Effects of untreated and heat-treated canola presscake on milk yield and composition of dairy cows

Five primiparous and five multiparous Holstein cows were used in two Latin square design experiments to determine effects of feeding unheated and heated canola presscake on milk yield and composition, and milk fatty acid concentrations of lactating dairy cows. Five diets that differed in level and source of dietary fat were formulated: a low fat control diet with 30 g kg⁻¹ fat from tallow, an unheated canola presscake supplemented diet (50 g kg⁻¹ fat), a heated canola presscake supplemented diet (50 g kg⁻¹ fat), a high tallow plus unheated canola meal supplemented diet (50 g kg⁻¹ fat), and a high tallow plus heated canola meal supplemented diet (50 g kg⁻¹ fat). In sacco ruminal degradability of heated and unheated canola presscake was compared with that of heated and unheated canola meal in a randomized complete block design using two ruminally fistulated cows. Heat treatment reduced ruminal DM and CP degradability of canola presscake. Multiparous cows fed diets supplemented with heated or unheated canola presscake produced more milk than those fed diets containing similar levels of fat from tallow with heated or unheated canola meal, respectively. High levels of fat from any diet reduced milk fat percentage for cows of either parity. Feeding heated canola products increased milk and milk protein yields in primiparous cows only, but cows of both parities fed diets containing canola presscake produced milk with lower concentrations of C12:0, C14:0, and C16:0 fatty acids than cows fed the canola meal and tallow diets, although concentrations of C18:1 n-9 were unaffected by fat source or level. Feeding canola products to dairy cows can alter milk fatty acid profile, but only primiparous cows have increased productivity as a result of feeding heated, versus unheated, canola presscake.     

Effects of feeding nutritionally balanced rations on animal productivity,feed conversion efficiency,feed nitrogen use efficiency,rumen microbial protein supply,parasitic load,immunity and enteric methane emissions of milking animals under field conditions

Milking animals produce milk commensurate with their genetic potential only when they are fed a nutritionally balanced ration in an amount that provides nutrients to express their genetic potential. As animals kept by smallholder farmers are rarely fed a balanced ration, a programme to feed balanced rations to animals of such farmers was launched in India. Based on their milk yield, the animals were categorized as: low (<8 kg/d), medium (8–12 kg/d) and high (>12 kg/d) yielders. Milk yield, milk fat and net daily income to milk producers were recorded before and after feeding a balanced ration. Nutritional status of animals showed that, for 71% of animals’, crude protein (CP) and metabolizable energy intakes were higher and, for 65% of animals’, calcium and phosphorus intakes were lower than requirements. Ration balancing improved milk yield by 2–14% and its milk fat proportion by 0.2–15%. Feed conversion efficiency, as kg of fat corrected milk (FCM)/kg of dry matter intake of buffaloes (n = 1131) before and after feeding balanced rations was 0.6 and 0.7, respectively, and in cows (n = 540) the values were 0.6 and 0.8. Dietary N secreted into milk increased from 0.16 to 0.25 and 0.16 to 0.19 in low and medium yielding cows and buffaloes, respectively. Rumen microbial CP synthesis also increased (P<0.05) by 36 and 38% in cows and buffaloes, respectively. On feeding balanced rations, levels (mg/ml) of plasma immunoglobulins IgG, IgM and IgA increased from 14.48 to 22.11, 2.69 to 3.29 and 0.48 to 0.67, and the parasitic load was reduced from 168 to 81 eggs/g of faeces. Enteric CH₄ emissions (g/kg milk yield) was reduced by 15–20% (P<0.05) in these lactating animals. Results demonstrate that feeding nutritionally balanced rations increased milk production and reduced enteric CH₄ emissions and N excretion from lactating cows and buffaloes. While implementation of a ration balancing programme under small holding systems is challenging, large scale use of this programme in tropical countries can help improve productivity of milking animals with available feed resources in an environmentally sustainable manner.     

