Utilization of milk energy by suckling mink kits

A total of 36 mink dams and their litters of 3, 6 or 9 kits were used for determination of milk intake of the suckling young by means of deuterium dilution technique, and chemical composition of milk and of kit bodies. Measurements were performed during lactation weeks 1?–?4, each week with 3 dams with each litter size. Milk intake was determined over a 48?h measurement period, and by the end of this milk samples were collected and 2 kits (litters of 6 and 9) or 1 kit per litter (litters of 3) were killed for body chemical composition. Based on the results, different models were applied for calculation of the energetic efficiency of milk. Dam milk yield increased steadily from week 1 until week 3 but only slightly from week 3 to 4. The increase declined with increasing litter size, and for dams suckling 9 kits the increment from week 3 to week 4 was only 2?g. The dry matter content of milk increased significantly as lactation progressed, being reflected in crude protein increasing from 6.9% in lactation week 1 to 8.1% in week 4. Milk fat increased concomitantly from 5.6% to 8.0%. In kit bodies, crude protein content increased from 9.4% in week 1 to about 12% in weeks 3 and 4. Body fat content increased from week 1 (4.1%) to week 3 (8.4%) and then declined in week 4 (7.1%). Animals suckled in litters of 3 kits had the highest milk intake and live weight and kits suckled in litters of 9 had the lowest milk intake, live weight and daily gain. In terms of milk intake per g gain kits in litters of 6 were the most efficient, with 4.1?g milk per g body gain. The metabolizable energy requirement for maintenance (MEm) was estimated to 448 kJ/kg^0.75 and the efficiency of utilization of ME for body gain (k_g) to 0.67, the estimates being higher (MEm) or in good agreement with previous findings (k_g) in suckling mink kits.     

Acoustic sensing and signal processing techniques for monitoring milk fouling cleaning operations

Large resource investments are necessary in order to minimize the limiting problems arising from food industrial intensive productivity. One of the most challenging concerns is the cleaning status uncertainty among heat transfer areas in dairy heat exchangers, since the effectiveness of this process cannot be easily validated. The present study aimed to develop a low‐power ultrasound sensing method for monitoring the removal of milk fouling deposits along cleaning processes inside an experimental plate heat exchanger structure, connected to a milk piping unit. For that purpose, signal processing, namely acoustic feature extraction, over different wave patterns combined with artificial neural network techniques was used. Measurements were taken in pulse‐echo mode with a handmade 4 MHz ultrasound transducer. While fouling deposits having initial average thickness values of 250 μm (34.5 ± 4.5 mg/cm²) were removed, the acoustic transmissivity increased. Results showed that the signal features follow the expected trends in both, clean and fouled cases, within right guess detection accuracies above 80%. Therefore, when calibrated well, this could be a very sensitive and noninvasive technique for material characterization, as well as a suitable validation method for industrial cleaning cycle operation optimization that could significantly reduce the associated costs.     

Structure activity relationship modelling of milk protein-derived peptides with dipeptidyl peptidase IV (DPP-IV) inhibitory activity

Quantitative structure activity type models were developed in an attempt to predict the key features of peptide sequences having dipeptidyl peptidase IV (DPP-IV) inhibitory activity. The models were then employed to help predict the potential of peptides, which are currently reported in the literature to be present in the intestinal tract of humans following milk/dairy product ingestion, to act as inhibitors of DPP-IV. Two models (z- and v-scale) for short (2–5 amino acid residues) bovine milk peptides, behaving as competitive inhibitors of DPP-IV, were developed. The z- and the v-scale models (p < 0.05, R² of 0.829 and 0.815, respectively) were then applied to 56 milk protein-derived peptides previously reported in the literature to be found in the intestinal tract of humans which possessed a structural feature of DPP-IV inhibitory peptides (P at the N₂ position). Ten of these peptides were synthetized and tested for their in vitro DPP-IV inhibitory properties. There was no agreement between the predicted and experimentally determined DPP-IV half maximal inhibitory concentrations (IC₅₀) for the competitive peptide inhibitors. However, the ranking for DPP-IV inhibitory potency of the competitive peptide inhibitors was conserved. Furthermore, potent in vitro DPP-IV inhibitory activity was observed with two peptides, LPVPQ (IC₅₀ = 43.8 ± 8.8 μM) and IPM (IC₅₀ = 69.5 ± 8.7 μM). Peptides present within the gastrointestinal tract of human may have promise for the development of natural DPP-IV inhibitors for the management of serum glucose.     

