the study was carried out for a period of 150 days on 120 holstein friesian crossbred dairy cows between mid to late lactation to quantify the influence of body condition score (bcs) on yield and composition of milk. total 12 dairy farms having same housing systems and holding at least 20 crossbred dairy cows per farm between mid to late lactation were selected for this study purposes. bcs of i...

the aim of this study was to evaluate the effect of replacing progesterone injections by progesterone vaginal inserts on productive and reproductive parameters of lactating cows with reproductive problems after prolonged periods of heat stress. fifteen holstein cows were randomly assigned to one of three treatments: 1) treated with two progesterone vaginal inserts (p4-ins); 2) treated with prog...

The objective of this study was to estimates the genetic and environmental components for the lactation curve parameters, milk yield, age at first calving (AFC), calving interval (CI) and somatic cell count (SCC) in Iranian Holstein cows. The dataset consisted of 210625 test day records from 25883 cows with milk yield in the first parity recorded from July 2002 to September 2007 in a total of 9...

The milk yields of 1824 cows were used to investigate the effect of lesion-specific causes of lameness, based on farmer treatment and diagnosis of lame cows, on milk yield. A three-level hierarchical model of repeated test day yields within cows within herds was used to investigate the impact of lesion-specific causes of lameness (sole ulcer, white line disease, digital dermatitis and other cau...

The purpose of the study was: (1) to test if the reindeer mammary gland (udder) could tolerate regular long-term machine milking, (2) to record milk yield of reindeer exposed to regular long-term machine milking and (3) to document changes in milk composition through a 3 months experimental period (July, August and September 1999). Adult female reindeer were allotted to four groups of four. Tre...

The objective of the study was to investigate the effects of supplementing different plant oils to the basal diet on milk yield and milk composition in mid-lactating dairy cows. Forty Chinese Holstein dairy cows averaging 120 days in milk (DIM) at the start of the experiment (body weight = 580 ± 18.2 kg; milk yield = 33.0 ± 2.00 kg/day) were used in a completely randomized block design. The ani...

A method of simulating individual cow milk yield per milking as a function of herd milk yield and month was formulated for milking parlor simulation models. Milk yield per milking was modeled for each month in three herd milk yield categories: 8165, 8845, and 9525 kg/yr of milk per cow. Actual individual cow DHIA test day milk weight data for three Florida dairy herds in each herd milk yield ca...

the aim of this study was to estimate genetic parameters of age at first calving and its relationship with productive traits of holstein dairy cows. a total of 24491 first lactation records (2x 305d) which were collected from 1995 to 2009 were used. the general linear model (glm) procedure was applied to determine effective factors on studied traits. herd-year-season (hys) and age at first calv...

A field trial was conducted on 5 farms to determine the effect of feeding distillers dried grains (DDGS) on milk production in the southern dairy region of Chile. The trial was repeated on each farm during winter (July and August; primarily silage-based rations) and spring (November and December; pasture-based rations). Only for one farm could the treatments be applied concurrently by feeding d...

Seventy six high and low producer cows were selected to determine the composition of the blood and milk parameters, and their interrelationships to determine the indices which could be useful to improve the milk yield. The highest mean blood concentrations were found in high producer cows. Mean values for blood urea nitrogen (BUN), serum protein (SPtn), creatinine, triglycerides (TGs), choleste...