Effects of dietary conjugated linoleic acid on metabolic status,BW and expression of genes related to lipid metabolism in adipose tissue of dairy cows during peripartum

Conjugated linoleic acid (CLA) dietary supplementation reduces milk fat content and yield, but its effects on lipid metabolism and energy status remain controversial. The objective of this study was to investigate the effects of dietary CLA on adipose tissue (AT) mRNA abundance of genes related to lipid metabolism, plasma indicators of metabolic status, body condition score (BCS) and BW changes in dairy cows. Sixteen multiparous Holstein cows (3.2 ± 1.4 lactations, 615 ± 15 kg BW) were randomly assigned to treatments: 1) CLA; rumen-protected CLA (75 g/d) or 2) Control; equivalent amount of rumen inert fatty acid (FA) as the previous diet (78 g/d), from − 20.2 ± 3.2 (mean ± SEM) to 21 d relative to calving (d 0). Subcutaneous AT was biopsied from the tail-head region at d 21 to determine the mRNA abundance of genes related to lipid metabolism. Blood samples were collected at − 20.2 ± 3.2, 0, 7, 14 and 21 d relative to calving to determine plasma non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), insulin and glucose. Conjugated linoleic acid decreased milk fat yield and milk fat content by 15 and 16%, respectively. Cows fed CLA had lower plasma NEFA and BHBA and greater glucose and insulin concentrations (P < 0.05). Mean BCS at 21 d postpartum was greater (P < 0.01; 2.89 vs 2.25), and BCS loss from the day of enrollment to 21 d postpartum was reduced (P < 0.01; − 0.13 vs − 0.64) in the CLA group. The expression of acylcoenzyme A oxidase, carnitine palmitoyltransferase 1A, hormone-sensitive lipase, β2 adrenergic receptor and acetyl-CoA carboxylase was downregulated by CLA supplementation, whereas the expression of sterol regulatory element binding protein, lipoprotein lipase and peroxisome proliferator-activated receptor gamma was upregulated (P < 0.01). In summary, CLA-supplemented cows showed signs of better metabolic status and less severe fat mobilization. Moreover, CLA increased mRNA abundance of genes related to lipogenesis and decreased mRNA abundance of genes related to FA oxidation and lipolysis in the AT of dairy cows during early lactation.     

Glucosinolates in animal nutrition: A review

Glucosinolates (Gls) are secondary plant metabolites that occur in all Brassica-originated feeds and fodders. Content and composition of Gls vary due to plant species, agronomic practices and climatic conditions. The Gls content is generally higher in rapeseed meal (RSM) varieties grown under tropical environment than those occur in temperate regions. The RSM from Indian sub-continent contain primarily 3-butenyl, 2-propenyl and 4-pentenyl glucosinolates. But 2-propenyl glucosinolate accounts more than 0.95 of their total glucosinolates present in RSM of European and other temperate countries, and did not contain 4-pentenyl glucosinolates. Depending on the pH, cofactors and Gls content and composition of RSM, major metabolites of glucosinolates are thiocyanates (SCN), isothiocyanates (ITC), nitriles, 5-vinyl-2-oxazolidinethione (VOT) and 5-vinyl-1,3-oxyzolodine-2-thione (5-VOT). Apart from total glucosinolate (TGls) content SCN, nitriles and VOT estimates are the chief attribute of RSM quality as these are produced upon hydrolysis of Gls following the processing of RSM. Major deleterious effects of glucosinolates ingestion in animals are reduced palatability, decreased growth and production. Progoitrin and epi-progoitrin impair palatability at a level between 2.3 and 4.65 μmol g⁻¹ diet, while at higher levels feed intake decreases. Nitriles are known to affect liver and kidney functions. The thiocyanates interfere with iodine availability, whereas VOT is responsible for the morphological and physiological changes of thyroid. Difference in Gls profile among the RSM induces varying levels of glucosinolates metabolites in animal tissues. Rapeseed meal feeding did not impair quality traits of carcass and increased unsaturated fatty acids (C_22:2 and trans C_18:1) content in carcass and milk fat. Ruminants are less sensitive to dietary glucosinolates. Pigs are more severely affected by dietary glucosinolate compared to rabbit, poultry and fish. The tolerance level (μmol g⁻¹ diet) of TGls in ruminants, pig, rabbits, poultry and fish is 1.5–4.22, 0.78, 7.0, 5.4 and 3.6 μmol, respectively. Water extraction, heat and CuSO₄ treatments were found suitable for RSM quality improvement. Iodine supplementation in the diet of pigs (1.0 mg kg⁻¹) and ruminants (500 mg I each kg RSM) seems promising because of economic and easiness compared to other treatments. Therefore, a desired amount of RSM can be used for animal feed formulation adopting a suitable technology to minimize or remove Gls-related deleterious effects on animals.     

