Protein and methionine hydroxy analog for lactating cows

A 2 X 2 factorial experiment (protein 12.5 and 15.5; methionine hydroxy analog 0 and .125% dry matter) included 144 cows for one complete lactation, distributed over seven locations. Rations were formulated to the desired protein, methionine analog, and constant amounts of fiber 17%, sulfur .225%, calcium .6%, phosphorus .4%, and salt .5%. Treatment effects were not apparent for dry matter intake, daily milk and fat-corrected milk production, conversion of energy, and body weight changes. Conversion of dietary crude protein into milk protein was 34.5% for the low and 25.8% for the high protein ration. Methionine analon (0% = 2.54; .125% = 1.90). Effect of methionine analog was most apparent at low protein as 0 analog cows produced 247 kg fat, required 2.9 services/contraception, and had 156 days open whereas cows on other treatments (.125% analog and/or high protein) produced 264 kg fat, required 1.8 to 2.2 services/conception, and had 124 to 134 days open. Methionine analog response is discussed in relation to tuminal and postruminal effects as well as the interrelation with protein and energy.     

The effect of diets on milk production and composition, and on lactation curves in pastured dairy goats

A 2-yr study investigated effects of different levels of concentrate supplementation on milk production, composition, and lactation curves in pastured dairy goats. For both years, 44 Alpine goats (Capra hircus; 55 ± 11 kg body weight) were randomly allocated to 4 groups. Animals were supplemented with 0.66 (treatments A and B), 0.33 (treatment C), or 0 kg of concentrate (treatment D) per kg of milk over 1.5 kg/d. Mixed vegetative forages were rotationally grazed by the goats (treatments B, C, and D), except that treatment A was confined and fed alfalfa hay. Individual milk production was recorded daily, and milk samples were collected once every 2 wk for the 7-mo period (March to September) and analyzed for fat, protein, lactose, urea-N, nonesterified fatty acids, and allantoin (second year only). Milk yield and composition varied among dietary treatments, with some measures affected by year. Average daily milk yield was lowest for treatment D. The increased level of concentrate supplementation in treatment A led to 22% greater milk yield compared with treatment D. Milk production increased by 1.7 and 0.9 kg for each additional kilogram of concentrate fed per day during the first and second years, respectively. Average peak yield, time of peak yield, and persistency were lower for treatment D than for other treatments. The percentage of milk fat was lower for treatment D than for other treatments. Concentration of milk protein was greater for treatments A and B during the first year, and was higher for treatment C than for other treatments during the second year. Average milk lactose concentration was higher for treatments B and C than for other treatments. However, milk urea-N concentration in treatment A was higher than other treatments. Milk allantoin, used to estimate microbial proteins synthesis, was 20 to 25% greater for treatment A than for other treatments. Averaged across year, plasma urea-N and nonesterified fatty acids concentration were lowest for treatment B. Average organic matter intake was similar among treatments during both years. Ratios of acetate and propionate concentrations for treatment A were lowest among treatments. In conclusion, milk production and composition were affected by the feeding treatment and year. Increased level of nutrition lead to an increase in daily milk yield, peak yield, time of peak yield, and persistency compared with treatment D. Alpine dairy goats grazing on fresh forages without concentrate supplementation can produce milk inexpensively, and response to concentrate supplementation is greater for low quality pasture.     

Relationship between level of milk production and multiple ovulations in lactating dairy cows

Our objective was to evaluate factors associated with spontaneous multiple ovulations in lactating dairy cows. Ovaries of cows [n = 267; >50 days in milk (DIM)] were evaluated weekly using ultrasound to determine spontaneous (i.e., no hormonal treatment) ovulation rate starting at 50 DIM and continuing until pregnancy diagnosis. Cows were fitted with a transmitter to record standing activity during estrus, and serum progesterone concentration was assessed weekly starting at wk 1 postpartum for all cows. Overall, 76 (28.5%) cows were anovular and 191 (71.5%) were ovular by 71 DIM. Incidence of anovulation was not associated with level of milk production but was associated with lower body condition. For anovular cows (n = 41) that spontaneously recovered, the multiple ovulation rate at first ovulation was 46.3%. For second and subsequent ovulations (n = 463), the level of milk production for 14 d preceding estrus was associated with increased ovulation rate. To illustrate, incidence of multiple ovulations was 1.6% (2/128), 16.9% (32/189), and 47.9% (70/146) for ovulations when cows were producing <35, 35 to <45, and ≥45 kg/d, respectively. Among cows for which estrous behavior was recorded, those with multiple ovulations (n = 48) had shorter duration of estrus (4.3 ± 0.7 vs. 9.9 ± 0.5 h) and higher production (47.2 ± 0.9 vs. 38.1 ± 0.5 kg/d) than cows with single ovulations (n = 237). Circulating concentrations of estradiol were lower (5.5 ± 0.3; n = 15 vs. 7.8 ± 0.4 pg/mL; n = 71) during periods of estrus with multiple ovulations despite a greater preovulatory follicular volume (4136 ± 123 vs. 3085 ± 110 mm³). Similarly, serum progesterone concentration 7 d after estrus was lower for cows with multiple than single ovulations (2.5 ± 0.3 vs. 3.2 ± 0.1 ng/mL) despite a greater luteal volume (8291 ± 516 vs. 6405 ± 158 mm³). In summary, the first spontaneous ovulation in anovular cows and a higher level of milk production for 14 d preceding estrus were associated with increased multiple ovulation rate. Additionally, cows with multiple ovulations had lower estradiol at estrus, a shorter duration of estrus, and lower progesterone at 7 d after estrus than cows with single ovulations.     

