Treating clinical mastitis in dairy herds: a role for on farm culture?

The focus on the rational use of antibiotics in dairy herds has meant that mastitis control has received renewed interest, particularly around prevention of new infections and alternative treatment strategies. The former has seen the development of a new industry initiative (QuarterPRO) to help advisors and farmers reduce the rate of new infections and index cases. The latter has seen widespread uptake of the selective use of intramammary antibiotic for infected cows at drying-off, a reminder to the veterinary profession as well as clients about the general lack of evidence for the use of parenteral antibiotic in combination with intramammary antibiotic for mild and moderate clinical mastitis events, and finally the potential to select intramammary antibiotic treatment for clinical mastitis using on farm culture (OFC). It is important that veterinary surgeons are aware of the research around the development and use of OFC and the suitability of individual herds for this approach. Whereas antibiotics may not be required for mild clinical mastitis events caused by some pathogens, particularly Escherichia coli, it is important that clinical mastitis events (particularly first cases in a lactation cycle) caused by Gram-positive pathogens such as Streptococcus spp. and Staphylococcus aureus are treated with intramammary antibiotic to optimise chance of cure and reduce risk of transmission. With this in mind, we need to consider individual herd cell count data, herd pathogen profile and ensure careful monitoring of outcomes for clinical mastitis cases in herds that are selecting treatment based on OFC, particularly for index (first) cases in a cow's lactation.

Changes of Plasma Analytes Reflecting Metabolic Adaptation to the Different Stages of the Lactation Cycle in Healthy Multiparous Holstein Dairy Cows Raised in High-Welfare Conditions

Here, we tested the changes occurring in several plasma analytes during different stages of the lactation cycle of high welfare raised multiparous Holstein cows, and provided reference intervals (RI) for plasma analytes concentrations. Eleven high-welfare farms (HWF) located in Northern Italy were selected and their herds used to recruit 361 clinically healthy cows undergoing the dry (from −30 to −10 days from real calving; DFC), the postpartum (from 3 to 7 DFC), the early lactation (from 28 to 45 DFC) and the late lactation phases (from 160 to 305 DFC). Cows affected by subclinical diseases (SCD) were retrospectively excluded, and a subset of 285 cows was selected. Data of plasma analytes underwent ANOVA testing using physiological phases as predictors. The individual effect of each phase was assessed using a pairwise t-test assuming p ≤ 0.05 as a significance limit. A bootstrap approach was used to define the reference interval (RI) for each blood analyte within physiological phases having a pairwise t-test p ≤ 0.05. The concentration of nonesterified fatty acids, albumin, cholesterol, retinol, paraoxonase and tocopherol changed throughout all the physiological phases, whereas the concentration of K, alkaline phosphatase and thiol groups remained stable. Triglycerides, Zn, and ferric ion reducing antioxidant power in the dry phase and BHB, Ca, myeloperoxidase, haptoglobin, reactive oxygen metabolites and advanced oxidation of protein product in postpartum differed compared with other physiological phases. During the dry phase, Packed cell volume, Cl, and urea concentrations were similar to during the postpartum phase. Similarly, Na, γ-glutamyl transferase and β-carotene concentrations were similar to during the early lactation phase; fructosamine and bilirubin concentrations were similar to during the late lactation phase. During the postpartum phase, fructosamine and P concentrations were similar to during the early lactation phase, and the aspartate transaminase concentration was similar to during the late lactation phase. During the early lactation phase, Mg, creatinine, total protein, globulin and ceruloplasmin concentrations were similar to during the postpartum phase, while the urea concentration was similar to during the late lactation phase. All these plasma analytes differed among the other phases. This study identifies physiological trends affecting plasma analytes concentrations during the different stages of the lactation cycle and provides a guideline for the duration and magnitude of their changes when animals are healthy and raised in optimal welfare conditions.

120 Impact of a Two-phase Lactation Feeding Program on Farrowing and Weaning Performance of Sows

The U.S. Pork Industry uses a one-phase lactation feeding program based on logistical constraints and ease. The objective of this experiment was to quantify the sow performance differences between a one-phase and two-phase lactation feeding program to allow pork producers to calculate the economics of switching to a two-phase lactation feeding program. 257 gilts and sows (PIC 1050; Hendersonville, TN) were randomly assigned to a two-phase or one-phase lactation feeding program. Animals on the one-phase treatment were fed a typical lactation diet (2.55 Mcal/kg NE, 12.7% NDF, 0.99% SID Lys) for the duration of the experiment. Animals on the two-phase treatment were fed a high-fiber, lower-lysine transition diet (2.35 Mcal/kg NE, 18.5% NDF, 0.65% SID Lys) from the time they were loaded into the farrowing room until switching to the lactation diet on d 3 post-farrowing. From loading to farrowing, animals on both treatments were fed 1.82 kg/d, split between 2 meals at 630 and 1530 h. Daily feed amount was increased on the farrowing day and the 2 subsequent days (2.73, 4.09, 5.45 kg) until allowed ad libitum access to the lactation feed for both treatment groups on the third day after farrowing. Data were analyzed using Proc MIXED (SAS 9.4; Cary, NC) with treatment as the main effect and sow as the experimental unit. Comparing treatments, no significant differences on total born (one-phase = 16.2 vs. two-phase = 16.0, pigs/litter), live born (one-phase = 14.6 vs. two-phase = 14.4, pigs/litter), stillborn rate (one-phase = 8.1% vs. two-phase = 7.4%), number weaned (one-phase = 12.1 vs. two-phase = 11.9, pigs/litter), or weaning weight (one-phase = 5.67 vs. two-phase = 5.71, kg/pig; P ≥ 0.37) were detected. In conclusion, a two-phase lactation feeding program did not impair sow performance can be utilized to reduce lactation feed costs by $0.42/female/lactation cycle.

