Milk Crude Protein Research Articles

Relationship between soil fertility and pasture composition on milk quality in Simmental-Fleckvieh production systems in the Peruvian Amazon

ABSTRACT This study aims to identify the relationship between soil fertility and pasture composition on milk quality in ten Simmental-Fleckvieh cattle production systems across four provinces in the Peruvian Amazon: Chachapoyas (system I), Bongara (system II), Rodriguez de Mendoza (system III), and Utcubamba (system IV). While no significant differences were noted in pasture composition, milk, and soil parameters such as pH, electrical conductivity, phosphorus, and potassium among systems, significant statistical differences were observed in soil carbon, organic matter, and nitrogen content (p < 0.05), with System IV exhibiting the highest values. Strong correlations were found between pasture dry matter and both milk fat (r = 0.62) and milk crude protein (r = 0.61). Moderate correlations between pasture dry matter and milk total solids (r = 0.52), milk lactose and soil phosphorus (r = -0.44), milk crude protein and soil potassium (r = 0.40), electric conductivity and pasture dry matter (r = 0.44), soil potassium and pasture crude ash (r = 0.49), and soil carbon and pasture crude fat (r = 0.40). These findings underscore the combined impact of pasture and soil composition on milk nutritional quality, emphasizing the need for optimized soil and pasture management to enhance productivity in these systems.

A New Design for Reference Values Assignment in Proficiency Testing for Fat and Crude Protein in Raw Milk for a Limited Number of Participants.

Proficiency testing (PT) allows food laboratories to endorse their competency to provide food safety guarantees to producers and consumers. One of the recommended methods for assigning reference values in PT with a small number of participants consists in considering the results that a laboratory obtains by means of a calibration test based on certified reference material (CRM). The present study delves into the results from eight PT rounds on the determination of fat and crude protein from raw milk, with modifications in the number of samples and the analysis sessions from that required by the ISO 13528:2022. The uncertainty criterion of the assigned value established by the ISO 13528:2022 standard was met by 93% of the participating laboratories, which allowed most participants to be evaluated through z-score. The assigned values were generally compatible with the results obtained by the participants. Thus, it can be concluded that the design for the assignment of the reference value is appropriate for PT with a limited number of participants. It is recommended for future PT to limit the uncertainty of the CRM according to their availability and to update the standard deviation of the proficiency assessment for the Mid-Infrared Spectroscopy method (MIR).

Do cows with stereotypic tongue-rolling behaviour cope better with their environment?

Stereotypic behaviours, especially oral stereotypic behaviours, are frequently expressed in farm animals. Tongue-rolling is the most common oral stereotypic behaviour in dairy cows (Bos taurus). If animals frequently display stereotypic behaviours, this is an indication of poor welfare. It has been suggested that animals express stereotypic behaviours as a way of coping with stress. As a result, animals with stereotypic behaviours may have lower levels of stress hormones than animals without stereotypic behaviours. In this study, 916 Holstein cows in the first lactation were subjected to scan sampling behavioural observations 200 times for 10 days. All cows were assigned to either a stereotypic behaviours group (SB) or a control group (CON). The SB group was further subdivided into a tongue-rolling group (TR) and an other-stereotypic behaviours group (OS). The TR group was also split into an only tongue-rolling group (OTR) and a mixed tongue-rolling and other stereotypic behaviours group (TROS). Some cows in the TR group belonged to an extreme tongue-rolling group (ETR). Hair and saliva samples were collected from 601 cows to test cortisol concentrations and dairy herd improvement (DHI) data were collected from a total of 762 cows. There were no differences in hair or saliva cortisol concentrations between the groups (p>0.05), and the frequencies of tongue-rolling were not associated with cortisol concentrations (p>0.05). For DHI in cows, the milk protein percentage (p = 0.028), milk true protein percentage (p = 0.021) and milk crude protein percentage (p = 0.023) of cows in the ETR group were significantly lower than those in the CON group. For cows in ETR group, as the frequencies of tongue-rolling increased, the milk protein percentage (p = 0.034, r = 0.365), milk true protein percentage (p = 0.022, r = 0.393) and milk crude protein percentage (p = 0.035, r = 0.363) increased. We investigated the relationship between stereotypic behaviours and stress by using a non-invasive sampling method to minimise harm to the cows. We suggest that tongue-rolling may not be a way for cows to cope with stress, at least in terms of cortisol concentrations.

