Antecedentes: La producción de leche vacuna en Ecuador se diferencia por regiones; en la Costa y de forma particular la cuenca baja del Guayas, tiende a decrecer, determinado por factores ...socioeconómicos y ecológicos, sin embargo, constituye una prioridad para el consumo familiar y local, con demanda del producto y sus derivados, representa ingresos diarios, asegura el pago de jornales al productor y genera diversificación en los sistemas de producción. Objetivo. Valorar la producción de leche en Ecuador y su proyección a partir de escenarios con énfasis en la cuenca baja del Guayas. Desarrollo: Se realizó una revisión bibliográfica para examinar la evidencia disponible sobre la producción de leche vacuna en Ecuador. Se constató un crecimiento, no obstante, la heterogeneidad de condiciones socioeconómicas y ecológicas existentes, determinaron respuestas productivas diferentes. Respecto a la cuenca baja del Guayas, reportaron los rendimientos más bajos, condicionados por factores climáticos y las características de los sistemas de producción, que determinan la búsqueda de alternativas que garanticen su sostenibilidad. Conclusiones: La producción de leche se diferenció por regiones, los mayores rendimientos se encontraron en la Sierra, seguido por la Amazonía y por último en la Costa, donde prevalecen los pastos naturales, existen desbalances estacionales y se prioriza la actividad agrícola. En correspondencia con lo planteado, la construcción de escenarios prospectivos constituye una alternativa para la toma de decisión en la relación a la sostenibilidad de la producción de leche en la región. Palabras clave: Cuenca baja, Escenarios, Ganadería vacuna (Fuente: MeSH) Background: The production of bovine milk in Ecuador differs by region; On the coast and particularly the lower Guayas basin, it tends to decrease, determined by socioeconomic and ecological factors, however, it constitutes a priority for family and local consumption, with demand for the product and its derivatives, it represents daily income, he assures. the payment of wages to the producer and generates diversification in production systems. Aim. Assess milk production in Ecuador and its projection based on scenarios with emphasis on the lower Guayas basin. Development: A bibliographic review was carried out to examine the available evidence on bovine milk production in Ecuador. Growth was noted, however, the heterogeneity of existing socioeconomic and ecological conditions will determine different productive responses. Regarding the lower Guayas basin, they reported the lowest yields, conditioned by climatic factors and the characteristics of the production systems, which determine the search for alternatives that guarantee their sustainability. conclusions: Milk production differs by region, the highest yields were found in the Sierra, followed by the Amazon and finally on the Coast, where natural pastures prevail, there are seasonal imbalances and agricultural activity is prioritized. In correspondence with what was stated, the construction of prospective scenarios constitutes an alternative for decision-making in relation to the sustainability of milk production in the region. Keywords: Low basin, Scenarios, Beef livestock (Source: MeSH)
The aim of this study was the evaluation of heat stress in milk production in dairy cows (daily milk yield; milk production in 1st lactation). The comparison was performed between fraternal twins ...(full sisters), produced on the same farm and same parity. One of the twins produced in a hot period whereas her sister produced in a cooler period. Also, there can be differences in milk production between fraternal twins. Therefore, a second group of fraternal twins was also created that produced without heat stress. Databases of fraternal twins were analysed using PROC GLM analysis of Statistica® with selected effects. In conclusion, a negative effect of heat stress on milk production was found. There was an obvious tendency (in some cases insignificant) for worse milk production during heat stress in both the daily milk yield during hot days and in 1st lactation started in the hot season. Fat content (in %) was also lower in the hot period but differences were insignificant. On the other hand, there was found very low differences in milk production (and milk components) between fraternal twins produced in season without heat stress.