Mammary gland adipocytes in lactation cycle, obesity and breast cancer

The mammary gland (MG) is an exocrine gland present in female mammals responsible for the production and secretion of milk during the process of lactation. It is mainly composed by epithelial cells and adipocytes. Among the features that make the MG unique there are 1) its highly plastic properties displayed during pregnancy, lactation and involution (all steps belonging to the lactation cycle) and 2) its requirement to grow in close association with adipocytes which are absolutely necessary to ensure MG’s proper development at puberty and remodeling during the lactation cycle. Although MG adipocytes play such a critical role for the gland development, most of the studies have focused on its epithelial component only, leaving the role of the neighboring adipocytes largely unexplored. In this review we aim to describe evidences regarding MG’s adipocytes role and properties in physiologic conditions (gland development and lactation cycle), obesity and breast cancer, emphasizing the existing gaps in the literature which deserve further investigation.

The Rumen Bacterial Community in Dairy Cows Is Correlated to Production Traits During Freshening Period

The rumen microbiome plays a vital role in providing nutrition to the host animal, thereby influencing ruminant production. Despite its importance, it is not fully understood how variation in the ruminal bacteria community composition influences dry matter intake (DMI), milk yield and ruminal fermentative parameters in dairy cows, especially during freshening period. Here, we hypothesized that during early lactation, high DMI cows having a different ruminal microbiota than low DMI cows, and that this difference persists over time. To test this, we enrolled 65 fresh and determinzed their DMI using an auto-feed intake recording system. Fourteen days after calving, the 10 animals with the lowest (LFI) and the 10 animals with the highest (HFI)-average DMI were selected for further analysis. Rumen fluid was collected from these two cohorts at 1 (Fresh1d) and 14 days (Fresh14d) after calving and their ruminal microbiota were assessed using 16S rRNA sequencing. Volatile fatty acid (VFA) concentrations were also quantified. Comparison of the ruminal microbiotas between Fresh1d and Fresh14d showed that Fresh14d cows had a significantly higher relative abundance of VFA—producing microbes (P < 0.05), such as Prevotella_7 and Succinivibrionaceae_UCG-001. This was commensurate with the concentrations of acetate, propionate, butyrate, valerate and total VFAs, were also significantly (P < 0.05) increased in Fresh14d cows. We also found that the differences in the ruminal microbiota between LFI and HFI cows was limited, but DMI significantly altered (P < 0.05) the relative proportion of bacteria in the families Coriobacteriaceae, and Succinivibrionaceae. Furthermore, specific operational taxonomic units belonging to the Anaeroplasma was significantly (P < 0.05) correlated with DMI and milk yield. Taking together, our findings provide a framework for future studies of freshening period cow that seek to better understand the role of the ruminal microbiota during this critical period in the lactation cycle.

Abnormal Lactation Lengths and its Consequences on Performance of Crossbred Cattle

Background: The study was conducted to unravel the consequences of abnormal lactation lengths (Extremely short, short, prolong and extremely prolong lactation length) on production and reproduction traits of crossbred cattle (Red Dane x Sahiwal x Holstein Friesian), which otherwise remains unutilized in routine breeding data analysis owing to normalization and standardization of lactation lengths. Methods: The performance data of 2541 lactations of 1001 crossbred cattle, sired by 146 bulls over a period of 30 years maintained at the Livestock Farms of Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Ludhiana were used for this study. The data on production and reproduction traits were analysed using general linear model procedures based on extremely short ( less than 102 days), short (102-179 days), prolong (483 - 560 days) and extremely prolong (≥ 560 days) lactation lengths on the basis of mean lactation length and its standard deviation. Result: Result indicated that the alteration of lactation lengths affected all important performance traits of crossbred cattle in contemporary as well as in next lactation. The values of 305 days milk yield, lactation milk yield, average fat (%), 305 days fat yield and lactation fat yield of contemporary lactation cycle were higher (P≤0.05) for the extremely prolong lactation length and reduced for shorter lactations. Similar trend was seen for next lactation cycle of the animal having abnormal lactation length in previous lactation cycle for all traits except calf birth weight, whereas days to reach peak yield and fat yield traits were not significantly affected by lactation length classes. The preferred lactation length for crossbred cattle for optimum performance was concluded as 180 to 483 days ranging one standard deviation from mean lactation length, covering more than 72% of population; however, it needs further studies to break it into groups in terms of productive life and economical merits. Farmers should avoid breeding of animal having extremely short and short lactation lengths, as their production and reproductive traits are lower in successive production cycle.

