Dry Pregnant Cows Research Articles

Lizunts for cows of the dry and transit period of the southern forest-steppe zone of the Republic of Bashkortostan with pasture maintenance

The research was conducted in 2023 in the department of feed production and animal husbandry (laboratory of feed technology and feed additives) of the Ufa experimental station of the UFIC RAS on the topic: “Development of the formulation, technology of preparation of a feed additive and determination of its effectiveness in the diets of feeding farm animals.” Considering the natural and climatic conditions (soil composition, herbage with maturation phases, temperature regime, moisture content and chemical composition of pasture feed), 3 recipes of lizunts for this group of cows with a live weight of 600 kg with a planned milk yield of 6 thousand kg of milk have been developed. Based on the available components, their chemical composition and the corresponding structure, experimental versions of lizunts with a weight of 1 kg have been developed. A comprehensive assessment of the nutritional value of one of the lizunts variants was carried out according to many indicators. The prototype has been tested for licking with a small number of pregnant dry cows.

Dose-dependent effects of rumen-protected choline on hepatic metabolism during induction of fatty liver in dry pregnant dairy cows.

Objectives were to determine the effects of supplementing increasing amounts of choline ion on hepatic composition and mRNA abundance in pregnant dry cows subjected to a fatty liver induction protocol. Holstein cows (35 primiparous and 41 multiparous) at mean (± standard deviation) of 211 ± 9.9 days of gestation were blocked by body condition (3.59 ± 0.33) and assigned to receive 0, 6.45, 12.90, 19.35, and 25.80 g/day of choline ion as rumen-protected choline (RPC) as a top-dress for 14 days. Cows were fed for ad libitum intake on days 1 to 5 and restricted to 30% of the required net energy for lactation from days 6 to 14 of the experiment. Hepatic tissue was sampled on days 5 and 14 and analyzed for concentrations of triacylglycerol and glycogen, and mRNA abundance was investigated. Orthogonal contrasts evaluated the effects of supplementing RPC (0 g/day vs. rest), and the linear, quadratic, and cubic effects of increasing intake of choline ion from 6.45 to 25.80 g/day. Results are depicted in sequence of treatments from 0 to 25.8. During feed restriction, RPC reduced the concentration of hepatic triacylglycerol by 28.5% and increased that of glycogen by 26.1%, and the effect of increasing RPC intake on triacylglycerol was linear (6.67 vs. 5.45 vs. 4.68 vs. 5.13 vs. 3.81 ± 0.92% wet-basis). Feeding RPC during feed restriction increased abundance of transcripts involved in choline metabolism (CHKA, PLD1), synthesis of apolipoprotein-B100 (APOB100), and antioxidant activity (GPX3), and decreased the abundance of transcripts involved in hepatic lipogenesis (DGAT2, SREBF1) and acute phase response (SAA3). Most effects were linear with amount of choline fed. Changes in hepatic mRNA abundance followed a pattern of reduced lipogenesis and enhanced lipids export, which help explain the reduced hepatic triacylglycerol content in cows fed RPC. Choline exerts lipotropic effects in dairy cows by altering transcript pathways linked to hepatic lipids metabolism.

Effects of stage of maturity at harvest of cereal crops on biomass and quality, estimated forage dry matter intake, beef cow performance, and system economics

The objective of this study was to evaluate the effects of maturity at harvest of cereal crops on biomass, quality, cow performance, and economics. In each of 3 yr, a 48-ha field was divided into 3 paddocks (16 ha per treatment) and seeded to either barley (Hordeum vulgare CDC Maverick, 135 kg/ha), oat (Avena sativa CDC 29 SO1, 135 kg/ha), or triticale (Triticosecale Taza, 135 kg/ha). Half of each field (8 ha) was swathed at either soft dough (SDo) or hard dough (HDo) stage for grazing. Each year, 120 dry pregnant beef cows (631 kg) were randomly allocated to 1 of 6 replicated (n = 2) paddocks for 90, 106, and 88 d in yr 1, 2, and 3, respectively. Triticale had 19 and 23% greater total yield than oat and barley, respectively. Barley CP was greater (P < 0.05; 10.9%) than oat (9.3%) or triticale (9.8%) at HDo stage. The animal unit months (AUM) per hectare were greater for HDo (11.5 ± 0.8 AUM/ha) than SDo (9.15 ± 0.8 AUM/ha) stage. Cow ADG was greater (P = 0.01) for barley (0.61 kg/d) compared with triticale (0.39 kg/d). Total crop cost averaged Can$426, Can$437, and Can$458/ha for oat, barley, and triticale, respectively. The HDo stage had Can$0.40 lower dollars per cow per day in-field costs (P = 0.02) than the SDo stage and 10% (Can$26.25 per cow/d) lower feeding costs (P = 0.02) over 3 yr. Delaying harvest to hard dough can increase yield and reduce feeding costs without affecting cow performance.