This study evaluated the effect of tannin extract from Acacia mearnsii on intravaginal temperature, production and milk composition of Holstein cows in a subtropical environment. The study period was ...29 days and 20 multiparous Holstein cows were selected with an average milk production of 50 ± 6 kg/day and 147 ± 83 days in milk. The cows were separated into two treatments: Control (n = 10) did not receive dietary supplementation. Tannin (n = 10) received Condensed Tannin (Tanac S.A., Montenegro, RS, Brazil) at a dose of 0.19% dry matter (40 g/cow/day). Animals were monitored for milk production and composition as well as intravaginal temperature. The environmental temperature and humidity index (THI) were monitored. The mean THI was 72.39 ± 0.69. The mean intravaginal temperature was 39.17 ± 0.14 °C in the Tannin treatment and 39.03 ± 0.14°C in the Control treatment (P > 0.05). The animals in the Tannin treatment exhibited an intravaginal temperature of 39.2 °C at THI 69.38, and the Control treatment exhibited the same temperature at THI 70.16 (receiver operating characteristic (ROC); P < 0.01). Milk production was higher in the Tannin treatment than in the Control treatment (51.38 ± 0.90 kg/day and 49.94 ± 1.05 kg/day, respectively; P < 0.01). The protein content in milk was higher in the Tannin treatment than in the Control treatment (3.20 ± 0.01% and 3.04 ± 0.01%; respectively; P < 0.01). The results of this study suggested that tannin extract from Acacia mearnsii can attenuate heat stress and its negative effects on animal production.
RESUMO: Este estudo avaliou o efeito do extrato de tanino de Acacia mearnsii na temperatura intravaginal, na produção e na composição do leite de vacas Holandesas mantidas em ambiente subtropical. O período de estudo foi de 29 dias e foram selecionadas 20 vacas multíparas Holandesas com produção média de leite de 50 ± 6 kg/dia e 147 ± 83 dias em leite. As vacas foram separadas em dois tratamentos: Controle (n = 10) não recebeu suplementação alimentar. Tanino (n = 10) recebeu Tanino Condensado (Tanac S.A., Montenegro, RS, Brasil) na dose de 0,19% de matéria seca (40 g/vaca/dia). Os animais foram monitorados quanto à produção e composição do leite, bem como à temperatura intravaginal. O índice de temperatura e umidade ambiental (ITU) foi monitorado. O ITU médio foi de 72,39 ± 0,69. A temperatura intravaginal média foi de 39,17 ± 0,14 °C no tratamento Tanino e 39,03 ± 0,14 °C no tratamento Controle (P > 0,05). Os animais do tratamento Tanino exibiram temperatura intravaginal de 39,2°C no ITU 69,38, e o tratamento Controle exibiu a mesma temperatura no ITU 70,16 (característica operacional do receptor (ROC); P < 0,01). A produção de leite foi maior no tratamento Tanino do que no tratamento Controle (51,38 ± 0,90kg/dia e 49,94 ± 1,05kg/dia, respectivamente; P < 0,01). O teor de proteína no leite foi maior no tratamento Tanino do que no tratamento Controle (3,20 ± 0,01% e 3,04 ± 0,01%; respectivamente; P < 0,01). Os resultados deste estudo sugerem que o extrato de tanino de Acacia mearnsii pode atenuar o estresse térmico e seus efeitos negativos na produtividade animal.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction Oxytocin is a key hormone in breastfeeding. No recent review on plasma levels of oxytocin in response to breastfeeding is available. Materials and methods Systematic literature searches ...on breastfeeding induced oxytocin levels were conducted 2017 and 2019 in PubMed, Scopus, CINAHL, and PsycINFO. Data on oxytocin linked effects and effects of medical interventions were included if available. Results We found 29 articles that met the inclusion criteria. All studies had an exploratory design and included 601 women. Data were extracted from the articles and summarised in tables. Breastfeeding induced an immediate and short lasting (20 minutes) release of oxytocin. The release was pulsatile early postpartum (5 pulses/10 minutes) and coalesced into a more protracted rise as lactation proceeded. Oxytocin levels were higher in multiparous versus primiparous women. The number of oxytocin pulses during early breastfeeding was associated with greater milk yield and longer duration of lactation and was reduced by stress. Breastfeeding-induced oxytocin release was associated with elevated prolactin levels; lowered ACTH and cortisol (stress hormones) and somatostatin (a gastrointestinal hormone) levels; enhanced sociability; and reduced anxiety, suggesting that oxytocin induces physiological and psychological adaptations in the