Effect of feeding schedule on apparent energy and amino acid digestibility by growing pigs

An experiment was conducted to investigate the effects of feeding schedule on dry matter (DM), gross energy (GE), crude protein (CP), and amino acid (AA) digestibility by growing pigs. Six growing castrates (initial body weight: 40.5 ± 2.25 kg) were equipped with a T-cannula in the distal ileum and allotted to a repeated 3 × 3 Latin square design with three animals and three periods in each square. A maize–soybean meal based diet (181 g CP/kg) was formulated and fed to the pigs in three different feeding schedules; i.e., one meal per day, two meals per day, or free access to feed. Pigs fed one or two meals per day were allotted a daily amount of feed equivalent to three times the maintenance energy requirement. Fecal and ileal samples were collected from all pigs in each period. The coefficients of ileal apparent digestibility (CIAD) for DM, GE, CP, and AA were calculated as were the coefficients of total tract apparent digestibility (CTTAD) of DM and GE. Results of the experiment showed that there were no differences in the CIAD for DM, GE, or for any of the AA among the three feeding schedules. In contrast, pigs given free access to the diet had lower (P<0.002) CTTAD for DM and GE compared with pigs fed a restricted amount of feed either once or twice daily. Therefore, the concentration of digestible energy in the diet was lower if calculated from pigs given free access to the diet compared with pigs fed the diet once or twice daily (14.38 MJ/kg versus 14.83 MJ/kg and 15.13 MJ/kg). It is concluded that the feeding schedule does not influence the CIAD for DM, GE, CP, or AA by pigs. Therefore, any of the three feeding schedules that were used in the current experiment may be used in experiments aimed at measuring CIAD in pigs. However, if the CTTAD of DM and GE are measured, it is recommended that pigs are given free access to feed.     

Growth performance and starch utilization in common carp (Cyprinus carpio L.) in response to dietary chromium chloride supplementation

A nutrition trial was conducted on juvenile common carp (Cyprinus carpio), initial mean body weight 15 ± 0.4 g within a controlled facility at 25 ± 0.5 °C. Six diets containing various levels of supplementary Cr (0, 0.2, 0.5, 1.0, 1.5, and 2.0) mg Cr/kg of diet as Cr chloride hexahydrate were fed to carp for a period of 10 weeks. Lower growth performance was observed in fish fed on the control diet and the diet supplemented with the highest level of Cr (2.0 mg Cr/kg). Although fish fed 0.5 mg Cr/kg showed the best growth performance, this was not significantly different (P > 0.05) from fish fed 1.0 mg Cr/kg. The regression of plasma glucose concentration was linear (R² = 0.97 and P value = 0.001) as the Cr content of the diet increased (up to 1.5 mg Cr/kg).Cr carcass content was elevated with an increasing level of dietary Cr supplementation up to 1.5 mg Cr/kg; but fish fed on the diet supplemented with the highest level of Cr (2.0 mg Cr/kg) showed a decrease in Cr carcass content.Histological examination to evaluate the impact of different Cr supplementation on liver and gut tissues showed notable changes. The higher level of Cr (2.0 mg Cr/kg) in the diet gave rise to elevated hepatocyte vacuolization and changes in gut tissue morphology.It appeared that Cr chloride significantly improved growth within a defined range (0.2–1.5) mg Cr/kg without any negative impact, while 2.0 mg Cr/kg in carp diet seems to be the threshold for the initiation of toxicity.     

Utility of buckwheat (Fagopyrum esculentum Moench) as feed: Effects of forage and grain on in vitro ruminal fermentation and performance of dairy cows

Buckwheat is of high value in crop rotations and overall agricultural ecology because of strong rooting and intensive flowering properties, but it is rarely cultivated and information on its nutritional value to ruminants is scarce. The contents of net energy for lactation (NEL), as estimated with the Hohenheim Gas Test (n = 3), were 4.3, 4.9 and 7.5 MJ NEL/kg dry matter (DM) for fresh and ensiled whole buckwheat plants and buckwheat grain, respectively. In two experiments with the Rumen Simulation Technique (Rusitec), ruminal fermentation characteristics of buckwheat forages and buckwheat grain (n = 4/diet) were evaluated. In the first experiment, 0, 300 or 600 g/kg of a pure hay diet were replaced by either fresh or ensiled buckwheat to create five diets. Neither form of buckwheat forages had effects on in vitro ruminal degradability and short chain fatty acid (SCFA) concentrations and composition. The use of fresh buckwheat reduced ruminal ammonia concentrations and enhanced estimated microbial N growth efficiency. These differences did not occur with silage, indicating a change in nutritional value by ensiling. Fresh buckwheat reduced the number of bacteria in the incubated fluid, while ensiled buckwheat reduced that of holotrich protozoa. Methane formation was not influenced by the buckwheat forages. In the second experiment, wheat meal (400 g/kg dietary DM), was replaced stepwise (0.5 and 1.0) by buckwheat grain meal. This did not cause differences in parameters of nutrient degradability, relative N efficiency and total amount and composition of SCFA. Holotrich protozoa counts increased, but total gas formation decreased with increasing dietary level of buckwheat grain. In a final experiment, cows yielding about 40 kg milk/day were fed mixed silage-concentrate diets (n = 4). A control diet contained no buckwheat. In a second diet, maize silage was partly substituted by buckwheat silage (98 g/kg dietary DM). In a third group, part of the energy concentrate was substituted by buckwheat grain meal (94 g/kg). There were no effects on feed intake, milk yield and milk composition. Buckwheat proved to be a plant that offers different feeds of a quality sufficient to be considered suitable in ruminant nutrition.     