Energy feed additive in the diets of pregnant dry cows

Relevance. In this article, the effect of an energy feed additive on obtaining healthy offspring and subsequent high milk productivity is established. As a result of feeding different doses of an energy feed additive with the same composition of the feed mixture to dry cows 14 days before calving, calves with an average live weight at birth were obtained in the second experimental group: heifers — 43 kg, bulls — 40.3 kg, in the third experimental group heifers at birth had a live weight of 36.6 kg, bulls — 43.6 kg. After 20 days of milk drinking, the heifers obtained from cows of the second experimental group, who were fed 190 g of energy feed additive, retained growth energy and exceeded the bulls by 1.3 kg, in the third experimental group, the bulls obtained from cows fed 200 g of energy feed additive, had higher growth energy and exceeded the heifers by 6.8 kg. Morphobiochemical blood parameters under the action of energy feed additive were within the physiological norm. However, the number of red blood cells increased in the second experimental group by 1.3 and in the third experimental group — by 2.0%, the hemoglobin content was higher by 3.6 and 6.0%, respectively. The concentration of total protein averaged 75.88 g/l.Methods. The studies were carried out on dry cows when feeding an energy feed additive as part of a feed mixture to understandits effect on reproductive functions. The productivity of newborn calves was taken into account by weighing. Morphobiochemical blood parameters of dry cows were determined by generally accepted methods in the Bryansk MVL FSBI. Daily monitoring of the feed mixture intake by animals was carried out.Results. The introduction of different amounts of energy feed additives into the diet provided the need for metabolic energy of dry cows, led to an increase in the reproductive functions of cows, obtaining viable calves and high growth energy during the dairy period.

Pharmacokinetics of 1,25-dihydroxyvitamin D3 glycosides from Solanum glaucophyllum extract given in a rumen bolus on blood mineral profiles in dry pregnant dairy cows

Providing tablets of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the biologically active metabolite of vitamin D3, in a rumen bolus may be used as prevention for periparturient hypocalcemia in dairy cows. This study investigated the pharmacokinetics of 1,25(OH)2D3 glycosides extracted from Solanum glaucophyllum (SGE) on blood serum 1,25(OH)2D3, Ca, P and Mg response in dry pregnant dairy cows. Boluses contained tablets of SGE which differed in their release properties (rapid release, slow release and combination) and galenics (200 μg uncoated, 300 μg and 500 μg uncoated or coated, 2 × 500 μg uncoated). Nineteen blood samples were collected from 29 cows between 96 h before and 336 h after bolus administration. Blood serum 1,25(OH)2D3, Ca and P increased between 12 h and 120 h, 12 h and 264 h and 24 h and 264 h, respectively. Highest values were reached at 30 h, 72 h and 120 h for 1,25(OH)2D3, Ca and P, respectively. Baseline values were then reached at 216 h for 1,25(OH)2D3 and 336 h for Ca and P. Concentration of Mg decreased between 24 h and 216 h, before reaching values comparable to baseline at 264 h. Highest Ca values were obtained with the combined rapid and slow release properties (500 μg) and there was no effect from coating on pharmacokinetics. In conclusion, the antepartum oral SGE bolus administration may be suitable for the prevention of periparturient hypocalcemia.

Effect of ZIGBIR® hepatoprotector on the body of pregnant dry cows

Relevance. ZIGBIR ® feed additive, consisting of a set of plants that affect the state and recovery of hepatocytes, is unique and is of interest for research. As a result of the experiment, the feasibility and effectiveness of using the plant feed additive ZIGBIR ® in the diets of pregnant dry cows was studied. Its effect on the absorption of nutrients in the diet, biochemical parameters, the safety of young animals and gynecological diseases is shown. Methods. The experimental part of the work was carried out in the Agricultural Cooperative “Named after Ilyich” of the Novgorod region on cows of the dry period. According to the principle of analogs, three groups of animals were formed — a control group and two experimental ones ( n = 10 in each) from cows that were in the run taking into account the dates of the planned calving. The animals of the first experimental group, in addition to the main diet, received a feed additive ZIGBIR ® in the amount of 20 g/head/day, the second experimental group — 25 g/head/day. Results. As a result of scientific research, it was found that groups of cows that received a feed supplement in addition to the main diet were better able to absorb nutrients. So the coefficient of dry matter digestibility in the first experimental group increased by 0.9%, in the second — by 0.4%. A similar increase in the digestibility coefficients was observed for organic matter (by 1.7–8.3%), crude protein, crude fat, BEV and crude fiber. The introduction of the supplement into the diet did not lead to a deterioration in biochemical parameters. For example, the value of the protein index (the ratio of albumins to globulins), indicating the intensity of protein metabolism, in the control group was 0.66, and was below the physiological limit by 27%. However, in both experimental groups its indicators increased and almost returned to normal with values of 0.9 and 0.8 respectively. The reduction of postpartum pathologies and the increase in the safety of young animals suggests the therapeutic effectiveness of the ZIGBIR ® feed additive.

