Negative relationship between dry matter intake and the temperature-humidity index with increasing heat stress in cattle: a global meta-analysis

Changes in frequency and severity of heat waves due to climate change pose a considerable challenge to livestock production systems. Although it is well known that heat stress reduces feed intake in cattle, effects of heat stress vary between animal genotypes and climatic conditions and are context specific. To derive a generic global prediction that accounts for the effects of heat stress across genotypes, management and environments, we conducted a systematic literature review and a meta-analysis to assess the relationship between dry matter intake (DMI) and the temperature-humidity index (THI), two reliable variables for the measurement of feed intake and heat stress in cattle, respectively. We analysed this relationship accounting for covariation in countries, breeds, lactation stage and parity, as well as the efficacy of various physical cooling interventions. Our findings show a significant negative correlation (r =  - 0.82) between THI and DMI, with DMI reduced by 0.45 kg/day for every unit increase in THI. Although differences in the DMI-THI relationship between lactating and non-lactating cows were not significant, effects of THI on DMI varied between lactation stages. Physical cooling interventions (e.g. provision of animal shade or shelter) significantly alleviated heat stress and became increasingly important after THI 68, suggesting that this THI value could be viewed as a threshold for which cooling should be provided. Passive cooling (shading) was more effective at alleviating heat stress compared with active cooling interventions (sprinklers). Our results provide a high-level global equation for THI-DMI across studies, allowing next-users to predict effects of heat stress across environments and animal genotypes.

Analysis of gene expression from human breastmilk cells: A comparison between low and high producers, and the influence of anxiety and depression on milk production, gene expression and bacterial production

Background

Breastmilk is considered the gold standard of infant nutrition. Many mothers have difficulty with breastfeeding and over 50% of women stop due to perceived low production.

Aims and methods

Our study compared gene expression in 8 samples of low and high producers of milk. All subjects were administered GAD-7 and PHQ-9 questionnaires. Low-producers were all found to have more depression and anxiety compared to high-producers.

Results

We did not find significant differences between gene expression between low and high milk producers. Only 5 of 8 samples contained a significant number of human cells. We did find differences in the amount of various bacterial populations.

Conclusion

Our results indicate that gene expression in breastmilk is complicated by collection methods. We recommend that even though some women produced less than 600 ml of milk over a 24-hour period of time, due to the nature of the bacteria found in milk they try to breastfeed as much as they can for the health benefits of their infants. the rich bacterial diversity in all patients including the low producers strongly suggests that even women producing lesser quantities of milk confer their children numerous benefits by breastfeeding them.

Culling and mortality of dairy cows: why it happens and how it can be mitigated

The United Nations estimates that the global population will total 9.7 billion in 2050. Rapid population growth pose a significant obstacle to achieving the Sustainable Development Goals, particularly eradicating hunger and poverty. In view of the expanding population growth, food production ideally should triple to prevent massive food shortages. Sustainable food and nutrition security is the focal point of the dairy industry. Dairy production plays a pivotal role in addressing and advancing global food and nutrition security. It serves as a major source of protein, calcium, and phosphorus in many families in developing countries with a fast-growing population. Consequently, the dairy industry is expected to grow by approximately 26% in the next 10 years and produce an estimated 1077 million tonnes of milk by 2050. However, the growth and distribution of the dairy industry is limited by many factors such as culling and mortality of dairy cows. Several studies highlight reproduction failures, old age, poor milk yield, diseases (mastitis, lameness, and dystocia), and heat stress as some reasons for culling of dairy cows. Hence, this review highlights the factors influencing culling and mortality in dairy production farms, and discusses mitigating measures to limit culling.

Moving towards sustainable breeding objectives and cow welfare in dairy production: a South African perspective

Genetic advancements have resulted in improved dairy production over many decades, due to the focus of breeding objectives on production as the driving force for genetic progress and overall farm profitability. Major advancements were made in the easy-to-measure traits with moderate to high heritability, which resulted in unintended consequences on herd fertility, health, and welfare of cows. In addition, climate change and animal welfare concerns demanded balanced breeding objectives and selection approaches for sustainable production-including health and longevity. The inclusion of genomic information into genetic evaluations has been proved to benefit traits associated with welfare and sustainable production. Cow welfare traits remain complex and suitable phenotypes are not always easy to measure or readily available for genetic evaluations. The challenge for improvement of cow welfare often lies within implementation of sensitive and measurable parameters. The aim of this review was to explore the reconsideration of breeding objectives in the dairy industry towards sustainable dairy production and cow welfare with reference to selection of dairy animals in South Africa.