Reproductive responses of ram lambs under short-term exposure to endophyte-infected tall fescue seed

Our objective was to determine the influence of short-term exposure to endophyte-infected tall fescue on reproductive function of ram lambs. Rams (214 days of age) were fed a diet free of endophyte-infected fescue seed (EF; n = 8) or endophyte-infected fescue seed (EI; n = 9; 34% of diet; 4.8 μg g⁻¹ ergovaline) for 6 weeks. Feed offered to EF rams, individually fed, was reduced to the average intake of EI lambs from previous day so that intake was similar between treatments and averaged 2.4% BW (DM basis), leading to daily intake of 33.7 μg ergovaline kg⁻¹ BW for the EI fed lambs. Daily high ambient temperature for the trial ranged between 16 and 26 °C. Respiration rate and rectal temperature were measured at 14:00 daily. Blood was collected for serum concentrations of prolactin (weekly) and testosterone (twice weekly). Body weight and body condition scores (BCS; 1 = thin; 5 = fat) were determined every 14 days. Scrotal circumference, scrotal skin temperature, and semen characteristics were determined weekly. Rams were slaughtered after 6 weeks of feeding. Signs of fescue toxicosis in EI fed rams included increased rectal temperature (P < 0.001, R² = 0.11) and respiration rate (day, P < 0.001, R² = 0.25) when high ambient temperature exceeded 22 °C and reduced serum concentrations of prolactin (diet × day, P < 0.001). Body weight of EI fed rams tended to decrease after 36 days of feeding compared with EF fed rams (−3.0 kg versus 0.51 kg; P < 0.07) and BCS was similar between treatment throughout the trial. Serum concentrations of testosterone were greater in EI compared with EF fed rams (diet × day, P < 0.005, R² = 0.08). Scrotal skin temperature, scrotal circumference, semen volume, percent sperm motility, and percent abnormal sperm were similar between treatments. Spermatozoa concentration tended to be greater in EF compared with EI fed rams after 43 days of feeding (P < 0.10; R² = 0.15). Rate of forward movement of spermatozoa tended to increase at a greater rate between Days 8 and 29 in EF compared with EI fed rams (diet × day, P < 0.08). Feeding endophyte-infected fescue seed to ram lambs was associated with potential decreased fertility and increased serum concentrations of testosterone. Short term exposure of endophyte toxins to male ruminants may negatively impact reproductive responses. Feeding for longer periods may further reduce fertility and merits further research.     

Effect of different level of roughage availability and contrast levels of concentrate supplementation on flavour of goat milk

