فهرست مقالات dry matter intake

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  1 - Effect of Dietary Buffers Supplementation on Milk Yield and Composition in Dairy Cows: A Meta-Analysis of Randomized Controlled Trials
  M. Hashemi F. Tavakolinasab
  Feeding high concentrates to high producing animals usually change the rumen environment and compromises the productivity of ruminants. Different feed additives are used to prevent the occurrence of sub-acute ruminal acidosis, among these additives, buffers are commonly چکیده کامل

  Feeding high concentrates to high producing animals usually change the rumen environment and compromises the productivity of ruminants. Different feed additives are used to prevent the occurrence of sub-acute ruminal acidosis, among these additives, buffers are commonly used. The aim of this meta-analysis was to investigate the effects of buffer supplementation on milk yield and composition in dairy cows. PubMed, Scopus, Web of Science and Google Scholar databases were searched from 1969 to 2020. A total of 86, 91, 94, 85, 27 and 34 trials were included to buffer supplementation effects on dry matter intake (DMI), milk yield (MY), fat, crude protein (CP), solid not fat (SNF) and lactose, respectively. The magnitude of the effect (effect size) was assessed using standardized mean differences (SMD) for continuous results, between the buffer supplementation addition and control treatments. The addition of buffer supplementation had no significant effect on DMI (SMD=-0.002, P=0.16), MY (SMD=0.001, P=0.99), CP (SMD=-0.002, P=0.34) and SNF (SMD=0.006, P=0.32), respectively. Milk yield increased in the group receiving the buffer supplementation in comparison with the control group. The percentage of fat (SMD=-0.185, P=0.001) significantly decreased in the control group compared to the group receiving the buffer. The dietary buffers significantly increased the content of lactose (SMD=0.008, P=0.014) in dairy cows’ milk. This meta-analysis indicated that buffer supplementation improved milk yield and composition in dairy cows. پرونده مقاله
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  2 - Effect of Season on Dry Matter Intake and Reproductive Activity of Merghoz Buck Goats in West of Iran
  م. سوری ر. میرمحمودی
  Ten male Merghoz goats with initial live weights of 29.2 ± 1.2 kg (Mean±SE) were used to investigate the effect of natural changes in photoperiod on dry matter intake (DMI) and reproductive activity during a 365 day study. The bucks were housed in individu چکیده کامل

  Ten male Merghoz goats with initial live weights of 29.2 ± 1.2 kg (Mean±SE) were used to investigate the effect of natural changes in photoperiod on dry matter intake (DMI) and reproductive activity during a 365 day study. The bucks were housed in individual pens, under natural daylength condition at west of Iran, Kermanshah (34˚ 18¢N and 47˚ 3¢E and 1420 m above sea level). A diet was offered with an estimated concentration of metabolizable energy and crude protein of 7.9 MJ and 98.8 g per kg dry matter (DM) respectively. Live weight, DMI, and additive daily gain (ADG) of individual animals were recorded weekly. The serum testosterone concentrations were determined in blood samples collected at monthly intervals. During the observation period, semen was collected monthly with the aid of an electro-ejaculator and examined microscopically immediately after collection. The physical parameters of semen and the semen index were recorded. The sexual behavior and testicular size of goats were assessed monthly throughout the study period. The highest DMI was observed during summer (64.3±0.9 g/kg BW0.75) and spring (62.2±2.9 g/kg BW0.75) however, the lowest was recorded in the winter season (54.0±0.9 g/kg BW0.75). The seasonal values of ADG (g/d) ranked spring > summer > winter > autumn. Bucks demonstrated the highest sexual behavior in late summer and, thereafter during autumn, using the lower (P<0.05) number of mounts per ejaculation and a higher frequency (P<0.05) to sniff, approach, and vocalize a doe with estrous status. This was coincided with a higher (P<0.05) level of plasma testosterone (8-10.1 ng/mL) and the best semen quality (semen index: 744-989×106/mL) and quantity (semen volume: 1.1-1.2 mL per ejaculate), higher testis length (13.3-14.7 cm) and width (6.0-6.1 cm) and scrotal circumference (32.2-35.5 cm). It is concluded that, in Merghoz bucks, the seasonal pattern of DMI and reproductive activity may be attributed to each other as well as photoperiod. پرونده مقاله
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  3 - Sward Factors Influence on Pasture Dry Matter Intake of Grazing Dairy Cows: A Review
  آ.ال. روکا فرناندز آ. گنزالو ردریگوئز
  Successful pasture-based milk production systems pivot on balancing dairy cows’ feed requirements with seasonal and annual fluctuations in pasture production. In order to maximise cow production from grazing dairy systems, it is necessary to reach an efficient uti چکیده کامل