Effect of rubber and concrete flooring on resting behavior, hock injuries, and milk production of primiparous Friesian crossbred dairy cows housed in a free-stall barn in Mid-Country, Sri Lanka

The floor surface of the cubicle is a detrimental factor on cow comfort. The effects of two floor types, rubber and concrete, on dairy cow comfort and milk production were compared for a period of 13 weeks. Fourteen Friesian crossbred dairy cows with an average body weight of 425.67 ± 61.12 kg (mean ± SD), nose to tail body length of 2.07 ± 0.15 m, rump height of 1.29 ± 0.02 m, hook bone width of 0.48 ± 0.05 m, and body condition score (BCS) of 4.13 ± 0.44 were used, with seven cows per flooring treatment. The cows produced a mean of 15.93 ± 4.03 l/cow/day and a constant feeding plan was practiced. The swelling and wound severity of hocks diminished (P < 0.05) starting at the third and tenth weeks, respectively. Daily lying time/h (concrete: 9.67 ± 1.24, rubber: 10.60 ± 0.69, P = 0.046) and average duration of lying bouts/min increased (concrete: 58.16 ± 7.74, rubber: 65.66 ± 9.85, P = 0.050) starting from the twelfth week on rubber bedding. Prevalence of mastitis, lameness, and cow cleanliness remained unchanged on floor treatments. A progressive increase in daily milk production/l (concrete: 13.37 ± 1.46, rubber: 16.67 ± 2.24, P = 0.007) of cows in rubber bedding was observed at the fourth week of the experiment. Hence, the current study suggests that the use of softer bedding such as rubber mats could improve cow comfort and daily milk production of cows.

Impacts on two dairy breeds of adding a third (night) cooling event under extreme ambient heat

Impacts of an additional cooling event during the night on physiological and productive parameters of two breeds (B) of dairy cows under severe heat stress conditions were determined. Fifteen Holstein (H) and 15 Jersey x Holstein (JxH) cows were assigned to one of the two cooling strategies (CS), where the difference was an added 1 h cooling event during the night (i.e., 3X and 4X cooling events) with the 4X group having the added night cooling event. Maximum and minimum average temperature/humidity indices during the study were 86 and 77 units, respectively. There were no CS x B interactions for any response variable. Body condition score (BCS) was similar between CS, but H cows had higher (P<0.05) condition than JxH. There were no differences in rectal temperature due to CS or B. Respiration rate between breeds and cooling strategies were similar throughout the day. However body surface temperatures of head, thurl, right flank, and udder were higher (P<0.05) in 3X versus 4X cows, and H cows maintained a higher (P < 0.05) temperature in thurl and right flank than JxH during PM hours. Metabolites and hormone concentrations were not affected by CS, but H cows had lower (P < 0.05) triiodothyronine and higher (P < 0.05) thyroxine, than JxH. The 4X cows had higher (P<0.05) milk yield and milk energy output than 3X cows. While H cows produced more milk than JxH, the latter had higher (P < 0.05) milk component levels. In general, JxH cows were judged to have to demonstrate a more desirable physiological response and milk composition outcome than H cows. An additional night cooling event was judged to result in more desirable physiological and productive responses than in cows without this extra night cooling event under the extremely hot and dry environmental conditions during the study.

Assessing the perceptions and practices of peri-urban dairy farmers regarding bovine mastitis management in North-Western Nigeria

Peri-urban dairy farming is an emerging industry in sub-Saharan Africa that risks being undermined by diseases like bovine mastitis (BM) if farmers do not implement appropriate management programmes. However, little is currently known about farmer perceptions and practices towards BM due to challenges with accessing these herds for research. In this study, 49 intensive and 53 extensive peri-urban dairy farmers having ≥10 milking cows in Kaduna and Zaria metropolises, North-Western Nigeria were recruited through snowball sampling and on-farm interviews were conducted to collect information on herd demographics, milking procedures, and mastitis management. Descriptive statistics were provided for all study variables and statistical comparisons were made between intensive and extensive herds. The mean herd size was 33 milking cows (range: 11-62). A greater proportion of extensive herds contained only indigenous breeds of cattle (36/53; 68 %) compared with intensive herds (6/49; 12 %). Hand milking was the most common milking method across both herd types (93/102; 92 %). Intensive herds had better hand washing and udder cleaning practices, but there was no statistical difference between management systems with regards to floor, udder, and tail cleanliness. Only a small number of farms performed on-farm diagnosis of BM via strip cup test (4/102; 4%) or rapid mastitis test (3/102; 3%). Treatment of clinical mastitis was typically by intramuscular antibiotic injection (71/102; 70 %) or topically applied herbal preparations (14/102; 14 %). Dry cow intramammary therapy was only used by 6/46 intensive farms (13 %) and 1/53 extensive farms (2%). Most extensive herds (40/53; 76 %) reported milking cows with clinical mastitis after apparently healthy cows, however this practice was less common among intensive herds (5/49; 10 %). Extensive herds were less likely to request veterinary assistance for mastitis than intensive herds (17/53; 32 % versus 28/49; 57 %) and had higher perceived costs for treating BM cases. Intensive farmers reportedly received higher prices for milk than extensive farmers and perceived that BM was causing significantly more production losses in their herds. Only a small number of farmers (20/102; 20 %) kept mastitis treatment records for their herds. Overall, the study findings indicate that peri-urban dairy farmers may be lacking in awareness of BM impacts and access to basic resources to implement good practices such as hand washing between milking cows and antibiotic intramammary infusions.