Rancid and tart flavours are the most common off-flavours in Norwegian goat milk. In a feeding trial, we examined the effects of different levels of concentrate and of supplementary hay feeding on the occurrence of these off-flavours. Forty-eight experimental goats grazed cultivated pasture in the lowland during spring and autumn, and mountain pasture in summer. Twenty-four of the goats were fed 0.2 kg/day of concentrate (low concentrate, LC) and the remaining 24 goats 0.7 kg/day (high concentrate, HC). Twelve animals in LC and HC groups grazed freely, while the remaining goats in the two groups were given feeding challenges (limited periods of roughage restriction and ad libitum hay feeding). This was done to examine the effect of differing roughage availability on milk flavour. The animals fed low level of concentrate and with free grazing represented the control group. During the challenge periods, the goats were kept indoors and fed 0.2 kg hay/day for 2 days (roughage restriction) or hay according to appetite for 2 days (ad libitum feeding). At least 10 days of uninterrupted grazing were allowed between the challenges. Milk samples for sensory and chemical analysis were taken at the end of the challenge periods.The level of concentrate feeding did not influence the flavour of the milk when the goats were on lush spring pasture. However, the low level of concentrate feeding (LC) increased the frequency of off-flavour during the mountain and autumn experimental periods (P < 0.05).In the end of the mountain experimental period when the frequency of rancid/tart flavour increased in all groups, the sensory quality of milk produced by goats fed hay ad libitum (S1) had better taste ratings (P < 0.001) than milk from goats that were grazing. When the goats were given restricted amounts of hay, they adapted to the treatment by reducing their milk yield. In the spring and mountain experimental periods, restricted roughage feeding resulted in higher fat content and better taste ratings, especially in the group fed low level of concentrate (LC/S1). However, this connection was not clear in the autumn.Probably, the goats are able to handle a negative energy balance as long as mobilizable body reserves exist, but start to produce milk with lower dry matter content and higher frequencies of rancid/tart flavour when the body reserves are empty and the energy deficit is still pronounced.It is concluded that increasing the level of concentrate and feeding hay supplements will reduce the frequency of flavour defects at times when grazing is suboptimal or the pasture is of medium or low quality.     

Lying patterns of high producing healthy dairy cows after calving in commercial herds as affected by age,environmental conditions and production

An animal expresses its physiological and well-being status by its behaviour. Changes in behaviour can be associated with health, production or well-being problems and therefore with the profitability of the farm. The objectives of the present study were to analyse lying patterns of healthy cows, collected with a commercial behaviour sensor, in early lactation in relation to environmental conditions, age of the cow and production performance. In future, these results may be used as a ‘baseline’ for detection of alterations in behaviour that indicate health problems. The study involved 210 healthy multiparous Israeli Holstein cows in three commercial dairy farms. Only healthy cows during the first 28 days after calving were included in this study. Data were analysed in relation to calving season, age of cows and correlation between milk production and lying time.The results show that lying time increased significantly with age and is significantly (P < 0.05) higher in winter than in summer (summer lactation 2: 491 ± 17 min/day (mean ± SD), summer lactation 3 and more: 520 ± 25 min/day, winter lactation 2: 531 ± 25 min/day, winter lactation 3 and more: 579 ± 38 min/day).The proportion of positively and negatively milk production and lying time correlated cows is affected by calving season.This study indicates that behaviour variables in early lactation are affected by calving season, lactation number and type of correlation between milk production and lying time.     

Postpartum resumption of ovarian cycling activity in first-calf suckled beef cows exposed to familiar or unfamiliar bulls

The objective of this experiment was to determine if the proportion of first-calf suckled beef cows that resumed ovulatory cycles and the interval to resumption of ovarian cycling activity differ after exposure to either “unfamiliar” bulls or cows on d 35 postpartum, after exposure to either “familiar” bulls or cows for the first 30–32 d after calving. Fifty Angus × Hereford cows were stratified by calving date, calf BW, and calf sex by d 3 postpartum, and assigned to be exposed to familiar epididectomized bulls (BEF; n = 25) or familiar mature ovariectomized (OVX) cows (CEF; n = 25). On d 35 after calving, 12 BEF cows were assigned to be exposed to unfamiliar bulls (BEU); likewise, 12 CEF cows were assigned to be exposed to unfamiliar OVX cows (CEU). Cows were in their treatments for either 95 d (BEF and CEF) or 60 d (BEU and CEU) during the experiment. Blood samples were collected every third d from the beginning to the end of the experiment. A rise in progesterone concentration of >0.5 ng/mL in consecutive samples was used as the criterion for resumption of ovulatory cycles. Exposing cows to bulls on d 5 after calving and then switching a subset of these cows to be exposed to unfamiliar bulls 30–32 d later did not (P > 0.10) alter: (1) the proportion of cows that resumed cycling activity; and (2) postpartum interval to resumption of ovarian cycling activity compared to cows exposed to familiar bulls. However, 32% more (P < 0.05) cows exposed to bulls (BEF and BEU) resumed cycling activity by approximately 14.8 d before cows that were exposed to OVX cows (CEF and CEU). We conclude that the familiarity of first-calf cows to either bulls or ovariectomized cows, did not affect the postpartum occurrence of cycling activity or the interval from calving to resumption of ovulatory cycles. However, bull exposure, whether familiar or unfamiliar, stimulates first-calf cows to resume ovulatory cycles sooner after calving than if they are not exposed to bulls.     

