: FC &lt; Fe2O3 &lt; Fe/AC &lt; Fe/SiO2 &lt; SiO2 &lt; AC &lt; γ-Al2O3. (iii) 1,3-propanediol production (mmol/L) and yield (mol 1,3PDO/mol glycerol consumed) increased in the following order: γ-Al2O3 &lt; SiO2 &lt; Fe/SiO2 &lt; AC &lt; Fe2O3 &lt; Fe/AC &lt; FC. (iv) Lactate production(mmol/L) and yield (mol Lactate/mol glycerol consumed) increased in the following order: γ-Al2O3 &lt; SiO2 &lt; AC &lt; Fe/SiO2 &lt; Fe/AC &lt; Fe2O3 &lt; FC. The study shows that in all cases, glycerol conversion was higher when the support assisted culture was used. It is noted that glycerol conversion and H2 production were dependent on the specific surface area of the support. H2 production clearly increased with the Fe2O3, Al2O3, SiO2 and AC supports. H2 production on the iron-impregnated AC and SiO2 supports was higher than on the corresponding bare supports. These results indicate that the support enhances the productivity of H2, perhaps because of specific surface area attachment, biofilm formation of the microorganisms and activation of the hydrogenase enzyme by iron species.

Computer vision and weigh scale-based prediction of milk yield and udder traits for individual cows

The measurement of the performance of dairy cow milk production contributes to improve the productivity and profitability of dairy farms. Milk yield is used on-farm for decisions around culling, drying off, heat detection and off-farm for estimation of sire breeding values. Milk yield is measured by herd testing at multiple times through a lactation and by individual milk meters, although the rate of herd testing is decreasing and only a minority of milking systems have milk meters. The goal of this study was to develop a non-contact computer vision and/or walk-over weigh scale technology based on cow 3D images and/or weights before and after milking to determine individual cow milk yield and the lactation milk yield for individual cows. This technology could provide some of the benefits of individual milk meters, although only 1–2 sensors would be required per milking apparatus as opposed to a milk meter per bale on the milking apparatus. An algorithm was developed to estimate the udder volume before milking, udder volume after milking and the difference in udder volume before and after milking. A calibration model based on in-line milk meter measured milk yield from 20 cows was developed to predict milk yield per milking. The model based on udder volume before milking and the difference in udder volume before and after milking had a calibration R2 = 0.92 and RMSE = 0.84 L. The algorithm RMSE was inferior to the in-line milk meter (RMSE = 0.5 L for this trial). This imaging technology provides an inexpensive method to determine the milk yield of individual cows, which can be used for better on-farm management of cows in the herd. The feasibility of determining lactation yield from walk-over weigh scale measurements of each cow before and after each milking was also demonstrated, with algorithm prediction (based on a 2.5% weigh scale error) of lactation milk yield estimated to be similar to that based on two herd tests per lactation. Furthermore, the potential of image-based phenotyping of udder traits such as front/rear teat placement, teat length and teat orientation were demonstrated, with an estimated model accuracy of 94% for front/rear teat placement on a 9-point scale. Average rear teat length was 39 ± 1.5 mm and average front teat length was 49 ± 1.3 mm. This highlights the potential for using computer vision for on-farm prediction of milk performance and udder traits from dairy cows.

Production of ethyl lactate by activated carbon-supported Sn and Zn oxide catalysts utilizing lignocellulosic side streams

In this study, activated carbon-supported Sn and Zn oxide catalysts were prepared from hydrolysis lignin and used for the conversion of model solutions of trioses, hexoses, and lignocellulosic biomass hydrolysates to ethyl lactate. Both catalysts, SnO2@AC and ZnO@AC, were able to produce ethyl lactate in high yields. SnO2@AC was a more active and selective catalyst in triose (dihydroxyacetone) conversion, providing 99% yield to ethyl lactate. ZnO@AC, by contrast, was more selective in glucose and hydrolysate conversion, with a yield of 60% and 85%, respectively. The ethyl lactate yields were significantly higher than those from the optimized model solution experiments when using ZnO@AC catalyst. These findings indicate that milder acidity of the ZnO@AC catalyst together with Na+ and SO42- in hydrolysate favored ethyl lactate production, preventing byproduct, furan derivatives and acetal, formation. Moreover, the catalysts were able to maintain their catalytic activity in recycling experiments.