Patterns of blood biochemical parameters of peripartum dairy cows raised in either smallholder or semi-commercial dairy farms in Thailand.

Background and Aim:Data about dynamics of serum biochemical parameters and negative energy balance (NEB) related conditions differ among geographical areas or farm types. It should be cautious about applying those data to justify control and prevention strategies of NEB problems. Therefore, dynamics of blood biochemical parameters related to NEB condition of peripartum dairy cows raised in either smallholder (SH) or semi-commercial (SC) farms were studied.Materials and Methods:Thirty-two healthy pregnant dry cows were selected from five dairy farms in Western part of Thailand, including 15 and 17 cows from three SH and two SC farms, respectively. Blood samples were collected at 2 weeks before the expected calving date, and 1, 2, 4, and 8 weeks postpartum to determine concentrations of glucose, non-esterified fatty acid (NEFA), and b-hydroxybutyrate (BHBA). Body condition scores (BCSs) and milk yields were also recorded.Results:Dairy cows in both farm types suffered from NEB by elevation of serum NEFA and BHBA, and loss of BCS postpartum. Degrees of elevation in serum NEFA and BHBA were different between farm types. The SC cows showed more BCS loss postpartum, but lower serum NEFA. In the SH cows, even with less BCS loss, the cows showed high serum NEFA concentrations.Conclusion:Dairy cows in our study entered NEB condition even with low milk yields. Moreover, elevation of serum NEFA and BHBA postpartum was higher in our studied cows as compared with other studies in high producing cows of commercial dairy farms in temperate areas.

Effect of dietary cation-anion difference on acid-base status and dry matter intake in dry pregnant cows

The objective was to determine if the reduction in dry matter (DM) intake of acidogenic diets is mediated by inclusion of acidogenic products, content of salts containing Cl, or changes in acid-base status. The hypothesis was that a decrease in intake is mediated by metabolic acidosis. Ten primigravid Holstein cows at 148 ± 8 d of gestation were used in a duplicated 5 × 5 Latin square design. The dietary cation-anion difference (DCAD) of diets and acid-base status of cows were manipulated by incorporating an acidogenic product or by adding salts containing Cl, Na, and K to the diets. Treatments were a base diet (T1; 1.42% K, 0.04% Na, 0.26% Cl; DCAD = 196 mEq/kg); the base diet with added 1% NaCl and 1% KCl (T2; 1.83% K, 0.42% Na, 1.23% Cl; DCAD = 194 mEq/kg); the base diet with added 7.5% acidogenic product, 1.5% NaHCO3, and 1% K2CO3 (T3; 1.71% K, 0.54% Na, 0.89% Cl; DCAD = 192 mEq/kg); the base diet with added 7.5% acidogenic product (T4; 1.29% K, 0.13% Na, 0.91% Cl; DCAD = -114 mEq/kg); and the base diet with 7.5% acidogenic product, 1% NaCl, and 1% KCl (T5; 1.78% K, 0.53% Na, 2.03% Cl; DCAD = -113 mEq/kg). Periods lasted 14 d with the last 7 d used for data collection. Feeding behavior was evaluated for 12 h in the last 2 d of each period. Reducing the DCAD by feeding an acidogenic product reduced blood pH (T1 = 7.450 vs. T2 = 7.436 vs. T3 = 7.435 vs. T4 = 7.420 vs. T5 = 7.416) and induced a compensated metabolic acidosis with a reduction in bicarbonate, base excess, and partial pressure of CO2 in blood, and reduced pH and strong ion difference in urine. Reducing the DCAD reduced DM intake 0.6 kg/d (T1 = 10.3 vs. T4 = 9.7 kg/d), which was caused by the change in acid-base status (T2 + T3 = 10.2 vs. T4 + T5 = 9.6 kg/d) because counteracting the acidifying action of the acidogenic product by adding salts with strong cations to the diet prevented the decline in intake. The decline in intake caused by metabolic acidosis also was observed when adjusted for body weight (T2 + T3 = 1.75 vs. T4 + T5 = 1.66% BW). Altering the acid-base status with acidogenic diets reduced eating (T2 + T3 = 6.7 vs. T4 + T5 = 5.9 bouts/12 h) and chewing (T2 + T3 = 14.6 vs. T4 + T5 = 13.5 bouts/12 h) bouts, and extended meal duration (T2 + T3 = 19.8 vs. T4 + T5 = 22.0 min/meal) and intermeal interval (T2 + T3 = 92.0 vs. T4 + T5 = 107.7 min). Results indicate that reducing the DCAD induced a compensated metabolic acidosis and reduced DM intake, but correcting the metabolic acidosis prevented the decline in DM intake in dry cows. The decrease in DM intake in diets with negative DCAD was mediated by metabolic acidosis and not by addition of acidogenic product or salts containing Cl.