18 Effect of precision feeding standardized ileal digestible lysine to lactating sows compared with conventional feeding strategies in a commercial farm

Abstract A total of 728 sows and litters were used in a 19-d lactation study to evaluate effects of precision feeding SID Lys and other amino acids on sow and litter performance and feed cost in a commercial farm. Sows were blocked by parity and allotted to 1 of 2 treatments at entry into farrowing. Treatments consisted of a control diet or a feed blending curve. Two diets were used to create treatment curves, a low Lys diet (0.60% SID Lys) or a high Lys diet (1.07% SID Lys). Sows on the control treatment were fed only the high Lys diet and sows on the blend curve were fed a blend of the low and high Lys diets using the Gestal Quattro Opti Feeder (Jyga Technologies, St-Lambert-de-Lauzon, Quebec, Canada) to target a specific Lys intake/d. Lysine intake targets were based on the NRC (2012) model requirements, except targets were increased by 20% to reach average Lys intake of approximately 63 g/d. The blend of the low and high Lys diet was adjusted on d 7 and 14 for sows fed the blend curve in an attempt to reach target Lys intake. Average Lys intake was 87% of target Lys intake because feed intake was lower than predicted. Sows fed the control diet had greater (P &amp;lt; 0.001; 72.0 vs 54.8 g/d) Lys intake compared with sows on blend curves because they were fed only the high Lys diet (Table). No differences (P &amp;gt; 0.05) in body weight (BW), backfat, loin depth, caliper score, or average daily feed intake (ADFI) were observed. There were no differences (P &amp;gt; 0.05) in litter size at d 2 after equalization or weaning; however, piglets and litters from sows fed the control treatment tended to have greater weaning weights (P = 0.090) and average daily gain (ADG; P = 0.071) compared with piglets and litters from sows fed the blend curve, likely due to insufficient Lys intake for sows on the blend curve to maximize litter growth performance. Feed cost per sow was less (P &amp;lt; 0.05) for sows fed the blend curve in both a low and high ingredient price scenario. No differences (P &amp;gt; 0.05) in feed cost per kg of litter weight gain were observed; however, feed cost per weaned pig was less (P &amp;lt; 0.05) for sows on the blend treatment. Serum urea nitrogen was greater (P &amp;lt; 0.05) at weaning compared with d 10 for control fed sows and was greater (P &amp;lt; 0.05) than blend-fed sows at both time points. Sows fed the control diet had greater milk crude protein (P = 0.05) compared with sows fed the blend curve. While precision feeding sows using diet blending during lactation can be used to reduce feed cost, future research should focus on using technology to automatically adjust diet blend for low or high-feed intake sows to avoid the over or under-feeding of nutrients.

Predicting some Milk Constituents from Linear Body Measurements and Udder Characteristics of Bunaji Cows Utilizing Machine Learning Techniques

Machine Learning techniques are capable of being used in agriculture since they are powerful, fast and flexible tools for classification and predictions of traits of economic importance, particularly those involving nonlinear systems. This study aimed to show how well machine learning methods could predict milk's crude protein and fat content based on the Bunaji cows' linear body measurements and udder characteristics. Forty (40) lactating Bunaji cows from two dairy farms in Yola South Local Government Area, Adamawa State, were purposefully selected for the study. Milk samples were collected from the cows (one-off measurement). The crude protein and fat content of the milk were determined in percentage. An ensemble model consisting of the random forest (RF), support vector machine (SVM) and neural network (NN) algorithms were created using the Orange Software. The models were cross-validated using five folds to assess their robustness. Mean squared error (MSE), root mean squared error (RMSE), mean absolute error (MAE) and coefficient of determination (R2 ) are the metrics utilized for the evaluation. Using the udder features, the approach was used to construct demonstrative models for the prediction of milk protein content. The SVM and RF learners had MSE that was lower than that of NN, showing that the two were superior to NN. The lower performance of NN in this study can be explained on the basis of extremely low data that was available for this study. RF learners exhibited a low likelihood of mistakes in predicting crude protein from udder traits despite the study's small data set. Large data sets were needed for machine learning techniques. As a result, these models must be improved with lots of data.