Pregnancy-lactation cycle: how to use imaging methods for breast evaluation

Pregnancy and lactation constitute states of intense hormonal variation with secretory and structural changes in the breast parenchyma. These changes translate into important features on breast imaging, as well as the emergence of specific benign and malignant lesions. This literature review aims to discuss the safety of the use of breast imaging methods (mammography, ultrasound, and magnetic resonance imaging) during the pregnancy-lactation cycle, and to present the expected physiological changes and imaging appearance of the main breast diseases that may occur in this period, such as galactocele, lactating adenoma, fibroadenoma, puerperal mastitis, and pregnancy-associated breast cancer.

278 Feeding a whole-cell inactivated Pichia guilliermondi yeast to gestating and lactating sows over two consecutive parities

A total of 535 sows and their progeny (PIC 359×1050) were used to determine the effect of feeding gestating and lactating sows a proprietary strain of Pichia guilliermondi as a whole-cell inactivated yeast product (WCY; CitriStim, ADM Animal Nutrition, Quincy, IL) on sow and litter performance in a commercial production system. Within 24 hours of breeding, sows were allotted to 1 of 2 dietary treatments. Parity distribution was equalized across treatments. Sows were fed either a basal gestation control (CON) diet or CON fortified with 0.1% (0.91 kg/ton) of the WCY at the expense of corn throughout gestation. Sow dietary treatments were also maintained through lactation. Of the 535 sows that completed the initial reproductive cycle (cycle 1), 358 sows were maintained on dietary treatment and followed through a second gestation and lactation (cycle 2). The direction and magnitude of the differences in total born and born alive pigs in cycle 1 and cycle 2 was similar between treatments. Supplementing sows with WCY in cycle 1 increased the number of total born pigs by 0.59 pigs/litter (P=0.038) and tended to increase the number of pigs born alive by 0.52 pigs/litter (P=0.064) compared to CON fed sows. For cycle 2, the total number of born and born alive pigs numerically increased by 0.44 pigs/litter (P=0.180) and 0.43 pigs/litter (P=0.179) respectively for sows fed WCY. The distribution of pig birth weights was not different between treatments in cycle 1 (P=0.536) nor cycle 2 (P=0.256). Also, the litter growth rate on a weight gain per pig per day basis was not different between treatments in cycle 1 (P=0.103) nor cycle 2 (P=0.379). In conclusion, feeding gestating and lactating sows a proprietary strain of Pichia guilliermondi as a whole-cell inactivated yeast product significantly increased the number of total born pigs during cycle 1.

Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows

The transhumance system, which consists in moving animals to high mountain pastures during summer, plays a considerable role in preserving both local biodiversity and traditions, as well as protecting against natural hazard. In cows, particularly, milk production is observed to decline as a response to food shortage and climatic stress, leading to atypical lactation curves that are barely described by current lactation models. Here, we relied on 5 million monthly milk records from over 200 000 Braunvieh and Original Braunvieh cows to devise a new model accounting for transhumance, and test the influence of environmental, physiological and morphological factors on cattle productivity. Counter to expectations, environmental conditions in the mountain showed a globally limited impact on milk production during transhumance, with cows in favourable conditions producing only 10% more compared with cows living in detrimental conditions, and with precipitation in spring and altitude revealing to be the most production-affecting variables. Conversely, physiological factors such as lactation number and pregnancy stage presented an important impact over the whole lactation cycle with 20% difference in milk production, and alter the way animals respond to transhumance. Finally, the considered morphological factors (cow height and foot angle) presented a smaller impact during the whole lactation cycle (10% difference in milk production). The present findings help to anticipate the effect of climate change and to identify problematic environmental conditions by comparing their impact with the effect of factors that are known to influence lactation.

Big dairy data to disentangle the effect of geo-environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows

1.SummaryThe transhumance system, which consists in moving animals to high mountain pastures during summer, plays a considerable role in preserving both local biodiversity and traditions, as well as protecting against natural hazard. In cows, particularly, milk production is observed to decline as a response to food shortage and climatic stress, leading to atypical lactation curves that are barely described by current lactation models. Here, we relied on five million monthly milk records from over 200,000 Braunvieh and Original Braunvieh cows to devise a new model accounting for transhumance, and test the influence of environmental, physiological, and morphological factors on cattle productivity. Counter to expectations, environmental conditions in the mountain showed a globally limited impact on milk production during transhumance, with cows in favourable conditions producing only 10% less compared to cows living in adverse conditions, and with precipitation in spring and altitude revealing to be the most production-affecting variables. Conversely, physiological factors as lactation number and pregnancy stage presented an important impact over the whole lactation cycle with 20% difference in milk production, and may therefore alter the way animals respond to transhumance. Finally, the considered morphological factors (cow height and foot angle) presented a smaller impact during the whole lactation cycle (10% difference in milk production). The present findings can help farmers to establish sustainable strategies for alleviating the negative effects of transhumance on productivity and preserving this important livestock practice.