In vivo ultrasound guided transvaginal oocyte collection in the cow

This paper describes the results of the in vivo ultrasound guided follicular aspiration for ovum pick υρ (OPU) in the cow. Twelve non pregnant dry cows aged 4-6 years were used in this experiment. Eight cows underwent OPU during three successive oestrous cycles and another four cows were used as controls having only transvaginal ultrasound scanning of their ovaries. Oocyte collection took place three times during the luteal phase of each natural oestrous cycle (days 3-4,9-11 and 14-17). The content of 326 follicles with a diameter of 4-15mm was aspirated and 104 oocytes were collected (recovery rate 31.9% or 1.55 oocytes per cow and session). The oocyte recovery rate increased after the first three sessions (from 13.04% to 35.0%) and reached levels of υρ to 52.6%. More follicles were aspirated on days 9-11 (133 follicles 40.8%) compared to 111 (34%) follicles on days 14-17 and 82 (25%) on days 3-4) (P&lt;0.05). The evaluation of the collected oocytes revealed that 60 oocytes (57.7%) were suitable for further in vitro manipulation. Neither the origin of the oocyte (left or right ovary) nor the stage of the oestrous cycle affected the recovery rate or the quality of the collected oocytes. There was no significant difference either in the length of the oestrous cycle between the experimental animals and the controls (21.6± 1.4 vs. 22.37±1.0 respectively), or in plasma progesterone concentration in daily collected blood samples from the animals of the two groups. The results of this study are compared to those from the international literature and to the results from endoscopical methods for oocyte recovery. The feasibility of application of this technique to projects designed to improve the genetic merit of cows is discussed.

Heat Stress and Body Temperature in Brown Swiss Cows Raised in Semi-Arid Climate of Ceará State, Brazil

Background: In tropical countries like Brazil, air temperature and relative humidity have a significant effect on animal physiology; there is a great impact of solar radiation on physiological parameters, especially on body temperature. This study evaluated the occurrence of heat stress in Brown Swiss cows in a tropical semi-arid climate, and checked for the correlation between internal body temperatures [rectal temperature (RT) and vaginal temperature (VT)] with surface temperature (ST) to determine if these variables are associated.Materials, Methods &amp; Results: Twenty-eight Brown Swiss cows at three stages of the lactation cycle were used in this study: 10 nonpregant lactating (NPL) cows, 8 dry pregnant (DP) cows, and 10 pregnant lactating (PL) cows. These animals were between the second and third calving, weighed between 346 and 720 kg, and had ages between 2 and 13 years. During the experimental period, air temperature and relative humidity (RH) at the experimental site were measured using a digital thermohygrometer. The temperature and humidity index (THI) was calculated according to methodology described by Thom (1958), and was used as an environmental comfort parameter. For the evaluation of RT and VT, two digital clinical thermometers, one inserted in the vagina and the other in the rectum, were used simultaneously to minimize stress. Surface temperature (ST) was assessed using a digital infrared laser thermometer at a distance of 50 cm from the animal. Surface temperature was measured in the forehead (FST), thorax (TST), flank (FLST), and legs (LST). During the study period, the ambient temperature (AT) was significantly higher outside (in the sun) than inside of the facilities (in the shade) (P &lt; 0.05). RH was inversely proportional to AT, and was significantly higher inside than outside the facilities (P &lt; 0.05). Like AT, THI was significantly higher outside (in the sun) than inside the facilities (in the shade), with significant differences between these locations (P &lt; 0.05). The amplitudes of the differences between the locations were as follows: 3.8°C for AT, 6.2% for RH, and 2.6 for THI. Mean values of rectal and vaginal temperatures were not significantly different from each other independent of lactation cycle stage, and were almost always significantly higher than the measured surface temperatures (P &lt; 0.05). The maximum values obtained for each lactation cycle stage in this study were higher when compared to the mean values, showing that they are more representative of the occurrence of heat stress. Correlations between internal temperatures (RT and VT) and surface temperatures (TSF, TST, TSFL, and TSP) were weak and non-significant. ST values exhibited mostly weak, non-significant correlations, with the exception of FST with FLST and LST, which had moderate, significant correlations, as shown by the following coefficient factors: FST x FLST, 0.34; LST x FST, 0.415; and LST x FLST, 0.37.Discussion: A temperature of 34°C with RH ranging from 46% to 80% (i.e., a THI between 83 and 89) has been reported to have a significant thermal impact on dairy Brown Swiss cows; the THI values found in the present experiment were close to those. Body temperatures exhibited significant variations depending on the lactation cycle stage of the cows. Lactation concomitant with pregnancy significantly increases internal temperatures (RT and VT) in DP and NPL cows. This finding may be explained by the fact that pregnancy concomitant with lactation accelerates the metabolism, which results in higher food intake and increased production of body heat with consequent increase in internal body temperature. The maximum values of internal body temperatures (RT and TV) at all stages of the lactation cycle were higher than their corresponding average values, which indicates that some cows exhibited, at given moments, hyperthermia.