PSIV-A-10 Effects of Canola Meal Inclusion in Gestation and Lactation Diets with or without Probiotic on sow Performance, Milk Composition and Piglet Performance

Abstract The experiment was conducted to determine the effects of high dietary canola meal (CM) inclusion in gestation and lactation diets with or without probiotic supplementation on sow and litter performance and milk composition. Seventy-five sows were randomly allotted 1 of 3 diets to give 25 replicates per treatment. Diets consisted of a corn and soybean meal (SBM) control (CTRL) or the CTRL diet with SBM replaced by 300g/kg CM and fed with (CM+) or without (CM-) probiotic ActisafÒ Sc 47 supplementation. Sows BW and backfat thickness were determined on d 80 and 111 of gestation, d 1 post-farrowing, and at weaning on d 21. Milk samples were collected on d 1 and d 21 post-farrowing to determine milk composition. Piglets were weighed on d 0 and at weaning. Data were analyzed using the PROC MIXED procedure of SAS 9.4 for a randomized complete block design. Dietary treatment had no effect on sow performance, milk crude protein and lactose oligosaccharide composition, piglet ADG and weaning weight, and piglet survivability (P &amp;gt; 0.10). Sows fed CM- diet tended to fewer (P = 0.07) weaned piglets compared to sows fed CTRL diet, but no difference was found between sows fed the CM+ and CTRL diets (P &amp;gt; 0.10). At weaning, milk fat content for sows fed with CM+ diet was higher (P &amp;lt; 0.05) and tended to be higher (P = 0.09) compared with those fed the CTRL and the CM- diet, respectively. In conclusion, including 300g/kg CM in gestation and lactation sow diets supported similar sow and piglet performance as those the control diet, without affecting piglet survivability at weaning. Also, probiotic supplementation in CM diet increased sow milk fat content at weaning.

Partial replacement of soybean meal with soybean silage in lactating dairy cows diet: part 1, milk production, digestibility, and N balance

The high reliance of the European livestock sector on imported soybean meal (SBM), especially from South America, poses environmental problems, like greenhouse gas emissions for transportation and land-use change with the loss of carbon stock and biodiversity. Aim of the present study was to evaluate the partial substitution of SBM with whole-plant soybean silage in the diet of dairy cows. Thirty-six lactating Holstein cows were arranged according to a change-over design, with 2 weeks of adaptation and 5 days of sampling per period. A control diet (CON) was based on maize silage and SBM, representing 10.7% of total dry matter (DM). In a soybean silage diet (SBS) 35% (on DM basis) of SBM was replaced by soybean silage. The dietary treatment did not affect DM intake, milk production, and dairy efficiency while cows fed SBS resulted in lower milk crude protein (3.43 vs. 3.55%, p < .001) and higher milk urea (30.5 vs. 28.7 mg/dL, p = .002), in comparison with CON. Nutrients digestibility was lower for SBS than CON; particularly fibre digestibility was 31.5 vs. 38.8% (p < .001). The efficiency of nitrogen utilisation was higher for CON than SBS (32.7 vs. 31.3%, p = .003). Soybean silage did not penalise feed intake and milk production. However, to fully exploit this forage, digestibility, and nitrogen utilisation efficiency should be improved. Highlights Soybean silage can substitute one-third of soybean meal in dairy cow diet Soybean silage inclusion in the diet did not affect milk yield and DMI Soybean silage inclusion in the diet reduced N use efficiency

Effects of dietary butyrate supplementation and oral nonsteroidal anti-inflammatory drug administration on serum inflammatory markers and productivity of dairy cows during the calving transition