  Successful pasture-based milk production systems pivot on balancing dairy cows’ feed requirements with seasonal and annual fluctuations in pasture production. In order to maximise cow production from grazing dairy systems, it is necessary to reach an efficient utilization of grazed grass for feeding cows and the development of appropriate grazing management systems designed to maximize daily pasture dry matter intake (PDMI) per cow and per hectare, while maintaining high sward quality over the grazing season by keeping high pasture levels of crude protein, water soluble carbohydrates and digestibility of organic matter and low levels of acid and neutral detergent fibers in the swards. To maximize PDMI, cows need to consume plants that have characteristics that allow rapid consumption and lead to fast rates of passage through the rumen. This review considers the role of sward factors which affect the short-term feed budget of cows at pasture and, therefore, condition cow feed requirements at grazing and influence on PDMI. Furthermore, it highlights the relevance that havefor the development of pasture-based milk production systems the study of the species of grasses and / or legumes that integrate the pastures, the changes on sward structure, the seasonality in grass production, the pasture chemical constituents, the sward botanical composition, the grass feeding value, the digestibility of pastures, the intensity of sward defoliation, and the importance of sward height and herbage mass in relation to maximizing PDMI. The amount of herbage consumed is the major determinant of cow production but it is yet one of the most difficult aspects of forage quality to predict. In this review, three methods for PDMI calculation are presented as faecal output/diet digestibility method, sward difference method and the grazing-behaviour method. Also, three equations for PDMI estimation are described considering different sward and animal variables. پرونده مقاله
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  4 - اثر افزودن مکمل های پری‌بیوتیک، سین‌بیوتیک و فیتوبیوتیک در جیره بر عملکرد رشد، صفات لاشه، قابلیت هضم ‌ظاهری مواد مغذی و برخی فراسنجه های خونی بره های پرواری نژاد زل
  مهدی سراوانی محسن حاجی پور کاوه جعفری خورشیدی سیدماکان موسوی کاشانی پروین شورنگ
  10.22034/ascij.2023.1992570.1519
  در این تحقیق اثر افزودن مکملهای پری‌بیوتیک، سین‌بیوتیک و فیتوبیوتیک در جیره روی عملکرد رشد، صفات لاشه، قابلیت هضم‌ظاهری مواد مغذی و برخی فراسنجه¬های خونی بره¬های پرواری نژاد زل مورد بررسی قرار گرفت. بدین منظور از تعداد 24 رأس بره نر زل با میانگین سن حدود 5 ماه و با میا چکیده کامل

  در این تحقیق اثر افزودن مکملهای پری‌بیوتیک، سین‌بیوتیک و فیتوبیوتیک در جیره روی عملکرد رشد، صفات لاشه، قابلیت هضم‌ظاهری مواد مغذی و برخی فراسنجه¬های خونی بره¬های پرواری نژاد زل مورد بررسی قرار گرفت. بدین منظور از تعداد 24 رأس بره نر زل با میانگین سن حدود 5 ماه و با میانگین وزن 50/0±4/25 به مدت 90 روز استفاده شد. تیمارهای آزمایشی شامل 1-گروه شاهد (فاقد مکمل)، 2-تیمار حاوی 2 گرم مکمل پری‌بیوتیک ای-مکس، 3-تیمار حاوی 4 گرم مکمل سین‌بیوتیک بایومین ایمبو و 4-تیمار حاوی 6 گرم مکمل فیتوبیوتیک بیوهربال به ازای هر رأس بره در روز بود. نتایج عملکرد رشد نشان داد که در وزن پایان پروار، ماده خشک مصرفی، افزایش وزن روزانه و ضریب تبدیل خوراک تفاوت معنی‌داری بین تیمارهای آزمایشی وجود داشت (05/0 > p). بیشترین وزن پایان دوره پروار، ماده خشک مصرفی و افزایش وزن روزانه در تیمار 4 گرم مکمل سین‌بیوتیک مشاهده شد. تیمار 6 گرم مکمل فیتوبیوتیک دارای کمترین ضریب تبدیل خوراک بود. بالاترین قابلیت هضم ظاهری ماده خشک، الیاف نامحلول در شوینده خنثی و الیاف نامحلول در شوینده اسیدی در تیمار 4 گرم مکمل سین‌بیوتیک مشاهده شد (05/0 >p ). نتایج برخی فراسنجه‌های سرم خون شان داد که تفاوت معنی‌داری در غلظت گلوکز، کلسترول، تری‌گلیسرید و نیتروژن اوره‌ای خون بین تیمارهای آزمایشی وجود داشت (05/0> p). بالاترین غلظت گلوکز در تیمار 4 گرم مکمل سین‌بیوتیک، پایین‌ترین غلظت کلسترول در تیمار 6 گرم مکمل فیتوبیوتیک وجود داشت. نیتروژن اوره‌ای خون در تیمار 4 گرم مکمل سین‌بیوتیک دارای پایین‌ترین غلظت بود. تیمار 4 گرم مکمل سین‌بیوتیک دارای بالاترین وزن لاشه گرم، درصد لاشه گرم، وزن لاشه سرد، درصد لاشه سرد، درصد ران و درصد سردست بود (05/0> p). تحقیق حاضر نشان داد که افزودن سطح 4 گرم مکمل سین‌بیوتیک در جیره سبب بهبود عملکرد رشد، قطعات با ارزش لاشه و قابلیت هضم ظاهری مواد مغذی در بره‌های پرواری زل شد. پرونده مقاله