Impact of alfalfa maturity and preservation method on milk production by cows in early lactation.

Ninety-six cows in early lactation were used in two experiments to measure the impact of alfalfa maturity (early or midbud vs. early or midbloom) and method of forage preservation (silage vs. hay) on DMI and milk production. Silage diets were fed as TMR, and hay was fed separately from grain. All diets contained 60% alfalfa (dry basis) and were balanced for 19% CP. Maturity had little effect on milk production in either experiment. Adjusted milk production for early cut silage, late cut silage, early cut hay, and late cut hay were 33.6, 33.4, 30.7, and 32.1 kg/d for Experiment 1 and 38.1, 37.0, 35.0 and 35.0 kg/d for Experiment 2. Increased alfalfa maturity tended to reduce DMI. Cows fed the silage diets consumed 1.2 kg more DM and produced an average of 2.1 kg more milk daily in Experiment 1 than those fed the hay diets. All treatment groups consumed similar amounts of DM in Experiment 2; however, cows fed silage produced 2.6 kg/d more milk than those fed hay. Preserving alfalfa as silage and feeding in a TMR to cows in early lactation resulted in greater milk production via increased DMI or improved feed efficiency compared with preserving alfalfa as hay and feeding grain separately.     

Utilization of ensiled corn crop residues by Holstein heifers.

Corn crop residues were harvested 1 to 2 d after harvest of high moisture corn. Half the harvested residues were treated with an aqueous solution of ammonia before ensiling to give 34 g of ammonia/kg of residue DM. The untreated half was the control silage. Both silages were ensiled in bunker silos. More residues were harvested 2.5 wk later from the same field and combined with Brassica napus L. before ensiling in a bag, and this constituted the third forage treatment. Three diets containing 48.8, 46.5, and 63.8% residue silage (DM basis), with the latter containing corn crop residue and brassica in a 3:1 ratio, were designated as control, ammoniated, and brassica, respectively. The other ingredients of the diet were alfalfa silage, cracked corn, and urea. The diets were fed to Holstein heifers averaging 186 kg (light BW) and 372 kg (heavy BW). Weight gains were similar at 84 d for heifers fed the control and the ammoniated residue diets. Light and heavy heifers gained 619 and 631 g/d with the control diet and 678 and 631 g/d with the ammoniated residue diets. At 70 d, the heavy heifers fed control, ammoniated, and brassica diets had weight gains of 629, 671, and 786 g/d, respectively. Digestion coefficients were similar between the control and ammoniated residue diets: DM (62.6 and 58.7%), NDF (56.7 and 56.2%), and ADF (56.3 and 55.8%). Ammonia treatment of corn crop residue silage had no effect on animal performance or digestibility. Brassica appeared to improve animal performance when it was mixed with corn crop residue silage.     

Single walled carbon nanotube based biosensor for detection of peanut allergy-inducing protein ara h1

Food allergies are global trending issues in the food industry. Peanut allergy is an especially serious problem with emerging allergen symptoms because peanuts are utilized worldwide as a processing food source. Arachis hypogaea 1 (Ara h1) is a main seed storage protein from peanut materials that derives allergic medical symptoms. In this study, a single-walled carbon nanotube (SWCNT)-based biosensor was developed to detect Ara h1. The developed biosensor utilizes an Ara h1 antibody as a receptor for the target material, SWCNTs as a signal transfer, and 1-pyrenebutanoic acid succinimidyl ester (1-PBSE) as a linker between the SWCNTs and the receptors. SWCNTs dramatically transferred the biological reaction between the antibody and the antigen into measurable signals of electrical responses. The sensor capacity of the developed SWCNT-based biosensor, including the limit of detection (LOD, 1 ng/mL), the detection range (1-1,000 ng/mL), and the washing amounts (three times), was confirmed.