The Effect of Feeding Management and Culling of Cows on the Lactation Curves and Milk Production of Primiparous Dairy Cows

The study attempted to estimate the lactation curves of primiparous dairy cows in relation to their feeding management. Therefore, the first aim of the study was to determine and compare the lactation curves of primiparous dairy cows using Wood’s model and to estimate the association between the lactation curves and feeding management. The second objective was to investigate the effect of the culling rate on improvement in the milk yield of primiparous dairy herds. The study was conducted on four commercial dairy farms of Polish Holstein–Friesian cows using different feeding systems (TMR—total mixed ration and PMR—partial mixed ration) and management (T1—one TMR throughout lactation; P1—one PMR throughout lactation; T2 and T3—three feed periods such as FRESH, TMR I and TMR II according to days in milk). The data used for the study were obtained from monthly milk performance evaluations of 1662 primiparous cows conducted by the Polish Federation of Cattle Breeding and Dairy Farmers throughout the year 2015. Wood’s lactation model was used to plot curves for milk yield, fat and protein content, lactose content, and milk urea contents. The highest milk yield for the whole lactation and in the peak lactation phase was recorded for cows in herd T1. This herd reached peak lactation on day 105 of milking, with an average milk yield of 42.1 kg, which was about 5 kg more milk than in the other herds. The study showed that the culling of primiparous cows in herd T1 after 30, 60 and 90 days of lactation prevented a significant reduction in milk yield in a 305-day lactation. It also increased average milk production by 1586.9 kg per primiparous dairy cow.

The Capacity of Holstein-Friesian and Simmental Cows to Correct a Negative Energy Balance in Relation to Their Performance Parameters, Course of Lactation, and Selected Milk Components

A significant factor in improving the performance of dairy cows is their physiological ability to correct a negative energy balance (NEB). This study, using Simmental (SIM) and Holstein-Friesian (HF) cows, aimed to assess changes in NEB (non-esterified fatty acid; body condition score; and C16:0, C18:0, and C18:1) and its effect on the metabolic efficiency of the liver (β-hydroxybutyrate and urea). The effects of NEB on daily yield, production at peak lactation and its duration, and changes in selected milk components were assessed during complete lactation. Up to peak lactation, the loss of the body condition score was similar in both breeds. Subsequently, SIM cows more efficiently restored their BCS. HF cows reached peak lactation faster and with a higher milk yield, but they were less able to correct NEB. During lactation, their non-esterified fatty acid, β-hydroxybutyrate, C16:0, C18:0, C18:1, and urea levels were persistently higher, which may indicate less efficient liver function during NEB. The dynamics of NEB were linked to levels of leptin, which has anorectic effects. Its content was usually higher in HF cows and during intensive lactogenesis. An effective response to NEB may be exploited to improve the production and nutritional properties of milk. In the long term, it may extend dairy cows’ productive life and increase lifetime yield.

Effect of Sprouted Trigonella foenum graecum L. Incorporation into the Diet on Milk Production of Rabbit Does and Growth of Young Rabbits in the Northeast of Algeria

The aim of this study was to assess the effect of sprouted fenugreek incorporation into the diet of rabbits on their dairy and growth performances. Data from 24 lactations performed by 8 Californian rabbit does were studied. They were divided into 2 homogeneous groups, a control (batch C) having received an ordinary ration and an experimental (batch E) having received the same ration supplemented with sprouted fenugreek. Growth rates of suckling pups were also recorded. Then, Growth performance of 152 young rabbits’ issue from these females was monitored. They were divided into 4 homogeneous groups, one control having received an ordinary diet (batch C) and 3 experimental having received the same diet with substitution of 12%, 15% and 25% (batch E1, E3 and E3) of the concentrate by sprouted fenugreek. The results showed an improvement in the dairy performance of the rabbit does of batch E, with an average peak lactation of 287 g/d vs 236 g/d in batch C (p <0.01). The daily weight gain of suckling pups was better in batch E (13 g/d vs 11.7 g/d; p <0.01). Likewise, the weaned young rabbits of the experimental batches recorded higher growth rates than the control batch (p <0.01). Sprouted fenugreek incorporation into the rabbit’s ration allowed to improve their performances.

Longitudinal Metabolic Biomarker Profile of Hyperketonemic Cows from Dry-Off to Peak Lactation and Identification of Prognostic Classifiers

Currently about 30% to 50% of all dairy cows are affected by a metabolic or infectious disease during the transition period. A key factor for preventive actions is the ability to precisely predict metabolic diseases at an early stage. We report the longitudinal metabolic profile of non-esterified fatty acids, beta-hydroxybutyrate (BHB), total bilirubin, and aspartate aminotransferase in hyperketonemic dairy cows. Aiming for a novel measurement regime to improve metabolic health in dairy cows, we evaluated prognostic classifiers for hyperketonemia. In the observational longitudinal study, 99 healthy adult primiparous and multiparous Simmental dairy cows were included. Every cow was monitored weekly for 14 consecutive weeks, beginning two weeks prior to the expected day of parturition until peak lactation. Cows with serum concentrations of BHB > 0.8 mmol/L were considered hyperketonemic. Biomarker profiles were fitted by the maximum likelihood method using a mixed effects natural cubic spline model. In the hyperketonemic group, the BHB profile remained significantly higher than that of the control group until the end of the study period. As a prognostic classifier, the cut-off level of 0.54 mmol/L BHB measured on the 10th day post partum had the highest area under the curve. These results provide new longitudinal insights into the metabolic biomarker progression of dairy cows and enable an early onset diagnosis of hyperketonemia.

