Response to Incremental Replacement of Palm Oil with Fish Oil in Starter Diet on Growth Performance, Plasma Metabolites, Ruminal Fermentation, and Behavior of Dairy Calves.

The objective of this study was to evaluate the effects of the incremental levels of n-3 fatty acids (FA) in starter feed (SF) on growth and metabolic performance of milk-fed calves. From day 3 of age, 30 female calves (39.4 ± 3.1 kg of body weight) were randomly assigned to one of three dietary treatments: (1) SF supplemented with 3.3% palm fatty acids (PO), (2) SF supplemented with 1.7% of PO and 1.9% fish oil (PFO), or (3) SF supplemented with 3.9% fish oil (FO). Chopped straw (7.5% of DM) was included in the SF of all treatments as total mixed ration (TMR). Diets had similar energy and protein contents. Total n-3 FA (% of total FA) and n-6/n-3 of PO, PFO, and FO were 1.90, 6.80, and 11.8 and 15.5, 4.50, and 2.70, respectively. The BW was greater for calves receiving FO (60.2 ± 0.3 kg) compared with PFO (58.7 ± 0.3 kg; p = 0.007) and tended to be greater for calves receiving FO vs. PO (59.0 ± 0.3 kg; p = 0.050). Because there was no interaction effect between diet × week of experiment, the greater BW of FO could not be attributed to the dietary treatment. Accordingly, average daily gain, total dry matter intake (DMI), starter DMI, and gain to intake ratio (G:FI) did not differ among dietary treatments during the entire period of the study (p > 0.05). Dietary treatments did not impact body size parameters such as body length, body girth, withers height, heart girth, hip height, and width (p > 0.05). Neither ruminal fermentation parameters nor blood variables were influenced by supplementing the types of oil at different time points. Calves' behavioral parameters, such as standing, lying, eating, and ruminating, were not influenced by different dietary treatments (p > 0.05). The number of days with abnormal fecal score was not different among dietary groups (p > 0.05). Overall, our findings suggest that changing the n-6/n-3 ratio in starter feed by incremental replacement of palm fatty acid with fish oil at a moderate supplemental level of ~3% of DM may not affect the growth and metabolic performance of young calves under non-challenged conditions.

Forage inclusion in calf starter has the best outcome when it is supplemented since 21 days after birth in Holstein calves.

To evaluate the optimum age of straw addition to starter diet on growth of calves, 40 Holstein calves (36.7 ± 4.96 kg) were assigned at 3 days of age to 1 of 4 treatments in a completely randomized design. Dietary treatments (% of dry matter) were as follows: control starter without any wheat straw (WS) inclusion until weaning (WS0); 90% calf starter concentrate (CSC) + 10% chopped WS offered from day 3 of age to weaning (WS3); 90% CSC + 10% chopped WS offered from day 21 of age to weaning (WS21); and 90% CSC + 10% chopped WS offered from day 40 of age to weaning (WS40). After weaning at 60 days of age, all calves received the same diet until finished at day 72 of age. Solid feed intake was affected by treatments whereby either pre- or post-weaning starter intake was greater for calves fed WS (P < 0.01), and WS3 fed calves had lower starter intake compared to WS21 and WS40 (P < 0.01). Weaning weight was the greatest for WS21 treatment compared to other groups (P < 0.01), although all forage fed calves were heavier than WS0 (P < 0.01). Accordingly, average daily gain also showed a similar pattern (P < 0.01). Without any difference at post-weaning, pre-weaning glucose was lowest in WS0 calves (P < 0.01). There were no effects of treatment on number of days that calves experienced a negative health criterion. In conclusion, we concluded that WS inclusion at d 21 of age is recommendable based on weaning and final BW.

Nucleotide Supplementation to Whole Milk Has Beneficial Effects on Post-Weaning Holstein Calf Performance.

The positive effects of nucleotide (NU) supplementation in milk replacer have been elucidated in infants and in dairy calves; however, NU addition to whole milk has not been evaluated previously. This study aimed to assess NU supplementation in the whole milk on calf growth and health. Thirty Holstein calves (body weight: 39.1 ± 1.0 kg; 3 d after birth) were randomly assigned to the following treatments: whole milk without any supplementation (NU0), whole milk + 0.5 g/d added a NU-containing supplement to whole milk (NUCS0.5), and whole milk + 1 g/d added a NU-containing supplement to whole milk (NUCS1). Calves were weaned at d 55 and stayed on study until d 75. Calves had free access to feed and water throughout the study. Dry matter intakes (DMI) were similar among treatments (p > 0.05) during the pre-weaning period; however, increasing NU resulted in a linear (p < 0.05) increase in DMI during the post weaning period (2158, 2432, and 2518 g/d for NU0, NUCS0.5, and NUCS1, respectively). Treatments did not affect body weight (BW) at the first and second month of study, but final BW linearly increased as NU was added (87.1, 90.6, and 95.4 kg for NU0, NUCS0.5, and NUCS1, respectively). Neither pre-weaning average daily gain nor post-weaning average daily gain was affected by treatments; accordingly, feed efficiency was similar among treatment groups. Days with loose fecal score were linearly decreased as NU was added to whole milk during the first month of life, while the fecal score did not differ among treatments until the end of the study. No difference was observed in the skeletal growth of calves in the current study. Therefore, it can be concluded that NU supplementation in the whole milk has some beneficial effects on calf performance in terms of final BW, post-weaning DMI, and less days with loose feces.