Dairy farm-workers' knowledge of factors responsible for culling and mortality in the Eastern Cape Province, South Africa

Milk serves as a significant source of protein for many families and aids in combating food insecurity. However, the demand for milk and milk-related products far exceeds the supply. The objective of the study was to evaluate dairy farm-workers' knowledge of factors responsible for culling and mortality of dairy cows in the Eastern Cape Province. Data was collected from 106 dairy farm-workers using a questionnaire. Any correctly answered question by the majority amounted to a point and a zero for incorrectly answered questions. Correct answering by the majority to more than half the questions of a subsection amounted to a pass. A less than 50% pass rate was considered a poor level of knowledge, 51-69% pass rate was considered an average level of knowledge, and anything higher than that was considered a good level of knowledge. Most farm-workers (66.0%) relied on their colleagues for dairy health information. Most dairy farm-workers (49.1%) indicated that lameness, milk fever (56.6%), and mastitis (47.2%) do not lead to culling and mortality of dairy cows. A majority (83%) of farm-workers agreed that reproduction problems, poor milk yield (77.3%), and age (81.1%) are the main reasons for culling dairy cows. The participants had varying perceptions and limited knowledge (28.3%) about the major contributing factors of culling and mortality. The lack of training courses and minimal use of other sources of information such as the internet might contribute to this poor knowledge and perceptions.

Effects of faba bean, blue lupin and rapeseed meal supplementation on nitrogen digestion and utilization of dairy cows fed grass silage-based diets

There is increasing interest in using locally produced protein supplements in dairy cow feeding. The objective of this experiment was to compare rapeseed meal (RSM), faba beans (FBs) and blue lupin seeds (BL) at isonitrogenous amounts as supplements of grass silage and cereal based diets. A control diet (CON) without protein supplement was included in the experiment. Four lactating Nordic Red cows were used in a 4 × 4 Latin Square design with four 21 d periods. The milk production increased with protein supplementation but when expressed as energy corrected milk, the response disappeared due to substantially higher milk fat concentration with CON compared to protein supplemented diets. Milk protein output increased by 8.5, 4.4 and 2.7% when RSM, FB and BL were compared to CON. The main changes in rumen fermentation were the higher propionate and lower butyrate proportion of total rumen volatile fatty acids when the protein supplemented diets were compared to CON. Protein supplementation also clearly increased the ruminal ammonia N concentration. Protein supplementation improved diet organic matter and NDF digestibility but efficiency of microbial protein synthesis per kg organic matter truly digested was not affected. Flow of microbial N was greater when FB compared to BL was fed. All protein supplements decreased the efficiency of nitrogen use in milk production. The marginal efficiency (amount of additional feed protein captured in milk protein) was 0.110, 0.062 and 0.045 for RSM, FB and BL, respectively. The current study supports the evidence that RSM is a good protein supplement for dairy cows, and this effect was at least partly mediated by the lower rumen degradability of RSM protein compared to FB and BL. The relatively small production responses to protein supplementation with simultaneous decrease in nitrogen use efficiency in milk production suggest that economic and environmental consequences of protein feeding need to be carefully considered.

Effects of photoperiod and light intensity on milk production and milk composition of dairy cows in automatic milking system

The purpose of this study was to determine the effects of photoperiod and light intensity on milk production, milk composition, hormones levels and blood metabolites indices of Korean Holstein dairy cows in automatic milking system (AMS). A total of 24 Holstein dairy cows were selected and used to four subsequent treatments for the experimental periods of 60 days. The light programs consisted of (1) Control: the natural photoperiod with 14.2 h of the light period and 9.4 h of the dark period (below 10 Lux); (2) T1: 16 h of the long day photoperiod (LDPP) with 50 Lux of light; (3) T2: 16 h of LDPP with 100 Lux of light; and (4) T3: 16 h of LDPP with 200 Lux of light, respectively. Importantly, there was a significant difference in the thurl activity of dairy cows between the different light intensity programs (p < 0.05). Milk yield was higher in T1 and T2 (40.80 ± 1.71 and 39.90 ± 2.02 kg/d, respectively) than those of Control and T3 (32.18 ± 1.51 and 35.76 ± 2.80 kg/d, respectively) (p < 0.05), but DMI was lower in T1, T2, and T3 compared to Control (p < 0.05). Also, milk fat percentage, the contents of milk fat and total solids were higher in T2 than those in the others (p < 0.05). The average daily melatonin level in milk was high to T3 (28.20 ± 0.43 pg/mL), T2 (24.62 ± 0.32 pg/mL), T1 (19.78 ± 0.35 pg/mL), and Control (19.36 ± 0.45 pg/mL) in order (p < 0.05). Also, the cortisol levels in milk and blood were lower in treatment groups than in Control (p < 0.05). The results of this study showed that it will be effective to improve the milk yield and milk composition, and to reduce the stress of dairy cows when the light conditions regulate to extend the photoperiod to 16 h at a light emitting diode (LED) intensity of 100 Lux under the AMS in dairy farm.