Implementation of hypocalcaemia prevention programmes in commercial dairy herds: From theory to practice

Hypocalcaemia prevention programmes have been widely studied in experimental settings, but their feasibility has not been assessed under field conditions. The main objective of this study was to evaluate, in the context of small dairy farms in western France, whether and how dairy farmers implement prevention programmes and manage the feeding of dry cows to prevent hypocalcaemia. Seventy-nine commercial Holstein dairy farms in Brittany (France) were enrolled in a qualitative study in 2019. We conducted in-person interviews with the farmers to 1) understand the rationale behind the type and seasonality of prevention programmes they implemented and 2) assess how closely they followed common recommendations when implementing them. Most farmers (80 %) used at least one prevention programme, especially supplying a mineral mix formulated to meet the needs of dry cows in late gestation (53 %), acidifying the diet in late gestation (37 %), and supplying calcium at calving (oral or injectable form, 37 %). The use of programmes depended on whether the diet composition varied throughout the year. Among farmers who provided an acidified diet, 25 % did not supply a specific mineral mix to dry cows to ensure an adequate amount of P, Ca, and Mg, which could decrease the effectiveness of the acidification programme. A lack of reliability in feeding practices, such as not weighing feed or not delivering feed frequently enough, was identified for 61 % of contributing farms. Management practices could result in supplying an unsuitable amount of P, Ca, or Mg immediately before calving; for example, inappropriate batching practices around calving were identified for 22 % (cows) to 32 % (heifers) of farms. In addition, nearly all contributing farmers had no processes in place to monitor the effectiveness of the programmes implemented. Reasons for this overall lack of compliance should be explored.     

Development of a new grading system to assess the foster performance of lactating sows

Increasing litter size has created the need for more sophisticated, accurate, and welfare-oriented systems for assessing the foster performance of lactating sows. The estimation of milk yield alone is not sufficient for meeting these requirements. Therefore, the aim of the current study was to develop a grading system for assessing the foster performance of lactating sows that can be easily applied in commercial farm practice. Data were collected in two German conventional farrow-to-feeder farms with a total sample size of 639 sows (4.05 ± 2.86 parities) and 1 728 litters. Besides general performance data, the piglets were weighed individually within the first 24 hours after birth and at the peak of lactation (day 18.22 ± 2.48). Based on these data, we proposed a new score referring to the milk score (MS). This score was compared with the commonly used formula for estimating milk yield (est. MY), which solely involves litter weight gain and litter size. The improvement of the developed MS allowed us to distinguish between the birth and foster performances of the lactating sows through considering cross-fostering, litter size, individual piglet weights, and piglet mortality during lactation. Both scores showed a similar progression across parities. It was found that litter size had a significant impact on the performance of lactating sows. A high est. MY was found to be associated with a significantly higher number of piglets per litter (15.79 ± 2.20), lower weight gain per piglet, and increased piglet mortality during lactation compared with sows with high MS, which showed a smaller litter size (13.51 ± 2.18) (P < 0.05). The focus on smaller litter size indicates a performance limitation, which seems to be related to the average teat number of 13–15 teats per sow. We recommend the consideration of the number of functional teats, because a litter size above it will not result in a sow having higher foster performance. In conclusion, as an extension of the common est. MY calculation, the MS considers cross-fostering as current farm-management practice when dealing with larger litters. Our recommendations emphasise the importance of an MS which indicates smaller litter size, higher piglet weight gain, and lower piglet mortality during lactation; these factors are related to an improvement in animal welfare for sows and piglets. Moreover, the presented MS could be used to develop a management tool for farmers to assess the foster performance of lactating sows, considering individual farm-management practices.     

Evaluation of type traits in relation to production,and their importance in early selection for milk performance in dairy buffaloes

Type traits (TTs) can contribute to breeding animals with good economic traits such as production, longevity, fertility, and profitability. Dairy buffaloes are the second largest source of milk supply in the world, and their TTs should be taken into consideration in future dairy buffalo breeding programmes. However, the relationship between TTs and milk production traits in buffalo remains largely unknown. The study aimed to establish an early selection method for buffaloes with desirable milk performance by TTs. Using 1 908 records from 678 buffaloes, the relationship between TTs and milk production traits was analysed and the optimal growth curves of TTs related to milk production traits were constructed. We examined the correlations between 45 TTs (33 body structural, 12 udder and teat morphological traits) and three milk production traits (milk yield (MY), milk fat percentage (MF), and milk protein percentage (MP)). The results showed that the highest correlation was found between MY and udder circumference (r = 0.438), teat length (r = ?0.380) or heart girth (r = ?0.341). The teat distance and teat circumference exhibited a significant negative correlation with MF and MP. Rump length was the only trait that had a significant positive correlation with milk production traits, suggesting that milk performance could be comprehensively improved by including rump length in the selection procedure. Notably, we found that high milk production traits was obtained from the buffaloes with short teats (<6 cm), small heart girth (<200 cm), large udder circumference (>104 cm), long rump (>39 cm), and small distance between teats. Moreover, an early selection method for buffaloes with excellent milk performance was developed based on the non-linear models. Brody model exhibited the best fitting effect for heart girth and rump length, while the Logistic model displayed the best fitting effect for teat length. Our findings provide theoretical basis for the early selection of buffaloes with desirable milk performance.     