Reticulo-rumen mass, epithelium gene expression, and systemic biomarkers of metabolism and inflammation in Holstein dairy cows fed a high-energy diet

Feeding a higher-energy diet by increasing cereal grains at the expense of forage during the last 3 to 4 wk prepartum is a traditional approach to help the rumen "adapt" to the traditional diets fed at the onset of lactation. Increasing grain/concentrate in the diet changes ruminal fermentation and in sheep and goats elicits marked changes in mRNA expression of immune-related genes in ruminal epithelium. Whether such changes at the epithelial and systemic levels occur in dairy cows when the dietary energy content increases at a fixed level of concentrate is unknown. Fourteen nonpregnant, nonlactating Holstein cows were fed a control lower-energy (CON, 1.30 Mcal/kg of dry matter) diet to meet 100% of estimated nutrient requirements for 3 wk, after which half of the cows were assigned to a higher-energy diet (OVE, 1.60 Mcal/kg of dry matter) and half of the cows continued on CON for 6 wk. Levels of forage and concentrate for CON and OVE were 80 and 79% and 20 and 21%, respectively. Plasma samples were collected 1 d before slaughter to examine biomarkers of metabolism, liver function, inflammation, and oxidative stress. The reticulo-rumen mass was recorded at slaughter, and samples of epithelium were harvested from all cows. The expression of 29 genes associated with tight junctions, immune function, and nutrient transport (volatile fatty acids, urea, and trace minerals) was examined. Overfeeding energy led to consistently greater dry matter intake over time, and lowered plasma concentrations of haptoglobin, paraoxonase, bilirubin, fatty acids, and myeloperoxidase (secreted by neutrophils). In contrast, OVE resulted in greater hydroxybutyrate and cholesterol concentrations. A greater reticulo-rumen mass in cows fed OVE did not alter genes associated with tight junctions (CDLN1, CDNL4, OCLN, TJP1), immune function (IL1B, IL10, NFKB1, TLR2, TLR4, TNF), oxidative stress (SOD1, SOD2), or most nutrient transporters. However, feeding OVE upregulated the acute-phase protein SAA3 by 3.5-fold and downregulated a volatile fatty acid transporter (SLC16A1) and a Fe and Cu transporter (SLC11A2). The lack of effect on mRNA expression along with lower plasma concentrations of inflammation biomarkers indicates that long-term intake of a higher-energy diet ad libitum was not detrimental to ruminal epithelium integrity. In that context, a protective function of SAA3 could be envisioned with a role in opsonizing gram-negative bacteria that produce endotoxins. The long-term control of volatile fatty acid absorption and trace minerals from the rumen in cows overfed energy does not seem to be controlled at the gene transcription level. The relevance of these findings to the nutritional management of pregnant dry cows merits further research.

Уровень кормления стельных сухостойных коров и его влияние на физиологическое состояние и продуктивность

Уровень кормления стельных сухостойных коров и его влияние на физиологическое состояние и продуктивность

EFFECT OF FLAXSEED OIL SUPPLEMENTION DURING PRE AND POSTPARTUM ON SOME PHYSIOLOGICAL PARAMETERS AND PRODUCTIVE PERFORMANCE OF FRIESIAN COWS