Use of unconventional agro-industrial by-products for supplementation of grazing dairy cattle in the Peruvian Amazon region

The effect of supplementation of grazing cattle with unconventional agro-industrial by-products on milk production and economic performance was evaluated in the Amazon region of Peru. Ten lactating cows were used in a simple crossover design with two periods of 21 days (11 days of adaptation and 10 days of measurements), and two treatments: conventional supplementation (rice polishing) and a mixture of unconventional agro-industrial by-products-MUABP (rice polishing, rice middling, cocoa hull, and coconut meal). Cattle supplemented with MUABP produced more milk than those fed the conventional supplement (10.2 vs. 8.8 kg/cow/day, p <0.001). No differences were found between the two treatments in protein, fat, or lactose content of milk (3.9%, 3.17%, 4.54% on average respectively; p ≥0.05). Daily weight gain with the MUABP treatment was 0.09 kg/day, while with conventional supplementation cow lost -0.04 kg/day (p =0.01). Body condition did not differ between treatments (p ≥0.05). Income due to supplementation with unconventional agro-industrial by-product was US $0.2 in comparison with only rice polishing. Cattle supplemented with MUABP improved milk production and their economic profitability.

Date press cake replaces corn grains in the diet of lactating Egyptian buffaloes and Barki rams

High prices of corn grains due to their shortage in some regions force researcher to explore nonconventional alternatives. Therefore, the present study aimed to evaluate the effect of replacing corn grains at 25% (dry matter (DM) basis) with date press cake (DPC) without/with exogenous enzymes at 2 L/ton feed in diets of Barki sheep (24 rams divided as 6 rams/treatment) and Egyptian buffaloes (16 buffaloes divided as 4 buffalo/treatment). Each experiment was conducted under 4 treatments regime: control diet containing only corn grains, T₁ diet where the control diet supplemented with exogenous enzyme, T₂ diet where the control diet contained DPC on corn replacement (25% DM basis), and T₃ diet where the control diet contained DPC on corn replacement (25% DM basis) along with exogenous enzyme supplement. The control diet contained concentrate feed mixture, corn silage, and rice straw at 50:40:10, respectively. Data on nutrient intake, digestibility, and nitrogen balance in sheep, as well as on blood parameters, milk production, and composition in buffaloes, were analyzed using the PROC GLM/MIXED procedure of SAS. The sheep under T₂ and T₃ treatments demonstrated greater digestibility of dry matter, organic matter, and neutral detergent fibers, along with improved nitrogen balance. The milk yield and its constituents were improved in the buffaloes under T₃ treatment followed by those buffaloes under T₂ and T₁ treatments. This investigation could conclude that replacing corn grains with DPC at 25% (DM basis) in ruminant diets had beneficial effects on nutrients digestibility and milk yield along with its composition.

Effects of parity and days in milk on milk composition in correlation with β-hydroxybutyrate in tropic dairy cows

The current study was conducted to evaluate the effect of parity and days in milk on milk yield and milk production traits and their correlation with β-hydroxybutyrate (BHB) concentrations in milk of Chinese tropic Holstein dairy cows which are adapted to a humid subtropical climate in central China. About 3055 milking records of Holstein cows were obtained from three farms in the hot region in the center of China. The records were classified according to parity to 4 categories: first parity, second parity, third parity, and greater than third parity. According to days in milk, there were 4 groups, first group from (1-100 days), second group from (101-200 days), third group from (201-305 days), and fourth group (>305 days). Milk samples collected between April and November 2019 from the three farms were routinely checked for milk components including BHB using mid-infrared spectroscopy a MilkoScan FT+ (Foss, Hillerød, Denmark). Data were analyzed by multivariate analysis of variance (generalized linear model, GLM). Pearson's correlation coefficients were used to measure the correlation between SCC and BHB with milk yield and milk production traits. Results showed the significant effect of parity and days in milk on milk yield and milk production traits. There was a negative effect of parity and days in milk on milk quality, with increasing parity and days in milk being associated with higher somatic cell count (SCC) (P <0.001). Days in milk significantly affected (P=0.001) BHB. It was concluded that with increasing parity and prolonged days in milk, there was a negative effect on milk quality and udder health of the tropic dairy cows in central China. Based on the results of the current study, sampling milk for specific metabolites, somatic cell count, and quality are sufficient to asses herd health.