Non-offspring nursing by a nulliparous pregnant female just before first parturition in free-ranging Japanese macaques

A nulliparous pregnant Japanese macaque, Macaca fuscata, suckled her 1-year-old sister 44 days before her own parturition. Other Japanese macaque yearlings did not hold the nipples of this nulliparous female in their mouths. Although this non-offspring nursing before first parturition did not improve the rate of milk secretion, the nulliparous female may have improved her indirect fitness and her suckling behavior.     

Milk production and composition in reindeer (Rangifer tarandus): effect of lactational stage

Milk yield and composition of major milk constituents were measured in captive, nursing reindeer. Registration of milk production was performed during two successive lactations (2001 and 2002). The milk yield was significantly affected by week of lactation (P<0.001) and by individual (P<0.001). The lactation curve had an asymmetrical peak 3 weeks postpartum and the milk yield at peak lactation was 983 g/day (range 595-1239). The length of lactation varied from 24 to 26 weeks and average total milk production was 99.5 kg. From peak lactation the milk production decreased linearly (P<0.001) until milk production was terminated. Mean values for content of major milk constituents were 15.5% fat, 9.9% protein and 2.5% lactose. The content of fat and protein increased markedly with the lactation stage (P<0.001), while lactose showed a slight decrease (P<0.001). The milk composition was significantly affected by stage of lactation (P<0.001). There was a marginally significant decrease in protein:fat ratio (P=0.06) as protein was substituted by fat with stage of lactation. The caloric value of the milk averaged 8.7 kJ/g and increased significantly with the stage of lactation (P<0.001). The overall increase in milk gross energy content during lactation was 67.6%. The energy output averaged 7996 kJ/day at peak lactation and decreased significantly during the course of lactation (P=0.002).     

Fetal and maternal tissue distribution of the new fluoroquinolone DW-116 in pregnant rats

We investigated maternal and fetal tissue distribution of DW-116, a newly developed fluoroquinolone with a broad antibacterial spectrum against both G(+) and G(-) bacteria, in pregnant rats. After oral administration of [14C]-DW-116 (labeled 1 mg and unlabeled 500 mg/kg) to female rats on the 18th day of gestational, groups of three rats were killed at various time points up to 24 h, and plasma and tissues were collected, processed and analyzed. [14C]-DW-116 was rapidly absorbed, and distributed into the maternal and fetal tissues, and it declined in a biphasic manner with elimination half-lives (t(1/2)) of 10-15 h and mean residence times (MRT(0-24 h)) of 4-9 h. The radioactivity in most tissues of both dams and fetus reached its peak within 1 h and radioactivity levels of up to 10-25% of the peak level were maintained until 24 h after dosing. Among various tissues, the radioactivity in the maternal lungs was the highest (27 times that of plasma) at the C(max). Radioactivity in other tissues including liver, kidney, heart, lung, brain, spleen, mammary gland, placenta, ovary and uterus was higher than that in the maternal plasma (one- to three-fold). The tissue-to-plasma partition coefficient (K(p), AUC(0-24 h,tissue)/AUC(0-24 h,plasma)) of [14C]-DW-116 in maternal tissues was highest in the lung (K(p)=3.7), followed by the spleen (2.2), kidney (2.0), liver (1.8), heart (1.5), placenta (1.3), brain (1.3), ovary (1.1), uterus (1.1), and mammary gland (1.0). The tissue-to-plasma partition coefficient values in fetal tissues were heart (K(p)=2.2), kidney (2.1), liver (1.9), lung (1.6) and brain (1.4). When lactating rats were given a single oral dose of [14C]-DW-116, the radioactivity was rapidly secreted into the milk with K(p) of 1.7 at T(max) (0.5 h). These results indicate that DW-116 or its related metabolite(s) rapidly cross the blood-placenta and blood-milk barrier, extensively distribute into the fetal tissues, and are eliminated from the body in a prolonged manner. This study sheds insights into the maternal and fetal tissue distribution of DW-116 and will be useful for assessing both therapeutic and toxicological relevance of DW-116 in pregnant subjects.     

Calibration for nonlinear mixed effects models: an application to the withdrawal time prediction

We propose calibration methods for nonlinear mixed effects models. Using an estimator whose asymptotic properties are known, four different statistics are used to perform the calibration. Simulations are carried out to compare the performance of these statistics. Finally, the milk discard time prediction of an antibiotic, which has motivated this study, is performed on real data.