four hundered and ninety five (495) smallholder dairy farms active in 52 villages of different cities in chaharmohalo bakhtiari province, keeping 1321 lactating within a total of 2811 mature cows (lactating and dry) were used. these herds were taken during winter 2009 to summer 2010 to assess some of the production, reproductive and economic performance traits under smallholder management syste...

The transverse sections of radius diaphysis in an 11-year-old giant Holstein cow with dermal dysplasia of a collagen disorder-related skin fragility (Cow 1), probably based on increasing turnover of the dermal collagen as reported previously, were morphologically and physico-chemically investigated. Cow 1 had about one and a half times as much as the body weight of normal Holstein cows, aged 5 ...

In pasture-based seasonal calving systems, failure to become pregnant during the breeding season results in important economic losses as maximum profit is attained by minimising costs and increasing the proportion of grass in the diet of the lactating dairy cow. In the United States, dairy producers primarily strive to maximise production potential but are becoming increasingly aware of the eco...

Milk urea nitrogen (MUN) has been proposed as a management tool for nutritionists and dairy farmers to use as a monitor for protein feeding rates and nitrogen metabolism in lactating dairy cows. Dietary crude protein (CP) content has the greatest nutritional influence on MUN concentrations and has the potential to be used as a management tool for assessing dietary protein feeding. The MUN conce...

This study aimed to evaluate the effect of short-term forage substitution with ensiled olive cake (OC), on yield, composition and fatty acid (FA) profile cows’ milk. Mid-lactating Holstein-Friesian cows were randomly assigned for 21 days two isoenergetic isoproteic feeding treatments (12 animals per treatment), containing 0 10% DM OC (C groups, respectively). Milk yield was recorded daily, milk...

BACKGROUND: Dairy cows undergo physiological changes during pregnancy and lactation and cardiovascular system may alter during these periods. OBJECTIVES: Understanding the physiological effects of production periods of dairy cows on heart electrical activities can aid to better monitoring the cardiovascular system in these animals. METHODS: Five multiparous Holstein dairy cows were studied from...

The objective of this study was to determine the long-term effects of feeding monensin on methane (CH4) production in lactating dairy cows. Twenty-four lactating Holstein dairy cows (1.46 +/- 0.17 parity; 620 +/- 5.9 kg of live weight; 92.5 +/- 2.62 d in milk) housed in a tie-stall facility were used in the study. The study was conducted as paired comparisons in a completely randomized design w...

OBJECTIVE To examine the effects of Rhodobacter sphaeroides (R. sphaeroides) supplementation as a direct-fed microbial (DFM) on rumen fermentation in dairy cows and on coenzyme Q10 (CoQ10) transition into milk, an in vitro rumen simulation batch culture and an in vivo dairy cow experiment were conducted. METHODS The characteristics of in vitro ruminal fermentation were investigated using rume...

The objective of the experiment was to determine the effects of fat supplementation on embryo quality of dairy cows and the subsequent success of embryo transfer into recipient heifers fed the same sources of fat. A total of 30 lactating Holstein cows were allotted on d 18 postpartum to 2 groups of 15 donor cows blocked for similar calving dates. Total mixed diets based on silage and fat supple...

The objectives of this study were to evaluate effects of feeding propylene glycol (PG) on feed intake, milk yield and milk composition, blood metabolites and energy balance in Holstein dairy cows from 1 to 63 days in milk. Thirty-two multiparous cows, blocked by lactation number, previous 305-day milk production and expected calving date, were arranged into four groups in a randomized block des...