Accuracy of oestrus detection in cows and its economic impact on Shiraz dairy farms
No report has been published on the economical losses associated with errors in oestrus detection in cows under Iranian intensive dairy management. The following study was carried out to determine the accuracy of oestrus detection by farmers using artificial insemination in Shiraz dairy farms. Milk samples were collected from 179 Holstein milking cows at the time of artificial insemination. Milk progesterone concentration was determined using a commercial radio-immunoassay kit. It was assumed that a milk progesterone concentration greater than or equal to 3 ng/ml indicated the presence of active luteal tissue and that all animals in oestrus had a concentration less than 1 ng/ml. Results of the present study showed that error in oestrus detection was higher in dairy herds with more than 85 milking cows compared to that of the smaller size herds (14.4 vs 7.3%; χ2 = 2.59; P = 0.1). Five out of 11 herds (45%) had an oestrus detection error higher than 10 percent while in the remaining six herds the oestrus detection error varied from 0 to 7.1%. Based on the assumptions and calculations made in the present study, the net cost of one day delay in conception for a cow producing 25 litres milk in peak lactation was calculated at 40591.98 Rials (4.51 $US) when conception is delayed from 85 to 100 days post-calving, increasing to 60120.89 Rials (6.68 $US) per day if conception occurred at 146 to 175 days post-calving.
no report has been published on the economical losses associated with errors in oestrus detection in cows under iranian intensive dairy management. the following study was carried out to determine the accuracy of oestrus detection by farmers using artificial insemination in shiraz dairy farms. milk samples were collected from 179 holstein milking cows at the time of artificial insemination. mil...متن کامل
This paper addresses detection of oestrus in dairy cows using methods from statistical change detection. The activity of the cows was measured by a necklace attached sensor. Statistical properties of the activity measure were investigated. Using data sets from 17 cows, diurnal activity variations were identified for the ensemble and for the individual cows. A diurnal filter was adapted to remov...متن کامل
the comparative impact of prompts and recasts in processing instruction versus meaningful output-based instruction on efl learners’ writing accuracy
the purpose of the present study was to see which one of the two instruction-processing instruction (pi) and meaningful output based instruction (mobi) accompanied with prompt and recast- is more effective on efl learners’ writing accuracy. in order to homogenize the participants in term of language proficiency a preliminary english test (pet) was administrated between 74 intermediate students ...
the geopolitics of afghanistan after september 11, 2001, and its impact on iranian national security
abstract u.s. attack to afghanistan after 9/11 provided opportunities for us who tried to become the dominant power after collapse of ussr and bipolar world. thinkers like fukuyama believed american liberal democrats thought would be universally accepted without resistances. liberal democracy is the best and final model of governance; in this regard, united state has moral responsibilities for...15 صفحه اول
an investigation of the impact of self monitoring on langauge teachers motivational practice and its effect on learners motivation
the central purpose of this study was to conduct a case study about the role of self monitoring in teacher’s use of motivational strategies. furthermore it focused on how these strategies affected students’ motivational behavior. although many studies have been done to investigate teachers’ motivational strategies use (cheng & d?rnyei, 2007; d?rnyei & csizer, 1998; green, 2001, guilloteaux & d?...
ذخیره در منابع من
دوره 8 شماره 2
صفحات 131- 137
تاریخ انتشار 2007-06-30
با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.