Evaluation of the glutathione concentration in whole blood of dairy Holstein cows

The objective of this study was to evaluate the concentrations of the total (T-GSH), oxidised (GSSG) and reduced (GSH) glutathione in the blood of dairy cows, assess the relationships of the phase and number of lactation, milk production, body condition score (BCS) and selected biochemical parameters on its concentrations. We analysed 79 samples of whole blood from dairy Holstein cows. The concentration of glutathione was assessed by the spectrophotometric enzymatic method. The whole dataset shows the mean concentration of T-GSH, GSSG and GSH of 803 ± 22 µmol/l, 23 ± 2.5 µmol/l and 757 ± 27 µmol/l, respectively. The GSH/GSSG ratio was 95 ± 17. The phase of the lactation had a significant impact on the levels of T-GSH and GSH, but the number of lactation and BCS had no effect. Dry cows had higher levels of T-GSH (938 ± 44 µmol/l) than the fresh (713 ± 46 µmol/l) and peak lactation (785 ± 45 µmol/l) cows. The fresh cows had significantly lower concentrations of GSH (618 ± 44 µmol/l) than the peak lactation (719 ± 46 µmol/l) and dry cows (827 ± 43 µmol/l). On the basis of a regression analysis, blood glutathione was affected mainly by the liver function and energy metabolism. Glutathione as the marker of oxidation stress seems to be a promising tool in monitoring the health and welfare of the herd, yet intensive research in this field remains necessary.

Desmodium tortuosum, Euphorbia heterophylla and Moringa oleifera Effect on Local Rabbit Does Milk Production and Pups’ Performances

Desmodium tortuosum and Euphorbia heterophylla are fields&rsquo; weeds. Moringa oleifera plant is adapted to several agroecological zones and has many food and medicinal virtues. This work assessed these three plants potential to induce milk production. Thus, 96 primiparous local breed rabbit does, 10 months old, with an average 2983.6&plusmn;212.4 g weight were used. They were grouped into 4 blocks containing 24 animals each. Then, one diet among 4 diets was randomly assigned to each group. Panicum maximum as fodder was mixed with a commercial pellet rabbit feed, the control (Pan). Then, this control diet was supplemented with Desmodium tortuosum (Des), Euphorbia heterophylla (Eup) and Moringa oleifera (Mor) in pellet partial substitution. The parameters monitored were the litter size, the pups&rsquo; average daily weight gain, the does&rsquo; weights before and during gestation, and after farrowing. Likewise, the milk production at peak lactation was evaluated. As a result, compare to Pan, Des, and Eup diets improved the total rabbit pups&rsquo; number from 96 to 112, and it represented a 16.67% gain. But Mor diet reduced Pan diet performance to 76 newborn rabbits, it was a 20.83% loss. Moreover, Des, Eup, and Mor diets induced an improvement in the milk quantity at peak lactation. In this order, these improvements were +15.51, +27.74, and +19.98%, respectively, compared to Pan diet which produced 109.6 g. In conclusion, Desmodium tortuosum and Euphorbia heterophylla could be used as green forages to improve milk production in local rabbit does breeding.

Negative effects of energy supplementation at peak lactation of sheep can be offset by the addition of Lactobacillus fermented plant extracts

Energy supplementation may reduce oxidative stress by correcting a negative energy balance, but in some contexts it has been shown to increase oxidative stress, especially at peak lactation. The current experiment examined if a pelleted energy supplement with or without the addition of Lactobacillus fermented seaweed or seaweed plus terrestrial plants extracts impacted oxidative stress of ewes from late gestation through to weaning and ewe and lamb production from lambing to weaning. Treatments were either no supplement (CON-), a pelleted supplement only (CON+, 100 g/ewe per d), CON+ with seaweed extract only (SWO, 10-mL/ewe per d), or CON+ with seaweed plus an arrangement of terrestrial plant extract (SWP, 10-mL/ewe per d). Ewes (n = 160; mean initial BW = 72.3 ± 9.5 kg [mean ± standard deviation]) were randomized to pastures (n = 4 pastures per treatment with 10 ewes each). After lambing, ewes with twins were reallocated to pastures (n = 3 pastures per treatment with 10 ewes each) according to lambing date. At 4 weeks in milk, supplementation tended to reduce total antioxidant status (TAS; P = 0.10) and increased glutathione peroxidase (GPx) activity compared with non-supplemented ewes (P = 0.04). The addition of seaweed and terrestrial plants extracts to the concentrate, i.e. SWO and SWP, increased TAS and reduced GPx activity compared with CON+ (P &lt; 0.01). Supplementation increased milk yield at wk 4, 6, and 8 of lactation, and protein, lactose, and total milk solids yield at peak lactation (wk 4; P &lt; 0.05). The CON- ewes had greater somatic cell count than the supplemented ewes at week 4, 8, and 10 of lactation (P = 0.03). Our results suggest energy supplementation, alone, increases oxidative stress of lactating ewes, which may relate to increased oxidative phosphorylation. Most importantly, these results indicate that in situations where energy supplementation is needed to increase animal performance, negative effects of energy supplementation around peak lactation can be offset by the addition of Lactobacillus fermented plant extracts (SWO and SWP) to improve antioxidant status.