Dairy cattle experience inflammation during the calving transition period, and butyrate and nonsteroidal anti-inflammatory drugs (NSAID) are expected to reduce the inflammation. Our objective was to evaluate the effects of dietary butyrate supplementation and oral NSAID administration on feed intake, serum inflammatory markers, plasma metabolites, and milk production of dairy cows during the calving transition period. Eighty-three Holstein cows were used in the experiment with a 2 × 2 factorial arrangement of treatments. The cows were blocked by parity and calving date, and randomly assigned to a dietary butyrate or control supplement, and NSAID or a placebo oral administration. Experimental diets were iso-energetic containing calcium butyrate at 1.42% of diet dry matter (DM) or the control supplement (1.04% commercial fat supplement and 0.38% calcium carbonate of diet DM). The close-up diets contained 13.3% starch and 42.4% neutral detergent fiber on a DM basis, and were fed from 28 d before expected calving date until calving. The postpartum diets contained 22.1% starch and 34.1% neutral detergent fiber on a DM basis and were fed from calving to 24 d after calving. Oral NSAID (1 mg of meloxicam/kg of body weight) or placebo (food dye) was administered 12 to 24 h after calving. Dietary butyrate supplementation and oral NSAID administration did not affect milk yield or postpartum serum concentrations of amyloid A and haptoglobin. However, butyrate-fed cows increased plasma fatty acid concentration on d -4 relative to calving (501 vs. 340 μEq/L) and tended to increase serum haptoglobin concentration (0.23 vs. 0.10 mg/mL). There was a supplement by drug interaction effect on plasma glucose concentration on d 4; in cows administered the placebo drug, butyrate supplementation decreased plasma glucose concentration compared with control-fed cows (62.8 vs. 70.1 mg/dL). Butyrate-fed cows tended to have lower milk crude protein yield compared with cows fed the control diet (1.21 vs. 1.27 kg/d). Dietary butyrate supplementation and oral NSAID administration did not have overall positive effects on production performance of dairy cows during the calving transition period.

Effects of rumen-protected methionine and lysine on milk yield and milk composition inHolstein dairy cows consuming a corn grain and canola meal-based diet

Methionine (Met) and lysine (Lys) are thought to be the two most important amino acids for lactation performance. Met and Lys dietary supplementation can thus be an effective approach to improve amino acid balance for lactation performance, particularly in early lactation. The purpose of this study was to determine how rumen-protected (RP) Met + Lys affect milk production, milk composition, and feed efficiency in primiparous Holstein dairy cows fed a corn grain and canola meal-based diet for 60 days (8.5 weeks) following calving. Two hundred primiparous Holstein dairy cows were randomly assigned to one of two dietary treatments based on their expected calving date: 1) a basal diet; or 2) a basal diet supplemented with RP Met + Lys. Milk production and feed consumption were tracked on a daily basis, and milk components were tested once a week. During the trial, drinking water was always available in front of the dairy cows. The RP Met + Lys considerably increased (p < 0.05) milk yield (+ 2.20 kg/d), fat corrected milk yield (+ 2.18 kg/d) and feed efficiency but had no effect on dry matter intake (p > 0.05). There was no effect of treatment on either starting or final body weight (p > 0.05). Cows receiving RP Met + Lys, on the other hand, showed a tendency (p = 0.09) of reduced body condition score (BCS) losses between weeks 1 and 8. The RP Met + Lys increased (p < 0.05) the proportion of milk fat, but had no effect on the other milk composition markers (p > 0.05). Except for milk crude protein, the yields of fat, true protein, lactose, and energy in milk were higher (p < 0.05) in cows fed RP Met + Lys vs. control cows. The results indicate that supplementing with RP Met + Lys after the first calving has a considerable impact on subsequent milk and milk fat production, as well as the yield of the majority of milk nutrients.

Effect of area specific mineral mixture supplementation on milk production, biochemical and blood mineral status of Black Bengal goats

This study was conducted to find out the effect of area-specific mineral mixture (ASMM) supplementation on production performances, the biochemical and mineral profile of Black Bengal does during the peripartum period. For this purpose, 20 pregnant does were made into two groups according to the bodyweight viz., Control-T 0 (n=10) and Treatment-T 1 (n=10) and supplemented with 0 and 6 g ASMM/animal/day, respectively starting from 3 months before the expected date of parturition to till the onset of the first post-partum estrus. Overall mean milk fat, total ash, total solids, solids not fat, milk crude protein and milk yield, blood glucose, non-esterified fatty acids, α-amino nitrogen, phosphorus and serum glutamic pyruvic transaminase concentration were non-significant (P&gt;0.05) between the groups. The overall mean of serum glutamic oxaloacetic transaminase, calcium, copper, and zinc concentration in control (T 0 ) and treatment (T 1 ) groups were127.05±1.27 vs.132.73±1.26 IU/L, 7.83±0.08 vs. 8.19±0.08 mg/dl, 0.66±0.02 vs. 0.94±0.02 ppm, 0.69±0.01 vs. 0.97 ± 0.02 ppm, respectively, and differed significantly (P&lt; 0.05) between the groups. So by the findings of this study, it is concluded supplementation of the area-specific mineral mixture@ 6 g/day during the peripartum period had a significant effect on blood biochemical parameters in Black Bengal does.