The objective of this study was to evaluate the effects of flaxseed oil supplementation into the ration of Friesian cows on their productive, somatic cell count (SCC), physiological and blood parameters during summer season. Twenty four dry pregnant Friesian cows averaged 607±22.5 kg live body weight (LBW) at 2-3 parities were randomly assigned into two groups (12 cows in each group). Cows in group 1st (G1) did not treatment and served as a control, while those in the 2nd were c received 2% of DM intake flaxseed oil from 45 days pre-partum until 120 days post-partum. Results revealed that body temperatures degrees of rectal (RT), skin at white (STW) and black (STB) as well as respiration rate (RR) during heat stress period in summer months (June, July, August and September) significantly (P<0.05) decreased with flaxseed oil as compared to the control group. Flaxseed oil diet improved (P<0.05) digestibility and rumen activity. Average daily dry matter intake (DMI) and DCP pre-partum were nearly similar for control and flaxseed oil treatment, while the intake of TDN increased significantly (P<0.05) with flaxseed oil supplementation compared to the control group. Cows of tested treatment On post partum state, DMI and TDN intake were significant higher with oil supplemental ration than the control group, but the difference did not significant between treatments respecting DCPI in this phase. Cows of treatments were higher in red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin (Hb) concentration and haematocrit percentage (HCT, %) than those of the control group. Cows treatment were higher significantly lymphocytes and significantly lower moncytes than control group. All protein fraction concentrations were higher in treated than in control group (G1). Concentrations of high density lipoprotein and triglyceride were higher significantly (P<0.05) in G2 than the control group (G1), but, plasma low density lipoprotein concentrations were lower significantly (P<0.05) in G2 than the control group (G1). Daily milk yield and 4% fat corrected milk were higher significantly by 19.37 and 29.99%, respectively compared with control. The G2 had higher (P<0.05) percentages of fat, lactose and total solids as compared to G1, while protein and solids not fat percentages were similar to G1. Diet supplemented with flaxseed oil showed lower (P<0.05) somatic cell count in milk as compared to G1. Feed conversion improved (P<0.05) in G2 than in G1. Economic efficiency was higher with flaxseed oil- ration than that of control one free from oil. It could be concluded that flaxseed oil supplementation in diet of Friesian cows (2% /kg DMI) during pre- and post-partum period heat stress could be eliminated and improved digestibility, productive performance and economic efficiencies as well as immune-response of Friesian cows without adversity effects on haematological and biochemical parameters.

Short communication: Effects of prepartum diets supplemented with rolled oilseeds on Brix values and fatty acid profile of colostrum

The objective of this study was to evaluate effects of oilseeds supplemented in prepartum diets on colostrum quality. Thirty-nine dry pregnant Holstein cows (14 primiparous and 25 multiparous cows) were blocked by body condition score and parity and assigned to 1 of 3 experimental diets containing rolled oilseeds at 8% of dietary dry matter (canola seed or sunflower seed) or no oilseed (control) at 35 d before the expected calving date. Canola seed is high in oleic acid and sunflower seed is high in linoleic acid content. Colostrum samples were collected at the first milking after calving, and concentrations of nutrient composition, fatty acid profile, and Brix value (an indicator IgG concentration) were determined. Cows fed sunflower seeds before calving produced colostrum with greater crude protein content (15.0 vs. 12.9%), colostral Brix values (24.3 vs. 20.3%), and conjugated linoleic acid concentration (18:2 cis-9,trans-11; 0.64 vs. 0.48%) compared with those fed canola seed. Positive effects of feeding sunflower seed might be mediated by ruminal metabolism of linoleic acid and subsequent enhanced production of conjugated linoleic acid. Oilseed supplementation in prepartum diets of dairy cows also altered fatty acid profile of colostrum in a way to reflect fatty acid profile of the supplemented oilseeds except for oleic acid. In conclusion, prepartum feeding of sunflower seed increased colostral Brix value, an indicator of colostral IgG concentration, compared with that of canola seed, but its mode of action and effects on health and productivity of calves need to be investigated.

Effects of day of gestation and feeding regimen in Holstein × Gyr cows: II. Maternal and fetal visceral organ mass

This study investigated the influence of day of gestation (DG) and feeding regimens (FR) on maternal and fetal visceral organ mass in Holstein × Gyr cows. Forty-four pregnant multiparous Holstein × Gyr cows with an average initial body weight of 480±10.1 kg and an average initial age of 5±0.5 yr were allocated to 1 of 2 FR: ad libitum (AL; n=20) or maintenance level (ML; n=24). Maintenance level was considered to be 1.15% of body weight (dry matter basis) and met 100% of the energy requirements; AL provided 190% of the total net energy requirements. Cows were individually fed a corn silage and concentrate-based diet composed of 93% roughage and 7% concentrate (dry matter basis) as a total mixed ration twice daily. Pregnant cows were slaughtered at 4 DG: 139 (n=11), 199 (n=11), 241 (n=11), and 268 (n=11) d, which was followed by necropsy. Mass of heart, liver, and gastrointestinal tract was heavier in AL- than in ML-fed cows. Mammary gland mass was heavier in AL- than in ML-fed cows, and the heaviest mass was observed at 268 d of gestation. Feeding regimen did not influence fetal body weight in this study. The majority of the visceral organ masses were similar in fetuses from cows fed AL or ML. These data indicate that maternal feed restriction does not affect the development of most fetal organs or fetal development; however, some maternal organs are affected by the FR provided. Moreover, the negative effect on mammary gland mass caused by ML feeding will probably not affect the subsequent lactation because the crude protein concentration in the mammary gland increased with ML feeding. However, we suggest that the AL diet in pregnant dry cows should be provided with caution because the amount of fat in the mammary gland increased at 268 d of gestation.