mother. Mechanical breast pumping, but not bottle-feeding was associated with oxytocin and prolactin release and decreased stress levels. Emergency caesarean section reduced oxytocin and prolactin release in response to breastfeeding and also maternal mental adaptations. Epidural analgesia reduced prolactin and mental adaptation, whereas infusions of synthetic oxytocin increased prolactin and mental adaptation. Oxytocin infusion also restored negative effects induced by caesarean section and epidural analgesia. Conclusions Oxytocin is released in response to breastfeeding to cause milk ejection, and to induce physiological changes to promote milk production and psychological adaptations to facilitate motherhood. Stress and medical interventions during birth may influence these effects and thereby adversely affect the initiation of breastfeeding.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study was aimed at determining the median days of calving to conception interval (days open) and identifying the major risk factors determining the days open in dairy cows. Both retrospective ...and longitudinal studies were conducted on dairy cows located in the Dessie and Kombolcha towns of South Wollo Zone, northeast Ethiopia from August 2019 to August 2020. The Kaplan-Meier model of survival analysis was used to determine the median days open and compare the survival distribution of each level of explanatory variables likely to influence the days open of dairy cows. Accordingly, the overall conception rate of dairy cows was 44.7%. The median days open in the study was 154 days. There is a 16% probability of surviving (i.e, the probability that the conception event has not yet occurred) at the end of 210 days postpartum period. The Cox proportional hazard model was used to quantify the effect of each of the explanatory variables on the days open in the first 210 days postpartum. Factors that had a significant effect (p0.05). Accordingly, cows inseminated in the autumn season (HR = 4.45), cows less than or equal to 85 days calving to insemination interval (HR = 2.41), artificially inseminated cows (HR = 1.45), and high herd milk yield cow had a higher probability of becoming pregnant. In conclusion, the management practices and breeding decisions seem to be important determinants to improve the conception rate or decrease the days open in dairy cows.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Currently, knowledge on the extent to which rumen microbiota differ in a large population of cattle fed the same diet and whether such differences are associated with animal performance is limited. ...This study was conducted to characterize the rumen microbiota of a large cohort of lactating Holstein dairy cows (
= 334) that were fed the same diet and raised under the same environment, aiming to uncover linkages between core and pan rumen microbiomes and host phenotypes. Amplicon sequencing of the partial 16S rRNA gene identified 391 bacterial genera in the pan bacteriome and 33 genera in the core bacteriome. Interanimal variation existed in the pan and core bacteriomes, with the effect of lactation stage being more prominent than that of parity (the number of pregnancies, ranging from 2 to 7) and sire. Spearman's correlation network analysis revealed significant correlations among bacteria, rumen short-chain fatty acids, and lactation performance, with the core and noncore genera accounting for 53.9 and 46.2% of the network, respectively. These results suggest that the pan rumen bacteriome together with the core bacteriome potentially contributes to variations in milk production traits. Our findings provide an understanding of the potential functions of noncore rumen microbes, suggesting the possibility of enhancing bacterial fermentation using strategies to manipulate the core and noncore bacteriomes for improved cattle performance.
This study revealed the rumen bacteriome from a large dairy cattle cohort (
= 334) raised under the same management and showed the linkages among the rumen core and pan bacteriomes, rumen short-chain fatty acids, and milk production phenotypes. The findings from this study suggest that the pan rumen bacteriome, together with the core bacteriome, potentially contributes to variations in host milk production traits. Fundamental knowledge on the rumen core and pan microbiomes and their roles in contributing to lactation performance provides novel insights into future strategies for manipulating rumen microbiota to enhance milk production in dairy cattle.
