Evaluation of Bulls and Related Groups of the Jersey Breed on Dairy Productivity and Reproductive Capacity of Offspring

The article presents the results of research on the influence of paternal origin and belonging to a related group on the level of milk productivity of cows and the reproductive capacity of Jersey cows in the farm “Dan-Milk” of the Zhytomyr Region. The purpose of this study is to establish the influence of paternal origin and belonging to a related group on the level of milk productivity and reproductive capacity parameters of Jersey cows. The study established a substantial level of differentiation in the main economically useful features between groups of half-sisters by father. The best quantitative indicators of milk productivity were noted among the daughters of bulls DJ Jante 302761 (P<0.001) and Headline 114114336 (P<0.001), the worst indicators – among daughters of Karl 67037285. The highest indicators of fat and protein content in milk were noted in the cows bred from the bull Legal 61929249, the lowest – from the bull Karl 67037285. The influence of the origin of cows by father on the variability of milk yield and yield of milk fat and protein was 20.3–30.3% (up to P<0.001), the content of fat and protein in milk decreased to 13.2-20.0% (P<0.01 and P<0.05), and according to the reproductive capacity features – to 7.8-19.0% with an unreliable level of statistical significance. Prepotent as to milk yield are bulls Legal 61929249 and Headline 114114336, as to the content and yield of milk protein – Legal 61929249. Cows of the related group bred from the bull Observer 553236 are characterised by the highest milk yield and yield of milk fat and protein for both the first and best lactation, and cows of the related group bred from Surville 604694 are characterised by the worst yield. The influence of belonging to a related group on the studied features was several times lower (0.2-10.5%) compared to the influence of paternal origin. With an increase in the milk yield of cows over the first lactation, there is a stable and substantial decrease in the reproductive capacity coefficient due to the lengthening of the service period between the first and second calving. Such natural antagonism does not imply the goal of increasing the duration of the service period to obtain maximum milk yields for firstborn cows, since this will lead to a decrease in the yield of calves and render timely replenishment of the herd impossible. It is optimal to milk the firstborn up to 8 tonnes over 305 days of lactation while maintaining a satisfactory reproductive level

Melatonin differences between day and night milk in primiparous holstein friesian and jersey dairy cattle

This study was conducted to determine the levels of melatonin in the day and night milk of Holstein and Jersey cows. In the study, samples of daytime milk produced from 27 head of Holstein and 27 head of Jersey cows in the first lactation, which were raised in a private dairy cattle enterprise in the Kaşınhanı neighborhood of Meram district of Konya city Turkey, and night milk samples taken from the same cows that were blackened for one (1) week were used. Melatonin levels in milk samples taken from day and night milk were determined separately for Holstein and Jersey cows with the help of Bovine Melatonin (MLT) Elisa Kit. In the study, it was determined that the ratio of melatonin in day and night milk in Holstein cows was 2.912 pg/ml and 11.314 pg/ml, respectively, and the ratio of melatonin in Jersey cows was 2.924 pg/ml and 6.954 pg/ml in the same order. The difference between the melatonin levels of the day and night milk of Holstein and Jersey cows was found to be statistically significant (p<0.01). At the end of the study, it can be stated that night milk can be used for medical purposes and a new production source may arise for producers since there is a significant difference in melatonin between day and night milk.

Effects of Postpartum Supplemental Oral Ca for Dairy Cows Fed Prepartum Dietary Acidogenic Salts