Effects of day of gestation and feeding regimen in Holstein × Gyr cows: I. Apparent total-tract digestibility, nitrogen balance, and fat deposition

This study investigated how feeding regimen (FR) alters apparent total-tract digestibility, performance, N balance, excretion of purine derivatives, and fat deposition in Holstein × Gyr cows at different days of gestation (DG). Forty-four pregnant multiparous Holstein × Gyr cows with an average initial body weight of 480±10.1 kg and an initial age of 5±0.5 yr old were allocated to 1 of 2 FR: ad libitum (AL; n=20) and maintenance level (ML; n=24). Maintenance level was considered to be 1.15% of body weight on a dry matter (DM) basis and met 100% of the energy requirements, whereas AL provided 190% of total net energy requirements. Data for hot and cold carcass dressing, fat deposition, average daily gain, empty body gain, and average daily gain without the gravid uterus were analyzed as a 4×2 factorial design. Intake, apparent total-tract digestibility, N balance, urinary concentration of urea, and purine derivatives data were analyzed as repeated measurements taken over the 28-d period (122, 150, 178, 206, 234, and 262 d of gestation). Cows were individually fed a corn silage-concentrate based diet composed of 93% roughage and 7% concentrate (DM basis) as a total mixed ration. Pregnant cows were slaughtered on 4 different DG: 139 (n=11), 199 (n=11), 241 (n=11), and 268 d (n=11). Overall, DM intake decreased as DG increased. This decrease observed in DM intake may be associated with the reduction in ruminal volume caused by the rapid increase in fetal size during late gestation. We observed an interaction for DM and organic matter apparent total-tract digestibility between FR and DG; at 150, 178, and 206 d of gestation, ML-fed cows had greater DM and organic matter apparent total-tract digestibility values than AL-fed cows. Rib fat thickness, mesentery, and kidney, pelvic, and heart fat were greater in AL-fed than in ML-fed cows at all DG, with the exception of rib fat thickness on d 139. Ad libitum-fed cows excreted more N in their feces and urine compared with ML-fed cows. Pregnant cows that were fed at maintenance had greater digestibility during some DG, excreted less N in feces and less N and urea in urine, and deposited less fat in the body. We therefore recommend ML (1.15% of body weight with 93% of roughage) as a FR for pregnant dry cows; however, during the last month of gestation, AL seems to be the most appropriate FR to avoid loss of body weight.

Effect of copper edetate injection in dry pregnant cows on hematology, blood metabolites, weight gain and health of calves

The objectives of the present study was to investigate the effects of the copper injection and injection timing to pregnant dairy cows at dry period on the hematology, some serum metabolites, health and growth of their calves. Thirty Holstein cows at the dry period were assigned to the three following experimental groups: 1) control (injections of 2.5 ml normal saline), 2) test 1 (125 mg Cu as copper edetate injection at the first week of the dry period) and 3) test 2 (125 mg Cu as copper edetate injection at the third week of the dry period). Ten milliliters of jugular blood was taken from all calves 24-48 h after birth and at 7, 14, 21 and 28 days of age for measuring hematological and biochemical parameters. For evaluation of growth and health, body weight of all of the calves was measured at birth and at the end of the trial, and the health of calves was checked by a technician twice a day and any sign of illness, treatment (if needed) and duration of illness was recorded. Copper treatment was proved to have a significant effect on the counts of WBC (lower in test 2, higher in test 1), lymphocyte (lower in test 2, higher in test 1) and the concentrations of fibrinogen (lower in test 1, higher in test 2), cholesterol (lower in control, higher in test 1) and copper (lower in test 1, higher in test 2) (p < 0.05). Age (sampling time) also influenced most measured parameters (p < 0.05) except values of WBC, neutrophil, monocyte, globulin and concentrations of iron, zinc and copper.