Lactation performance, nitrogen utilization, and profitability in dairy cows fed fermented total mixed ration containing wet corn gluten feed and corn stover in combination replacing a portion of alfalfa hay

To effectively use corn by-products for ruminants, lactation performance, nitrogen utilization, and profitability in lactating dairy cows fed fermented total mixed ration (FTMR) that contained wet corn gluten feed (WCGF) and corn stover in combination replacing a portion of alfalfa hay were studied. Thirty-six multiparous Holstein dairy cows (602 ± 46.8 kg of body weight; 109 ± 18.5 day in milk; 30.1 ± 1.53 kg of milk production; and 2.44 ± 0. 51 of parity; mean ± SD) were blocked into 12 groups based on DIM, milk production, and parity and were allocated randomly to 1 of 3 diets for a 14-week period, with the first 2 weeks allowed for adaptation to the diets. The TMR was prepared with same mixed ration of concentrate mixtures and corn silage but different proportions of alfalfa hay, corn stover and WCGF. The treatments were designed as (1) TMR A containing 220 g/kg DM alfalfa hay; (2) TMR B containing 118 g/kg DM alfalfa hay, 68.8 g/kg DM WCGF, and 34.4 g/kg DM corn stover; and (3) Fermented TMR (FTMR) prepared with same ingredient as TMR B. The FTMR diet had higher crude protein (CP) and lactic acid contents content, the ratio of ammonia nitrogen to total N while decreased pH value, neutral detergent fiber (NDF), acid detergent fiber (ADF) and dry matter (DM) content compared to other two diets. The milk fat concentration, milk fat yield, DM and CP degradation, estimated microbial CP yield and feed efficiency were higher (P < 0.05) in the cows fed FTMR treatment but DM intake was lower (P < 0.05) in the cows fed the FTMR treatment than the cows fed the other treatments. The concentrations of rumen volatile fatty acids, except for butyrate, were highest (P < 0.0001) in cows fed the FTMR diet followed by cows fed TMR B and TMR A diets. The cows fed the FTMR diet had a higher molar proportion of acetate, total-tract apparent digestibility and ammonia-N concentration and a lower molar proportion of butyrate, organic matter, NDF, and ADF intakes than the cows fed the other diets. The cows fed the FTMR diet decreased fecal N excretion and retention N, increased the urea nitrogen concentration in the urine and milk and improved income over feed cost per cow per day compared with the cows fed the other diets. The results confirmed that FTMR prepared with WCGF and corn stover in combination replacing a portion of alfalfa hay is a suitable choice for improving lactation performance of dairy cows.

Longitudinal Changes in Crude Protein and Amino Acids in Human Milk in Chinese Population: A Systematic Review.

More than 20% of the world population live in China, which has made significant achievement in human milk research. Part of the data that were published in Chinese were, however, unavailable to non-Chinese speakers. There was also no comprehensive overview of crude protein and amino acid levels in human milk in Chinese population. This systematic review aimed to compile the data on human milk crude protein and amino acid levels in Chinese population. After searching for and screening original research articles in both English and Chinese, 23 published from 1987 to 2019 were identified (18 in Chinese and 5 in English). The data were pooled into 9 defined lactation stages. Crude protein and amino acids (protein bound plus nonprotein bound) concentrations gradually decreased during the first 60 postpartum days and remained relatively static thereafter. The concentrations and dynamic change of crude protein and amino acids were similar to those in other populations. By contrast, the longitudinal changes in free amino acids (nonprotein bound) were less clear due to the limited data available. Several common weaknesses were identified in these studies. Our study represented the most comprehensive overview on crude protein and amino acid concentrations in human milk in Chinese population, and enhanced the knowledge of protein and amino acid intakes and requirements by Chinese infants.