When is a "breed" not a breed: the myth of the Mpwapwa cattle of Tanzania

Almost all of Tanzania's huge cattle population is native Tanganyika Shorthorn Zebu (TSZ) (Bos indicus), an animal of small stature and reputably low productivity. Attempts to improve productivity started in 1925 by crossing local cattle with European (B. indicus) bulls and by disease control using TSZ cattle to produce antirinderpest serum. Efforts to create a beast adapted to central Tanzania's hot semiarid environment were initiated in the 1930s using B. indicus breed such as Red Sindhi and Sahiwal bulls from India and Bos taurus such as Ayrshires from the UK. These attempts were halted in 1940. A new programme, started in 1944, aimed to create a composite animal capable of producing 2300 kg of milk in a 305-day lactation with a calving interval of 380 days and a 250-kg carcass from a 4-year old steer. Additional genetics were introduced including Kenya Boran (B. indicus) and UK Jersey and Guernsey (B. taurus) in addition to the Ayrshire. The composite was declared a breed in 1958 but the animal was nowhere near a fixed type and genetic modification continued for many years. Development was complicated by factors including disease, drought, inadequate nutrition, the political and economic climates and lack of professional staff. Production targets were never achieved and new genetics, especially Sahiwal (B. indicus) from Kenya, continued to be introduced. By the early 21st century, the Mpwapwa animal was almost 80% Sahiwal. There has never been more than 1000 live Mpwapwa-type animals at one time and there has been little dissemination outside the original station. Declared as endangered by international organizations and within Tanzania, it could be considered that the Mpwapwa has never been a breed in the conventional sense of an animal breeding true to type with consistent production outputs.

Short-term effect of foot-and-mouth disease (FMD) vaccination on the milk yield in the Deoni and crossbred cows

Biannual vaccination of the cattle with inactivated foot-and-mouth disease (FMD) vaccine is the control strategy in endemic countries. Reduction in the milk yield is one of the main reasons for poor compliance of the cattle owners to FMD vaccination. As it can adversely affect the herd immunity, the present study aimed to quantify the losses in the milk yield post-FMD vaccination. Retrospective data on the milk yield (kg) recordings, days in milk, parity, and age at vaccination of the Deoni and crossbred cows were collected from 10 days before (-10) to 10 days after (+10) FMD vaccination (dpv). Days in milk were categorized into three stages of lactation for Deoni and crossbred cows. Age (month) was categorized into four classes. Least squares means of the milk yield were generated after adjusting for year, age, parity, and stage of lactation. Based on exploratory data analysis, the corrected milk yield records from -2 to +2 dpv for 5 years comprising 614 data points on Deoni cows (n=54) and 488 data points on crossbred cows (n=55) were used for the final analysis. Because of the correlated errors on the corrected milk yield, linear mixed model ANOVA was done by fitting dpv as fixed effect and cow as random effect, and the results revealed the effect of dpv was non-significant (P>0.05) in either breed. With respect to dpv 0, a marginal reduction of 90 g in the corrected milk yield in the Deoni cow was recorded on dpv 1, while the reduction was about 360 g on dpv 0 as compared dpv -1 in the crossbred cow. It was concluded that FMD vaccination caused a transient non-significant reduction in the milk yield in the Deoni and crossbred cows.

Influence of heat stress on milk production and its financial implications in semi-arid areas of South Africa

Heat stress affects dairy cows' feed intake, reproductive system and milk production. This study analysed the financial implications of heat stress for small scale milk producers. The semi-arid regions of the Free State - Bloemfontein, Bothaville, and Bethlehem were selected for the study. To estimate the impact of heat stress on milk production, baseline (1950-1999) and mid-century (2040-2070) climate data and Temperature Humidity Index thresholds (THI_thershold) of 70 and 65 were used. Mid-century data with no adaptation strategy resulted in a doubled loss, while moderate heat-mitigation strategies (wetting and forced ventilation) resulted in positive improvements in milk production and income of farmers. Results show strong polynomial correlations (R² of 0.73-0.79) between the T_max and milk-production losses where above T_max of 25°C, milk-production loss increased sharply. The combined average loss of milk production during the hot summer was estimated at 0.35 liters per cow in a day, which is equivalent to ZAR1.27 per cow per day. With changing climate, the highest revenue loss was recorded in the MPI_ESM_MR future climate scenario. Moreover, results from the questionnaires show that heat stress reduces farmers' milk production significantly in the summertime, and for most of the respondents, measures that should be taken are too costly to apply. Exhaustive analysis of the economic impacts of heat stress on milk production is recommended for future studies, as it is an important sector in alleviating household food insecurity in South Africa.

Effects of replacing soybean meal with pumpkin seed cake and dried distillers grains with solubles on milk performance and antioxidant functions in dairy cows

