peer reviewed | Objective: To explore feeding strategies and identify eventual errors that could cause poor pro-duction and reproduction performances in dairy farms in the north of Algeria.Materials and Methods: A survey was conducted among 211 farms of different sizes, from 2014 to 2018 to compose a database that is analyzed statistically.Results: The results relative to the nutritive value of the rations showed an average dry matter intake of 15.9 ± 4.74 kg/cow/day, providing 13.2 ± 4.34 UFL (Feed Unit for Lactation) of net energy and 1306 ± 456 gm of protein digested in small intestine (PDI)/cow/day. A high proportion of concentrate intake is observed, with an average of 64.7% ± 17.4% of energy intake and 70.2% ± 16.2% of nitrogen intake.Dairy cows performances were characterized by a low milk productionregarding their genetic potential (14.2 ± 4.73 kg of milk/cow/day), a calving interval > to one year (397 ± 20.4 days), though the coverage rates of their nutrient requirements reached 120%.The typology of the dietary rations allowed grouping them into three categories: deficient rations cluster (DR), correct rations cluster, and excessive rations cluster (ER). DR and ER, which are not adjusted to animals’ needs, were found in 57.8% of farms.Conclusion: It is obvious that the feeding management in the dairy farms in the North of Algeria is not based upon scientific achievements, contributing to relatively low performances of cows as well as to important financial losses. This finding imposes the necessity to adopt a correct and accurate rationing of animals.

Data on production and reproduction performances of 373 Jersey cows born and reared at the Exotic Cattle Breeding Farm, Eachenkottai, Tamil Nadu, India, pertaining to 27 years were collected. They were analysed to study the effects of various non-genetic factors on milk production and reproduction traits. The least-squares means (± SE) for 305-day and total lactation milk yields for all the parities were 1491.6 ± 25.9 and 1560.9 ± 29.9 kg respectively. The averages for lactation length, service period, calving interval and dry period for all lactations were 303.1 ± 4.0, 177.0 ± 10.0, 461.0 ± 9.7 and 160.2 ± 9.7 days respectively. Years grouped into five periods had significant (P<0.01) influence on all the traits studied. Season of calving showed a significant (P<0.01) source of variation in milk yield traits and calving interval. Parity was found to influence 305-day milk yield, service period, dry period and calving interval significantly (P<0.01). The study revealed that the performance of the Jersey cattle was much lower than those maintained under high altitude conditions in Tamil Nadu and other places in India.

A survey was conducted among the small holder dairy farmers in 80 Panchayaths of 14 districts in Kerala in order to evaluate the reproductive performance of crossbred cattle population in Kerala at field level. Analysis of the data showed that the herd size of cattle in Kerala was around 3 per house during the period of 2012 and 2013. Three fertility traits, age at first calving (AFC), calving interval (CI) and number of services per conception (NSC) were studied in detail and the averages of these traits were 1093 ± 10.52 days, 551 ± 48 days and 2.02 ± 0.01 services per conception, respectively. Fixed model analysis was carried out to see the effect of some of the major factors leading to variation in AFC, CI and NSC and found that there was significant difference in reproductive performances among different genetic groups. AFC and NSC of crossbred Holstein Friesian cows and CI of Sunandini cows were lower compared to other genetic groups. Other factors significantly influencing AFC were period of birth and season of birth. Apart from genetic groups, number of services per conception was influenced by type of semen used and also the level of peak milk production.

A survey was conducted among the small holder dairy farmers in 80 Panchayaths of 14 districts in Kerala in order to evaluate the reproductive performance of crossbred cattle population in Kerala at field level. Analysis of the data showed that the herd size of cattle in Kerala was around 3 per house during the period of 2012 and 2013. Three fertility traits, age at first calving (AFC), calving interval (CI) and number of services per conception (NSC) were studied in detail and the averages of these traits were 1093 ± 10.52 days, 551 ± 48 days and 2.02 ± 0.01 services per conception, respectively. Fixed model analysis was carried out to see the effect of some of the major factors leading to variation in AFC, CI and NSC and found that there was significant difference in reproductive performances among different genetic groups. AFC and NSC of crossbred Holstein Friesian cows and CI of Sunandini cows were lower compared to other genetic groups. Other factors significantly influencing AFC were period of birth and season of birth. Apart from genetic groups, number of services per conception was influenced by type of semen used and also the level of peak milk production.

Objective: The study was conducted to investigate the effect of mastitis on post-partum conception in crossed cows (Local x Friesian or Sahiwal x Friesian) in Chittagong area of Bangladesh. Materials and methods: A total of 100 lactating cows were randomly selected from thirteen small and medium size commercial dairy farms. The cows were reared under traditional feeding and management systems. Age and number of parity of the cows were 2.5 to 6 years and 1-5, respectively. On-farm California Mastitis Test (CMT) and Whit Slide Test (WST) were performed with the milk samples to diagnose mastitis. Besides, productive and reproductive data were recorded by examining the animals and interviewing the farmers. Results: The incidence of mastitis was significantly (P=0.037) higher (76% for CMT and 62% for WST) in 3.5-4.5 years old cows and lower (P=0.037) (47% for CMT) in 2.5-3.5 years old cows. The highest percentage of CMT (72%) and WST (59%) positive cases were found in cows having parity number 2. The CMT (71%) and WST (53%) test results were similar in third parity cows. The first parity cows were less prone to mastitis (47%). Mastitis had significantly (P=0.002) negative effect on days required to first heat after parturition. Mastitis was also negatively correlated with calving interval (CI) (P=0.030). More the incidence of mastitis prolongs the calving interval and the highest percentage (85% for CMT and 71% for WST) of mastitis was found in cows having 380-400 days calving interval. Lowest mastitis (54% for CMT and 48% for WST) incidence detected cows’ lowest calving interval. Significantly, more number of Service per Conception (SPC) was also required in cows having more incidence of mastitis (P=0.03). SPC was 4 for subclinical to clinical cases and 3 for clinical cases. Conclusion: Significant correlation between mastitis and post-partum conception is recorded in this study that may hamper reproductive performances. [J Adv Vet Anim Res 2017; 4(2.000): 155-160]