Effects of yeast culture (Saccharomyces cerevisiae) on ruminal digestion in non-lactating dairy cows

Six non-lactating dairy cows fitted with ruminal cannulas were used in a cross-over design, to investigate the effects of supplemental yeast culture (Saccharomyces cerevisiae) (YC) and interaction of YC by sampling time on ruminal fermentation and in situ fibre degradation. Cows were fed twice daily with a diet composed of 67% corn silage, 32% concentrate and 1% vitamin and mineral mixture, on a dry matter (DM) basis. Concentrates were not mixed with silage. YC (0.5% DM) significantly decreased rumen ammonia from 148.5 mg l⁻¹ to 103.1 mg l⁻¹ 3 h post-feeding, and significantly increased by about 20% the concentration of total volatile fatty acids before and 1 h after feeding. YC significantly increased molar percentage of propionate and decreased the acetate : propionate ratio before feeding. No significant effect was observed on ruminal pH and molar percentages of acetate or butyrate. Pattern of degradation of DM, neutral and acid detergent fibre from hay was affected, with a cubic effect of interaction of YC by incubation time. However, magnitude of degradation was not significantly different at any time. These results show that modifications of ruminal fermentation due to YC addition are time dependent when the diet is fed twice daily.     

Escape protein supplementation of growing steers grazing stargrass

A grazing trial utilizing 35 individually supplemented growing steers (211±42 kg initial body weight (BW)) was conducted to study the effect of supplemental escape protein on the performance of steers grazing on stargrass (Cynodon plectostachyus) during the dry season. N in supplements was 100%, 50%, or 0% natural protein (bloodmeal, coconut meal, and soybean meal), and 0%, 50% or 100% urea. All steers received 2 kg of supplement dry matter (DM) (2.2% N) daily during the 90 days of the experiment. Steers fed the urea supplement had the lowest ADG (0.97 kg day⁻¹). There was a linear (P<0.05) response in ADG to the natural protein level (50 and 100%) in supplements containing bloodmeal (1.11 and 1.21 kg day⁻¹) and coconut meal (1.05 and 1.21 kg day⁻¹), but no response was observed with soybean meal (1.01 and 1.0 kg day⁻¹). Forage intake was not affected by supplementation. As a result of the growth response observed for supplements containing bloodmeal and coconut meal above the urea-based and soybean meal supplements, it was concluded that growing ruminants grazing stargrass in the dry season were deficient in escape protein. ©1997 Elsevier Science B.V.     

Effects of dietary sources of vegetable fats on performance of dairy ewes and conjugated linoleic acid (CLA) in milk

Two experiments were carried out to study the effects of supplementing the ration of lactating ewes with vegetable fats (sunflower oil, SO or hydrogenated palm oil, HPO; HIDROPALM^®) on diet digestibility, milk yield and milk composition, and on the concentration of the conjugated linoleic acid (CLA) C18:2 cis-9 trans-11 and C18:1 trans-11 (vaccenic acid, VA) and other main fatty acids in milk fat. Treatments involved a control diet, without added oil, and 2 diets supplemented with either 12 g/kg SO or 12 g/kg HPO on a dry matter (DM) basis. In the first experiment, 6 non-pregnant, non-lactating Lacaune ewes were used following a 3 × 3 replicated Latin Square design. Addition of vegetable fat supplement to the diet increased digestibility of DM, organic matter (OM) and crude protein (CP), but did not affect that of the ether extract (EE), neutral detergent fibre (NDF) or acid detergent fibre (ADF). In the second experiment, 60 Lacaune dairy ewes mid-way through lactation (120 ± 12 days in milk, 0.98 ± 0.03 kg/day average milk yield) were divided into three equal-sized groups each of which was assigned to one of the three experimental diets for 4 weeks. Compared with the control treatment, supplementation with HPO increased milk yield and energy-corrected milk. But neither vegetable fat supplement modified percentages of fat and protein in milk. Supplementation with HPO increased C14:1, C16:1 and C16:0 content and reduced C18:0 and C18:1 cis-9 content in milk fat. Supplementation with SO increased the VA content in milk fat by 36% and that of cis-9 trans-11 CLA by 29% in comparison with the control diet. Supplementation with HPO led to milk fat with 15% more cis-9 trans-11 CLA than control milk. In conclusion, adding a moderate dose of HPO or SO to the diets increased CLA concentration in milk fat. Nevertheless, supplementation with SO was more effective than HPO in increasing CLA concentration in milk fat and reducing the atherogenicity index, improving milk quality from the human health standpoint.     