Effect of Season and Factory on Cheese-Making Efficiency in Parmigiano Reggiano Manufacture.

The assessment of the efficiency of the cheese-making process (ECMP) is crucial for the profitability of cheese-factories. A simple way to estimate the ECMP is the measure of the estimated cheese-making losses (ECL), expressed by the ratio between the concentration of each constituent in the residual whey and in the processed milk. The aim of this research was to evaluate the influence of the season and cheese factory on the efficiency of the cheese-making process in Parmigiano Reggiano cheese manufacture. The study followed the production of 288 Parmigiano Reggiano cheese on 12 batches in three commercial cheese factories. For each batch, samples of the processed milk and whey were collected. Protein, casein, and fat ECL resulted in an average of 27.01%, 0.72%, and 16.93%, respectively. Both milk crude protein and casein contents were negatively correlated with protein ECL, r = −0.141 (p ≤ 0.05), and r = −0.223 (p ≤ 0.001), respectively. The same parameters resulted in a negative correlation with casein ECL (p ≤ 0.001) (r = −0.227 and −0.212, respectively). Moreover, fat ECL was correlated with worse milk coagulation properties and negatively correlated with casein content (r = −0.120; p ≤ 0.05). In conclusion, ECLs depend on both milk characteristics and season.

Increased dietary protein levels during lactation improved sow and litter performance

The study was conducted to investigate the effect of increasing balanced dietary protein for hyper-prolific lactating sows. In total 544 sows (parity 1–4) was allotted to one of six diets from day 2 post-partum until weaning. The diets were analyzed to have a standardized ileal digestible (SID) crude protein (CP) level of 104.3, 113.3, 120.9, 128.5, 139.2 or 150.0g/kg. At d 2 post-partum litters were standardized to 14 piglets and body weight (BW), back fat (BF) thickness of sows and litter weight were recorded. Body weight, BF thickness and litter weight was also recorded at weaning. On a subsample of 70 sows (parity 2 and 3) milk samples were obtained at day 3, 10 and 17 post-partum and analyzed for fat, CP and lactose. In the analysis of the dose-response data the dietary SID CP concentration were used as explanatory variable. The abovementioned response variables were fitted with linear broken-line, quadratic broken-line and linear regression models. Sow BW and BF loss reached a break point at 143g SID CP/kg and 127g SID CP/kg, where sows lost 0.58kg/d and 3mm, respectively (P<0.001). Multiparous sows had a higher average daily gain of the litter than first parity sows (3.07 vs. 2.53kg/d) at the break point at 135g SID CP/kg (P<0.001), but litter size (13.0±1.2 piglets) at weaning was unaffected by dietary treatment (P=0.30). Milk CP increased to 5.0g/100mL until a breakpoint at 136g SID CP/kg, milk lactose decreased until a breakpoint at 120g SID CP/kg to 5.3g/100mL (P<0.001) and milk fat increased linearly (P<0.05). The daily output of milk protein was increased at day 17 until a breakpoint at 130g SID CP/kg (663–670g/d; P<0.001). The content of milk fat increased linearly with increasing dietary SID CP (P<0.05). There was a tendency towards an increased number of total born piglets in next litter with increased dietary SID CP (P=0.06), whereas the weaning-to-estrus interval was unaffected by treatment (P=0.83). In conclusion, increasing dietary SID CP up till 135g/kg or 850g SID CP/d increased ADG of the litter, and this increase was caused by increased milk yield and increased daily protein output in milk.

Agentes causadores de mastite e relações entre a CCS com a produção e com a composição do leite em vacas leiteiras

Este estudo teve por objetivo avaliar o efeito da prevalência de patógenos causadores de mastite e da contagem de células somáticas (CCS) sobre a produção e composição do leite. Amostras de leite de 1163 vacas da raça Holandesa com 30.97±10.22 kg·d-1 de produção de leite foram coletadas e avaliadas. Staphylococcus spp. foi o patógeno mais prevalente. No geral, o aumento da CCS reduziu a produção de leite e a concentração de lactose e aumentou a concentração de proteína. Coliformes tiveram uma relação diferente entre CCS e teor de proteína no leite. A relação entre CCS e concentração de lactose foi diferente para S. aureus e Streptococcus spp. Lactose e proteína bruta são os componentes do leite mais sensíveis à variação da CCS e esta relação é dependente da presença do patógeno.