The objectives of this study were to identify factors associated with the relative change in prepartum dry matter intake (RCDMI) of 273 cows fed individually, evaluate the performance of linear ...models to estimate RCDMI using different classes of predictors, and characterize the implications of RCDMI to transition metabolism, health, and subsequent milk production. Two periods of interest were established. Period 1 comprised d −21 to −12 relative to calving, when DMI was stable. Period 2 comprised d −4 to −1, when average DMI was distinctly declined. The RCDMI from period 1 to 2 was calculated as a percentage value, which ranged from −75 to 15% and averaged −18.1% (±15.0). Season, parity, body fatness, body weight, milk production in the previous lactation and at dry-off, and length of dry period were associated with RCDMI and explained 11% of the variation in all cows, and 19% when only parous cows were considered. Performance of linear models to predict RCDMI was improved when data on rumination and physical activities and target blood metabolites were added. The adjusted R2 increased to values between 0.45 and 0.55, and selected models performed consistently in cross-validation analyses. To evaluate the implications of RCDMI, cows were ranked within parity according to RCDMI and classified into terciles as large decline (LD), moderate decline (MD), or small decline (SD). By design, DMI did not differ between tercile groups in period 1 (13.3 ± 0.2 kg/d), but differed substantially in period 2 (LD = 8.8; MD = 11.2; SD = 12.7 ± 0.2 kg/d), creating important differences in RCDMI among groups (LD = −33.8; MD = −16.2; SD = −3.4% ± 0.8%). At enrollment, cows in the LD and MD groups were heavier (LD = 788; MD = 775; SD = 750 ± 7 kg), and the proportion of cows with BCS >3.5 was higher in LD (LD = 63; MD = 47; SD = 38%). An interaction of group and time was observed for postpartum DMI, which started lower in LD than in SD cows, but equaled by the end of transition, and inverted at wk 13 and 14 after calving. Yields of energy-corrected milk were greater in LD than in SD cows, and both groups did not differ from MD (LD = 41.0; MD = 40.3; SD = 39.0 ± 0.5 kg/d). LD cows had decreased energy balance and greater concentrations of nonesterified fatty acids, β-hydroxybutyrate, and aspartate aminotransferase in serum, and greater glutathione peroxidase activity in plasma than SD cows. Larger declines in prepartum DMI were also associated with increased risk for postpartum disease, although the associations were only weak to moderate. In conclusion, a large decline in prepartum DMI was associated with important adjustments in the energy metabolism and antioxidants activities, and greater milk production in the subsequent lactation. These findings indicate that feed intake decline close to parturition is likely a normal response to physiological adaptations at the onset of lactation when cows are fed at libitum.
Piglets from 116 sows were weighed at birth, on the 1st; 2nd and 3rd day of life and upon weaning. Based on the weight growth, the sow milk production was calculated. On the first 3 days of suckling, ...the mammary glands were examined and the rectal temperature, vaginal pH, and the feeding rate were determined in order to diagnose the MMA syndrome.The results in growing and the mortality rate were compared in piglets from sows with ascending suckling curve and sows with non-uniform suckling curve, affected by MMA. It was observed that, on the first 3 days of suckling, the 116 sows had an average daily milk production of 4,21 l. The healthy sows with an ascending suckling curve represent 20.69% of the livestock and produced 4.03l; 5.68l and 7.14l milk on suckling days 1; 2 and 3. Comparatively, the milk production of the MMA affected sows represented 78.41%; 54.40% and 54.62% respectively of the healthy sows’ milk production. As an average, on the first three suckling days, the milk production in MMA affected sows represented 60.4% of the healthy sows’ milk production. The average piglet mortality on the first three days of life was 0.46 piglet / sow, for the MMA affected ones.Until weaning, the total mortality rate was of 0.96 piglet/healthy sow and 1.87 piglet/MMA affected sow and the average daily growth rate for the entire suckling period was reduced from 181.07 g/day to 166.78 g/day.