Effect of increasing dosage of a multi-mineral-vitamin supplement on productive performance and blood minerals of fattening male Ghezel × Afshar lambs.

This study was conducted to evaluate the effects of supplementation with different levels of mineral-vitamin supplement (MVS) on performance and health of fattening lambs. Thirty-nine fattening male Ghezel× Afshar lambs (averaging body weight 31.02 ± 3.46 kg) were used in a completely randomized design for a period of 84 days. Treatments consisted of 0 (CON), 15 (MVS15), or 30 (MVS30) g/day of MVS mixed into the concentrate. The results showed that inclusion of MVS in the ration linearly enhanced body weight (BW) on day 29 (P < 0.002), 45 (P = 0.05), and 70 (P < 0.002). Dry matter intake (DMI) was increased linearly (P < 0.02) and quadratically (P < 0.001) with increasing supplement between days 58 and 70. Overall DMI tended (P = 0.1) to be greater for the MVS 30 treatment. Total average daily gain (ADG), ADG between days 16 and 29, days 58 and 70, total gain: feed ratio, gain: feed ratio between days 16-29 and days 58-70 linearly increased with increasing amount of MVS in the ration (P < 0.01). The days with loose fecal scores were not affected by treatments (P > 0.05). There was a linear and quadratic (P < 0.01) effect on serum Ca concentration. Phosphorus concentration tended to quadratically increase (P = 0.06) with MVS. Blood serum Zn increased linearly (P = 0.01) with increasing level of MVS. Collectively, the results showed that, under the conditions of the current experiment, MVS addition to ration improved performance of fattening lambs.

Short communication: Test of the relationship between prepartum milk leakage and blood calcium concentration in Holstein cows-An observational study.

Prepartum milk leakage happens in some pregnant dairy cows close to calving. It has been hypothesized that low blood Ca is a cause of this event. To investigate the possible reason(s) of milk leakage, 137 multiparous pregnant Holstein cows were enrolled in the experiment and categorized by the presence (72 cows; leak group) or lack (65 cows; control group) of milk leakage before calving. The concentrations of Ca and P and the length of the teat were measured for all cows. Data showed that Ca concentration was not different between cows in the leak group (7.90 mg/dL) and those in the control group (7.99 mg/dL). Moreover, neither P concentration (4.62 vs. 4.54 mg/dL) nor teat length (4.28 vs 4.10 cm) differed between leak and control groups. Milk yield was greater for the leak group (53.6 kg/d) compared with the control group (50.1 kg/d) through 4 mo in milk. The leakage did not affect the odds of postpartum disorders such as retained placenta, metritis, mastitis, displaced abomasum, or lameness occurrence. The current results show that hypocalcemia is not a reason for observed prepartum leakage and that cows in the leak group produced more milk in the subsequent lactation period.

Effects of dam parity and pre-weaning average daily gain of Holstein calves on future milk production.

This research communication describes relationships between pre-weaning average daily gain (ADG) and dam parity with future productivity of dairy calves. Higher ADG before weaning has been shown to be related to greater milk production in the first lactation of Holstein calves fed milk replacer. However, data is limited on the relationship between pre-weaning ADG and first lactation performance of Holstein calves fed whole milk. Data of three hundred and thirty-two Holstein calves from 35 primiparous and 297 multiparous cows was investigated to evaluate the relationship between the dam parity and pre-weaning ADG with the first lactation performance. Results indicated that birth (P < 0·01), and weaning body weight (P < 0·001) were greater in calves born from multiparous cows. Neither 305 d milk production nor pre-weaning ADG differed significantly between calves born to primiparous or multiparous cows, although milk yield tended to be higher in the former and ADG higher in the latter. Correlations between 305 d milk yield and pre-weaning ADG, dam parity and birth body weight were low and non-significant, although there was a tendency for a positive correlation between ADG and milk yield.