Effect of barley and oats on feed intake,live weight gain and some carcass characteristics of fattening lambs

The influence of whole, crushed and ground barley and oats on intake, performance and carcass characteristics of lambs was examined. A comparison of diets was conducted with individually-fed male and female lambs in six groups. The study was repeated in three successive years (1995–1997) using the same experimental design. A total of 192 lambs of a mean initial age of 74 days (SD 13.0) and live weight 20.6 kg (SD 4.54) were daily fed their respective concentrates, 72 g dry matter (DM)/kg metabolic live weight (kgW^0.75), for 98 days from weaning to slaughter. Hay was provided ad libitum.The lambs adapted more quickly to diets containing barley than to those containing oats. Compared to oats, the total daily DM intake was higher on barley (1162 vs. 990 g DM/lamb, 89 vs. 78 g DM/kgW^0.75, P < 0.001). Hay consumption was significantly lower on oats than on barley (182 vs. 344 g DM/day, P < 0.001). On oats the lambs experienced energy and protein deficiencies with their energy and protein intakes being 20% below feeding recommendations. On the barley diets the energy and protein requirements of the lambs were satisfied. When processed cereals were offered, there was no increase in the total DM, energy or protein intakes. Processing did not improve the organic matter digestibility of barley or oats.The growth rate (P < 0.01), carcass weight (P < 0.001) and slaughter percentage (P < 0.001) were higher on a barley diet than on oats. A barley diet resulted in more kidney fat (P < 0.01) and fattier carcasses. Processing had no positive influence on the live weight gain. On the contrary, lambs receiving crushed or ground barley or oats had a lower final live weight than those receiving whole grains (P < 0.001). The utilisation of whole grain was more efficient than that of processed grain. There were no advantages in processing barley and oats for the feeding of lambs.     

Effect of Concentrate Crude Protein Level on Grass Silage Intake,Milk Yield and Nutrient Utilisation by Dairy Cows in Early Lactation

Twenty-one multiparous dairy cows were fed concentrates containing three levels (119, 154 and 191g/kg DM) of crude protein (CP) during the first ten weeks of lactation. Part of the grain and molassed sugar beat pulp was substituted with 0% (RSM0), 15% (RSM15) or 30% (RSM30) rapeseed meal. Wilted grass silage was fed ad libitum after calving. The average response between RSM0 and RSM15 was +1.66kg milk/d per percentage unit change in concentrate CP content. No further response occurred between RSM15 and RSM30. The positive effect of RSM inclusion was seen throughout the experimental period and was associated with increased plasma non esterified fatty acids (NEFA) and decreased plasma insulin concentration one week after calving, and higher efficiency of metabolisable energy utilisation for milk production. Digestibility of the diet remained unaffected. Milk and plasma urea tended to increase with RSM30 indicating excessive supply of rumen degradable protein. Because of the limited potential of cows to compensate for a deficit in feed protein supply by mobilising tissue protein, a substantial milk yield response can be achieved with a moderate level of protein supplementation during early lactation.     

Milk fatty acid composition of dairy cows grazing at two pasture allowances and supplemented with different levels and sources of concentrate

Milk fatty acid (FA) composition of dairy cows from two grazing studies was examined. In the first study, effects of concentrate supplementation and pasture allowance were evaluated using 20 multiparous Holstein cows in five 4 × 4 Latin squares. The four treatments resulted from the combination of two pasture allowances (i.e., low, 25 versus high, 40 kg dry matter/cow/day) and two concentrate supplementation levels (i.e., 0 versus 1 kg concentrate/4 kg milk). No interactions occurred between concentrate supplementation and pasture allowance for milk FA composition. Concentrate supplementation increased short-chain FA content, and reduced the content of long-chain FA, trans11 C18:1, and cis9, trans11 conjugated linoleic acid (CLA) (1.36 versus 1.18 g/100 g). Concentrate supplementation increased saturated FA (58.6 versus 54.0 g/100 g) and reduced unsaturated FA content (39.9 versus 43.8 g/100 g). Grazing at high pasture allowance increased short-, medium-, and long-chain FA content, without affecting cis9, trans11 CLA content. Saturated FA content was higher (57.1 versus 55.6 g/100 g), and unsaturated FA content was lower (41.3 versus 42.5 g/100 g), when cows grazed at high pasture allowance. Concentrate supplementation reduced unsaturated FA and cis9, trans11 CLA in milk of dairy cows grazing at two pasture allowances. In the second study, two experiments evaluated effects of different energy supplements in grazing dairy cows. In Experiment 1, 25 multiparous Holstein cows were assigned to a cracked corn (CC) or a steam flaked corn (SFC) supplement containing 667 g/kg of corn grain plus a pelleted protein/mineral supplement. In Experiment 2, 22 multiparous Holstein cows were assigned to a ground corn grain (GC) or a non-forage fiber (NFF) supplement. The GC supplement contained 850 g/kg of corn grain, and the NFF supplement contained 440 g/kg of non-forage fiber sources (i.e., beet pulp, soyhulls, wheat middlings) that partially replaced corn grain. Milk FA composition was not affected by corn processing or carbohydrate source. The content of short-, medium-, long-chain FA, and cis9, trans11 CLA (2.5 g/100 g in Experiment 1; 2.1 g/100 g in Experiment 2) was similar between supplements in both experiments. The type of supplement did not affect the content of saturated (62.6 g/100 g in Experiment 1; 65.4 g/100 g in Experiment 2) and unsaturated FA (37.5 g/100 g in Experiment 1; 34.6 g/100 g in Experiment 2). Supplementation with supplements differing in the rate and extent of ruminal carbohydrate digestion did not affect the milk FA composition of grazing dairy cows.     

