Oestrus and ovarian activity were studied in a group of crossbred SahiwalShorthorn beef cows over four lactation periods of varying length throughout different seasons of the year. In the first lactation, cows were in poor condition (body weight 303 kg) and the mean interval from calving to first oestrus was 2202 16 days. Five COWS were still anoestrus 18 months after calving and were culled. T...

Nine mathematical models were compared for their ability to predict daily milk yields (n = 294,986) in standard 305-d and extended lactations of dairy cows of Costa Rica. Lactations were classified by parity (first and later), lactation length (9 to 10, 11 to 12, 13 to 14, 15 to 16, and 16 to 17 mo), and calving to conception interval (1 to 2, 3 to 4, 5 to 6, 7 to 8, and 9 to 10 mo). Of the nin...

OBJECTIVE To evaluate the effects of physical training of mother rats during pregnancy associated with a low-protein diet offered during pregnancy and lactation on the development and growth of the femur of their offspring. METHODS Forty 90-day old male Wistar rats were divided into four groups: pups of sedentary nourished mothers, pups of sedentary malnourished mothers, pups of trained nouri...

The study was conducted to determine the effect of long term use of bovine somatotropic hormone (bST) on days to first oestrus post-partum, number of services per conception, pregnancy rate, lactation length, dry period and calving interval for a period of three years, from 2004 to 2007. Thirty Nili-Ravi lactating buffaloes with approximately similar milk yields and stage of lactation were sele...

Lactation yield estimates standardized to common lactation lengths of 270-d or 305-d equivalents are commonly used in management decision support tools and dairy cow genetic evaluations. The use such measurements quantify the (genetic) merit individual cows fails penalize that do not reach length, indeed reward lactate for more than length. objective present study was nongenetic factors associa...

to have an, idea about the relation between the length of birth interval and lactation, and birth control program this study have been done. the material for such analysis was nomad women's fertility history that was in their reproductive period (15-44). the material itself was gathered through a health survey. the main sample was composed of 2,165 qualified women, of whom 49 due to previous or...

Objective- The aim of this study was to determine the normal ultrasonographic and morphologic appearance of mammary gland and teat in Caspian mares during lactation and dry period. Design- Experimental study. Animals- Seven mature Caspian mares Procedures- Using a 6.5-8.5 MHz linear transducer the ultrasonographic appearance of lactating and dry mammary glands was determined in 7 mature Casp...

The proportional hazards model with censoring was used to assess the effects of breeding value, disease, calving, size, and udder and lactation traits on length of herdlife of 3881 heifers in five herds. Data were recorded over 10 yr from three lines: a Holstein line, an Ayrshire-based line, and a crossbred line. Influences on survival were assessed from data collected at birth, 34, 50, and 82 ...