The potential of the development of Holstein crossbreed dairy cows intropical lowland Indonesia: study of physiological and milkproduction by body cooling treatment

The research aimed to evaluate the effectiveness of body cooling techniques on physiological and milk production of Holstein crossbred dairy cow at lowland area during the dry season. Three treatments have been done for 30 days that were: none, fans, and water sprinkling cooling, for 30 minutes each at 08.00 and 11.00 h. The effects of treatment are not significant (P &gt; 0.05) on air temperature, RH, THI, respiration rate, heart rate, and heat tolerance coefficient. The rectal temperature by sprinkling (38.76 °C) was within the normal range, lower (P less than 0.05) than the fans (39.59 °C) and none (39.57 °C). Sprinkling increased serum T3 concentrations (2.81 ng/ml), higher than none (1.58 ng/ml) (P less than 0.05). The effect of treatment is not significant (P &gt; 0.05) on milk production, dry matter, TDN and crude protein intake. The research highlighted that water sprinkling was effective in maintaining normal physiological condition of Holstein crossbreed cows in hot lowland environments.

Lactation and body composition responses to fat and protein supplies during the dry period in under-conditioned dairy cows

An experiment was designed to study the effect of precalving supplementation with protein (Pr) and rumen-inert fat (F) on body composition and subsequent milk production and composition. Forty Holstein-Friesian dairy cows were allocated to 1 of 4 dietary treatments in the dry period (DP) based on a first-cut ryegrass silage, with 6 mature (in their third or greater pregnancy) and 4 young (in their second pregnancy) cows per treatment. These were low Pr, low F (silage alone); low Pr, high F (silage with 10% rumen-inert fat, mixed on a dry matter basis); high Pr, low F [silage with 5% high-protein corn gluten meal (CGM)]; and high Pr, high F (silage with 5% CGM and 10% rumen-inert fat). All the diets were individually offered ad libitum and dry matter intake (DMI) was recorded daily during the DP. After calving, all cows received ryegrass silage plus 8 kg/d of a commercial dairy concentrate. During the DP, DMI was higher for mature than for young cows. All animals recovered body condition score (0.13 units/wk, 1-5 scale), reaching a maximum score of 2.4 some days before calving. Precalving maximum muscle longissimus dorsi (LD) depth was greater for mature (47.5 mm) than for young cows (45.7 mm), and milk fat concentration was also higher for mature than for young cows (40.2 and 39.0 g/kg, respectively). Supplementation with CGM increased maximum LD depth (from 45.9 to 47.6 mm), calf birth weight (low Pr = 43.2, high Pr = 46.3 kg), and milk crude protein concentration (from 30.8 to 31.6 g/kg). Fat supplementation in the DP of the mature cows increased maximum back fat depth (from 3.6 to 4.5 mm), milk yield (low F = 26.3, high F = 28.7 kg/d), and Pr yields (low F = 837, high F = 899 g/d). Inclusion of F in the DP diets reduced casein concentration in milk at wk 3 of lactation from 26.3 to 24.5 g/kg. Milk CP yield was also increased by CGM supplementation when compared within cows receiving F-supplemented silages (low Pr, high F = 832 g/d; high Pr, high F= 877 g/d). It can be concluded that CGM supplementation in the DP increased subsequent milk Pr concentration, but milk Pr yield increased only in those animals also receiving F supplementation. Dry period diet supplementation with F increased maximum back fat depth and milk and CP yields in the mature cows, and led to more LD muscle mobilization during early lactation. Second-calving cows had a lower DMI and milk fat concentration than mature cows.