Effects of diets of differing fiber contents on digestibility,passage rate of digesta and heat production in lesser mouse deer (Tragulus javanicus)

The effects of different levels of dietary fiber on feed intake, digestibility, mean retention times of solute and particle and heat production were studied in twelve male lesser mouse deer (Tragulus javanicus). The animals were randomly assigned into four groups of three mouse deer each and fed on individual basis. Four diets, namely A, B, C and D were prepared in pellet forms. Each diet contained ～14% crude protein and ～18 kJ/g gross energy. The crude fiber contents of diet A, B, C and D were 4.2, 11.3, 16.8 and 22.5%, respectively. The results showed that the crude fiber intake of mouse deer was 1.4 ± 0.04, 3.8 ± 0.4, 5.8 ± 0.7 and 6.0 ± 0.6 g/kg W^0.75/d fed diet A, B, C and D, respectively. Mouse deer fed diet D had significantly lower DM intake than those fed lower levels of fiber. The digestibility values of DM decreased gradually with increasing levels of fiber in the diet. The mean retention times (MRTs) of particles (～1.5 mm) in the reticulorumen were in the range of (19.0–22.9 h), with the shortest time for mouse deer fed diet D. However mouse deer fed diet C and D showed significant shorter solute MRT in the reticulorumen (17.1–18.5 h) when compared to mouse deer fed lower fiber diets (21.4–21.9 h). The selectivity factor in the reticulorumen was in the range of 1.04–1.18, indicating the mouse deer to be a ‘moose-type’ ruminant. Fiber levels had no significant effect on water intake of mouse deer. Heat production tended to decrease with increasing levels of fiber (448.3–435.7 kJ/kg W^0.75/d) but differences among the mouse deer fed the four diets were not significant.     

Feeding soybean meal increases the blood level of isoflavones and reduces the steroidogenic capacity in bovine corpora lutea,without affecting peripheral progesterone concentrations

Thirty-three Holstein-Friesian cows were followed from 14 days pre partum until the fourth ovulation post partum. Housing conditions and basic ration were identical for all animals. Concentrates were individually supplemented according to the daily milk production level, using two different types of protein rich concentrates: soybean meal and rapeseed meal. Soybean and rapeseed meal are known to be respectively high and low in isoflavones. Cows were randomly divided into three groups and blocked for parity. Group I (n = 11) was supplemented with soybean meal and acted as control group. Groups II (n = 11) and III (n = 11) were respectively supplemented with soybean and rapeseed meal and were subjected to a biopsy sampling of the corpus luteum at day 9 of the first three postpartal estrous cycles.Soybean meal supplementation to lactating dairy cows (1.72 kg on average) induced an increase in the blood concentration of equol, dihydrodaidzein, o-desmethylangolensin in both soy groups and resulted in a reduced area occupied by steroidogenic (P = 0.012) and endothelial cells (P = 0.0007) in the luteal biopsies. Blood concentrations of equol and glycitein were negatively correlated with the areas occupied by steroidogenic (r = −0.410 with P = 0.0002, respectively r = −0.351 with P = 0.008) and endothelial cells (r = −0.337 with P = 0.01, respectively r = −0.233 with P = 0.085) in the 3 first estrous cycles. The latter however did not affect the diestrous peripheral blood progesterone concentration.