Pumpkin seed cake (PSC), a byproduct of pumpkin seed oil processing, is used in ruminant feed as a beneficial protein source. Experiments were conducted to evaluate PSC as a substitute for soybean meal in the diets of lactating cows based on performance, rumen fermentation, antioxidant function and nitrogen partitioning. Six multiparous lactating cows were used in a replicated 3 × 3 Latin square experiment with 27-day periods. The cows were randomly divided into three treatment groups: group (1) was fed a diet containing no PSC (0PSC), and groups (2) and (3) were fed diets in which soybean meal was replaced with PSC and dried distillers grains with solubles (DDGS) at levels of 50% (50PSC) and 100% (100PSC), respectively. The diets were isonitrogenous and contained identical roughage but different proportions of PSC and DDGS. Replacement of soybean meal with PSC and DDGS did not influence rumen degradation, milk performance, rumen fermentation, DM intake or apparent total tract digestibility, and nitrogen partitioning between milk, feces and urine did not differ in the animals fed the three diets. However, compared with a diet containing no PSC, the total antioxidant capacity (P < 0.05) and antioxidant enzymes (total superoxide dismutase, glutathione peroxidase and catalase) activities (P < 0.05) were increased in the animals that received the 50PSC and 100PSC diets. In contrast, addition of PSC significantly reduced concentrations of aspartate transaminase (P < 0.05), alkaline phosphatase (P < 0.05) and malondialdehyde (P < 0.05) in the plasma. These results demonstrate that PSC can be completely substituted for soybean meal in the diet of dairy cows without any negative impact on milk performance, rumen fermentation or apparent digestibility and that this dietary change improves antioxidant functions and blood parameters in dairy cows, indicating that PSC has the potential for use as a feed source for dairy cows.

Intake, digestibility, and milk yield response in dairy buffaloes fed Panicum maximum cv. Mombasa supplemented with seeds of tropical açai palm

The use of alternative tropical feeds, such as açai seeds, under tropical pasture production systems, may help to optimize buffalo milk production mainly in the Amazon region, which has the largest worldwide açai production. This study evaluated the effects of dietary inclusion of açai palm seeds in the supplement on nutrient utilization and milk yield response of lactating buffaloes grazing Panicum maximum cv. Mombasa. The treatments comprised four levels of açai palm seeds (0, 198.4, 396.8, and 595.2 g/kg of dry matter) and a treatment without concentrate supplementation (WCS). Five half-breed Murrah female buffaloes with average body weight ± (SEM) of 577 ± (20.4) kg were used in a 5 × 5 Latin square design. There was no effect of the inclusion of açai palm seeds on the total dry matter and nutrient intakes (P>0.05). The digestibility of dry matter, organic matter, neutral detergent fiber, and total digestible nutrients showed a linear decreasing pattern (P<0.05), whereas the digestibility of crude protein demonstrated a quadratic pattern, as açai palm seed inclusion level increased (P<0.05). Milk production demonstrated a quadratic pattern as açai palm seed inclusion increased (P<0.05). There was no effect of açai palm seed inclusion on milk composition (P>0.05), except for fat (%), protein (%), and the concentration of total dry extract (P<0.05). There was no difference in nutrient intake and digestibility and milk performance, between supplemented and WCS animals (P>0.05). In conclusion, the inclusion of açai palm seeds at 198.4 g/kg DM in the supplement of grazing buffaloes improves the digestibility of crude protein and milk production, without detrimental effects on nutrient intake. Also, açai palm seeds may be a potential replacer of Panicum maximum cv. Mombasa under tropical conditions.

Supplementation with green tea and oregano extracts on productive characteristics, blood metabolites, and antioxidant status of Jersey cows during the transition period

Plant extracts have been recognized as beneficial to human health and have been evaluated as feed additive for domestic and companion animals. This study evaluated oregano and green tea extracts fed to Jersey cows from approximately 21 d before calving to 21 d after calving on milk production, milk composition, and blood metabolites as well as investigated immunological and antioxidant attributes. Twenty-four Jersey cows with 441 ± 27 kg of BW, 3.5 ± 0.3 of body condition score (BCS), and 2.7 ± 1.8 lactations were selected at approximately 28 d before the expected parturition date and were randomly assigned to three treatments with eight cows each: without plant extracts in diet (control - CON), addition of 10 g per day of oregano extract (OR), and addition of 5 g per day of green tea extract (GT). Feed intake, BW, BCS, blood metabolites, hemogram as well as oxidative stress biomarkers were evaluated from approximately 3 weeks prepartum to 3 weeks postpartum (transition period) while milk production and composition were evaluated during the first 3 weeks of lactation. Plant extracts did not change BW, BCS, and DM intake (DMI) throughout the transition period, but OR increased in approximately 20% total digestive nutrients and metabolizable energy intake on days 15 and 16 postpartum compared with CON. In the prepartum, OR increased in 48% platelets count compared to the CON, while GT augmented in 142% eosinophils compared with CON. Oregano extract reduced the levels of reactive species in the erythrocytes in 40% during prepartum and postpartum compared with CON, while GT reduced its levels in 24 and 29% during prepartum and postpartum, respectively, when compared with CON. In the postpartum period, OR increased in 60% the carbonylated protein content compared with CON, while GT reduced in 45% the levels of reactive species in plasma compared with CON. During the postpartum, both extracts increased in 33% the concentration of reduced glutathione when compared with CON. Moreover, GT tended to decrease feed efficiency in 11% when compared with CON; OE reduced milk pH and somatic cell count when compared with CON. In conclusion, OE and GT did not expressively affect immunological attributes in blood but reduce some oxidative stress biomarkers without compromising productive traits of Jersey cows during the transition period.