Predictions of enteric methane emissions for various summer pasture and winter feeding strategies for cow calf production

Mechanistic (COWPOLL and MOLLY) and empirical (IPCC Tier 2 and ELLIS) models were used to predict enteric CH4 emissions from 2 summer pasture systems and 4 winter feeding strategies for cow calf production in the Western Canadian Parkland. The models used average values for nutrient composition of diets, body weight and body condition score of multi- and primiparous cows to predict 90d emissions for each strategy. Average values were determined from data collected over 5 production years with British-Continental crossbred cows assigned to each strategy for life. Each production year began in June with summer grazing of cow calf pairs (n=288/yr including 76 primiparous cows) assigned to either alfalfa-grass (AG) or grass (G) pastures until weaning in September. November post weaning, pregnant cows (n=240/yr) were assigned to either extended grazing (EG) of dormant regrowth of perennial pastures and swathed annual crops, or one of 3 diets fed in a drylot: hay (HY), straw/barley (SB; 700 oat straw:300 steam-rolled barley grain dry matter (DM)), or silage/straw (SS; 400 barley silage:600 oat straw DM). Cows were fed common diets between weaning and wintering, and pre-calving and grazing of summer pastures. Differences in prediction of enteric CH4 emissions were much bigger among models (26–35%) than among systems (3–5%). For suckled beef cows, the mechanistic and empirical models predicted similar enteric CH4 between AG and G summer pasture groups. The COWPOLL, MOLLY and ELLIS models predicted enteric CH4 emissions from dry pregnant cows to be higher for EG and HY than SB and SS winter feeding strategy groups. In contrast, IPCC Tier 2 predictions were lowest for EG. Enteric CH4 emissions from cow calf production can be lowered in the winter by feeding dry pregnant cows conserved feeds containing straw combined with barley silage or grain, rather than hay alone. A more comprehensive assessment is required to determine the net contribution of extended grazing or drylot feeding programs to greenhouse gas mitigation strategies for beef production. Finally, the substantially higher differences in the prediction of enteric CH4 emissions among models than among production systems preclude their use for regulatory purposes in their current form.This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

Recumbence syndrome around calving in cattle: A Study of Risk Factors of Milk Fever in Dairy units in Dar Es Salaam, Tanzania

A recumbency syndrome around calving in cattle was reported in Dar es salaam during the dry season and was thought to be associated with milk fever a disease common in high producing mature dairy cattle and is related to age, dry cow nutrition and general management. This study was conducted to establish the length of dry period of cows, determine the nutritive value of concentrate supplement fed to dry pregnant cows, levels of crude protein, calcium, phosphorus and magnesium and also to establish presence of other periparturient diseases in semi intensively kept dairy crosses cattle. The nutritive value was determined in 70 samples of concentrate supplement collected from purposively selected farms. Semi structured, pre tested questionnaires were used to get information on individual farms dry pregnant cows management including length of dry period of cows, feeding regime, supplement feeding also to establish presence of other periparturient diseases. Only 22.9% farmers dry cows around the recommended 60 days, 52 % dry cows between 60 – 90 days, about 21.4% of the farmers dry their cows more than 90 days, while 1.4% continue to milk their cows until the next calf is born. About 34% of the farmers reported to have experienced the problem of milk fever during the dry season. Daily intake of CP in concentrate supplement ranged from 110 – 245g, calcium 0 – 80 g, phosphorus 16 – 25.3 g and magnesium 5 – 10.2 g. Daily intake of nutrients from herbage was 3.7 g CP, 7.98 g Ca, 1.3 g P, and 0.6 g Mg. The daily recommended levels in dry cow ration are 150g, 20-40g, 5 g, and 10 g DM for crude protein, calcium, magnesium and phosphorus respectively. Periparturient diseases reported by farmers were mastitis 44%, retained placenta 43%, udder edema 20%, delayed estrus 24%, and repeated heat 24%. These findings indicated that dry period length and management of dry cows at close up period is variable among livestock farmers. Daily requirements of nutrients were within recommended limits. It is likely that the recumbency syndrome reported was due to hypocalcaemia but further studies should be conducted to assess plasma ionized calcium levels peripartum in Dar es salaam. Starvation ketosis in the dry season when herbage nutritive value is low may not be ruled out.

Blood plasma mineral profile and health status in postpartum cows fed an anionic diet before parturition

The effects of an anionic versus cationic (control) diet on plasma mineral levels and health status were investigated in 24 dry pregnant Holstein-Friesian cows during the last 3 weeks of pregnancy. The cows were in their third or fourth parity, had a moderate level of milk production in their previous lactation, and did not have a history of milk fever. The anionic diet significantly improved plasma calcium status, as compared to the control (2.18 vs. 1.99 mmol L^{-1}) and nonsignificantly reduced the incidence of subclinical hypocalcemia (1/12 vs. 5/12) without affecting other periparturient diseases. Other plasma mineral levels were unaffected, except chloride, which was higher in the anionic group. The results show that an anionic diet could improve calcium status around the time of parturition and reduce the incidence of subclinical hypocalcemia when fed to moderate producing dairy cows not predisposed to milk fever.