Postpartum hypocalcemia is a problem in dairy cows. Both the Jersey vs. Holstein breed and increasing parity are known risk factors. Our objectives were: (1) to evaluate a simple approach to provide dietary acidogenic salts suitable for application on small dairies and (2) to evaluate the combined effects of degree of acidification and oral Ca supplementation along with breed and parity group on periparturient Ca status of Holstein and Jersey cows. Cows were moved weekly from the far-off dry pen at 260 days pregnant to the close-up pen, where all cows received the acidogenic diets. The diet was offered as a total mixed ration and CaCl2, and our source of acidogenic salts was top-dressed in liquid form and mixed in by hand. Thirty-six cows were blocked by parity group (parity = 2 vs. parity ≥ 3) and breed (Holstein vs. Jersey) and assigned to one of two treatments (no intervention or postpartum oral Ca bolus supplementation) in an alternating fashion, based on expected date of parturition. Urinary acidification appeared complete within 3–4 days. Increased urinary Ca excretion was >93% of maximum from 7–21 days before falling to <5% of maximum by 28 days. Serum Ca concentrations 12–24 h postpartum were lower for Jerseys vs. Holsteins and for parity ≥ 3 vs. parity = 2 cows. Serum Ca over 6–48 h postpartum decreased and increased, respectively, with oral Ca supplementation for parity = 2 and parity ≥ 3 cows. Decreased prepartum urinary Ca excretion and increased colostrum yield appear to be independent risk factors of hypocalcemia for parity ≥ 3 Jerseys.

Effects of Milk Urea Nitrogen (MUN) and Climatological Factors on Reproduction Efficiency of Holstein Friesian and Jersey Cows in the Subtropics

This study investigated the effects of MUN and climatological factors on the inter calving period (ICP), reproductive performance (RP%), and reproductive index (RI) in Holstein Friesian (n = 1177) and Jersey cows (n = 3305) in different seasons in the subtropics. Threshold values for MUN on the reproduction of dairy cows in the subtropics remain controversial due to complex environmental interactions, especially with high environmental temperatures. A retrospective analysis was conducted of data obtained from the National Milk Recording scheme of the Agricultural Research Council (ARC) in South Africa. The results confirm that MUN influences the reproduction of dairy cows in the subtropics. MUN concentrations exceeding 18.1 ± 4.28 mg/dL in Holstein Friesian cows and 13.0 ± 4.70 mg/dL in Jersey cows extended the inter calving period (ICP), and decreased RP% and RI. Jersey cows have a lower threshold MUN concentration compared to Holstein Friesian cows, but they are not adversely affected by high humidity or temperatures, while Holstein Friesian cows are.

PSII-3 Daily weather patterns associated with colostrum production in dry cows

Insufficient consumption of colostrum and/or intake of poor-quality colostrum reduces thriftiness and survival of dairy calves. Additionally, heat stress during gestation of primiparous Holstein cows can impact hormone synthesis, leading to decreased colostrum and milk production. Previous research has primarily focused on Holstein cows who have a larger frame compared to other breeds. It is possible heat stress may impact Jersey cow colostrum production differently. Therefore, the objective of this research was to determine the relationship between temperature-humidity index (THI) and colostrum volume and quality in Jersey cows. Colostrum data was collected from Jersey cows (n = 75) from three farms and compared to the average THI values during the dry period. Colostrum data included volume, Brix score, fat, true protein (TP), solids non-fat (SNF), lactose, somatic cell count (SCC), and urea. Daily air temperature and humidity records were determined via local weather stations and used to calculate THI values. These values were averaged for the far-off and close-up periods. The data were analyzed separately for each farm using linear regression models in R version 1.3.1073. Covariates included season, dry period length, date of colostrum collection, and parity. Close-up and far-off THI tended to predict an increased volume (β=0.3656; P = 0.0724) and somatic cell count (β=82.07; P = 0.0964) for Farm 1. Far-off THI was a significant predictor for Brix for Farm 2 (β=0.2482; P ≤ 0.01) and Farm 3 (β=-0.1762; P ≤ 0.01) and increased Brix score in Farm 2 but decreased it in Farm 3. THI was not a significant predictor for any other colostrum values. Based on these results, we suggest that an increased THI during the far-off period potentially increases Brix score without compromising other values. However, more research is needed to further investigate the effects of the close-up period on volume and of covariates on other values.