Combination effects of milk feeding methods and starter crude protein concentration: Evaluation on performance and health of Holstein male calves

The aim of this study was to examine whether the increasing crude protein (CP) content of starter feed together with the different milk feeding procedure would improve performance, and health responses in dairy calves. Two milk feeding procedures [step-down (STEP) or conventional (CON)] and two levels of starter crude protein (20 or 24% of starter DM) were combined in 2×2 factorial arrangements. Forty Holstein male calves were included in four following experimental treatments (10 calves per treatment): (1) conventional milk feeding with 20% CP starter (C20); (2) conventional milk feeding with 24% CP starter (C24); (3) step-down milk feeding with 20% CP starter (D20); (4) step-down milk feeding with 24% CP starter (D24). For the conventional method, calves (n=20) received 5.5L/d milk until day 56 of the study, and then they were fed 2L/d milk from day 56 to 59 of the study. For the step-down method, calves (n=20) received 7L/d milk until day 35, and 4L/d milk from day 35 to 49 of the study followed by feeding 2L/d milk from day 50 to 59 of the study. The total amount of milk consumed with both milk feeding procedures (STEP and CON) was similar, during milk feeding period (311L±3). Calves in all groups were weaned on day 60 and they were followed up until day 74 of the study. Starter dry matter intake, body weight, average daily gain, feed efficiency, and structural growth were not affected by experimental treatments. On d 35 and d 74 of the experiment, rumen fluid samples were collected with a stomach tube 4h after morning feeding and were analyzed for volatile fatty acid (VFA) by gas chromatography. Rumen pH and molar concentration of ammonia-N were higher in STEP method during milk feeding period, while calves consuming 24% CP starter had a higher molar concentration of ammonia-N on d 74 (P<0.05). Calves fed starter containing 24% CP had less rumen butyrate and valerate molar concentration on d 35 and 74, respectively (P<0.01). There were interactions between milk feeding and CP concentration of starter for days with scours (P<0.05). Calves fed D20 have greater pre-weaning fecal score and overall scour days than other treatments. Blood samples were taken on d 35 and d 74 of study for metabolites assessing and −7 and +1 d of weaning for evaluating hematological parameters. There was no effect of milk feeding procedure or CP level on lymphocyte levels; however, there was a significant CP x milk feeding procedure interaction at d 61. No treatment effects were observed on red blood cell (RBC) count, glucose, total protein, albumin, and hemoglobin concentration, but highest values of blood urea nitrogen (BUN) were found with the 24% CP starter diets on d 74 (P<0.05). In conclusion, increasing starter CP concentration in both milk feeding procedures had no effects on calf performance, structural growth or health.

Composition of the milk of yaks raised at different altitudes on the Qinghai–Tibetan Plateau

We examined the nutritional quality of milk from yaks raised at 3016, 3824 and 4750 m above sea level on the Qinghai–Tibetan plateau. The Trolox equivalent antioxidant capacity, vitamin A concentration, fat content, conjugated linoleic acid, γ-linolenic acid, total unsaturated fatty acids and Fe, Zn and Na concentrations of yak milk increased while vitamin C concentration, crude protein content and Cu and Mn concentrations decreased with increasing altitude. Also, the atherogenic index was lower at the middle and highest altitudes than at the lowest altitude. Thus, in general, there was an increase in nutritional quality in the milk with an increase in altitude. We concluded that the observed differences resulted from the combined effects of altitude, forage composition and forage availability. Crude protein in milk and forage both decreased while fat in milk and neutral detergent fibre in forage both increased with increasing altitude.

Crude Protein and Non-protein Nitrogen Content in Dairy Cow Milk

Abstract Milk composition is of prime economic importance for farmers. Milk total proteins are composed of casein, whey proteins and non-protein nitrogen. The objective of this work was to establish milk crude protein, non-protein nitrogen (NPN) and urea content in dairy cow milk produced in different farms in Latvia. Cow milk samples (n=30) were collected in September 2012 from four different farms breeding diverse cow breeds. Average crude protein, casein and urea content in milk varied significantly among farms. NPN content in cow milk varies among farms - from 0.194% to 0.232%. Average crude protein and casein content was significantly higher (p&lt;0.05) for Latvia Brown breed cows, while NPN content did not differ significantly among breeds. Regression between NPN and urea content in milk was R² = 0.458. Correlation between NPN and urea content was significant (r = 0.677). This study allowed establishing that crude protein and NPN content in milk varied significantly (p&lt;0.05) in farms with differing dairy cow housing and feeding technologies