Effect of heat stress amelioration through open-ridge ventilated thatched roof housing on production and reproduction performance of crossbred Jersey cows

The present study was conducted to assess the impacts of loose house roofing designs and materials on modulation of micro-climate of the cow shed and its influences on production and reproduction performance of lactating crossbred Jersey cows. The control group (T0) was kept in a traditional single-slope asbestos roof shed and treatment group (T1) at a specially designed open-ridge ventilated, double-slope thatch roof shed. Lactation stage, average daily milk yield, and average parity at the beginning of the experiment were kept similar between T0 and T1 cows. The specifically designed T1 shed had significantly (P < 0.05) lower temperature, humidity, and thermal humidity index as compared to the traditional shed (T0). The T1 shed was cooler and more comfortable than T0. Housing significantly (P < 0.05) influenced cardinal physiological parameters of resident cows. Body temperature, pulse rate, respiration rate, and discomfort index were significantly (P < 0.05) higher in T0 as compared to those in T1 cows. Improved housing significantly (P < 0.01) influenced milk yield, composition, quality, and udder health of cows. Daily milk yield depending on parity, monthly milk yield, milk fat, SNF, and protein were significantly (P < 0.01) higher in T1 than those in T0 cows. The milk somatic cell count, modified California mastitis test score, electrical conductivity, and pH of milk samples of T0 cows were significantly (P < 0.0) higher than those of T1. Effect of housing type, parity, and interaction of housing × parity did not cause any significant (P > 0.05) differences in reproductive traits such as service period, break period, calving interval, pregnancy rate, and other cow fertility parameters. Post-partum body condition score and body weight loss did not differ significantly (P > 0.05) between the two groups; however, more loss occurred in T0 than T1. The estimated net profit from housing of cows (N = 20) in a comfortable shed was 2200 kg milk per annum, i.e., 110 kg/cow/annum. The study concluded that a central open-ridge ventilated, double-slope thatched roof design created a favorable micro-environment and it significantly affected cows' comfort index; thermo-comfortable housing significantly reduced the heat stress-oriented drop in milk yield and decline in milk composition, and improved udder health and other milk production traits; however, its impact was non-significant on reproduction and fertility traits in Jersey crossbred cows.

The effect of dairy heifer pre-breeding growth rate on first lactation milk yield in spring-calving, pasture-based herds

Optimising heifer growth rate may offer an opportunity to improve lifetime milk yield per cow, enhancing the environmental and economic efficiency of dairy farming operations. The effect of dairy heifer pre-breeding average daily weight gain (ADG_PB) on first lactation milk yield was investigated. This observational study employed a data set comprising 265 Holstein-Friesian, or Holstein-Friesian-cross-Jersey heifers from seven commercial, spring-calving, pasture-based dairy herds, where the major component of the diet was grazed grass. These were weighed at birth and prior to breeding and ADG_PB was calculated. Milk recordings were performed throughout the heifers' first lactation and 305-day yield figures calculated from these records. Yields were corrected to 4% fat and 3.1% protein to create standardised 305-day milk yield (SMY), which was the outcome of interest. Median ADG_PB was 0.72 kg/day. Median 305-day yield was 5 967 kg. Linear regression was used to investigate the effect of weight and genetic, age and first calving factors on SMY. Pre-breeding average daily weight gain, age at first calving and predicted transmitting abilities for milk protein production and calving interval were all significant in the final model, which also included the random effects of farm and month of calving within year. ADG_PB was quadratically related to first lactation SMY, with an ADG_PB of 0.82 kg/day corresponding to the maximum predicted SMY. The model predicted that a heifer growing at 0.82 kg/day would produce 1 120 kg more SMY than a heifer growing at 0.55 kg/day, 218 kg more than a heifer growing at 0.7 kg/day and 103 kg more than a heifer growing at 0.90 kg/day. Manipulation of heifer growth rate may offer a viable method of increasing first lactation milk yield.

Lipopolysaccharide and lipoteichoic acid influence milk production ability via different early responses in bovine mammary epithelial cells

Lipopolysaccharide (LPS) and lipoteichoic acid (LTA) are cell wall components of Escherichia coli and Staphylococcus aureus, which cause clinical and subclinical mastitis, respectively. However, the reason of the difference in symptoms by pathogen type remains unclear. In this study, the influence of LPS and LTA on early response and milk production in lactating bovine mammary epithelial cells (BMECs) was comparatively investigated. The results showed that LPS decreased the secretion of β-casein, lactose, and triglycerides, whereas LTA decreased the secretion of lactose and triglycerides but increased lactoferrin production without any influence on β-casein secretion. In addition, the influence of milk lipid droplet size in BMECs and gene expression related to milk fat synthesis was different between LPS and LTA. LPS increased the gene expression of interleukin (IL)-1β, tumor necrosis factor-α, and IL-8 through the activation of the nuclear factor-κB (NF-κB), p38, and c-Jun N-terminal kinase pathways, whereas LTA increased IL-1β and CC chemokine ligand 5 expression through the activation of the NF-κB pathway. Moreover, these cytokines and chemokines differently affected the milk production ability of BMECs. These results suggested that the pathogen-specific symptoms may be related to the differences in the early response of BMECs to bacterial toxins.

