Nutrient requirements of dairy cattle , Nutrient requirements of dairy cattle , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Nutrient requirements of dairy cattle

https://www.webpages.uidaho.edu/ruminant_nutrition/Reading%20materials%20411/dietary%20factors%20affecting%20feed%20intake-Allen2000.pdf

Effects of Diet on Short-Term Regulation of Feed Intake by Lactating Dairy Cattle

Clinical Biochemistry of Domestic Animals

The aim of this work was to evaluate the effects of in situ incubation time and particles size on the estimates of indigestible fractions of dry matter (iDM), neutral detergent fiber (iNDF), and acid detergent fiber (iADF) in cattle feeds and feces. Samples of corn grain, wheat bran, corn silage, elephant grass, sugarcane, signal grass hay, corn straw, and feces obtained from cattle fed high and low concentrate diets were used. The samples were ground through 1 mm, 2 mm, and 3 mm screen sieve and put in 4 × 5 cm non-woven textile bags (20 mg DM/cm² of surface). The samples were divided in three groups, being each group incubated in the rumen of a crossbred heifer. The incubation procedure was conducted three times with the change of groups among animals. The following incubation times were used: 0, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, and 312 hours. The contents of iDM, iNDF, and iADF were evaluated sequentially in each bag. The degradation profiles were interpreted by a non-linear logistic model. The particles size did not influence the estimates of iNDF and iADF. However, the particles size altered the rumen degradation dynamic rates of DM for corn silage and corn grain; of NDF for sugarcane, corn silage, and corn straw; and ADF for sugarcane. For those samples, the particle size has been positively associated with the incubation time necessary to estimate the indigestible fraction. Incubation times of 240 hours for DM and NDF, and 264 hours for ADF were suggested for obtaining more accurate estimates of indigestible fractions. The use of 2 mm particle size can increase the precision of estimates.

http://www.scielo.br/pdf/rbz/v37n2/21.pdf

Influência do tempo de incubação e do tamanho de partículas sobre os teores de compostos indigestíveis em alimentos e fezes bovinas obtidos por procedimentos in situ

Feeding- and management-related diseases in the transition cow

Nutrição de ruminantes

Resistance of Santa Ines and crossbred ewes to naturally acquired gastrointestinal nematode infections

The ability to adapt to a range of edaphic conditions favours the widespread use of marandu palisade grass in high as well as low input systems of animal production in Brazil. However, little information exists regarding the influence of grazing management practices on sward structure and the carry-over effects on animal responses. The present experiment was planned to evaluate animal behaviour, herbage intake (HI) and nutritive value, herbage accumulation and body weight gain (BWG) of beef cattle heifers grazing marandu palisade grass subjected to intensities of continuous stocking management. Treatments corresponded to four sward surface heights (SSH: 100, 200, 300 and 400 mm) and were allocated to experimental units (1200 m 2 paddocks) according to a randomized complete block design with four replications. Herbage accumulation rate (HAR) varied with season of the year and SSH, with highest and lowest values recorded during summer and winter, respectively. During the summer, herbage accumulation was larger on swards managed at 200, 300 and 400 mm, with the opposite occurring during winter/early spring. Stocking rate (SR) and number of grazing days (GD) followed a similar seasonal pattern of variation, with values decreasing as SSH increased. Crude protein (CP) and in vitro organic matter digestibility (IVOMD) of hand-plucked herbage decreased as SSH increased from 100 to 400 mm, while the inverse happened with BWG (from 0·190 to 0·930 kg/day, respectively). Bite mass (BM) increased and rate of biting and grazing time (GT) decreased as SSH increased, with daily HI being larger on tall (300 and 400 mm) relative to short (100 and 200 mm) swards. Grazing management affected the nutritive value and the amount of herbage consumed, particularly through changes in BM. However, variations in intake were relatively more important than variations in nutritive value in influencing animal performance, highlighting the importance of providing favourable harvest conditions for grazing animals by establishing adequate sward targets for management.

/pdf/grazing-behaviour-herbage-intake-and-animal-performance-of-3ze2yozu4e.pdf

Grazing behaviour, herbage intake and animal performance of beef cattle heifers on marandu palisade grass subjected to intensities of continuous stocking management

Effects of Heat Treatment and Physical Processing of Cottonseed on Nutrient Digestibility and Production Performance by Lactating Cows

The objective of this work was to evaluate the effects of raw soybean on lamb performance, carcass yield and lamb cuts. Raw soybean was added at 0, 7, 14 and 21% of the diet dry matter (isonitrogenous). Sixty-four Santa Ines lambs (initial body weight 19.5±0.19 kg and 75±2 days old) were assigned to a complete randomized block design according to body weight and age at beginning of the trial. Dry matter intake (1.1, 1.0, 0.9 and 0.9 kg per day), crude protein intake (199.2, 181.5, 179.0 and 175.2 g per day) and average daily gain (298, 275, 280, 255 g per day) decreased linearly, and ether extract intake (43.8, 49.7, 57.2 and 66.0 g per day) increased linearly, as levels of raw soybean increased. Feed conversion, carcass yield and lamb cuts were not affected by raw soybean inclusion in the diet. The inclusion of raw soybean in high concentrate diets provides satisfactory feedlot lamb performance.

/pdf/desempenho-e-caracteristicas-da-carcaca-de-cordeiros-39xz1805qr.pdf

Alexandre Vaz Pires

Papers

Nutrição de ruminantes

Resistance of Santa Ines and crossbred ewes to naturally acquired gastrointestinal nematode infections

Grazing behaviour, herbage intake and animal performance of beef cattle heifers on marandu palisade grass subjected to intensities of continuous stocking management

Effects of Heat Treatment and Physical Processing of Cottonseed on Nutrient Digestibility and Production Performance by Lactating Cows

Desempenho e características da carcaça de cordeiros confinados alimentados com grãos de soja