Pasture-based production systems typically require highly fertile, healthy, and robust genetics, with greater emphasis on milk solids (MSo; kg of fat + protein) production as opposed to milk yield. ...This study assessed milk production, production efficiency, reproductive performance, body weight (BW), body condition score, and functional traits in 3 different dairy cow genotypes: Holstein-Friesian (HF), Jersey × Holstein-Friesian (JEX), and Norwegian Red × (Jersey × Holstein-Friesian) (3-way). The 3 genotypes were rotationally grazed on 4 different grazing treatments after calving in spring and were stocked at a rate of 2.75 cows/ha. Holstein-Friesian cows produced higher daily and total milk yields compared with JEX and 3-way cows (5,718 vs. 5,476 and 5,365 kg/cow, respectively). However, JEX and 3-way cows had higher milk fat and protein contents (4.86 and 4.75%, respectively, for JEX and 3.87 and 3.88%, respectively, for 3-way) compared with HF (4.52 and 3.72%), resulting in similar MSo yield for JEX and HF (469 and 460 kg/cow) and slightly lower MSo yield for 3-way (453 kg/cow) compared with JEX. As parity increased, milk and MSo yield per cow increased. Reproductive performance was not significantly different between the 3 genotypes, which had similar 24-d submission rates, 6-wk pregnancy rates, and overall pregnancy rates over the 4-yr period. No difference in calving difficulty, incidence of mastitis, or incidence of lameness was observed among the 3 genotypes. Body weight was significantly different among all 3 genotypes, with HF being the heaviest followed by 3-way and JEX (530, 499, and 478 kg, respectively), and 3-way cows had a higher body condition score throughout lactation compared with HF and JEX cows. The differences in BW coupled with similar MSo production resulted in JEX cows having the highest production efficiency (4.58 kg of MSo/kg of metabolic BW), 3-way cows being intermediate (4.30 kg of MSo/kg of metabolic BW), and HF cows having the lowest (4.16 kg of MSo/kg of metabolic BW). In conclusion, HF herds with poor reproductive performance and low milk fat and protein contents are likely to benefit considerably from crossbreeding with Jersey, and all herds are likely to benefit in terms of production efficiency. However, where herd performance, particularly in relation to reproductive performance, is comparable with HF in the current study, crossbreeding with Jersey or Norwegian Red is unlikely to lead to significant improvements in overall herd performance.
Genome-wide association study (GWAS) is a powerful approach to identify genomic regions and genetic variants associated with phenotypes. However, only limited mutual confirmation from different ...studies is available. We conducted a large-scale GWAS using 294,079 first-lactation Holstein cows and identified new additive and dominance effects on five production traits, three fertility traits, and somatic cell score. Four chromosomes had the most significant SNP effects on the five production traits, a Chr14 region containing
mostly had positive effects on fat yield and negative effects on milk and protein yields, the 88.07-89.60 Mb region of Chr06 with
, and
for milk and protein yields, the 30.03-36.67 Mb region of Chr20 with
and
for milk yield, and the 88.19-88.88 Mb region with
as well as the 91.13-94.62 Mb region of Chr05 with
, and
for fat yield. For fertility traits, the SNP in
of Chr06, and the SNPs in the 65.02-69.43 Mb region of Chr01 with
, and
had the most significant effects for daughter pregnancy rate and cow conception rate, whereas SNPs in
of Chr06, the 47.54-52.79 Mb region of Chr07,
of Chr29, and
of Chr18 had the most significant effects for heifer conception rate. For somatic cell score,
of Chr06 and
of Chr20 had the most significant effects. A small number of dominance effects were detected for the production traits with far lower statistical significance than the additive effects and for fertility traits with similar statistical significance as the additive effects. Analysis of allelic effects revealed the presence of uni-allelic, asymmetric, and symmetric SNP effects and found the previously reported
antagonism was an extreme antagonistic pleiotropy between fat yield and milk and protein yields among all SNPs in this study.
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