Climate change vulnerability of confined livestock systems predicted using bioclimatic indexes in an arid region of México

Climate change is a major world-wide challenge to livestock production because food security is likely to be compromised by increased heat stress of the animals. The objective of this study was to characterize, using bioclimatic indexes, two livestock regions located in an arid zone of México, and to use this information to predict the impact of global warming on animal production systems of these regions located in the state of Baja California (México). A 5-year database (i.e., 2011 to 2015) consisting of about one million data points from two zones (i.e., coast, valley) from four meteorological stations in the north of Baja California were used. Bioclimatic indexes were constructed for the four types of livestock production systems most common in this region, being: dairy cattle, beef cattle, sheep, pigs. The temperature-humidity index (THI) thresholds used to classify heat stress were determined and scaled for each livestock species as: THI_beef and THI_pig 74 units; THI_milk 72 units; and THI_sheep 23 units. Statistical differences between indices were detected (P < 0.01) during summer for the valley and coast zones as (THI_beef = 72.9 and 51.8; THI_milk = 80.6 and 67.4; THI_pigs = 83.9 and 65.2; THI_sheep = 29.5 and 20.1 units). Coast zone weather did not suggest vulnerability of livestock production systems to heat stress at any time of the year, but heat stress risk during summer for valley zone dairy cattle, sheep and pigs was classified as severe, but lower for feedlot cattle. Prediction models showed significant adjustment just in the coastal zone for THImilk, THIsheep, and THIsheep, suggesting more impact of global warming during summer in the coastal zone. Use of management strategies to reduce heat load of domestic animals during summer in northern Baja California is essential to maintain their productivity, with more emphasis in the valley zone.

Which oilseed meal provides a higher yield and better nutrient profile of milk in grazing cows?

This study aims to verify which of the oilseed meals will provide a higher milk production efficiency and milk nutrient profile in grazing cows to optimize the production system and improve milk nutrients for the benefit of nutrition and human health. A Latin square experiment was conducted with 12 cows for 84 days, fed Tanzania grass, and concentrated with cottonseed meal (CotM), sunflower meal (SunM), soybean meal (SoyM) and peanut meal (PeaM). SunM tended to have a higher production of 3.5% fat milk and higher milk urea nitrogen compared with the other treatments. SunM tended to have higher amount of fat in the milk compared with SoyM. PeaM tended to have lower fatty acids C13:0, C15:0 anteiso, C15:0 in milk compared with SunM. PeaM tended to have lower C16:0 and C17:0 iso compared with SoyM and CotM. PeaM had lower C18:1trans in comparison to the other meals. The addition of SoyM tended to have higher C18:1 cis15 compared with PeaM and tended to have lower thrombogenicity index compared with CotM and PeaM. Aiming at milk health in pasture production systems, SoyM presented the best nutritional quality of the lipid fraction. For productivity and fat yield, SunM had better results.

Suppressive effects of curcumin on milk production without inflammatory responses in lactating mammary epithelial cells

BACKGROUND

Curcumin is a naturally occurring polyphenol found in Curcuma longa with multiple therapeutic properties, such as anti-inflammatory, wound healing and anti-cancer effects. Curcuma longa is also used as a galactagogue to improve milk production during lactation.

PURPOSE

To assess curcumin could have therapeutic potential for breastfeeding mothers, we investigated whether and how curcumin influences milk production in lactating mammary epithelial cells (MECs) at the cellular and molecular levels.

METHODS

We prepared a lactating MEC culture model that produced milk components and formed less-permeable tight junctions (TJs) to investigate the molecular mechanism of curcumin on milk production, TJs, and inflammation in vitro.

RESULTS

Curcumin downregulated milk production in lactation MECs concurrently with inactivation of lactogenesis-relating signaling (STAT5 and glucocorticoid receptor). The maintenance of a less-permeable TJ barrier was also confirmed, although the TJ protein claudin-4 increased. Curcumin inactivated NFκB and STAT3 signaling, which are closely involved in inflammatory responses in weaning and mastitis mammary glands. The expression levels of IL-1β and TNF-α were also decreased by curcumin treatment. Furthermore, curcumin blocked activation of inflammatory signaling by lipopolysaccharide treatment in MECs, similar to those in MECs that were treated with diclofenac sodium. The drastic phosphorylation of ERK was induced by curcumin treatment in the absence of EGF. U0126, an inhibitor of ERK phosphorylation, attenuated the adverse effects of curcumin on lactating MECs.

CONCLUSION

The results of the present study suggests that curcumin downregulates milk production via inactivation of STAT5 and GR signaling with concurrent suppression of inflammatory responses via STAT3 and NFκB signaling in MECs. These findings provide new insights into the role of curcumin as a mild suppressor of milk production without inflammatory damages in breastfeeding mothers.